Between 1999 and 2020, gastrointestinal cancers were responsible for over three million deaths, emphasizing the critical role of minimally invasive surgical techniques like Endoscopic Submucosal Dissection (ESD) in managing such life-threatening conditions. ESD, which dissects the connective tissue between the mucosal and muscular layers using an electrosurgical knife connected to an endoscope, requires a constant traction force to stabilize tissues and expose underlying anatomical structures. This paper introduces a miniature magnetic flexible robot, actuated by a permanent magnet on a robotic manipulator, designed to enhance ESD by providing traction forces consistently on lesions. The robot was fabricated by casting magnetic silicone composites, and its safe deployment through the endoscope instrument channel was successfully demonstrated, avoiding tissue contact. Experiments in a rubber intestine model validated the feasibility of providing constant traction and 2 DOF orientation control via the robot, allowing real-time fine-tuning of the force direction. This reduces the difficulty and improves the precision and safety of ESD. This research presents a practical method for achieving stable force output in medical miniature robots, particularly in gastrointestinal procedures.

This study proposes a novel strategy for cross-scale position of robotic micromanipulation. The strategy utilizes multiple-scale augmented reality (AR) markers for locating the robotic manipulator on different scales. The macro-marker (3.0 cm-per side, 5 mm×5 mm each square) is applied to position the robot to the microscopic manipulation area. The micro-marker (2.4 mm-per side, 400 μm×400 μm each square) is used for positioning the end-effector under microscopic view. After the fabrication of the markers, the camera's internal parameter matrix was first calibrated. Subsequently, we conducted the detection effect of macro- and micro-markers. Since the observation effect of micro-markers is different under the microscope, the detection distance of the micro-marker was corrected and compensated, and the fixed reference marker was introduced for the correction in different focus heights. Finally, based on detection markers, a robotic manipulator, integrated with a microfluidic chip as an end-effector, was employed to demonstrate the micromanipulation of loading oocytes. The proposed strategy has a potential application in the biology laboratory automation.

This study proposes a novel movable microfluidic chip in which a microfluidic chip is integrated into a robotic manipulator for manipulating oocytes. The microfluidic device has the ability to release a single oocyte with a gap effect. The robotic manipulator can control the position of the microfluidic chip. The microfluidic chip with a pipette tip is directly fabricated using 3D printing. Xenopus oocyte was used in the experiment. When oocytes move from the back side of the channel to the front side, they generate gaps between each other. The gap distance can reach about 16 times the diameter of the oocyte. In addition, a capacitive sensor was used to detect oocytes in the manipulation processes. The results showed that oocytes were successfully released one by one with no deformation in shape using the movable microfluidic chip. The method has significant advantages in biomedicine engineering and micro-nano-manipulation.

This paper presented the three-dimensional oocyte manipulation system for the two-electrode voltage clamp (TEVC) experiment under stereomicroscopy. We firstly developed a sequential calibration method to correlate the workspace of the stereomicroscopy with the image and the micromanipulator. Even though the focal depth of the microscopy was limited, the proposed method functioned the three-dimensional position detection and calculated the homogeneous transformation matrix. We secondly employed hybrid use of the image-based manipulation and the quartz crystal resonator (QCR) force sensor. The imaging technique was used to detect the tip of the glass capillary and the contact to the cell membrane, whereas the QCR force sensor was incorporated to detect the force interaction between the sample and the glass capillary. Using the system and proposed technique, we demonstrated the automatic capillary insertion for TEVC experiment, at which the low insertion depth was preferable. The results indicated that the coordination calibration technique provided the positioning accuracy of the capillary tip on the order of 10 μm. The imaging technique could detect the contact to the elastic objects and cell membrane. QCR force sensor achieved quite small force measurement and feedback control at the control frequency of 100 Hz without latency.

This paper presents a system that picks up protoplasts produced by removing the surrounding cell wall of root cells while preserving their positional information. The fundamental concept of this system involves scanning the root tip over time using a confocal microscopy to measure the positional information of each cell. Then, the protoplast pickup is conducted after switching to a brightfield microscopy to ensure the certainty of pickup. The system measures the position of single protoplasts, adjusts the position of the pipette using a 3-axis micromanipulator, and picks up the target protoplast using a microfluidic pump driven by a piezoelectric actuator. To automate this pickup process, we achieved calibration of the system. The fully automatic 3D calibration of the pipette tip was achieved, allowing 3D micromanipulation under the microscope with an accuracy of 3.1 μm in the XY-plane. Furthermore, by implementing multiple functions such as automatic detection of protoplasts, the process of protoplast pickup has been achieved.

Microbubble-induced acoustic microstreaming for efficient on-chip micromanipulation is widely developed in biological applications. However, it is still challenging to simultaneously transport, trap, and rotate single cells using one device in a biocompatible manner, while expensive and bulky traditional acoustic driving system also increases its limitation. This paper presents a portable acoustofluidic device for multifunctional cell manipulation and 3D reconstruction, using acoustically oscillating bottom bubble array. Based on the Arduino-based driving system, multiple bubble-induced microvortices were generated and utilized to achieve multifunctional manipulation in a noninvasive manner. Self-propelled transportation of single or multiple cells is first accomplished by bottom bubble array; Controllable trapping, 3D rotation (in the x-y or x-z plane) of DU145 cells are further performed by every single microbubble. Through experiments, rotation direction, speed and axis can be modulated by tuning the driving frequency and voltage. Finally, 3D cell reconstruction combining imaging processing algorithm with out-of-plane rotation enables a sufficient illustration of cell structures and surface morphology, providing an efficient properties measurement function. All these aspects of this device show great potentials in bioengineering, biophysics and biomedicine.

Non-contact manipulation technology has extensive application in the manipulation and fabrication of micro/nanomaterials. However, the manipulation devices are often precise and complex, operated only by professionals and subject to site constraints. We propose a simple optoelectronic tweezer platform, which can be controlled remotely and simply for the manipulation of microparticles at different scales, based on the novel manipulation technique called optically-induced dielectrophoresis. In this work, we design and set up the optoelectronic tweezer manipulation platform and develop the full-function human-computer interactive control interface and graphics rendering system to simplify the micro-operation process. Using Qt5.0 development environment, an experimental image processing system with multi-thread characteristics is developed, and the information interaction requirements needed in the experimental operation of optoelectronic tweezers are integrated into a control system to achieve unified information management and data analysis. Combined with cloud computing technology, the system realizes local/remote synchronous linkage operation, with cross-platform operation capability of various portable operating terminals like laptop and iPad.

Micro-nano-robots are considered to be a promising platform for drug delivery in biological organisms, but there are still urgent technical problems in biocompatibility and degradability of 3D-printed-based micro-robots that need to be solved. Therefore, in this paper, we design a magnetized bio-hybrid robot, which uses mouse macrophages as carriers, and allowed it to swallow Fe2O3particles with a diameter of 10 nm. The robot takes advantage of macrophage’s natural biocompatibility and targeting characteristics to reach and function in complex environments such as: eye, knee, tumor, etc., and finally being able to be actively metabolized by the organism. More importantly, the cell robot can move precisely along a preplanned path under the control of a three-dimensional magnetic control system built in this study, and be delivered accurately to the vicinity of cancer cells in vitro environment. In future work, cellular robots could be allowed to carry anti-cancer drugs and release them in a targeted manner at the lesion. These microrobots have shown great potential for tumor reginal targeted drug delivery.

In this study, we propose the manipulation and cell injection of a fluorescent microsensor using multiple wavelengths of light. The fluorescent microsensor is made of a 1-μm polystyrene particle containing infrared (IR: 808 nm) absorbing dye and Rhodamine B. The polystyrene particle can be manipulated in water using a 1064-nm laser because the refractive index of the polystyrene is 1.6 (refractive index of water: 1.3). The IR absorbing dye absorbs 808-nm light but does not absorb the 1064-nm laser. Rhodamine B is a temperature-sensitive fluorescent dye (excitation wavelength: 488 nm, emission wavelength: 560 nm). The functions of manipulation, heating for injection, and temperature measurement are achieved by different wavelengths of 1064 nm, 808 nm, and 488 nm, respectively. The temperature increase of fluorescent microsensor with 808-nm (40 mW, 10 s) laser was approximately 15°C, and enough for injection of fluorescent microsensor. We demonstrated manipulation and injection of the microsensor into Madin-Darby canine kidney cell using 1064-nm and 808-nm lasers. These results confirmed the effectiveness of our proposed cell injection of a fluorescent microsensor using multiple wavelengths of light.

Monitoring of biosignals on a daily basis plays important roles for the health management of elderly. The monitoring system for the daily life, the system should not require the subjects to take special effort like wearing a sensor. We propose biosignals measurement using wide-range load sensor on the bed. The sensing system can detect the body weight, heartbeat and respiration simultaneously by just lying on the bed. We have developed load sensor using quartz crystal resonator (QCR load sensor) as wide-range load sensor. However, the measurement range was not sufficient for the simultaneous measurement of biosgnals on bed. To realize such sensing system, we propose a QCR load sensor utilizing vacuum sealing technology for expanding the measurement range. We improved the oscillation characteristics of the QCR by the vacuum sealing to stabilize the sensor output. Accordingly, the resolution of the sensor was improved. Moreover, the load capacity of the sensor was increased by improving the bonding strength of sensor structure. The fabricated sensor had a measurement range of 0.27 mN - 1180 N (4.4 × 106). This wide enough compared with the conventional force sensor (103- 104).Also, we developed mechanically robust jig of QCR load sensor for practical use of QCR load sensor. We succeed in simultaneous measurement of weight, heart rate, and respiration rate using fabricated QCR load sensing system. The accuracy of heart rate and respiration rate measurement are 0.4 bpm (0.6 %) and 1.1 brpm (6.1 %), respectively, in standard deviation of error compared with ECG signal.

Circulating tumor cells (CTCs) are the primary cause of tumor metastasis after surgery. Metastatic tumor recurrence is the leading reason of cancer death. It is prerequisite to develop a platform for CTCs separation to predict the cancer cell transfer in important organs. Herein, a novel acoustic microfluidic device was designed to capture the "true" CTCs from the whole blood sample. The blood got from the mice with breast tumors removed. There are some CTCs that have escaped from the solid tumor contained in these blood samples, instead of artificially mixing individual tumor cells into normal blood. In addition, the predictions of tumor prognosis are made based on the number of CTCs captured by the acoustofluidic device. Finally, the prediction has been confirmed through long-term observation of mice with tumor excised. The acoustofluidic device can efficiently capture CTCs and predict the tumor metastasis, which can help clinicians plan follow-up treatment for patients who have had their tumors surgically removed.

In this paper, we present a magnetized cell-robot using macrophages as templates, which can be controlled under a strong gradient magnetic field, to approach and kill cancer cells in both vitro and vivo environment. Firstly, we establish a magnetic control system using only four coils which can generate gradient field up to 4.14 T/m utilizing the coupled field contributed by multiple electromagnets acting in concert. Most importantly, the cell-robot which is based on the macrophage is proposed, and can be transported to the vicinity of cancer cells precisely using strong gradient magnetic field. Then the cell-robot will actively phagocytose the cancer cells and eventually kill them, achieving the cancer treatment at the cellular level. It has important significance for guiding accurate targeted therapy in vivo for the future, under the premise of zero harm to the human body.

Magnetic microrobots can be propelled precisely and wirelessly in vivo using magnetic field for targeted drug delivery and early detection. They are promising for clinical trials since magnetic fields are capable of penetrating most materials with minimal interaction, and are nearly harmless to human beings. However, challenges like the biocompatibility, biodegradation and therapeutic effects of these robots must be resolved before this technique is allowed for preclinical development. In this study, we proposed a cell-robot based on macrophages for carrying drugs to kill tumors propelled by magnetic gradient-based pulling. A custom-designed system with strong gradient magnetic field system in three-dimensional (3D) space using the minimum number of coils is used for precise control of the cell-based microrobot. The cell-based microrobots were fabricated by assembling magnetic nanoparticles (Fe3O4), anti-cancer drugs (DOX) into macrophages for magnetic actuation and therapeutic effects. Vitro experiments show that cell-based microrobots can be accurately transported to the destination or approaching a targeted cancer cell. The magnetic nanoparticles have negligible effects on the cell-based microrobot and the organism, which makes the cell-based microrobot safe for in vivo experiments. The carried drugs in the cell-based microrobot can be released by the irradiation of the near-field infrared and kill the cancer cells. Further in vivo experiments prove that the cell-based microrobot can be transported to tumor area and release drugs to kill cancer effectively. The research provides biocompatible and biodegradable cell-based microrobots for early tumor prevention and targeted precision therapy.

Sonoporation, which typically employs acoustic cavitation microbubbles, can enhance the permeability of the cell membrane, allowing foreign matter to enter cells across the natural barriers. However, the diameter nonuniformity and random distribution of microbubbles make it difficult to achieve controllable and high-efficiency sonoporation, while complex extern acoustic driving system also limits its applicability. Herein, we demonstrate a low-cost, expandable, and portable acoustofluidic device for cell sonoporation using acoustic streaming generated by oscillating sharp edges. The streaming-induced high shear forces can (i) quickly trap target cells at the tip of sharp edges and (ii) transiently modulate the permeability of the cell membrane, which is utilized to perform cell sonoporation events. Using our device, sonoporation is successfully achieved in a microbubble-free manner, with a sonoporation efficiency of more than 90%. Furthermore, our acoustic driving system is designed around the open-source Arduino prototyping platform due to its extendibility and portability. In addition to these benefits, our acoustofluidic device is simple to fabricate and operate, and it can work at relatively low frequency (4.6 kHz). All these advantages make our novel cell sonoporation device invaluable for many biological and biomedical applications such as drug delivery and gene transfection.

We propose an on-chip micromanipulation method based on mode switching of vibration-induced asymmetric flow. The asymmetric flow can be induced around rotationally asymmetric structures on a microfluidic chip by applying a circular vibration to the chip. Thus, the flow pattern can be switched by changing directions of applied vibrations as clockwise or counter-clockwise. In this study, we applied the switching of flow patterns (e. g., trap mode and transport mode, or trap mode and alignment mode) to change the manipulation modes of microobjects. Furthermore, we demonstrated the proposed method for two applications, local cell concentration and single particle loading. These demonstrations show that the proposed manipulation method can realize versatile on-chip micromanipulations and will contribute to high-throughput and high-reliability cell analysis or diagnosis.

An automatic system for evaluating single cell viscoelasticity is proposed and tested in this paper. The system includes three main operations, and they are the operations of catch, load and launch. In the catch operation, the system is capable of capturing a target cell by high-speed vision and high-frequency flow control. The captured cell is pushed into a narrow constriction for the load operation. Different durations of loading time are applied to cells for evaluating cell viscoelasticity. Finally, the cell is launched out from the constriction, and the recovery response of the cell is monitored for cell characterization. Human red blood cells are experimentally tested by the proposed system. The experimental results show that the system successfully perform the evaluation, and the viscoelastic characteristics of the cells are discussed.

Monitoring of biosignals plays important roles in health management in daily life. Especially, the sensing method of biosignals, which does not require special efforts such as restraining people or wearing the sensors to measure them, is really important to maintain monitoring activities of people. We call such method what a sensing way should be for monitoring of biosignals as casual sensing methods. Previously, we have developed highly sensitive and wide-measurement-range load sensors based on measuring frequency shift of quartz crystal resonator (QCR) as the sensing principal. We have integrated the load sensor into a chair, and measure the load when people just sit on it. Since the load sensor has wide measurement range of 105order, multi-biosignal; heartbeat, respiration, and body motion under the weight-loaded environment can be measured from load information. Thus, people can casually monitor the biosignals by sitting on the chair. However, the previous sensing system required us to measure the frequency shift of one-Hz order in tens-MHz of the resonant frequency of a QCR. In this case, the sensing system requires a expensive frequency counter, and it is not suitable for daily use situation such as in-home sensing. In this paper, we presents the detection of multi-biosignal method using a newly developed load sensing system which utilizes the developed frequency counter unit. In order to measure the frequency shift of one-Hz order in tens-MHz of the resonant frequency, we use a differential method of signal for two QCRs with an electrical signal-mixing circuit. By using the method, we can reduce the required measurement range for frequency from tens-MHz to tens-kHz. The load sensing performances were evaluated, and the results showed that the sensitivity and withstand load were 2.9 [mN] and 300 [N], respectively. Finally, we demonstrated the measurement of multi-biosignal by using constructed system, and succeeded in detecting respiration, heartbeat, and body motion.

Quality evaluation of oocyte and embryo has become one of the most important issues for many biomedical applications such as domestic animals and fertilization treatment. We developed measurement of oxygen consumption rate of individual oocyte by indirect fluorescence measurement using fluorescence oxygen sensor array having stripe-shape on a microfluidic chip. The fluorescence oxygen sensor was made of the mixture of photo-crosslinkable resin, polyethylene glycol diacrylate (PEG-DA) and Tris (2, 2'-bipyridyl) dichloro ruthenium (II) hexahydrate (Ru(bpy)3Cl2). The sensor was patterned to stripe-shape in the polydimethylsiloxane using photofabrication and molding technique. Oxygen concentration around the oocyte was distributed according to spherical diffusion theory because of similar oxygen permeability of polydimethylsiloxane and that of medium. The sensor array detects two-dimensional distribution of oxygen concentration and oxygen consumption ratio of the oocyte is calculated by image processing and Fick's low. We demonstrated non-contact measurement of oxygen consumption ratio of single mouse oocyte on a microfluidic chip (0.59 ± 0.03 fmol/s).

