This paper presents a multi-particle parallel manipulation optoelectronic tweezers system integrated with computer vision technology, enabling the parallel and precise manipulation of dozens of particles. This system significantly enhances manipulation efficiency while maintaining high precision. By real-time monitoring of particle motion and light patterns, the system can rapidly adjust and optimize its manipulation strategy, thereby improving the stability and reliability of multi-particle synchronization in complex environments. Extensive experimental results demonstrate the system’s outstanding performance. For instance, it can quickly arrange complex patterns and letter sequences, facilitate the coordinated assembly of organoids from particle groups, and efficiently perform the precise separation and arrangement of mixed particles. The core advantage of this system lies in its high parallelism and flexibility, enabling it to handle large-scale synchronous manipulation tasks with exceptional operating accuracy. With continuous technological advancements and the broadening of application scenarios, this system is expected to have a profound impact in fields such as cell sorting, micro-device assembly, and organoid construction, providing robust support for research and technological development in these areas.

The efficacy of targeted cancer drug therapy is significantly compromised by imprecise drug delivery mechanisms. Micro/nano robots (MNRs), characterized by their controllable motion, present a promising solution to this challenge. However, the non-Newtonian nature of blood, with its high viscosity and blood cells’ interference, poses substantial limitations on the upstream efficiency of MNRs. This paper innovatively discusses for the first time the effects of blood viscosity and blood cell interference on the motion of MNRs, investigating their upstream motion capabilities in blood through comprehensive theoretical modeling, simulation, and experimental validation. A dynamic model of MNR motion was developed, and the velocity formula for MNRs in non-Newtonian fluid was derived. Experiments were conducted using different magnetic fields in pure water, high-viscosity simulated blood, and diluted blood. Results indicated that under a gradient magnetic field, the upstream velocities of MNRs in pure water, simulated blood, and diluted blood were 45.0, 14.4, and 11.1 mm/s, respectively. Under a rotating magnetic field, the velocities of vortex swarms were 825, 240, and 145 µm/s, respectively. Increased fluid viscosity reduced MNR velocity by 70%, while blood cells caused an additional 10% reduction. This research establishes a theoretical and experimental framework for the upstream motion of MNRs against blood flow, enhancing their potential in targeted drug delivery and broader biomedical applications.

In recent years, capsule robots have gained wide acceptance among doctors and patients for the examination of gastrointestinal diseases due to their non-invasive, safe, and painless advantages. However, the image resolution captured by capsule robots is limited by space size and power, which hinders doctors' ability to accurately assess patients' stomach conditions and real-time control of the capsule robot. This paper proposes the design of two super-resolution networks for capsule robot videos. The first network, EndoVSR, is a high-performance offline video super-resolution network based on a generative adversarial network. It is designed to enhance the resolution of captured videos during offline processing. The second network, Bi-RUN, is a real-time video super-resolution network based on recurrent neural networks. It is designed to enhance the resolution of videos in real-time, enabling doctors to have a clearer view of the stomach condition during the examination. Extensive training and verification of these networks have been conducted using different datasets. All the performance indicators achieved leading positions. Furthermore, simulation experiments were carried out on pig stomachs in vitro to further validate the performance of the proposed networks in practical applications.

Magnetically controlled micro-nano robots hold