We present a super wide-measurement range load sensor with high-durability for multi-biosignal sensing in daily life. We employed quartz crystal resonator (QCR) load sensor with super wide range (from 6 × 10-5to 30 [N]) for sensing of biosignals ranging from mN order (e.g. heartbeat) to 100 N order (e.g. body motion). Furthermore, we implemented an outer case which makes the sensor durable against unexpected loads in practical use. The outer case increased the durability of the sensor 88 times higher than the sensor without outer case. Finally we succeeded in simultaneous sensing of heartbeat (≈ 100 [mN]) and body motion (≈ 25 [N]) with identical sensor.

This paper proposes the method for mechanical characterization of floating cells on a microfluidic chip. We measured the reactive force of cells on the chip by applying mechanical deformation to the cells. Particularly we focused on the method to improve the sensing resolution of the probe position by using the phase detection of moiré fringe. This method realized approximately ten times higher resolution compared to the previous method. The detailed data suggest some unique characteristics of cells. We discussed the phenomenon seen on the data with a mechanical model, which is based on Heltzian contact theory in the light of stiff nucleus.

Cyanobacteria have ion channels which response to osmolarity change in living environment. Since it may lead to the mechanical characteristics changes of the cell itself due to the intracellular pressure changes, we focus on constructing the mechanical characteristics measurement system of Synechocystis sp. PCC 6803, one of unicellular cyanobacteria. There are two important issues in constructing the system. Because of features of the cyanobacteria, which is a kind of floating cell whose diameter is a few micrometer, one is how to transport the cell to the measurement point. The other is how to deform the target cell. In this paper, we propose the system combining optical tweezers for transportation of the target cell with the robot integrated microfluidic chip (robochip). The robochip contains an on-chip probe actuated by an external actuator, and a force sensor. We present the concept of the total system, and demonstrated the results of mechanical characterization of a single cyanobacteria.

We present a novel cell manipulation method based on vibration-induced flow in open-chip environment. By applying circular vibration to a chip having micropillar patterns on its surface, local whirling flow is induced around the micropillars. Therefore, by patterning micropillar array on a chip and applying the circular vibration to the chip, we can achieve cell transportation along the array in an open chip environment. We theoretically analyzed this phenomenon with a single micropillar, and experimentally evaluated behaviours of manipulated microbeads with two micropillars. We confirm there are different manipulation modes according to the pitch of micropillars. We designed the micropillar array for an oocyte transportation based on these evaluations. We succeeded in the transportation of oocytes with up to 35.6 μm/s and confirmed that the velocity can be changed by changing the frequency and amplitude of the applied vibration.

We have developed a highly functional untethered micro-robot that can manipulate cells with high gripping force in a micro-fluidic chip. The robot has gripping mechanism for grasping and transportation of cells with sufficient power. A permanent magnet is attached at the center of the gripping mechanism, and an electrical magnet controls the position of the magnet from the bottom of the micro-fluidic chip. The distance accuracy of the gripper is 3.0 μm, and it can activate about 50 Hz. The robot has four permanent magnets for positioning, and other four permanent magnets control the robot from the bottom of the micro-fluidic chip. The robot is made very thin and small to allow maneuverability in a micro-fluidic chip. We succeeded in high-power handling and cutting of a cell using this micro-robot.

A load sensor with high sensitivity, a wide measurement range, and a small size was developed by using an AT-cut quartz crystal resonator (QCR). The quartz crystal generates a charge that is proportional to the external force. Because it has high sensitivity and excellent temperature stability, it has been used for various sensors. In particular, a QCR has an inherently superior static-load-sensing characteristic. However, a QCR is fragile and easily broken by a stress concentration. Moreover, a retention mechanism is required to efficiently transmit the load, and it is necessary to fix the QCR firmly to avoid a horizontal force. Moreover, it is very difficult to miniaturize the retention mechanism because the fabrication and assembly process is complicated. We previously proposed a miniaturized sensor element that was developed using microfabrication. The QCR load sensor had an enormously wide force-sensing range of greater than 104N. However, the output was easily affected by a change in the parasitic capacitance around the QCR. The objective of this study was to improve the load-measurement resolution and stabilize the sensor output for application to biological signal detection. We fabricated a QCR sensor with a sensitivity of 973 Hz/N and succeeded in detecting multiple biological signals (respiration, heartbeat, and posture) with using proposed QCR load sensor.

Bio-actuated, especially flagellated bacteria-driven, micro/nanorobots have been actively studied to develop novel technologies such as drug delivery systems (DDS), though the characteristics of the actuator (flagellar motor) have not been sufficiently investigated. For analysis or control of the bacterial flagellar motor, we previously proposed the local environmental control system with nano/micro dual pipettes to dynamically generate arbitrary local ion/reagent concentration change. In the result, transient-state and steady-state of local Na+concentration were manipulated with high facultativity. However, in this system, over time, the local ion/reagent could not be fully flushed out due to the increase of the diffusion rate caused by high external (in the bath) ion/reagent concentration. Therefore, in this paper, to achieve more arbitrary local environmental control, we propose the local environmental control system by combination of microfluidic chip with world-to-chip interface (WtCI) and pipette. We fabricate the WtCI microfluidic chip by two-step photolithography, and develop the system by using precisely controllable syringe pump. And, we demonstrate the basic feasibility of the local environmental control system by combination of WtCI microfluidic chip and pipette.

We propose a microrobotic platform that stimulates swimming microorganisms in a microfluidic chip with high speed and accuracy. The developed platform comprises (1) high-speed microrobots that can generate a millinewton-level driving force, micrometer-level positioning accuracy, and a millimeter per second level drive speed through the actuation of motorized stages with permanent magnets and (2) high-speed online vision sensor capable of capturing images on the order of 1000 frames per second. The specific design and architecture of the proposed platform are also presented. The proposed platform stimulates and observes swimming microorganisms in a microfluidic chip through a mechanical approach. This platform provides on-chip investigation with high functionality that has been difficult to achieve with previous approaches and contributes towards the discovery of previously unknown functions of swimming microorganisms in the bioscience fields.

In the study of the oocytes/embryos, such as enucleation, microinjection in order to increase the success ratio of the fertilization and characteristics study of the oocytes, all of these research and clinical applications involve 3-D rotation of mammalian oocytes. The gesture or the orientation of the oocyte is critical for improving the enucleation success rate, and characteristics investigation of the oocyte. Cell rotation in conventional approaches mainly are electrorotation or manual operation by skilled professionals based on trial-and-error, repeating the vacuum aspiration and release. The poor reproducibility and inconsistency entail a simple and convenient approach for single oocyte rotation. This paper reports a 3-D rotational control of bovine oocyte. By using customer designed magnetically driven microtool (MMT), the oocyte orientation control could be achieved. Comparing with the conventional works, rotation control by using MMT shows great advantage in control accuracy and the rotation speed. Orientation with an accuracy of 7°, and the average rotation velocity of 3 rad/s have been achieved. Rotation by utilizing MMT demonstrated overall out-of-plane and in-plane in a quite simple way. And by utilizing this approach, the cell manipulation for cell study becomes much easier on investigating single cell characteristics and analysis mechanism properties.

We developed selective and rapid injection of fluorescence sensor into the cell for intracellular measurement. The sensor encapsulated in the liposome contains photochromic chemical, 1, 3, 3-Trimethylindolino-6'- nitrobenzopyrylospiran, for optical control of zeta potential. The molecular structure of spiropyran changes between spiropyran type and merocyanine type by UV/VIS illumination. Zeta potential of merocyanine type is higher than that of spiropyran type. The charge of the liposomes are normally negative. Zeta potential of the liposome is switched from negative to positive by photoisomerization of spiropyran. Positive-charged liposome manipulated by optical tweezers adheres to the cell membrane by electrostatic force since the charge of the cell membrane is negative. The local vibration stimulus using optical tweezers is applied to the cell membrane for rapid injection of the sensor by membrane fusion and endocytosis. We demonstrated selective adhesion of the liposome to the cell membrane by optical control of zeta potential (adhesion rate: 71%). Moreover, we also demonstrated rapid injection of 1 μmφ fluorescence sensor (approximately 30 minutes, injection rate: 100%) into a cell using local vibration stimulus by optical tweezers.

For molecular analysis of the rare cells, such as Circulating Tumor Cells (CTCs), the rare cells isolation from the suspension which contains large population of other cells on the single cells level is required. In this paper, we fabricated and demonstrated a cell isolation system for rare CTCs. We utilized the technique of convective self-assembly, which is a technique for depositing uniform onto the microfluidic device, to array single CTCs. Under the suspended cancer cells experiments, we demonstrated that by using this system, the collection efficiency of cells which could be deposited on the microfluidic device was 98.3% while the flow rate was 57.1 μl/min. This system will be conducive to single rare cells analysis because the deposited cells could be picked up by glass pipette easily.

Cell manipulations and cell surgeries are key techniques in biotechnology today. Micro/nanorobots integrated on a microfluidic chip (on-chip robot) are a promising technology for cell manipulations and cell surgeries because of their operator skill independency and robustness for external environments. These features enable high-throughput cell manipulations and cell surgeries on a microfluidic chip. However, it is difficult to apply previous on-chip robots for small cells of order ≈ 10 \bm μ m because the manipulation or surgery probes of those robots are a few micrometers in size. This size has been restricted by their fabrication, employing a standard mask lithography process. We fabricated on-chip robots of nanometer size by femtosecond laser exposure (nanorobots). The processing resolutions were 270 nm (linewidth) and 600 nm (thickness). Furthermore, our fabrication technique enabled the nanorobot to have a hybrid structure integrating functional nanomaterials (hybrid nanorobot). By integrating the various functional nanomaterials on the nanorobot, we can create a new function for the nanorobot. In this study, we fabricated a hybrid nanorobot with carbon nanotubes (CNTs) of high photothermal efficiency. We demonstrated a single-cell puncture with this nanorobot by irradiating the CNTs with an infrared laser and generating heat at that point. Additionally, we demonstrated an optical manipulation of the nanorobot that makes it possible to perform a cell puncture with high spatial flexibility and high positioning accuracy.

We developed fabrication and manipulation of hybrid nanorobots by 3D nano exposure and optical tweezers. Hybrid nanorobot is composed of photoresist and silicon nanowire. The robot is fabricated by femtosecond laser exposure and is connected to the glass substrate by a micropillar. The processing resolutions of the femtosecond laser exposure are 270 nm (line width) and 600 nm (thickness), respectively. The robot is released by cutting of the pillar by ablation with femtosecond laser. Release time is within four minutes. The released robot is manipulated by holographic optical tweezers (HOT). We succeeded in high-speed manipulation of the robot using HOT (transport speed: 100 μm/s, rotation speed: 1140 deg/s). The robot can be fabricated by incorporating temperature indicator to the robot body and inserting a silicon nanowire to the probe. The robot can be used as a thermal sensor by measuring temperature change from the probe to the robot body because silicon nanowire has high thermal conductivity (168 W/m·K). In this paper, we demonstrated fabrication, on-demand release, and manipulation of the robot in a solution. We also demonstrated temperature calibration and measurement to confirm the effectiveness of the temperature sensor.

We have successfully produced mono-dispersed micro-gas bubbles for less than around 10 μm diameter by micro-bubble knife which produce micro-bubble in an electrically induced ultrasonic field. The discharged output power and conductive area of micro-electrode in micro-bubble knife which cuts the cell by micro-bubble were controlled by glass shell insulation around the copper micro-wire. A small space which is called “bubble reservoir” between the wire and glass tip contributes to stabilize the electric discharge and directional bubble generation. The directionally dispensed bubbles can be used for processing of soft materials such as biological cells. For the present study the cell membrane has successfully processed with a few μm order resolution.

We developed selective injection of a single particle sensor into a specific cell by optically-regulated cell adhesion and membrane fusion of liposome for intracellular measurement. Fluorescence sensor encapsulated in fusogenic liposome is fabricated by spontaneous transfer method. The liposome is consists of neural lipids and spiropyran (SP). SP is a photochromic chemical and used to control the surface potential of the liposome. The surface potential of the liposome is neutral under VIS illumination. On the other hand, the surface potential becomes positive by UV-induced photoisolation of the SP. Charged liposome adheres to the cell membrane by coulomb's force since the surface potential of the membrane is negative. The estimated coulomb's force is approximately several hundred pN. The particle sensor can contain various fluorescence indicators such as Rhodmaine B as temperature sensor. The sensor is manipulated by optical tweezers and contacted to the cell membrane. We evaluated encapsulation efficiency of the single sensor into the liposome and adhesion efficiency to cell membrane under UV illumination. We demonstrated the optically-controlled adhesion of the sensor to MDCK cell and observed the injected sensor by laser confocal fluorescence method. As results, we succeeded in injection of particle sensor into the cell cytoplasm and nucleus.

This paper presents a new in-vitro simulator that can simulate the new technology of three-dimensional digital subtraction angiography (DSA) to perform a cerebral aneurysm surgery. Then, propose a new technique for the numerical evaluation of the surgical tools applied within this interventional surgery to aid in the design and selection of surgical instruments. Initially, the in-vitro intravascular simulator was constructed, followed by cerebral aneurysm models that were fabricated with highly sensitive photoelastic materials of epoxy resin. Then reconstruct virtual reality modeling of the blood vessel and catheter to record the position information and realize virtual guidance for training. Meanwhile, conduct image processing of photoelastic effects for numerical evaluations of surgical instruments such as catheter insertion and stent expansion. During the stent expansion experiment, the average stress in the selected region of interest caused by the expansion was calculated and compared with the corresponding value obtained before the expansion. The presented simulator and measurement technique can assist in improving a surgeons skills, quantifying the performance of medical mechanisms, and contribute to 3D analysis of stress distribution. This approach can also provide feedback control for robot assisted endovascular systems.

This paper discusses the observability of cell stiffness by utilizing a micro-channel whose diameter is slightly smaller than that of a cell. By modeling each cell with distributed springs and dampers, we discuss how many sensing points are necessary and sufficient for evaluating cell stiffness. We define the observability by the velocity of each cell through a micro-channel based upon the experimental observation that the equilibrium velocity of a cell varies corresponding to its stiffness. We conclude that for evaluating cell stiffness, two points are necessary and sufficient while using an infinitely long channel, and three are necessary and sufficient for judging whether cell stiffness is observable or not. This study attempts to provide a practical guidance for developing a simpler, faster, low-cost sensor in the future.

3D tailor-made biodegradable scaffold integrated with biological cells or molecules is of great importance for tissue engineering. This paper addresses an improved method for exploring magnetic tweezers in patterning and aligning magnetic hydrogel fiber to fabricate large-scale engineered cell-hydrogel constructs. Magnetic hydrogel fibers were fabricated based on microfluidic device. The fabricated hydrogel fiber is made of alginic acid sodium and with a diameter of 34 μm. Magnetic nanoparticles is added into the alginic acid sodium solution to append magnetic material inside the fibers. The magnetic material inside the hydrogel fiber is regulated by the microfluidic device. Magnetic tweezers system based on solenoid electromagnet is utilized to evaluate the magnetic response of the magnetic hydrogel fiber. Evaluation results show the hydrogel fiber can be maneuvered by the proposed system with a positioning resolution of sub-micro level. The cultivation results of hydrogel fiber with C2C12 cells shows the potential for real applications of the proposed method in tissue engineering.

This paper presents a novel measurement system of cellular mechanical properties based on a robot integrated microfluidic chip. In order to achieve the high throughput measurement of cellular mechacal properties, we proposed the robot integrated microfluidic chip (robochip), taking advantages of both of micromechanical manipulator and Lab-on-a-Chip devices. The robochip contained a pair of a magnetically driven on-chip robotic probe and a force sensor. The characterization system based on the robochip performed by the visual feedback control, and the continuous cell measurement was demonstrated. The throughput of our system was 15 to 20 seconds per one oocyte. Moreover, the measurement of the viscoelastic properties were demonstrated as a quality evaluation of oocyte. Experimental results shows that the oocyte has the viscoelastic properties among the same culture condition, and it is important to analyze the mechanical properties of oocyte for the evaluation of the quality. From these results, we concluded that the high through put cellular mechanical characterization was achieved, and our robochip approach was a promising technique for a cellular characterization because the chip part was disposable.

Microrobots are promising tools for the treatment of biological cells because of their lack of skill dependence, high throughput, and high repeatability. Integration of a microfluidic chip and robotics based on microelectromechanical systems technology is a key challenge for biomedical innovations. In addition to the advantage of environmental control by a microfluidic chip, robots enable physical operations on the cell with high throughput. This paper presents high-speed microrobotic actuation driven by permanent magnets in a microfluidic chip. The developed microrobot has a milli-Newton-level output force from a permanent magnet, micrometer-level positioning accuracy, and drive speed of over 280 mm/s. The riblet surface, which is a regularly arrayed V-groove, reduces fluid friction and enables high-speed actuation. Ni and Si composite fabrication was employed to form the optimum riblet shape on the microrobot's surface by wet and dry etching. The evaluation experiments show that the microrobot can be actuated at a rate of up to 90 Hz, which is more than ten times higher than that of the microrobot without a riblet. Two distinguish applications of the developed microrobots were demonstrated in a microfluidic chip.

A new concept of μ-cell fatigue test is proposed. By reciprocating a cell across the throat of a micro channel repeatedly, the dynamic deformation behavior of the cell is measured. We define a new index of fatigue characteristics of cells as the number of reciprocatory motion leading to a prescribed recovery ratio. The test system is composed of a piezoelectric (PZT) actuator, a high speed vision sensor and a micro channel with a throat. Preliminary experiments were conducted by using Red Blood Cells (RBCs). The result suggested that the activation level of a cell can be evaluated based on its fatigue characteristics.

This paper presents the high speed microrobot actuation driven by permanent magnets in a microfluidic chip. The riblet surface, which is regularly arrayed V groove reduces the fluid friction and enables stable actuation in high speed. The comprehensive analysis of fluid force, the optimum design and its fabrication were conducted and proved the friction reduction by riblet. The Ni and Si composite fabrication was employed to form the optimum riblet shape on the microrobot surface by wet and dry etching. The evaluation experiments show the microrobot can actuate up to 90 Hs, which is 10 times higher than the original microrobot. In addition, it can be applied to cell manipulation without harm since the microrobot is covered by Si, which is bio-compatible. One of the applications of developed microrobot was demonstrated by assembling cell aggregation in high speed.

In this paper, we introduce an untethered type of magnetically driven microtool (MMT) with a force sensing function to investigate the stimulus characteristics of aquatic microorganisms in a microfluidic chip. The microchip is composed of the proposed MMTs, which have a Si-Ni hybrid structure, a transparent cover made of polydimethylsiloxane (PDMS), a glass substrate, and a microspacer to prevent both friction during the force measurement and damage to the micropattern of the MMT. The fabrication and drive performance of the MMT, which is actuated by permanent magnets from the outside of the microchip, verified in basic experiments. Finally, we succeeded in on-chip manipulation and sensing of microorganisms using this MMT, which we found to be easy to use.

Holographic optical tweezers (HOT) has ability to trap and manipulate a few hundred of small particles. Previously the manipulation speed is greatly limited to the calculation speed of holograms. But recent progress in parallel computing made it possible to generate the holograms in real-time. Therefore, HOT is thought to play an important role in dexterous micromanipulation. In practical application, the teleoperation of HOT is thought to improve the manipulability. But, the maximum number of objects which can be manipulated at once is limited by the master devices. In this research, we applied a multi-touch user interface for the master. And we designed and constructed the HOT teleoperation system. In the optical system, we implemented a zero-order beam filtering system to avoid the disturbance. In control system, we applied an Apple iPad2 as a master device. The design and the processing of the interface were proposed and discussed in consideration of the manipulability. And, we discuss the manipulation method making the best use of multi-touch user interface. With the constructed system, we demonstrated the parallel teleoperation of 10 particles. And the time response of manipulation shows the potential of smooth manipulation. Based on these discussions, we concluded that the constructed system is effective for micromanipulation.

For the development of medical micro-robotics and robotic manipulation of catheter it is necessary to ensure tissue integrity. In-vitro evaluation of tissue manipulation can be achieved using photoelastic stress analysis and vasculature modeling with photoelastic materials. In this research we propose epoxy resin as photoelastic material for vasculature modeling as it has a larger photoelastic coefficient than previously studied materials and it has a young modulus similar to human vasculature. A model of a saccular aneurysm with bleb was built with the purpose of measuring stress overshoots that enable to differentiate embolization techniques according to the respect for tissue integrity. During embolization using a coil with smaller size than the aneurysm dome diameter, an average area of 0.72 mm2with stress above 90 kPa was measured. This area increased to 0.77 mm2when the dome was touched with the release mechanism of the coil, and to 0.74 mm2for embolization with larger size coil. The presented modeling material and measurement technique is useful for tissue respect quantification for micro-mechanisms evaluation.

In this study, we present a smooth enucleation process on a microfluidic chip. To improve the success rate of enucleation and increasing the potential viability of the enucleated oocyte, a microfluidic system is specially designed. Magnetically driven MicroTool (MMT) control the flow distribution in the microchamber. Designed microchannel with height difference is for the purpose of confining oocyte with its nucleus located in the withdrawal microchannel to achieve the high precision control in cutting volume. By utilizing these aspects, first, oocytes are sequentially loaded to the operation port; MMT constrains the oocyte location and controls the distribution of micro flow simultaneously letting hydraulic force cut off the nucleus from the oocyte. Enucleated oocyte is smooth in shape and incision is neat. With cutting volume control, this system can achieve high-speed enucleation with less cutting volume while removing the nucleus. Since the flow distribution could be managed by MMT significantly, therefore, the new system is proposed here to show advantages by the means of operation speed, cutting precision and great potentiality on continuous cutting process.

Magnetic field has been used for manipulation of micro-robots; in this research we use it for scaffold fabrication. Magnetic sugar particle (MSP) was used as porogen to control pore size, pore structure and pore density in the scaffold. We studied the influence of the strength of magnetic fields for controlling the coating thickness of unmagnetized MSPs during the fabrication of sheet-like scaffolds. The experimental relationship between magnetic flux density and the thickness of MSP layer was illustrated. Furthermore we investigated the infiltration capacity of poly(L-lactide-co-ε-caprolactone) (PLCL) which was used as scaffold material on the MSP clusters. 5% and 10% PLCL solutions were employed in the experiments. After polymer casting and removal of the sugar template, spherical pores were generated inside scaffold, the thickness evaluation of a single layer scaffold was carried out and the cytocompatibility experiment of NdFeB powder used in fabrication of MSP was confirmed with human umbilical vein endothelial cells.

Quantification of human skills is a challenge for simulator based medical training, particularly for endovascular intervention. For that purpose it is needed to measure different biometric parameters from the user and additionally measure the interaction between endovascular instruments and vasculature models membrane. For that purpose in this research we present an optical sensor for encoding linear and rotational motion of the catheter through the insertion port. Additionally we present two studies for measuring tissue integrity, time to complete a task, reaction time, and wasting motion using two populations of expert and beginner. The optical encoder showed an average error of 0.39mm and 10.78deg. In both studies the presented cyber-physical system is useful to identify the users with qualities closer to the expert among users with low performance.

In this paper, we proposed long-lifetime and high-sensitive measurement using fluorescent intensity by compensation of photo-bleaching with the difference compensation for cell measurement. Photo-bleaching of fluorescence is one of the most crucial factors to cause measurement error in physiological measurement. In our approach, difference of fluorescent intensity between imaging time is compensated using single exponential function to make the difference amount uniform in each imaging time. We evaluated the dependencies of measurable time and the sensitivity by fluorescent lifetime and the decay coefficient of fluorescent lifetime using numerical simulation. From these results, the proposed method has much higher sensitivity and longer measurable time against conventional compensation method of photo-bleaching. By using the proposed method, we demonstrate the photosynthesis activity of single Synechocystis sp. PCC 6803 in the micro chamber with gas barrier layer.

In this paper, we newly propose an organ-explanted bionic simulator (OBiS) using an isolated organ tissue. We use a heart isolated from the chick embryo for proposed simulator. To achieve the OBiS, we perform the concurrent microvascular anastomosis by using suction-induced vascular fixation (SVF) method for easily connection to artificial tubes with blood vessels led to the explanted chick's heart. Through the experiment with a simulated cardiovascular, it is confirmed that vessels can be aligned by using the proposed method. In addition, we have succeeded in connecting the Alg tubes with the blood vessels led to the heart of chick embryo. OBiS is available for the evaluation of new drugs immune response not only without using large animals but also as a response of organs beyond cellular level.

For the development of artificial intelligent diagnosis for cerebrovascular intervention, it is desirable to forecast the growth of cerebral aneurysms. In order to achieve such purpose, it is needed to evaluate wall shear stress, strain, pressure, deformation and flow velocity in the aneurysm region. In this research, we focus on in-vitro strain and deformation measurements of cerebral aneurysm models, and propose a cyber-physical system, in which a scaled-up membranous silicone model of cerebral aneurysm was built and integrated with a specialized pump for the pulsatile blood flow simulation, and a vision system was constructed to measure the strain on different regions on the model with pulsatile blood flow circulated inside. Experimental results show that both distance and area strain maxima were larger for the aneurysm neck (0.042 and 0.052), followed by the aneurysm dome (0.023 and 0.04) and then by the main blood vessel section (0.01 and 0.014), which were complemented with computer fluid dynamics simulation for the inclusion of wall shear stress, oscillatory shear index and aneurysm formation index. Medical imaging data of the cerebral aneurysm in 2008 and 2011 was obtained. Diagnosis results have concordance with the aneurysm growth in 2011. The presented measurement method offers an option for measuring strain and deformation to be complementary with computer fluid dynamics and photoelastic stress analysis for advanced diagnostic in the endovascular surgery.

This paper describes an innovative driving method for magnetically driven microtools (MMT). 1.1 μm positioning accuracy of the MMT was obtained by applying a piezoelectric ceramic, which induced nanoscale vibration to the microfluidic chip, and reducing the friction on the MMT. Using this drive method, the enucleation process was conducted by dual-arm MMT. Permanent magnets are used to supply the driving power to the MMT allowing sufficient positioning accuracy to cut oocytes precisely. The nucleus was cut within 10 s, and the removed area was less than 25% of the original oocyte.

The video presents high power, high precision and high speed drive of on-chip robot and its biomedical applications. The magnetically driven microtool (MMT) actuated by permanent magnets was employed as a microrobot because of its strong output force in the order of millinewtons and the ultrasonic vibration was applied to the microfluidic chip in order to reduce the friction on the MMT. We have achieved 1.1 μm positioning accuracy of the MMT and applied this drive method to the enucleation of oocyte process. The dual-arm MMT removed the nucleus part in a few seconds.

In this paper, we newly propose an on-chip force sensing by using a magnetically driven microtool (MMT) equipped with a frame structure for measurement of stimulant property of Pleurosira laevis. The design and fabrication of the force sensing structure with a displacement magnification mechanism based on beam deformation is discussed. Through the basic experiments, the advantages of the proposed layer fabrication technique and the performance of the force sensor are confirmed. The basic characteristics of P. laevis are also confirmed by using the developed MMT.

We developed Optical pH regulation using functional nanotool impregnated with photo-responsive chemical for selective cell injection of nanotool. The nanotool was modified by fluorescent dye for intracellular measurement. The nanotool was included in the fusogenic liposome. Membrane fusion of the liposome to the cell membrane was used for invasive cell injection of the nanotool. The liposome fuses to the cell in weak acidic condition. Local pH regulation inside the liposome was developed using photochromic chemical for selective cell injection of the nanotool. The nanotool was modified by Leuco crystal violet (LCV). LCV emits the proton by ultraviolet (UV) illumination. The emitted proton decreases the pH value in the liposome. This pH regulation is reversible by UV/VIS illumination. The liposome was manipulated by optical tweezers. After contact of the liposome to the cell, the liposome was adhered to the cell by UV induced membrane fusion. Injected nanotool was manipulated by optical tweezers. Intracellular temperature was detected by measuring the fluorescence intensity from the nanotool. We demonstrated optical pH regulation, selective cell injection of the nanotool, and manipulation of the nanotool in the cell.

Multi-beam optical tweezers is important technique to manipulate multiple small objects. Computer Generated Hologram (CGH) is one of the techniques and it can trap more than 200 objects in three dimension. For dexterous micromanipulation, it is useful to apply robotics into optical tweezers. In this research, we designed the optical system and control system of Holographic Optical Tweezers (HOT). For optical design, we considered working space and positioning resolution. For control design, we applied teleoperation. For online generation of hologram, we developed GCH generator applied General-purpose GPU (GPGPU) acceleration. This system achieved high-speed generation of hologram (250 Hz). For full automatic control, we applied stability control theory to the multi-beam control system. With the built system, the positioning precision and response were revealed with trajectory control and teleoperation experiments. As the result, we checked the effectiveness of HOT enhanced by robotics.

In this paper, on-chip particle loading and dispensing modules are presented with their results for the automation of a single particle retrieving from a microfluidic channel. Our proposed microfluidic chip has several modules. Each one of them has important functions as (a) loading micro-particles singly to main microfluidic flow by the aid of magnetically driven microtools (MMT); (b) finding particle position in a microfluidic channel by micro-capacitance sensors; (c) adjusting micro-channel height locally by pneumatic pressure valve; (d) dispensing particles out from the microfluidic chip to incubation environment. Novelty of this paper is summarized as follows: (1) Multi-photoresist combination technique for the pneumatic pressure valve; (2) Automatic on-chip particle dispensing with micro-capacitance sensors. We showed feasibility of automatic dispensing of a single polystyrene bead (about 100 μm) from the chip to atmosphere. The performances of each module (hybrid structure, sensor and dispensing parts) were evaluated individually. We succeeded in determination of the movement of micro-particles (about 50-100 μm) with the velocity of over 6 mm/sec. by the micro-capacitance sensors. The advantages of the proposed system are that composed of the reusable drive system such as xy motorized stage, pumps and a disposable microfluidic chip.

This paper reports a magnetic steering method for controlled porogen fabrication of scaffold for blood vessel regeneration. The method described involves generating gradient magnetic field by a combination structure of Helmholtz coils and Maxwell coils to propel particularly prepared magnetic sugar particles (MSPs) moving in fluid environment at desired trajectory and forming a specified 3D shape as templates for particulate leaching. The movement properties of MSP are theoretically analyzed and the corresponding dynamic mechanics model is established. Further the magnetic field distributions inside the combined coils are calculated and optimal control parameters of coils configuration are obtained. Preliminary motion control experiment is also conducted to prove the feasibility of proposed method. The result demonstrates that MSP cluster can be manipulated with average speed of 0.25 mm/s for a cluster of 12 MSPs and 0.116 mm/s for a cluster of 37 MSPs with the proposed coil system and used for improving interconnection of MSP dot patterns.

In this paper, we discuss the design and fabrication approach to increase the success rate of single particle dispensing. Two pairs of capacitance sensors are placed in a biochip to detect the flow velocity of particles, and the air pressure is applied to eject particles by synchronizing the timing. Comprehensive design theory, which is taken into account of the back pressure caused by air pressure, the response time of the system, sensor property, and the delay of the dispensing from the air pressure, is developed in order to minimize the disturbance of the system and maximize the throughput of the ejection system. Then, the system has capability to eject 3 particles/sec and maximum flow velocity is 10 mm/s. The novelty of the system is that the biochip is disposable which is unlike the conventional mechanical inkjet system and it can prevent contamination. Therefore, the fabricated disposable biochip based on photolithography is low cost and the drive system is reusable. Finally, we succeed in automatic dispensing of a single particle (=100 µm) from a biochip to culture well atmosphere using developed cell ejection system with the success rate of 50 %.

In this paper, we proposed cell investigation tool for measurement of physiological conditions of single cell. We developed a novel temperature measurement method using temperature dependence of the quantum dot. The cell investigation tool encapsulates the quantum dot and adheres to the cell membrane. These tools can be manipulated in a solution by optical tweezers. We proposed image processing of the tools using the color information for temperature measurement. We calibrated the temperature using the tool impregnated with quantum dot by several color spaces such as HSV and YCrCb (H: hue, S: saturation, V: values (brightness). Y: brightness, Cr: color difference of red, Cb: color difference of blue). Y and Cr represent the monotone decrease according to the temperature increase, while H and Cb do not represent monotone variation. Measurement value by Cr is stable rather than the values by Y and V information because the color difference is robust against brightness fluctuation. From these results, we confirmed temperature measurement using Cr information suitable for cell analysis. Sensitivity is −1.3 %/K and accuracy is 0.3 K.

Micro/Nano robots have attracted scientific attention to develop novel technologies such as drug delivery systems. Recently, flagellated bacteria have been used as the driving force of microobjects to develop bacteria-driven microrobots. In this paper, we propose a method of smart manipulation of multiple bacteria-driven microobjects with single manipulated guiderobot based on bacterial autonomous movement, named ¿SMARTBOT¿, for enabling arbitrary and low cost manipulation of multiple bacteria-driven microrobots. We verify the capability of smart manipulation of multiple bacteria-driven microobjects based on bacterial autonomous movement by using micro/nano pipettes instead of a guiderobot. For the fabrication of the guiderobot and the cargo driven by the bacteria, the fabrication of the arbitrarily-shaped microobjects using photo lithography technique is demonstrated. Additionally, we demonstrate the remote control using optical tweezers and driving using flagellated bacteria of the fabricated arbitrarily-shaped microobjects.

Cell stiffness could be an index for evaluating its activity. Although various systems measuring cell stiffness have been proposed so far, they are slow for adaptively connecting to cell sorters capable of handling more than 1000 [cells/sec]. This paper proposes a new approach that can indirectly evaluate the cell stiffness by measuring the passing time for a narrow channel. When a cell passes through the channel, it receives a viscous force depending upon how much deformation is exerted on the cell. We show that the stiffness is a function of both the passing time and the initial diameter of cell. We also show that the stiffness is proportional to the passing time and inversely proportional to the initial diameter, under the assumption that the thickness of fluid film is inversely proportional to the normal force. The experimental validation is given together with the basic working principle.

Production of functional microtools having an arbitrary shape by self-assembly of microparticles and heat treatment above the glass transition temperature of the microparticles was developed. Polystyrene microbeads were used as a material of the microtool. A solution including microparticles was dispersed onto the silicon substrate having microtool patterns fabricated by photolithography and etching. Dispersed particles were introduced to the pattern by gravity force. Microparticles in the pattern aggregate autonomously by surface tension through evaporation of the solution. Aggregated microparticles were fused by heating above the glass transition temperature (100 Celsius degrees). Fused microparticles were detached from the pattern by ultrasonic treatment and used as microtools. Produced microtool has spherical part since the microtool is made of microparticles. Spherical part is suitable for trapping point of optical tweezers. We demonstrated production of microtools using self-assembly and manipulation of the fabricated microtool on a chip. Position and attitude accuracy of the fabricated microtool controlled by TSS were evaluated by image processing. Finally, the transport speed of the fabricated microtool was compared with that of the photofabricated microtool. We confirmed the improvement of the transport speed and the effectiveness of our proposed microtool.

We have successfully produced emulsion droplets on a chip with size-control and on-demand droplet generation by using magnetically driven microtool (MMT) which has a parallel plate structure to be constrained in translational motion. With a lateral motion of MMT in microchannels, the continuous phase can be cut into different size of droplets and the dispersed phase flow can inflow into the microchannels by the movement of MMT to obtain both of size-controlled and on-demand droplets actively. The size range of the produced droplet was three times as large as the previous system by using novel hydraulic design of the chip, and also the dispersing the fluid was successfully prevented from leakage when it is chopped by using MMT.

This paper presents two innovative driving methodologies using magnetically driven microtools for precise cell manipulations and its automation systems. First, the magnetic analysis has been conducted to show the current MMT problem. Then, the new driving methodologies are introduced and backed up with FEM analysis and the experimental results. The positioning accuracy improves 3–10 times and the following response become 10 times higher against the driving linear stage. Using this methodology, the enucleation of oocytes is demonstrated to show the effectiveness of the method.

In noncontact cell manipulation with optical tweezers, we need to use microtools to avoid damages to the cells by direct laser irradiation. When we manipulate complex structures such as microtools, a multi-beam optical tweezers which can manipulate multiple objects is suitable; however manipulation speed or trapping number are not so good. Therefore, we developed an integrated optical tweezers by using time-shared scanning method for high speed manipulation and generalized phase contrast method for a lot of trapping. Then, we proposed cell manipulation method which suits for the integrated optical tweezers and then we designed the shape of microtools made of SU-8. A new fabrication method of SU-8 microtools was proposed to improve productivity. At last, we made the experiment system and the effectiveness of proposed methods was confirmed.

As cancer becomes the No.1 cause of the death in Japan, endoscopic surgery is gaining attentions. In this paper, endoscopical tool to grip and lift the targeted tumor in ESD (endoscopic submucosal dissection) surgery is proposed. This articulated microarm is part of new ESD surgery concept in which two wire-driven microarms (1 times 1 times 25 mm) from the tip of the endoscope help lift the tumor to cut. This research needs to emphasize a new fabrication method of arm which is fabricated by photolithography and electroplating. The microarm is composed of five layers. Individual layers are fabricated separately and assembled together in the end. The microarm uses the elastic deformation of metal to bend (Cu or Phosphor Bronze). It is feedback control with PID using a strain gauge attached to the articulated joint. This technique enabled the further miniaturization of the microarm, but it also comes with a downside. It is difficult to build a 3-dimensional structure. We overcame this problem by proposing an assembly method (STAMP: stacked microassembly process). Electroplated layers are assembled by stacking up on top of each other. This assembly process is feasible to produce multiple microarms at one assembly, thus mass-production with low cost is possible. A strain gauge is attached to the elastic joint as an angle sensor.

We succeeded in powerful noncontact actuation of magnetically driven microtool (MMT) by magnetizing it and focusing magnetic field in a microfluidic chip. Novelty of this paper is summarized as follows. (1) We employed neodium powder as the main component of MMT. The density of magnetic flux was improved about 100 times larger after magnetization. (2) We fabricated a pair of magnetic sharp needles in the chip by electroplating. MMT was placed between the needles and the density of magnetic flux was improved about 3 times larger. As a result, we succeeded in powerful actuation of MMT in a chip. Drive frequency was improved about 10 times faster (up to 180 Hz). We applied it for sorting of copolymer beads in a chip. MMT is put in the microchannel. The size of the bead was measured by image processing (15 Hz). Moving frequency of the MMT was made higher than the sampling frequency of measurement and secure sorting was achieved.

In this study, we successfully produced a functional microtool made of gel microbeads using size-dependent microparticle classification. Gel microbeads are made by salting-out hydrophilic photo-crosslinkable resin ENT-3400. These gel microbeads were separated according to their size using microfilters made of polydimethylsiloxane (PDMS). The first filter is a row of fluidic microchannels that block microbeads with a size greater than the channel's width. Another filtration method has been examined using a magnetically driven microtool (MMT) to separate the beads using the centrifugal force created by this MMT actuated with a DC motor. Separated gel microbeads were recovered after filtration and used to fabricate functional microtools, for example, a tether-shaped gel tool, by contact with other gel microbeads under UV illumination. The produced gel tool is manipulated using optical tweezers in a microchip. We successfully achieved size-dependent separation of gel microbeads and production of a tether-shaped gel tool.

Optical adhesion control of a functional gel microtool, made of hydrophilic photo-crosslinkable resin, was developed for on-chip cell manipulation. The functional gel microtool used can be manipulated by optical tweezers and functionalized by spiropyran chromospheres, which is a photochromic polymer. Spiropyran chromospheres were used for temporal cell adhesion of the gel microtool. The adhesiveness of the gel microtools was controlled by photo irradiation. The gel microtools adhere to glass and other gel microtools, in an electrolyte solution of adjusted concentration, after ultraviolet (UV) illumination. By controlling the electrolyte concentration, the adhesion to cells can be selected as either permanent or temporal cell adhesions. UV illumination caused the cell to adhere to the gel microtool, while VIS illumination detached it from the gel-microtool. We also produced a pH sensing gel microtool by modifying the gel microtool with a pH indicator, bromothymol blue (BTB). The pH value was measured by detecting the color of the gel microtool with calibrated color information. Local measurements of the ambient pH value of a single yeast cell were performed by a ring shaped gel microtool and by immobilizing the cell on the surface of the pH sensing gel microtool.

We proposed a fabrication method for multiscale transparent arteriole and capillary vessel models and demonstrated the fabrication of microchannels with circular cross sections ¿10 - 500 ¿m. First, we demonstrated fabrication of ¿10 - 500 ¿m arteriole and capillary vessel block models using photolithography. The circularity of fabricated ¿10, 50, and 500 ¿m microchannels were 84.0%, 61.5%, and 82.3%, respectively. Flow experiments demonstrated that these channels had no leakage. Next, we proposed a fabrication method for ¿100 - 500 ¿m arteriole membrane models, which connect larger membrane models and smaller block models. These models were prepared with grayscale lithography and a wax and PVA (polyvinyl alcohol) mixture material. The proposed approach overcame the brittleness of a previous sacrificial model fabricated by ink jet rapid prototyping. The membrane model had a circular cross section with a channel circularity of 90%. Finally, we succeeded in making transparent membranous and block arteriole model with which we can simulate blood circulation.

We have investigated an active size controlled droplet generation system by using magnetically driven microtool (MMT). With a lateral motion of the MMT in microchannels, the continuous phase can be pinched off by the movement of MMT to obtain size-controlled droplets actively. With this method, particle-enclosed droplet can be produced on demand to fit the size of each enclosed particle, and which is difficult to carry out only by the fluid dynamic force. For the current study, the system has been evaluated in terms of the frequency of the actuation of MMT and the size of the produced droplets, and found out the response time to change the droplet size by MMT actuation is one third of that only by the fluid dynamic force. This system contributes to the effective transportation of cells in microchannel.

A novel on-chip environment measurement with functional gel-microtool was developed. Environment measurement gel-microtool was fabricated by connecting the gel-microbeads impregnated with indicators in a microchip. In this paper, Bromothymol blue (BTB) and Bromocresol green (BCG) were employed as pH indicators. BTB and BCG have the different indicator range. Rhodamine B is temperature sensitive fluorescent dye and is used for temperature measurement. Gel-microbead is made by salting-out of hydrophilic photo-crosslinkable resin and is manipulated by optical tweezers. Moreover, gel-microbead is polymerized by UV illumination and connected to other gel-microbead under an electrolyte solution. The connection of gel-microbeads is performed by contact of gel-microbeads under UV illumination. Environment measurement gel-microtool with an arbitrary shape is fabricated by connection of the gel-microtool impregnated with arbitrary indicator. Multiple environments measurement gel-microtool included with several indicators is realized by assembly of the gel-microbeads impregnated with different indicators. Environment measurement is performed by detecting the color and the fluorescence intensity of each gel-microbead. We succeeded in the on-chip fabrication of the environment measurement gel-microtools such as circular pH measurement gel-microtool and wide range pH measurement gel-microtool in a microchip.

Technologies to develop scaffolds with controlled pore layout and porosity have great significance in tissue engineering. As one method of scaffold fabrication, porogen leaching has been commonly used to control pore size, pore structure and porosity in the scaffold. In this paper, we describe a novel approach to fabricate 2D and 3D porous biodegradable scaffolds made of poly(L-lactide-co-ε-caprolactone) by using magnetic sugar particles as porogens. First, ferrite micro/nano particles were encapsulated in sugar microspheres to make them magnetized. After sieving magnetic sugar particles, those diameter-controlled particles were attracted by a magnetic force to form an assembled template for polymer casting. A magnetic field with polka-dot pattern was also utilized to align particles on desired positions. After polymer casting and removal of the sugar template, spherical pores were generated inside scaffold. For future application in vascular tissue engineering, we extended the scaffold fabrication to straight tubular scaffolds by winding 2D porous sheets on sacrificial molds. The biocompatibility of the developed scaffold was confirmed by viable cells after 4-day culture.

We have developed magnetically modified polymeric soft microactuators in microchip as replacement of conventional manual cell manipulations such as pipetting and centrifugation. In the past papers in Yamanishi, Y., et al, (2007) we have reported novel magnetically driven polymeric microtools for non-intrusive and no contamination experiments on a chip. The main features of them were 1. fabrication of any shape, 2. soft (harmless to cellls) 3. no stiction and 4. mass production at low cost enabling disposability. For the current research, we have demonstrated manipulation of oocyte with produced novel soft microactuators. These magnetic microtools provide a number of functions such as microvalve and microrotor. The potential impact of this technology includes sample preparations, selection and separation, loading and immobilization, genetic operation, tracking, mixing and reaction techniques into portable microfluidic labs-on-a-chip, culture systems.

A compact force sensor with the AT-cut quartz crystal resonator was developed. The quartz crystal resonator has the characteristic that the resonance frequency changes by the external force, which achieves high sensitivity, high-speed response, and wide range of measurement by a simple structure. Also it has the superior feature in the temperature and frequency stability. In the past, the quartz crystal resonator had been hardly applied to the force measurement because of low degree of mechanical characteristic, that is, it is weak to stress concentration by bending. The objective of this study is to construct the sensor mechanism that safely maintains the quartz crystal resonator for the external force with flat structure. We designed and analyzed a novel retention mechanism of the quartz crystal resonator. The proposed force sensor is flat, small, and sensitive. It can be applied to several usages such as medical treatment and contact force detection of human.

In this paper we describe a novel fabrication method of three dimensional polymeric magnetically driven microtools (MMT) for non-intrusive and no contamination experiments on a chip. In order to obtain precise and complicated three dimensional patterns of magnetically driven 3D microtools, a grayscale photolithography technique has been applied by making good use of thick nega-photoresist as sacrificed mold. By controlling an amount of ultraviolet light with a gradation of gray tone mask, we have fabricated smoothly curved (100 mum gap) object without steps which tend to be appeared in case of conventional layer by layer photolithography techniques. A wide range of on-chip application of microactuators can be proposed by using a softness of polymer-based 3D MMT. For example, microrotor was operated as miromixer and micropump, also microloader was actuated by the magnetic and fluidic force. The surface of the 3D MMT was fabricated with a group of spiked pattern to reduce the contact area between PDMS (poly dimethyl siloxane) microchannel and PDMS-based 3D MMT. The produced 3D MMT can be applied to complicated on-chip manipulations of sensitive materials such as cells.

The paper describes a novel non-contact manipulation system using an on-chip, magnetically driven micro-tool (MMT) rather than conventional biomanipulation by hand, which has a higher risk of contamination and lower success rate and repeatability. MMTs can sort particles individually, and have the unique feature that they can be installed directly in a microchannel (width = 150 mum), unlike conventional cell sorting systems. The drive unit was significantly downsized by amplifying the magnetic power using a permanent magnet. Lower power consumption could also be realized, because no energy is required to keep MMTs stationary at a particular position. Sorting was performed using real-time sensing images of microbeads, where the system successfully sorted beads of different sizes at switching speeds up to 18 Hz. The MMT developed in this study is unique with respect to its flexibility and biocompatibility; in addition, since the PDMS (polydimethylsiloxane) microchip is disposable, it can be applied to cell sorting without any risk of contamination. Potential fields of application of this technology include cloning techniques, which require sorting of oocytes with and without nuclei.

In this research, we propose a method to construct an artificial blood vessel scaffold with patient-specific complex 3-dimensional shape and biocompatible porous polymer membrane adapted for cell cultivation, by introducing salt leaching technique into a fabrication technique for patient-specific 3D blood vessel model proposed by authors. In this method, a membranous PVA (polyvinyl alcohol) structure of desired 3-dimensional blood vessel shape was fabricated based on CT data. And the PVA structure was dip coated with polymer solution made by dissolving the Caprolactone (3wt%) and NaCl particle (27wt%) into chloroform (organic solvent), Finally, the NaCl particle and the membranous PVA structure were both eluted from the structure by dissolving these materials under water, and finally a patient-specific blood vessel scaffold with desired 3D vascular shape was constructed. Presented scaffold has the mechanical compliance similar to human blood vessel and provides porous polymer structure appropriate for cell cultivation.

In this paper, a series of in situ nanofabrication techniques of nanostructures, including cutting, bending and welding of carbon nanotubes (CNTs), inside a field emission scanning electron microscope (FE-SEM) is reported. In the CNT cutting technique, a CNT was exposed to a low energy beam assisted with 1 seem oxygen gas flow. The proposed technique is effective being capable of cutting a CNT in less than 1 minute. It was found that, although the total pressure of specimen chamber reached 10-2Pa, high speed cutting occurs only in the area close to the nozzle. The presence of oxygen gas in the vicinity of the CNT can be applied also for the bending of CNT, if some conditions of the cutting technique are changed. These include the increase of the acceleration voltage and/or setting the oxygen gas nozzle farther from the sample, and/or reducing the irradiation time. Using the proposed bending method the angles larger than 90deg can be formed and the location of the kink can be set accurately. It is also shown, that tungsten can be deposited on a substrate by the electron-beam-induced deposition (EBID), if the oxygen of the proposed cutting technique is replaced by W(CO)6. In this paper, these three nanofabrication methods were exploited in creation of a two dimensional (2D) nanostructure, the letters N and U, and a three dimensional (3D) nanostructure, the letter N. The 2D letters were constructed from 6 CNTs assembled on a substrate while the 3D letter N was bended from a single CNT and fixed to stand on a substrate. Based on the high performance of the proposed techniques, it is suggested that the cutting, bending, and welding techniques inside SEM will become widely utilized in the fabrication and assembly of nanodevices and in the characterization of nanomaterials.

A local pH measurement method in a microchip using a functional gel-tool was developed. We used salting-out gel-tools impregnated with Bromothymol Blue (BTB), which is a pH indicator. The gel-tool is made of hydrophilic photo-crosslinkable resin. The primary constituent of this photo-crosslinkable resin is polyethyleneglycol. A solution mixed with photo-crosslinkable resin, BTB, high concentrations of an electrolytic solution are stirred, and gel beads impregnated with BTB are obtained. Gel-tools are cured by UV-ray and adhere to the glass plate, but we can manipulate them by the optical tweezers. We can measure pH value locally from the color of gel-tool using calibrated color information in YCrCb color space. We succeeded in measuring local pH value with the pH sensing gel-tool by manipulating and locating it at the desired point in the microchip.

We developed a novel technique to manipulate lipid nanotubes in 3D by laser tweezers in water solutions. Laser tweezers are well known as one of the noncontact manipulation methods used in a closed space. We reported on 3D 6DOF manipulation of microbeads using 3D Synchronized Laser Micromanipulation (SLM), however, the blur is generated in the microscope image when multiple points at different height are trapped by scanning the focal point of laser. Moreover, it is difficult to manipulate a nano scaled rod-like object stably in 3D, since optical trap force is weak. To manipulate a lipid nanotube for example, firstly, we newly developed an observation system to improve blur of image by synchronization of shutter timing of CCD camera and laser scanning. As a result, we can obtain a clear image of the targets at different height while manipulating them. Secondly, we developed functional gel microtools which can adhere to the lipid nanotubes. We succeeded in controlling the position and orientation of the lipid nanotubes by using 3D SLM with shutter timing control method and novel functional gel microtools.

A force sensor with quartz crystal resonator has the characteristic that the resonance frequency changes by the external force, which achieves high sensitivity, high-speed response, and wide range measurement by a simple structure. Also it has the superior feature in the temperature and frequency stability. On the other hand, the quartz crystal resonator had been hardly applied to a dynamic force measurement because of low degree of mechanical characteristic, that is, it is weak to the impact, bend, and tension. The objective of this study is to construct the sensor mechanism that safely maintains the quartz crystal resonator for the external force with flat structure. We designed and analyzed a novel retention mechanism of the quartz crystal resonator for the flat structure. The proposed force sensor is flat, small, and sensitive enough to be applied to several usages such as medical treatment and dynamic contact force detection of human.

In this paper we describe novel magnetically driven polymeric microtool for non-intrusive and no contamination experiments on a chip. The composite is formed by suspending magnetite particles (Fe3O4) in polydimethylsiloxane (PDMS). In order to obtain precise and complicated pattern of micromagnetic tools, a photolithography techniques has been applied by making good use of thick KMPR-1050 photoresist as sacrificed mould. The surface of the produced micromagnetic tools is specially coated in order to suppress stiction in the biochip. The novelties of these tools are (1) fabrication of any 2D shape, (2) softness (harmless to cells), (3) no contact actuation (no stiction), 4. mass production with low cost. Here we have demonstrated that the mass-produced versatile micromagnetic tools such as stirrer and valve. The potential impact of this technology includes sample selection and separation, cell immobilization, genetic operation, tracking, mixing and reaction techniques into portable microfluidic labs-on-a-chip, culture systems and cell loading system.

Laser tweezers is suitable for manipulation of a single microscopic biological object. It can manipulate micro bioobject without contact in the closed space. Single cell manipulation is important for biological research, and 3D 6DOF manipulation (position control and orientation control) is useful technique in many biological experiments. In this paper we propose 3D synchronized laser manipulation system that can manipulate multiple micro-objects along separate trajectories in 3D space. The position as well as the orientation of microbeads can be controlled using this system. We succeeded in achieving orientation control of the microbead by using the laser trapped microtools. We demonstrate experimentally 3D 6DOF manipulation of microbeads

An in vitro patient-specific vascular model, for simulating endovascular intervention is presented. Proposed vascular model reproduces the 3-dimensional vessel lumen structure using CT/MRI information with 13 mum resolution, and it also reproduce the physical characteristics of arterial tissue (elastic modulus and friction coefficient). Furthermore, in this paper, we propose a novel method to evaluate the stress on vasculature which is applied by surgical operations. This method allows quantitatively evaluating 3-dimensional stress conditions in real-time during surgical simulation. Finally, we constructed a comprehensive surgical simulation system, which reproduces whole human aorta structure (with more than Imm inside diameter), reproduce patient-specific pulsatile blood streaming, allowed to evaluate the stress applied to the aorta structure by surgical operations with almost same manner and environment as the practical endovascular intervention. Consequently proposed model, evaluation method and resultant system provides a very valuable platform for evaluating the performance of surgical robots and instruments developed by developers and researchers, and surgical procedures

In this paper we propose a remote touch screen (RTS) as an application for flexible tactile array units. RTS is a combination of a flexible tactile display, a camera, a conventional touch screen and a monitor. While the user may press a button shown on the monitor under the touch screen in a conventional touch monitor configuration, in RTS, the user may press a button that is felt and shown. For visual guidance the user's hand motion is captured by an overhead camera, and is merged with the screen menu image and shown on the monitor. For tactual guidance, a tactile pattern is provided at the center of the button locations shown on the monitor. Hence the user's button pressing motion is visually as well as tactually guided in RTS configuration. To confirm the effectiveness of tactile display units in RTS, experiments were performed with and without the tactile display units

We report a single tungsten nanowire successfully grown by controlling the distance between the emitter and substrates with a robotic nanomanipulator moved at a speed of 15 nm/s. When we draw the emitter far from the substrates during electron emission, the longest nanowire at the tip can grow continually, because the electron field at the tip is stronger than the other parts of nanowires. Although multiple nanowires grow at the beginning, the result is that only one nanowire can grow continually at the tip of carbon nanotubes (CNTs). We also show tree-like nanowires on the tip of a CNT without inter-electrode control. These nanowires were induced by field emission, with tungsten hexacarbonyl as precursors. The nanowire's geometric properties were characterized with transmission electron microscopy (TEM) and its composition was detected with TEM energy dispersive X-ray spectrometry (EDS). The EDS spectrum showed that the nanowires are mainly made of tungsten and carbon. The degradation of CNT emitter is an important problem and influences the device's stability and lifetime. We propose that the growth of nanowires can be used for modifying degraded emitters

We propose a new tactile sensor utilizing piezoelectric vibration. This tactile sensor has a high sensitivity, wide measurement range, pressure resistance, flexibility, and self-sensing function. This tactile sensor comprises two piezoelectric materials. One is used for the vibration of the sensor element and the other is used for the measurement of the change in mechanical impedance induced by an external force. We achieved the wide measurement range by implementing two ideas. One was to apply the external force to the sensor element through an elastic body and the other was to use two or more modes of vibration. Moreover, for the elastic body, it is preferable to use a material whose elasticity and viscosity are easily changed by an external force, such as a gel. In this study, first, this tactile sensor was analyzed, and then its characteristics were derived. The analytical results qualitatively corresponded to the experimental results. Next, a prototype tactile sensor was fabricated and evaluated. The evaluation results showed that this tactile sensor can measure a pressure of 2.5 Pa or less and a pressure of 10 kPa or more and its pressure resistance is 1 MPa or more

In situ fabrication and electrostatic actuation of a telescoping multi-walled carbon nanotube are presented. The inner core of the telescoping nanotube is actuated by applied bias voltage with a certain gap inside a vacuum chamber. From modeling analysis, the electrostatic forces are mainly driven force for actuation. At the experimental section, one end opened telescoping multi-walled carbon nanotube (MWCNT) is directly observed inside a transmission electron microscope (TEM). The telescoping MWNT is fabricated by peeling off outer layers through destructive fabrication process. Its inner core is extended and retracted with applied DC bias voltage. These processes have been done through a hybrid nanorobotic manipulation system, which are integrated nanomanipulators inside a scanning electron microscope (SEM) and a TEM. From experimental and analytical results, the possibility of nano-scale actuator applications using telescoping MWCNT with precision has been presented

There are many electric power generators employing dynamos. However, most of them require large mechanical energy input at a time to get large electric power output. This task is not easy for elders because of heavy load. Therefore, we aimed to develop a new ubiquitous power generator suited for light power input. In order to generate large electric energy with light force, we propose a new generator mechanism to store mechanical energy using a spiral spring and gears. Large mechanical energy is stored in the spring by iteration of light force input. We designed a mechanism which can store mechanical energy in the spring by rotating an input lever several times with light force. The energy is restored to rotate the dynamo at high speed to generate electric energy efficiently. While restoring the mechanical energy, reverse rotation of the input lever is avoided by the clutch. Analysis as well as experiment of the proposed mechanism was performed here for optimal design of gear train. As an application, a power generation device which generates energy from door motion is shown to see effectiveness of this mechanism

The essential challenge in the future ubiquitous networks is to make information available to people not only at any time, at any place, and in any form, but with the right thing at the right time in the right way by inferring the users' situations. Several psychological experiments show that there are some associations between each user's situations including the user's emotions and each user's task selection. Utilizing those results, this article presents a situation-based task selection mechanism that enables a life-supporting robot system to perform tasks based on the user's situation. Stimulated by interactions between the robot and the user, this mechanism constructs and updates the association between the user's situation and tasks so that the robot can adapt to the user's behaviors related to the robot's tasks effectively. For the user adaptation, Radial Basis Function Networks (RBFNs) and associative learning algorithms are used. The proposed mechanism is applied to the CRF3 (Character robot face 3) system to prove its feasibility and effectiveness. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 973–1004, 2006.

Nanoscale linear servomotors with integrated position sensing are investigated from experimental, theoretical, and design perspectives. Prismatic motion is realized using the interlayer motion of telescoping multiwalled carbon nanotubes (MWNTs). Position sensing can be achieved by monitoring field emission or by measuring resistance change between an MWNT and a gold substrate during sliding movement. Experimental results demonstrate resolution in the nanometer range. Actuation experiments demonstrate the feasibility of a linear nanoservomotor with integrated position sensing based on field emission. A local "kink"-like fluctuation of emission current is observed, which is caused by the change of the protruding length of the nanotube core, thus demonstrating the potential of using emission as a "linear encoder." The complete extension of the inner core is observed and the electrostatic force is calibrated to be tens of nano-Newtons for individual nanotubes-16.5 nN under a 30-V bias. These results demonstrate the possibility of fabricating linear servomotors at the nanometer scale with integrated position sensing. Note to Practitioners-Nanometer scale actuators and sensors that can provide motion and measurement with nanometer-order resolution will enable new industrial applications in which only a few atoms or molecules are measured, transported, or processed. Linear servomotors will play a significant role in such applications because they provide precision prismatic motion directly without requiring a conversion from rotary to linear motion. Nano linear servomotors are experimentally and theoretically investigated in this paper. The devices take advantage of the ultra-low interlayer friction of a multiwalled carbon nanotube (MWNT). Position sensing feedback is achieved by monitoring field emission, which depends on interelectrode distance, or by measuring resistance change between an MWNT and a gold substrate during sliding movement. Whereas this paper targets long-term nanotechnology contributions, some intermediate results are ready for applications in the near future. The interlayer sliding motion demonstrated would enable the building of devices, such as Gigahertz oscillators and attolitter nanosyringes, and the sensors used for position feedback could find applications independently in a macro or microscale machine for detecting proximity, touch, displacement, or orientation.

Nanoscale linear servomotors with integrated position sensing are investigated from experimental, theoretical, and design perspectives. Prismatic motion is realized using the interlayer motion of telescoping multi-walled carbon nanotubes (MWNTs). Position sensing can be achieved by monitoring field emission or by measuring resistance change between a MWNT and a gold substrate during sliding movement. Experimental results demonstrate resolution in the nanometer range. Actuation experiments demonstrate the feasibility of a linear nano servomotor with integrated position sensing based on field emission. A local “kink”-like fluctuation of emission current is observed, which is caused by the change of the protruding length of the nanotube core, thus demonstrating the potential of using emission as a “linear encoder”. Complete extension of the inner core is observed and the electrostatic force is calibrated to be tens of nano-Newtons for individual nanotubes— 13.3 to 23.3 nN for voltages from 20 to 30V. These results demonstrate the possibility of fabricating linear servomotors at the nanometer scale with integrated position sensing.

In recent years, single cell experiment has become very important for investigating unknown cell properties. We developed a novel technique to investigate individual cell properties on a chip using newly developed cell manipulation method by laser tweezers with the photo - crosslinkable resin. We propose new fabrication method of functional microtools, such as colored microtool, fluorescent microtool, cell binding microtool, rotation free microtool, rope shaped microtool, on a chip. These microtools are made of photo - crosslinkable resin. Colored microtool and fluorescent microtool are for cell manipulation using Image processing with low cost. Cell binding microtool is made for high - speed transportation of target cell. Rotation free microtool is made for position control and precise force measurement of cell and DNA. Rope shaped microtool is for versatile manipulation. Laser tweezers is employed to position control of microtools. We used mercury lamp for UV - ray illumination at the local area for combination of microtools. We succeeded in fabrication of our functional microtools and manipulation of cell in the microchip.

In this paper, grasping strategy using deformation of soft finger is addressed. Soft fingers, which are made of macromolecular and have large elastic deformation, have gotten a lot of attention. Soft fingers have a peculiarity that high friction force, which stabilizes a grasping condition, is generated by expansion of contact area between tip of soft finger and grasping object. However, until now nobody focuses on the fact that deformation of soft finger enables multi-fingered hand to generate force to manipulate a object which has high aspect ratio and restricted by environment. Accordingly, we focus on a task to pick up a thin plate on a floor using deformation of soft finger. The effectiveness of grasping strategy is confirmed by experiments.

We propose a novel tactile sensor, of which sensitivity and sensing range is adjustable. This sensor is a mechanical resonator sensor using a piezoelectric bimorph which measures elastic deformation of media by external force. The sensor is robust and has self-sensing capability. We derived the relationship between sensor output and spring constant at each vibration mode by the piezoelectric analysis and vibration analysis. The validity of sensor was demonstrated by experiment. As an application, a robot fingertip with tactile sensor was fabricated and evaluated.

A novel approach appropriate for rapid separation and analysis of single cell by concomitantly utilizing noncontact laser manipulation and locally thermo sensitive hydro gelation is proposed in this paper. We have employed a single laser beam as optical tweezers for separating a target cell and locating it adjacent to a fabricated transparent micro heater. Simultaneously, the target cell is immobilized or partially entrapped with thermo sensitive hydro gel by heating up the micro heater. The state of the thermo sensitive hydro gel can be switched from sol to gel and gel to sol reversibly by controlling its temperature through heating up and cooling down the micro heater. Having got rid of the other unwanted cells by the high speed cleaning flow in microchannel, the entrapped cell will be isolated effectively. It is possible to collect the immobilized target cell after analysis or culture process by switching of the micro heater and releasing the cell from the entrapment. We have demonstrated that the proposed approach is feasible for rapid manipulation, immobilization, cleaning, isolation and extraction of a single cell. Experiment results are shown here.

In this paper, we propose an in vitro patient-tailored biological model of human cerebral artery, an innovative platform for simulating intravascular neurosurgery to evaluate medical robots and devices. This anatomically accurate model reproduces 3-dimensional configuration of individual arteries with an artery-like thin membranous structure made of silicone elastomer. Its modeling resolution is 13 /spl mu/m. Presented modeling methodology also allows constructing any hollow structure, which is suitable for robot evaluations, making use of CAD. Presented model also reproduces the physical properties of arterial tissue with errors less than 5% (that include elastic modulus, poisson's ratio and frictional coefficient). Thus the cerebral arterial model reproduces not only the behavior of arteries caused by surgical operations, but also the dynamic behavior of surgical robots and devices (e.g. elastic deformation and slip/stick motion). Furthermore, we also propose a novel method that allows developers to evaluate 3-dimensional stress condition on arterial wall, which is caused by surgical operations, by making use of the photoelastic effect. As there are almost no realistic hardware platform enough to fairly evaluate medical robots and devices, it should provide an advanced testing environment for developing robots and other various medical equipments, especially for intravascular neurosurgery.

The purpose of this research is to control human state and biological rhythm. The system has to be adaptive and intelligent because it must deal with human information including personal differences. As a first step to achieve the function, we try to estimate a human's state in sleep using a wearable sensor device, under less physical movement than daytime. In the next step, we try to control human biological rhythm using the method to estimate human sleep state. We consider the simplest way to control human's sleep is to control awakening timing and sleep time. The proposed system can estimate human sleep quality and rhythms, and provide stimuli based on wake up timing. The system uses only pulse wave to estimate sleep quality because the pulse wave can be measured more easily than PSG.

Field emission properties of individual multi-walled carbon nanotubes (MWNT) have been investigated and applied to several nano devices. Field emission current changes with the distance between the tip of a carbon nanotube (CNT) emitter and a counterpart anode, which can be applied as the principle for an approaching sensor to detect nanometer scale distance by the observation of field emission current in real time. Higher field emission current in microampere-scale from a CNT emitter has been shown strong enough for performing electron-beam-induced deposition (EBID) without obvious degradation of emitters. EBID with CNT emitters can provide much higher specific deposition rate, potentially better productivity due to the possibility to be used in parallel, and richer metallic composition as introducing organometallic precursors such as W(CO)/sub 6/ as presented In this work. Energy dispersive X-ray spectrometry (EDS) analysis on deposits from W(CO)/sub 6/ shows that the mass of tungsten reaches up to over 80% among the compositions.

Isolation and separation of the target microbe is quite important. We propose a new touch sensor for separation of the target microbe on the plate using a micromanipulator with the glass pipette. Principle of this touch sensor is based on detection of mechanical impedance change after contact of the vibrating pipette tip with the plate. We improved the fixation method of the sensor with the pipette as well as electrode design of the sensor. We performed the FEM analysis to improve sensitivity of this sensor. The prototype sensor has high sensitivity and high rigidity and is excellent in durability. This sensor is sensitive enough to protect the fragile pipette tip from abrupt collision. Thus, separation task of the microbe by the micromanipulator under the microscope is improved.

Laser micromanipulation is suitable for non-contact manipulation of a small object, such as a bacteria and microbe, at the closed space. We proposed synchronized laser micromanipulation (SLM) for the trajectory control of the multiple targets by the single laser. We used the laser scanning system for scanning of the focal point of laser in high speed to realize simultaneous trajectory control of multiple objects. Condition for secure transportation of multiple objects is derived analytically and verified through the experiment. We used SLM for indirect manipulation of the microbe by the microtools, which are directly manipulated by SLM. Here we propose the force measurement method using SLM. Recognition of the microtool is improved by using a fluorescent microbead as a microtool.

Handling of microorganisms is of great interest in biology and biotechnology. Single cell capture technology has been demonstrated in our previous work with thermal gelation material and micro fluidic devise. This paper extends the system by local flow rate control to stabilize the trap with in-situ fabrication by photo-crosslinkable resin. Target cells are captured by gel and enclosed with the micro-structure. The cells, therefore, are protected from high-speed-channel flow or disturbances. This system succeeds in the separation and continuous culture of yeast cells, reaction and monitoring of the cultured cells stably by fluorescence staining in situ on a chip.

An in vitro soft membranous model of individual human cerebral artery reproduced with visco-elastic behavior, for intravascular neurosurgical simulation, preclinical testing, and testing of medical devices, is presented. The presented arterial model is reproduced with soft visco-elastic tissues, existing around the cerebral artery, in addition to the elastic membranous structure of artery, and constructed based on individual information obtained with medical imaging modality. Its human-like constitution realizes surgical simulation accompanied with realistic feel and visco-elastic structural deformation under actual surgical environment. In this report, we present a production methodology for this anatomically accurate cerebral arterial model. With this methodology, arteries with complicated or high aspect structures are precisely reproducible. We also present a technique to improve its visibility against refraction and reflection that take place on surfaces around arterial model. As the presented arterial model is compatible with current major imaging modalities such as computed tomography (CT), magnetic resonance (MR) and transcranial Doppler (TCD), it should be useful for a wide range of applications, such as hemodynamic study and radiological investigations, as well as surgical simulations.

This paper presents a situation-based task selection mechanism which enables a life supporting robot system to perform tasks-based on the user's situation. Stimulated by interactions between robot and user, this mechanism constructs and updates the association between the user's situation and tasks so that the robot could adapt to user's behaviors related to the robot's tasks effectively. For the user adaptation, radial basis function networks (RBFN) and associative learning algorithms are used. The proposed mechanism is applied to CRF3 (character robot face 3) system to prove its feasibility and effectiveness.

A hybrid nanorobotic manipulation system, which is integrated with a nanorobotic manipulator inside a transmission electron microscope (TEM) and nanorobotic manipulators inside a scanning electron microscope (SEM), is presented. The new type of nanomanipulation system has high enough resolution to identify nano-scale objects due to the adoption of a TEM, and efficient and rapid nanomanipulations are realized with wide enough working space of the SEM nanomanipulators. The TEM nanomanipulator has been constructed with 4 multi-layer piezoelectric actuators for driving in 3 translational degrees of freedom (DOFs) and a passively driven 3-DOF sample stage through SEM nanorobotic manipulators to perform relatively complex manipulations whereas to keep compact volume to be installed inside the narrow vacuum chamber of a TEM. To show the effectiveness of the system, the interlayer resistance of a destructively fabricated multi-walled carbon nanotube has been measured inside a SEM whereas the telescoping structure formed by pulling out inner layers from outer layers of the tube is observed inside a TEM.

This paper describes a robotic-head system as a multimodal communication device for human-robot interaction, and the system's potential application in home environments. Most robotic systems for natural user interaction have facial expressions, since facial expressiveness is regarded as a key component to developing personal attachment along with prosodic expressiveness. In the first part of the paper is the description of our robotic head system Character Robot Face (CRF). A deformation approach and a parametric normalization scheme are proposed to produce facial expressions of nonhuman face models with high recognition rates. In the second half of the paper, CRF is endowed with artificial emotions and assigned tasks conceivable in home environments. A coordination mechanism between the robot's mood (an activated emotion) and its task is proposed so that the robot can, by referring to the emotion-task history, select a task depending on its current mood if there is no explicit task command from the user. When the robot performs a task, a particular emotion value gets boosted according to the same emotion-task history so that the emotion is more likely to be activated.

Isolation and separation of the target microbe is quite important. We propose a new touch sensor to get contact information that is needed for separation of the target microbe by the pipette. This sensor is sensitive enough to protect the fragile pipette tip from abrupt collision. Using this sensor, we developed a novel screening system for separation of target microorganisms from the randomly distributed samples on the plate by the local viscosity control of the thermosensitive hydro gel.

Force measurement with pico-Newton (pN) order resolution using a carbon nanotube (CNT) probe, which is calibrated by the electromechanical resonance is presented. Based on the theoretical analysis, a CNT is suitable material for the sensitive force measurement. A CNT probe is constructed by attaching a CNT to the tip of the commercially available atomic force microscope (AFM) cantilever or tungsten needle probe by the electron-beam-induced deposition (EBID) though the nanorobotic manipulators inside a field-emission scanning electron microscope (FE-SEM). In order to attach a CNT quickly and correctly, CNTs are dispersed in ethanol by ultrasonic waves for several hours and oriented by electrophoresis. The elastic moduli of CNTs are calibrated from electromechanical resonance frequency by applied electrostatic forces. We measured pico-Newton order contact forces with a CNT probe, which is constructed with nanorobotic manipulators, by measuring deformation of a CNT probe from FE-SEM images.

A nano laboratory-a prototype nano manufacturing system-is presented, which is composed with a nanorobotic manipulation system with 4 units and 16 degrees-of-freedom (DOFs), a nano fabrication system based on electron-beam-induced deposition (EBID) with an internal or external precursor evaporation reservoir equipped with a thermal field emission electron source or a nanotube cold cathode, and a real-time observation and measurement system based on a field emission scanning electron microscope (FESEM) equipped with 3-4 conventional atomic force microscope (AFM) cantilevers, piezoresistive levers or nanotube probes. Nanotube devices including a mass flow sensor, a linear bearing, and nanotube scissors are fabricated in the nano laboratory.

Many entertainment and healing robots have been developed. These robots have synthetic emotions so that they select behavior based on their current emotional state. On the contrary conventional robots which have designed to perform repetitive factor or office jobs do not have such emotions. Usually human operators assign tasks in explicit manner using keyboard or voice commands. In this paper we propose a coordination mechanism between robot mood (an activated emotion) and its task. On one hand, referring to the emotion-task history of the mechanism, the robot selects a task depending on its current mood if there is no explicit task command from the user. On the other hand, when it performs a task, a particular emotion gets boosted based on the same emotion-task history so that this emotion is more likely to be activated by external stimuli.

A laser micromanipulation is suitable for non contact manipulation of a microscopic object, such as a bacteria and microbe, in the closed space. Here we propose the Synchronized Laser Micromanipulation (SLM) for the trajectory control of the multiple targets by the single laser. We used the laser scanning system for high speed transportation of multiple objects. Condition for secure transportation was derived and verified through the experiment. Using the SLM, we can manipulate multiple microbeads with each designed trajectories. We assembled a band of 4 adhesive microbeads. Both ends are trapped, and it is manipulated by the SLM. It is possible to transport the microbe by the indirect manipulation of the assembled microstructure by the SLM. Experiment results are shown here.

Properties and potential applications of carbon nanotubes are summarized by emphasizing the aspects of nanoelectronics and nanoelectromechanical systems (NEMS). The main technologies for the assembly of nanodevices through nanomanipulations with scanning probe microscopes and nanorobotic manipulators are overviewed, focusing on that of nanotubes. Key techniques for nanoassembly include the preparation of nano building blocks and property characterization of them, the positioning of the building blocks with nanometer-scale resolution, and the connection of them. Nanorobotic manipulations, which are characterized by multiple degrees of freedom (DOFs) with both position and orientation control, independently actuated multiprobes, and a real-time observation system, are one of the most promising technologies for assembling complex nanodevices in three-dimensional space. With a nano laboratory, a prototype nanomanufacturing system based on a 16-DOF nanorobotic manipulation system, the assembly of nanodevices with multiwalled carbon nanotubes are presented. Nanotube-based building blocks are prepared by directly picking up, in situ property characterization, destructive fabrication, and shape modifications. Kinds of nanotube junctions, the fundamental elements for both nanoelectronics and NEMS, are constructed by positioning the building blocks together under the real-time observation with a field-emission scanning electron microscope, connecting them with naturally existing van der Waals forces, electron-beam-induced deposition, or mechanochemical bonding.

Manufacturing systems have become more and more complex for adapting to various process conditions. Various and numerous sensors are equipped in the system for measuring various states in process. For efficient manufacturing, a sensor fusion method is needed for inferring state which conventional sensors cannot measure. We (2001) have proposed a sensor fusion method with sensor selection based on the reliability of the sensor value and knowledge database for a response to various environmental conditions. In this paper, we propose a sensor selected fusion system with the sensor selection based gating neural network. The gating neural network is stored, which links the neural network for the inference that should be used. Thus, the gating neural network decides the configuration of the neural network from the sensor selection rule and process conditions. For showing the effectiveness, we apply the proposed method to the inference of the surface roughness in the grinding process.

Minimum invasive surgery that supports doctors and reduces patient's physical pain has attracted attention. We consider a new intravascular neurosurgery system. There are two problems in intravascular neurosurgery: one is doctor's exposure to x-ray, and another is the lack of skilled doctors. We developed a remote control system by using a master-slave system to solve these problems. In this paper, we describe the development of a new slave device in the master-slave system and construct the new remote control system of catheter operation with safety. To overcome some of the problems encountered on the previous slave device (2000), we develop a new slave device with a disposable structure employing the mechanism of a mechanical pencil for safe operation.

Reports separation of the target microbe by the laser trapped micro tools for minimum invasion of laser irradiation. The size of a micro tool (MT) is around micrometer. The micro tools are manipulated by the focused lasers under the microscope to manipulate the target microbe. We propose a pinpoint injection method of micro tools at the desired location in the micro chamber, which is filled with liquid. First, we classified the injection method of the micro tools in 4 categories. We employed a new method to install the micro tools inside the micro chamber. We developed a micro tool holding chip to install the micro tools. The micro tools were injected in the micro chamber, and were manipulated successfully by the laser scanning micromanipulator to separate the target microbe. The proposed method is useful for the pinpoint injection of MTs and separation by the indirect micromanipulation.

Nanoassembly of multi-walled carbon nanotubes (MWNTs) in three-dimensional space is realized by positioning these building blocks with nanometer order accuracy, joining them together through van der Waals forces, and fixing them with electron-beam-induced deposition (EBID) or chemical bonds through mechanochemical nanorobotic manipulations. MWNT I-junctions and Y-junctions are constructed. For parallel nanoassembly, the concept of parallel EBID is presented, a MWNT electron-beam emitter is prepared through nanoassembly of MWNTs onto commercially available atomic force microscope (AFM) cantilevers, and the feasibility of using them for parallel EBID is investigated.

We have fabricated a micro touch sensor array. Every touch sensor unit is composed of Ti substrate and PZT thin film. The PZT thin film was synthesized by a hydrothermal method and used as both micro sensor and micro actuator. The micro actuator is driven at the resonant frequency point of the structure. The impedance change can be detected before and after contact by the micro sensor. This micro touch sensor array can be used as the controlling touch sensor pad of a car instead of the conventional capacity type touch pad, because it can resist high temperature. In order to improve the property of the micro touch sensor, the mechanics model, which is used to analyze the relationship between the input voltage and output voltage, was set up. According to cantilever beam theory, the response of the micro touch sensor to electric input has been discussed. Based on the model, the structural characterization of the micro touch sensor has been evaluated. The parameters that affect the output voltage have been analyzed.

This paper explores a human-robot mutual communication system, which human users can either communicate with or use as an information terminal. In particular, we propose the deformation based facial expression system. We also propose a robotic vision system, which changes its visual attention according to the environment. Firstly, the system must have advanced abilities to express their intention by means of making facial expressions, gestures, or speech. Above all, facial expression. Reconsidering the facial action coding system and action unit from the point of what expression of the robot human recognize easily. We propose the deformation based expression system. Secondly, to realize fluent communication between human and robots, we propose a robot vision system changing its gazing communication according to the environment and situation based on visual recognition. We developed an original character robot (CR) and evaluated the proposed methods. Consequently, it was shown that human-robot mutual communication is achievable.

Recently, micromanipulation for bio-engineering has been developed. The purpose of this research is to develop the minute size knife for the cutting of the minute object such as the cell. In this paper, we report on the microknife that cuts off the object by using ultrasonic vibration of the sharp needle. We applied the multilayer piezoelectric actuator for generating the ultrasonic vibration for cutting. We developed the touch probe sensor for microknife by the PZT thin film which is made by the hydrothermal method. We evaluated the performance of cutting and the touch probe sensor by experiments.

We propose a dome shaped touch sensor unit, which is small and is applicable in high temperature environment. The PZT thin film was made on the half-round Ti substrate, and the electrodes were deposited on its surface to form the sensor and driving actuator. The PZT thin film was made on the curved surface of the substrate by the hydrothermal method. The actuator part is driven by the high frequency voltage at the resonant frequency of 6.2 kHz and the sensing part can detect the impedance change before and after the contact. The sensor works with the low voltage (5 V). It works under the high temperature (over 50/spl deg/C). The structure is simple and easy to miniaturize. This sensor can be used as the control touch-pad of the car instead of the conventional capacitive type computer touch pad, because it can resist high temperature and disturbance from the electrostatic inductance change. The basic property of the sensor is shown.

We develop a new micromanipulation system for anatomical operation of the micro-object such as an embryo, cell, and microbe. The image of the microscope is two-dimensional, so it is hard to manipulate the target in the 3D space. To improve the manipulation work, we proposed a 3D bio-micromanipulation system combined with a virtual reality (VR) space. We propose a 3D object modeling method for presenting 3D visual information to the operator and improve the operation environment. In this system, we still have difficulty in changing the orientation of the microscopic object by manipulating a mechanical manipulator. The bio-aligner proposed is a micro device for the posture control of an object. We develop a 2D bio-aligner by microfabrication. Here we show its fabrication process and a basic rotating experiment with yeast cells.

Multi-walled carbon nanotubes (MWNTs) are manipulated in 3D space with a 10-DOF nanorobotic manipulator, which is actuated with PZTs and Picomotors/sup TM/ (New Focus Inc.) and operated inside a scanning electronic microscope (SEM). The coarse linear resolutions of the manipulator are better than 30 nm (X, Y, Z stages actuated by Picomotors) and the rotary one 2 mrad, while the resolutions of fine motions (actuated by PZTs) are within nano-order. AFM cantilevers are used as the end-effector. Several kinds of manipulations of MWNTs are performed with the developed manipulators with the assistance of dielectrophoresis and van der Waals forces. A single MWNT with estimated dimensions of /spl phi/ 40 nm /spl times/7 /spl mu/m has been picked up on an AFM cantilever. Another /spl phi/ 50 nm /spl times/6 /spl mu/m MWNT is placed between two cantilevers, and still another /spl phi/ 40 nm /spl times/8 /spl mu/m MWNT is bent between a cantilever and sample substrate. Carbon nanotube (CNT) junctions are basic building blocks for more complex devices based on CNTs. A cross-junction was constructed with two MWNTs of dimensions of /spl sim//spl phi/ 40 nm /spl times/6 /spl mu/m and /spl sim//spl phi/ 50 nm /spl times/7 /spl mu/m, and a T-junction was made of two MWNTs with the dimensions of /spl sim//spl phi/ 40 nm /spl times/3 /spl mu/m and /spl sim//spl phi/ 50 nm /spl times/2 /spl mu/m. Force measurements are performed and the flexural rigidity and Young's modulus of an /spl sim//spl phi/ 30 nm /spl times/7 /spl mu/m MWNT are estimated to be 8.641/spl times/10/sup -20/ Nm/sup 2/ and 2.17 TPa respectively. Such manipulations are essential for both the property research of CNTs and the fabrication of CNT-based NEMS.

The purpose of the study is to build a relaxation system which can control a user's body condition, changing the operation mode and intensity of the massage seat according to the user's current condition. Heart rate is an index of human conditions which can be easily measured, and it has chaotic dynamics. We show relations between the intensity of the massage operation and two indices which express chaotic properties such as correlation dimension and Lyapunov exponent. These data are indispensable for building a feedback loop between the relaxation system and a user.

We developed a new system for random separation of a single microorganism, such as a living cell and a microbe, in a micro fluidic device under the microscope using laser manipulation and microchannel flow. The main flow in the microchannel splits at the exit of the sample chamber. One flow goes to the extraction port with high speed to take out the target. Another flow goes to the drain. The target was transported by laser manipulation from the sample chamber to put on the main flow. Since the force balance of the laser-trapped object is important for stable manipulation of the target, we propose the stagnation point control around the sample chamber exit. Pressure balance was adjusted and the stagnation point was controlled. Some preliminary experiments are conducted to show the effectiveness. The target was trapped by the laser transported to put on the main flow around the split area through the stagnation, and was taken out from the extraction port. Separation time was reduced less than 10 seconds.

In grinding process, sensor fusion methods for inferring the surface roughness from online sensing information have received much attention, because it takes a long time to measure the surface roughness during process. We propose a sensor selected fusion system using reliability based on possibility. This method can select sensor information by selection rules of reliability determined by an operator in advance. However, this method cannot select sensor with consideration of the characteristic for each sensor because selection rules for all the sensors are same. In this paper, we propose an acquisition method of selection rules for each sensor using an evolutionary strategy (ES) for the sensor selected fusion system.

A need has arisen to manipulate a small biological object, such as an embryo, cell, and microbe. Bio-micromanipulation is important for biology and the bioengineering field. However, it is very difficult, since the object is very small, kept in liquid, and observed by an optical microscope. The image of the microscope is two dimensional, so it is hard to manipulate the target in 3D space. The object is fragile, so it is hard to manipulate safely. To improve the manipulation works, the authors propose the viewpoint selection method in VR space, and a bilateral control system to improve manipulation of the micro object under the microscope.

The micro/nano manipulation is the key technology to produce an integrated system as well as to examine the micro/nano world. For example, the micro/nano manipulation is needed for assembly and maintenance of the micro machines and their parts. It is also important for biology and bio-engineering field to explore the micro/nano world. The micro/nano manipulation is classified into the contact type and the non-contact type based on the manipulation method. The manipulation method and system depend on the manipulation environment and the observation system. System design and control methods are completely different depending on the size of the object and the manipulation environment. Here we present highlights on-going research works on the prototyping of the micro/nano manipulation system.

We propose a flexible object manipulation system by a dual manipulator system. Flexible objects like rope or paper have shapes of irregular form, even if the manipulator goes to the same position. We use a flexible object model and vision sensor to recognize flexible object form, and we use a force sensor and vision sensor to confirm the task execution. The dual manipulator system tied a cylindrical object with rope in an experiment.

A parallel beam structure has many significant features, as follows. (i) The tip moves in parallel at the end. (ii) This structure converts a small displacement into a concentrated large strain. (iii) Each unit doesn't interfere with the other units by piling up structures. (iv) The lateral rigidity is high. We propose this structure for a piezoelectric vibrating gyroscope (angular rate sensor), and detected angular rate using this gyroscope. In this paper is shown the method for super sensitizing by bringing two resonance frequencies (drive resonance frequency and sensing resonance frequency) close together. Then we propose the suppression method of the mechanical coupling that arises by bringing two resonance frequencies close. From this result, this structure suits for the gyroscope. Experimental results are shown.

We proposed a new teleoperation method using the bilateral control to improve the operability of the laser scanning micromanipulation of the microobject. We propose indirect non-contact manipulation methods of the microbe. It has been reported that direct irradiation of the laser beam to the microbe may give some damage. This phenomenon depends on the target, wavelength, irradiation time and power of the laser. To avoid this problem, we proposed the indirect manipulation of the target by the laser trapped microtools. As a microtool, we tested a micro bead and Lactobacillus bulgaricus (LB) as a micro-chopsticks and a liposome as a micro capsule. Experimental results on indirect manipulation of the microbe are shown.

This article deals with an operational assistance system for a rough terrain crane. The operation of rough terrain cranes is very difficult because of the complexity of the control system, the swing of payload, and the difficulty of controlling an underactuated system. We propose an operational assistance system for performance improvement based on an interactive adaptation interface. The system does not carry out automatic control directly. It provides information which is useful for the operator to operate more efficiently and safely. We propose a haptic display for swing suppression of a payload. Some experiments on a VR crane simulator have been carried out and show the effectiveness of the proposed system.

We have previously developed a navigation system for an autonomous mobile robot. It can find the landmarks on the ceiling for navigation. However, when the robot fails to recognize a landmark, the robot can not calculate the self-position. So, the robot has to prepare for the behavior of error recovery. But an error that is not able to recover may occur. In such a case, the robot needs to relocate the self-position. In this paper, we define global matching as the behavior that is able to relocate the self-position and propose to use this module for the error recovery in HALAS (hierarchical adaptive and learning architecture system) that we have proposed as a hierarchical system.

It is important to manipulate a biological small object, such as a cell and embryo. Three-dimensional high speed micromanipulation is needed as a fundamental technology for biology and bio-engineering application. In this paper, we focus on the contact type micromanipulation in the liquid. We designed and made a contact type micromanipulation system which has a 3-DOF narrow range positioning system on a 3-DOF wide range positioning system. We developed a micro tri-axial force sensor which can be installed near the tip of the end effector. Performance of this micro-force sensor is presented.

Vibration control for flexible structures has been studied by many researchers. We also have proposed decentralized vibration control for flexible structures by decoupling the mode quantities of other links. However if the modeling errors exist in the control system, the performance of the decoupling control goes down since the control method is based on the mathematical model. In this paper, in order to consider the modeling errors, adaptive control based on a neural network is applied to the vibration control of a flexible multi-link system. And by considering the axial forces in modeling, it is found that the modal dynamics is given as a nonlinear system. The effectiveness of the proposed control method is shown by the simulations of a 5-link robotic arm.

Robotic or manufacturing systems become more and more complex for adapting to various environmental conditions. In these systems, sensor fusion methods for estimating states of a system from multiple sensor information have received much attention. Also, it is necessary to select the sensor information for adapting to various situations flexibly. In these days, various methods of fusing multiple information have been proposed so far, but these methods cannot select the sensor information. We propose a sensor selected fusion system using a recurrent neural network. The sensor selection method is based on the production system, considering the reliability calculated by the possibility measure. The effectiveness of the proposed method is shown through a simulation of a mobile robot.

A parallel beam structure has many significant features, as follows: (i) the tip moves in parallel at the end; (ii) this structure converts a small displacement into a large strain; and (iii) when piling up this structure, each unit doesn't interfere with the other units. We used this structure for a piezoelectric vibrating gyroscope (angular rate sensor), and detected angular rate using this gyroscope. In the paper, we analyze features of the parallel beam structure by the finite element method. We show that the resonance frequency of the drive unit and sensor unit can be easily adjusted by changing the mass at the tip. From this result, this structure suits the gyroscope.

We have proposed a force display method to improve safety and operativity in a teleoperation system for intravascular neurosurgery. This method consists of two parts. One is improvement of operator's feeling of force feedback by displaying two force sensors' information. The another one is variable impedance characterization, which changes the impedance parameters of the master arm dynamically by reflecting the situation of the slave side. We present some experimental results of this force display method and show the effectiveness of this method.

It is a difficult operation to suppress the swing of round payload of a rough terrain crane. We propose a control rule to assist the operation. The stability by the control rule is confirmed with the Lyapunov stability criterion. We propose an operational assistance method with haptic display based on the rule. The system can adapt the strength of assistance to operator's state using recursive fuzzy inference. Some experiments on a crane simulator are performed and show the effectiveness of the proposed system.

We propose a new methodology for isolation of a microbe by the optical radiation pressure and dielectrophoretic force under the microscope. Our methodology is based on the fact that an arbitrary single microbe can be isolated speedily in a microchannel, even though there are a large number of these microbes in a solution. We show that once the target microbe is trapped at the focal point of the laser manipulator, we can easily realize the non-contact exclusion of a large number of excess microbes immediately by controlling the electric field, while keeping the target at the focal point. To improve the operability of the micromanipulation in solution and to realize high-speed separation, the technique of sequential, precise and non-invasive handling is necessary. We propose a new teleoperation method using bilateral control to improve the operability of micromanipulation. Our method can be extremely useful in the pure cultivation of the targeted microbe and will be a promising method for biologists in discovering a new microbe.

In recent years, reinforcement learning has been used as one of methods for making decisions for autonomous robots. However, the algorithm for learning concludes a parameter, and has a fault that adaptation speed for unknown environment changes, according to the value of the parameter. Because of the fault, the robot with reinforcement learning is often delayed in adapting to environmental change. In this paper, we propose a method to reduce the adaptation delay. Our idea is to make it possible for the robot to know if environmental change has happened. We found that if the robot uses reinforcement learning with two different parameters, the correlation between the reinforcement values lowers due to environmental change. Thus, we use the correlation as an index showing environmental change. The effect is proved through computer simulation.

In the biotechnology field, it is very difficult to manipulate microscopic material through human handling. There is a great need for a new experiment system that is easy to operate. We show a 3D calibration technique for improving positional errors of a glass pipette tip, furnished on a micro-manipulator. We then propose a method of observing the manipulator tip of sub-micron order accuracy using a newly developed lighting method by an optical fiber. We also take account of the influence of the positional error of the z-axis introduced from the optical system. In the last part of the paper, we show the effectiveness of these methods through experiments.

We have previously developed a navigation system for autonomous mobile robots. It can find landmarks on the ceiling to move and work. However, it is impossible to recognize landmarks when the size of landmark is different from the size of template. In such cases, the robot cannot continue to work. Therefore we proposed variable template matching (VTM) that makes it possible to recognize landmarks of different sizes. We realize VTM by using the optimization method called the evolution strategy (ES). The robot can recognize the landmark faster, inferring landmark parameters by binary density projection.

Working robots with agents in the same place has become known by the expansion of the use of a remote control robot. For that reason, we need a safety system which prevents a robot from collision with an agent. An ER-joint realizes high-speed response and force-limiting mechanism at the same time. We apply these properties to an automatic safety mechanism to prevent a collision accident. Then we prove the stability of this system in the case of normal operations by Lyapunov's direct method, and apply the system to a micro-injector in order to show the effectiveness of the mechanism.

Many studies on swarm intelligent systems have been presented. However, analytical treatment on swarm intelligence has not been performed sufficiently, because of difficulties in finding general criteria to evaluate system performance. In this paper, we regard flexibility as one property of the robustness, and evaluate the flexibility of swarm intelligent systems. We propose indexes to evaluate the behavior of swarm intelligent systems, which focus an "flexibility". The proposed indexes provide a way to compare the performance between different swarm intelligent systems. We apply the indexes to evaluate two swarm intelligent systems using computer simulation, and discuss the results.

Piezoelectric materials are used for sensors and actuators. It is difficult to form complicated structures with piezoelectric materials, so the actuators and sensors are simple. Using the hydrothermal method, we can fabricate PZT thin film on a three dimensional titanium substrate. We use this feature for actuators and sensors, and made a new sensor/actuator unit using this method on a parallel beam structure. We propose application examples to a two degrees of freedom actuator, G-sensor, and vibration gyroscope.

We propose a novel methodology on high throughput screening of microbes. We have developed a prototype of microchannel system for high throughput screening of Escherichia coli. Experimental demonstration of noncontact transportation and manipulation of Escherichia coli by dielectrophoretic force and radiation pressure of laser tweezers has been carried out with laser manipulator system. We discussed the basic strategies to improve the working efficiency and the operability of the micromanipulation and presented a new direction in this field. In experiments, we show that transportation and separation of Escherichia coli with electric field and optical radiation pressure is feasible in the future practical application for the high throughput screening of microbes.

A catheter is one of the medical tools for intravascular neurosurgeries. However, to control a catheter in narrow and complex blood vessels is a very difficult task, so there are not many surgeons who can operate a catheter appropriately. Moreover, these surgeons are exposed to X-ray radiation when they perform the operation. A solution to these problems is a telesurgery system. There are, however, some problems in telesurgery system. In this paper, we focus on the problem of operativity involved in a teleoperation system, and propose a new control strategy to display forces which are measured between a slave arm and the environment based on the variable impedance characterization of the master arm.

We propose a technique of grasping and manipulating an object in three-dimensional space by using a four-fingered robot hand, which is applicable to a real robot hand. In our approach, we select the condition of the passive closure as grasping form with an object by the robot hand, and then simplify the necessities for grasping using passive closure. We move the object in parallel motion from that grasping condition by using the slip. Furthermore, we show the new four-fingered robot hand with tension-difference type torque sensors and characteristics. By using this way, for some objects with different shapes, we carry out experiments with this robot hand in practice. Last of all, we verify the proposed method and examine the result.

We present a vision based navigation system which has an error recovery function for an autonomous mobile robot. A misrecognition of landmark causes the robot to mislocate itself. When this happens, the robot is unable to perform its primary objective. In order to solve this kind of problem, we have proposed a hierarchical control architecture "HALAS" (hierarchical adaptive and learning architecture system). This consists of some modules which are arranged hierarchically and each module means a single function of this robot. When one module fails in its aim, the upper module detects the error and recovers from it using other useful information from its knowledge data base. We show experimentally that the robot gets a higher reliability in autonomous mobility because the map correspondence module finds the error which has been caused by an anemo perception module (landmark recognition module) and it corrects the error utilizing its map information.

Micro manipulation is required for assembly and maintenance of micro machines and their parts. In this paper, we propose a new pick up and release method for micromanipulation. The proposed method utilizes pressure change based on temperature change inside the micro holes made on the end-effector surface. In order to pick up the micro object, the end-effector temperature is increased to exceed room temperature before touching the object. After contact with the object, its temperature is decreased and negative pressure is generated inside the micro holes to pick it up. To release it, the end-effector temperature is increased again. This method realizes quick response due to its scale advantage as long as it is miniaturized in micro order. We made a prototype end-effector by Si surface micromachining. We analyzed the static performance of this end-effector and conducted experiments. Finally, effectiveness of the proposed method is shown.

This paper proposes a control system for the flexible material handling robot. In the past, there has been reported much research work on flexible material handling robot systems. In most of the previous work, control system parameters were treated as fixed. However, they often change due to variation of the flexible payloads. In some cases, control performance is degraded and the production process is terminated in some situations. To deal with these cases, we propose an error detection method and a replanning system. If system parameters change and control performance is degraded, this system detects error by itself and changes control parameters to recover from the error automatically. Some experimental examples are shown to confirm effectiveness of this proposed system.

In this paper, we propose a new algorithm to control a distributed autonomous robotic system under dynamically changing environment based on immunological interaction between robots. Our algorithm can organize the robot population for dynamically changing multiple works. At first, we designed a control architecture for a multiple robotic system based on B-cell (which is main agent of immune system) interaction. Immune system has various kinds of B-cells, and B-cell interaction can organize its population balance against dynamically changing environment. We set the analogy between distributed autonomous robotic system and biological immune system. We verified the performance of our algorithm by computer simulation. As a simulation example there is considered the transportation of multiple objects to multiple locations against a deadline, with time-varying demand.

We propose a new methodology on noncontact transportation of DNA molecules by dielectrophoretic force together with the micro DNA flow system. We utilize the conformational transition in the higher order structure of DNA for transportation. We have designed a simple micro electrode-flow system. Experimental demonstrations of DNA transportation in the globule state using dielectrophoretic force and direct observation of the DNA molecule in a nonuniform electric field were carried out with fluorescence microscopy. We discuss the experimental results on the motion of the DNA molecule. We show that transportation of DNA with the state of compacted globule is profitable in the future practical application for the separation of giant DNAs such as the human gene.

Minimum invasive surgery using intravascular surgical tools is getting greater attention in the medical field. This technique allows us to reduce physical pain for patients. For example, a catheter is one of the medical tools for endovascular surgeries. The catheter is frequently used for neurosurgical operations. We propose a new type of force sensor for intravascular neurosurgery. This micro force sensor can be installed on the tip of the catheter. We developed a prototype micro force sensor whose diameter is 1.6 mm and length is 12 mm. Using this micro force sensor, we can measure the contact force between the catheter and blood vessels. It is possible to push the blood vessel wall hard when operators use the catheter. So, to express the contact force between catheter and blood vessels is very important for safe operation. In this paper, we show the structure of the micro force sensor and its characteristics.

We apply the interactive adaptation interface to an operation system. Such a system can adapt to an operator considering the following two points. One is the operator's psychological state and the other is the operator's skill. For adaptation to an operator, the system tunes the time constant of the operation controller by recursive fuzzy inference, and has a "multimodal display" which consists of various types of operational assistance such as visual display, acoustic display, force display, etc. In this paper, we propose many types of operational assistance for a rough terrain crane system. We propose a good control pattern which can suppress the payload's oscillation. The operational assistance becomes more effective by using the control pattern. We made a computer simulation and a joystick for the proposed crane system, and did operational experiments on this simulator. We show the effectiveness of the proposed assistance system for crane operation.

Micromanipulation is important in bio-science and bio-engineering field. In this paper, we propose a new micromanipulation system using a micro bio-jig and electrorheological (ER) joint. First, we propose a micro-fixture device for bio-micromanipulation (bio-jig). Property of the bio-jig is also shown based on the FEM analysis of the electric field. Next, we propose a joint containing the ER fluid (ER joint). We show its application examples to a safety mechanism and variable stiffness type microgripper. We made a prototype of the microgripper with the ER joint. The stiffness of the flexible finger is adjusted by the ER joint. We succeeded in accurate force sensing and fast motion control by controlling the applied voltage to the ER joint.

Problems of information sharing among multi-robots in cellular robotic systems (CEBOT) are described. Information sharing in three aspects (task descriptions, acquiring of robot states and acquiring of environment states) and hierarchical control architecture related to the sharing in three levels are proposed to enhance the efficiency of reasoning and planning for cooperative actions. Then, sensing information sharing related to acquiring of environment states is mainly dealt with, which is refereed to as distributed sensing focussing on sensing information exchange and integration among robots. Through analyzing the nature of distributed sensing, an approach for integration of distributed sensing information, based on evidential reasoning, is proposed. The proposed approach is examined with an application environment map building and maintaining through simulation, and the effectiveness of the distributed sensing approach for acquiring of environment states is shown.

Force measurement of the micro objects is very important for micromanipulation. For high accuracy, stiffness of the finger tip can be reduced for force measurement. It is not suitable for manipulation. So we consider to evaluate the stress on the micro structure to measure the force. Force measurement based on stress information has advantages when the structure is miniaturized. This can be shown by the scaling analysis. Hence, we propose a new force measurement and micromanipulation method using the laser Raman spectrophotometer (LRS). We design a micro gripper that employs the proposing force measurement method. We show experimental results of force measurement with the analytical evaluation to explain the effectiveness of the proposed system.

We propose a multimedia tele-surgery system for training, diagnosis, and assistance in surgery. To realize this system, a high speed optical fiber network with asynchronous transfer mode (ATM) is used to provide high quality moving pictures. We designed a new teleoperation system based on ATM, which is different from the conventional one that is based on Ethernet. We built a prototype of the virtual simulator system for the intravascular neurosurgery that consists of a 3D-computer graphics simulator and two types of joysticks. The joysticks are used for the controller and force display of catheter head direction, position, and orientation. A visual assistance method is proposed to assist the operator. We performed teleoperation experiments between Nagoya and Tokyo, about 350 km apart from each other, using high speed optical fiber network, and evaluated the effectiveness of the proposed system.

In this paper, path planning for robots of distributed autonomous robotic system (DARS) in unknown or partially known environment is described based on the distributed sensing. We believe that the basic problem of optimality for motion planning and replanning in unknown or partially known environment is related to the environmental information sensed by robot. Particularly the key to enhance the efficiency of path replanning is to strengthen robot's sensing ability to environment. Considering the characteristics of sensing information in DARS-distributed in time-space-function, we propose that it is practical for each robot in DARS to use (integrate) sensing information of other robots so as to compensate the lack of single robot's sensing ability. Through our simulation experiments, the fact that the efficiency of path planning and replanning for robots of DARS in unknown or partially known environment is evidently raised based on distributed sensing is showed. Approach for planning and replanning in considering the uncertainty of environmental information is also described.

A template matching is a popular method for visual recognition. It costs much time to detect the target object. We have applied fuzzy and neural network algorithm to solve this problem. However, the problem to mistake recognizing the target object is not solved. Hence, in this paper, we propose robust visual recognition algorithm for the autonomous robot navigation. The proposing algorithm employs a fuzzy template matching with the target object as well as the similar objects in the environment. As a result, the robot verifies the tentative recognition by comparing the likelihood of plus elements (target objects) with that of minus elements (similar objects). To integrate this algorithm into the robot navigation system, we propose a hierarchical control architecture. The validity of the proposing navigation system is shown with experimental results.

We have proposed a new prototype model of micro catheter with active guide wire that has two bending degrees of freedom using ICPF (ionic conducting polymer film) actuator on its front end as the servo actuator. In this paper, the bending characteristics of the micro active catheter (MAC) have been measured by application of electricity in physiological saline solution. By using simulators (whose conditions are similar to those of a body cavity), we also carried out simulation experiments "in vitro" and the contrast experiments of operability between the proposed catheter and conventional guide wire catheter. The experimental results indicate that the proposed MAC is applicable to intracavity operations.

This paper proposes a population control architecture for a multiple robotic system inspired from biological immune networks. The authors' architecture organizes suitable population balance against dynamic environment independently of any centralized control, while each robot decides its action without a global world model. This group behavior, suitable population balance, is organized as side-effect of the interaction of the individual robots in the world.

In this paper, we propose a new approach to noncontact transportation of DNA molecules by dielectrophoretic force and the idea of the micro DNA flow system. Such system can be made by using microfabrication technology. At first, we designed a simple micro electrode-flow system and carried out experiments. Experimental demonstration of DNA transportation using dielectrophoretic force and direct observation of the DNA molecule in a nonuniform electric field was carried out with fluorescence microscopy. We showed a simple electrode design and the possibility of noncontact transportation of DNA molecules based on micro DNA flow system. In future we consider the possibility of the micro DNA flow system as one of the biomanipulation and automation systems for DNA sequencing.

Micro manipulation is required for assembling and maintenance of micro machines and their parts. As the handling objects are miniaturized, attractive forces such van der Waals force, surface tension force and electrostatic force between micro objects and gripper surface become dominant in the air, and they work as adhesive forces. We cannot neglect such adhesive forces in micro manipulation. Considering the physical phenomena in the micro world, we propose reduction methods of adhesive forces. Surface roughness of the endeffector surface is effective to reduce the van der Waals force. We propose to make micro pyramids on the end-effector surface by micromachining techniques. We designed and made a prototype of the micro gripper with a micro end-effector whose gripping surface is covered with micro pyramids. Experimental results show effectiveness of micro pyramids for reduction of the adhesive force. We also made a semiconductor strain gauge at the end of the micro end-effector surface for force measurement. Both micro pyramids and the integrated piezoresistive force sensor are fabricated on the micro end-effector by the micromachining techniques. Performance of this force sensor is shown.

We propose noncontact sensing and control methods of flexible plate materials handled by a robotic manipulator. A displacement sensor and a force/torque sensor are introduced to measure vibration. Based on the proposed neural network controller, which employs the feedback error learning method as the basic control architecture, this paper deals with the spillover effect to asymptotic convergence of learning. The conditions for asymptotic convergence of feedback error learning method for each trials are obtained. The influence of the vibration modes unmodeled on the conditions for asymptotic convergence is discussed. Based on the results obtained here, we present a new learning method to improve the control performance. The control system consists of a low pass filter and two neural networks. The learning method is to change the learning rate according to the convergence conditions. From simulation results, we show that the tracking performance is improved by using proposed learning method.

Describes the hierarchical control architecture of real mobile robots for Cellular Robotic System Mark-V (CEBOT Mark-V). A parallel processing control system has been adopted, and by adjusting the role of parallel processes standing for the states of independent primitive behaviors, the change of system organization is realized to adapt the redefinition of plural tasks and the variation of environments. The authors propose a method for decision making of a mobile robot's behavior through integrating multiple behavioral processes. The authors define two relation matrices denoting the relationship among the processes: the priority matrix and the interest relation matrix. The matrices are used to adjust the outputs of behavioral processes and optimize the behavior of mobile robots. To obtain the most suitable priority matrix, the authors introduce a learning-adapting algorithm. The results of simulation and experiment with a real CEBOT Mark-V showed the effectiveness of the proposed matrices and learning-adapting algorithm. On the other hand, instead of simply selecting processes for decision making of the robot's behavior, the integration of multiple processes based on the proposed matrices enhanced the control robustness of robot system.

This paper describes a walking method and inclination control experiments of the new omni-directional walking robot, which has six legs and can move in any direction. The mechanism consists of a parallel link mechanism connecting the two frames with three linear actuators. Legs are attached to each frame. The relative position and angle of the two frames are selected arbitrarily in accordance with the length of three actuators, and the posture of it's upper surface are changed with extendable legs. The walking mechanism is composed by combining the two functions. The mechanism and control method of this robot are presented in this paper.

This paper deals with a micro mobile robot in water utilizing a PZT(Pb(Zr,Ti)O/sub 3/) as an actuator. A robot driven by a PZT requires a magnification mechanism and the effects of the resonance to enlarge the displacement of the PZT. In this paper, the authors propose a prototype micro mobile robot which has a new steering mechanism. The robot possesses a pair of legs and each leg has a pair of fins with some angle, which is essential to the improvement of the robot performance. A leg generates force both forward and backward according to frequency because the offset angle between a pair of fins works properly. Therefore, the robot can steer efficiently by combination of both modes. The size of the robot is 32 mm in length and 19 mm in width. This robot has many possible applications, such as small pipelines inspection and use in biomedical fields.

In this paper, we propose a new prototype model of micro-catheter with active guide wire that has two bending degrees of freedom. The design and fabrication methods of this micro active catheters (MAC) are described. Prototype models are 3Fr, 4Fr, 6Fr (1Fr=1/3 mm) in diameter and consist of catheter tube and active guide wire with ionic conducting polymer film actuator on its front end as the servo actuator. The bending characteristics of the MAC have been measured by application of electricity in physiological saline solution. We also modeled this MAC for characteristic evaluation. Experimental results show that the model of the active catheter is reasonable for practical applications. By using simulators (whose conditions are similar to those of a body cavity), we also carried out simulation experiments "in vitro". The experimental results indicate that the proposed MAC is applicable to intracavity operations.

The distributed micro robotic system is a group robotic system, which consists of many micro robots. A mobile robot plays an important role in the distributed micro robotic system. In this paper, the authors propose two types of the micro mobile robot. One is a micro line trace robot that runs along a black line using a pair of photo-sensors. The other is a micro autonomous robotic system constituted by some micro mobile robots controlled by a simple logic. The micro line trace robot consists of a pair of photo-sensors, a pair of electromagnetic actuators and a programmable logic device, but does not include a battery and the interfaces between the controller and actuator. The micro mobile robot constituting the micro autonomous robotic system moves toward the direction of high illumination of light, and includes a battery and interfaces.

Micro manipulation is required for assembling and maintenance works of micro machines and their parts. This paper proposes a handling strategy for micro objects based on micro physics. Attractive forces are modeled and their reduction methods are presented. The authors show experimental results of reducing these forces. Based on the proposed reduction methods, the authors present a new micro manipulation strategy. Grasping of the micro object or press motion is required in some situations, and force information becomes important. The authors propose to use a laser Raman spectrophotometer with single crystal silicon and a strain gauge for the measurement and calibration of the force applied to the micro object. The experimental results of calibrating the force sensing system is presented.

We propose a vision based navigation system for autonomous mobile robots that recognizes outlets of air conditioning system (anemo) located on the ceiling as landmarks. Because landmarks on the ceiling are not obstructed by other objects, robots can find them easier than landmarks on the floor. To detect the landmark, we applied the fuzzy template matching (FTM) method. Based on FTM, a fuzzy template (FT) is modeled based on the edge information of landmarks in the image. In addition, we use neural network (NN) to detect landmarks quickly. Inputs of NN are the grades of fuzzy memberships and the learned NN directs FT to the landmark in the image. Because FTM does not use image processing, except edge extraction, it does not make processing error and the landmark can be detected precisely. The navigation system can calculate the distance and the angle of the anemo from the map information. As a result, the navigation system can identify the present robot's position and orientation. By the proposed algorithm, precise and fast landmark detection become possible even if the landmark follows the shadow.

We propose a new prototype model of micro-active guide wire catheter that has two bending degrees of freedom. The fabrication methods of this micro-active catheters (MAC) are described. Prototype models are 3Fr, 4Fr, 6Fr (1Fr=1 mm) in diameter and consist of catheter tube and active guide wire with ionic conducting polymer film on its front end as the servo actuator. The bending characteristics of the MAC have been measured by application of electricity in physiological saline solution. By using simulators (whose conditions are similar to those of a body cavity), we carried out simulation experiments "in vitro" and the contrast experiments of operability between the proposed catheter and a conventional guide wire catheter. The experimental results indicate that the proposed MAC is applicable to intracavity operations.

Proposes a trajectory control method for a flexible plates handling system with unknown parameters and joint friction. First a recurrent neural network (RNN) learns the dynamics model of the flexible plate handled by a robotic manipulator. Next, the authors obtain the feedfoward control input based on the RNN model using the proposed learning control method. The authors applied this repetitive method to both linear system and nonlinear system control. Coulomb friction is considered at the joint as the nonlinear effect. Simulation examples are conducted to show effectiveness of the proposed method.>

In this paper, we propose a new prototype model of serial-parallel type of active micro catheter (MAC) with two bending degrees of freedom. It is 4 Fr, 5 Fr and 6 Fr (1 Fr=1/3 mm) in diameter and consist of 3 active units incorporating SMA wires in lumina as the servo actuator. The bending motion, bending direction and bending angle of the MAC have been measured by application of electricity in air and in physiological saline solution. We also modeled this MAC. Experimental results show that the model of the MAC is reasonable for practical applications. By using simulators (conditions similar to a body cavity), we carried out the simulation experiments of "in vitro" and "in vivo". The experimental results indicate that the proposed MAC is applicable to intracavity operations.>

This paper addresses an optimization method of the group behavior on decentralized autonomous robotic systems. Decentralized autonomous robotic systems refer to multiple robotic systems, such as cellular robotic system (CEBOT). The CEBOT, which has been proposed by the authors, consists of a number of robotic units called cells. In the research on the CEBOT, the same as decentralized robotic systems, the optimization of the behavior of each robot is one of the most important issues, since it is difficult to predict the behavior of the each robot in multiple robotic systems. In order to optimize the behavior in a dynamic environment, the authors propose a concept of self-recognition for the decision making of the behavior in a group. According to the proposed concept, this paper shows the learning and adaptation strategy for the group behavior, and presents some simulation results.>

This paper deals with a micro-mobile robot in water utilizing PZT(Pb(Zr, Ti)O/sub 3/) as an actuator. A robot driven by PZT requires a magnification mechanism and the effects of the resonance condition to enlarge the displacement of the PZT to some extent. In this paper, we show a prototype micro-mobile robot in water (double-fin-fish robot), which possesses a pair of fins and moves them symmetrically. Therefore, the momentum of this robot is canceled and the tendency to move straight ahead is improved. The size of the robot is 50 mm in length. We propose a structure for the magnification mechanism, which is made by the wire cut method. The magnification ratio is 326 geometrically. This robot has many possible applications, such as small pipeline inspections and biomedical fields.>

Deals with the improvement of learning speed based on the analysis of the convergence of the feedback error learning method. The authors derive the condition for the asymptotic convergence of the feedback error learning method for each trial. This condition is the relationship between the learning rate and the /spl alpha/ function, which is calculated from the input-output relationship of the system. Using the /spl alpha/ function obtained above, a high-speed learning method for a trajectory control system is obtained. Simulations results are given for the trajectory control of a 1 link robot manipulator in two cases: (1) using a general feedback error learning method and (2) using the proposed high-speed learning method. The simulation results show the effectiveness of the proposed conditions and learning method.

Presents a new approach to communication in an autonomous distributed system, focusing on the cellular robotic system (CEBOT). The CEBOT is a self-organizing robotic system composed of a large number of robotic units (cells) with a simple function. In order for cellular robots to implement a task efficiently, cooperation and coordination among cells are of great importance and require efficient communication. Since communication takes place in the process of task execution, it is likely to be intensive and biased by the small number of cells related to the task. This could decrease communication efficiency. To deal with these problems of robot communication, the authors propose demand-based intensive communication (DBIC), and show its effectiveness with simulation and experimental results for the prototype CEBOT Mark IV.

Most of the explicit force control algorithms published so far assume the switching of the control law from position control to force control when a transition occurs from a free motion to a constrained motion, but the ideal switching of the control law is impossible for a rapid transition. Implicit force control algorithms, such as stiffness control, damping control, impedance control, etc., can be applied to both free motion and constrained motion without switching the control law. However, precise force control is difficult, especially with nonrigid environments. The authors propose an alternative force control algorithm for nonrigid environments based on damping control, so that the transition occurs naturally. They model a damping control system with environmental dynamics and design a predictive control algorithm so that the force is precisely controlled when the motion of the robot is constrained. The proposed method is applied to a manipulator with one degree of freedom, and experimental results illustrate the validity of the method.

A primitive approach to the self-organization of the structural configuration of the CEBOT is described. CEBOT consists of a large number of autonomous robotic units called cells. Assuming that there are sufficient cells in the environment to configure the cellular robots, the cells, which have information about a structure, use random walk to search for other cells to configure the structure. Since each cell organizes a cellular module/robot distributively, these cells must cooperate and negotiate to achieve the configuration of the goal structure. The behavior of the cells is examined on the basis of the selfish criterion. The entropy of structure configuration is proposed as an evaluation criterion in the global environment. The simulation represents the influence of the selfish behavior and the sensing range for the configuration of the cellular robots.>

The authors propose a center of gravity control method for a manipulator/vehicle system to ensure that the system cannot fall down. The algorithm controls the tip position of the end effector and the combined center of gravity of the manipulator and the payload. This control algorithm has been applied to a system in which a human cooperates with a robot. The trajectory of the manipulator is given by the operator and the center of gravity is pre-set so that it does not tumble. An experiment was carried out to confirm the effectiveness of this control algorithm for the manipulator/vehicle system.>

The authors present a scheme for intelligent control of robotic manipulators. This is a hybrid system of neuromorphic control and symbolic control of a robotic manipulator, including a neural network for the servo control and a knowledge-based approximation. The neural network in the servo control level is for numerical manipulation, while the knowledge-based approximation is for symbolic manipulation. In neuromorphic control, the neural network compensates for the nonlinearity of the system and the uncertainty in the environment. The knowledge base develops the control strategy symbolically for the servo level. This is an analogous control system to the human cerebral control structure.>

The authors consider a grouping issue for a cellular robotic system (CEBOT) with multiple master cells. The CEBOT consists of a large number of autonomous robotic units called cells, that is, the system is one of group robotic systems. To evaluate the grouping effectiveness, the authors use the network energy. They consider each master cell as a coordinator in each sub-network. To evaluate the grouping network, they propose the cross-dependence matrix, which presents the relation between the cells and the task steps depending on a given task. The simulation results present the grouping examples of the cellular network. By describing the grouping issue, the authors also describe the effect for the group structure of an organization or a society.>

This paper presents hierarchical control system for compensation & vibration control of flexible material handling robot using neural network for t he control parameters scheduling and dynamic control. In this paper, compensation control method is classified into two cases; (i) a method based on estimated value of tip position, and (ii) a method based on measured value of tip position. The method (i) is only available for the simple cases (i.e., the deflection is small and the section of the material is unity). In the method (ii), by choosing control parameters properly, it is shown that the compensation & vibration control with small position error is possible. However, it is quite difficult to select proper control parameters for each different payloads so that the control system remains stable. To solve this problem, we propose hierarchical control system. This system has a gain scheduler at the upper level to roughly select proper control parameters for each different materials, and has a neural network controller at the lower level to improve control performance. After designing gain scheduler and neural network controller properly, the system can adapt to improve the response time for the large number of different kinds of materials.

A six-degree-of-freedom micromanipulator using PZT actuators has been designed and tested. The micromanipulator is very small and light, because it is made of PZT actuators. Since this micromanipulator has a position and force feedback system, it can control desired poses and forces. Since the manipulator has 6 degrees of freedom, its tip can move along three axes, and can also rotate along each axis. A fuzzy-like variable gain feedback control system is employed, making this system perform better than the fixed gain feedback system. These technical merits will make it possible to operate this dextrous micromanipulator in much more complicated environments under a microscope.>

A control strategy for a network of cellular robots (CEBOT) is proposed. The strategy is based on the selection of a master cell and assumes centralized control of the CEBOT network. The selection is made using a network energy, in which an energy function is calculated based on the information flow in the CEBOT network and the state space of the communication transition probability. The authors describe both a method of mastering, which implies the determination of the master cell of the network based on the information flow between cells, and a method of mastering by a local energy sensitive estimation as a method of finding the master cell for the CEBOT network. It is assumed that the network has a binary tree structure for control and communication. The master cell is defined as a window for interaction between users and the CEBOT. Simulation results on the mastering are shown.>

A new mechanism of an electrostatic micromanipulator which has 6 DOF is proposed. Its main features are summarized as follows. First, it can be constructed in a very compact form, since the actuator system is fabricated and assembled through the photoetching process. Second, it can move along three axes (6 DOF) and rotate around each axis, and has high resolution with no backlash. In the experiments, a movable range of 3.15 micron and a rotatable angle of 1.1*10/sup -2/ degree are attained with an applied voltage of 350 V. A simulation result for dynamics to estimate the motion of the micromanipulator is shown.>

Deals with a new type of dynamically moving mobile robot modeling a gibbon, namely a long armed ape, that moves branch to branch swinging its body like a pendulum. The manner of moving like a gibbon is called brachiation. The authors present the method to control the brachiation robot and show the results of simulation using a 2-link-model robot. The most difficult subject in this study is how to control it naturally, dynamically and with taking advantage of the gravity force. They introduce a heuristic approach to generate the driving forces by exercising motions to move by the robot itself, and show that the interpolation by CMAC (cerebellar model arithmetic computer) between the generated forces in some situations makes new forces suitable to inexperienced ones. They also show that the proposed control system using CMAC gives a natural and dynamical motion of the brachiation robot even under disturbances.>

Deals with a kind of cellular robotic system (CEBOT), called self organizing manipulator system. In this system the configuration of the manipulator can be changed according to the given task. The authors use two manipulators to assemble, disassemble, and reassemble cellular universal manipulator by cooperation work. When a simple task is given, the system can analyze the task and generate the structure of the cellular manipulator. The assembling work was divided into modular subtasks, and then the system generate the macro command based on the database. The order of subtask and the collision avoidance are considered for planning the cooperation work by using the collision database which was calculated before hand. They show the algorithm for calculation the collision database and for planning the cooperation work. The results of the simulation and the experiment are shown.>

Describes the communication architecture for 'cellular robotic system (CEBOT),' which is based on the selection of the master cells. CEBOT is one of the distributed intelligent systems. It is a 'dynamically reconfigure robotic system,' and the network is constructed by a large number of units called 'cells'. The authors deal with the number and the allocation of the master cells in the network, in which each cell is active stochastically. They describe the cross-dependence among cells on executing the task. This idea is based on the state of each agency, as in the field of artificial intelligence. The estimation of the number and the allocation of the master cells is based on the 'network energy'. In order to estimate the communication probability among the master cells, the idea of cross-dependence among cells is applied. The simulation results of the number and the allocation of the master cells, in the example, of the organized network are given.>

Impact sound is emitted when a collision occurs between objects. The authors propose a robotic control method to reproduce the impact sound emitted by the collision between the endpoint of the robotic manipulator and the object. The feedback control of impact sound is very difficult, because the impact phenomenon occurs in a very short period of time. Instead of a feedback control method, a learning control algorithm is proposed to control the impact phenomena. The learning control algorithm modifies the reference signal to the servo controller of the robot manipulator so that the desired impact sound is reproduced. The algorithm is based on the optimization of the least-squares criterion of learning error and does not require the dynamic model of the impact phenomena. The algorithm is applied to the planar manipulator with one degree of freedom driven by a pneumatic actuator. Experimental results illustrate the effectiveness of the proposed algorithm.>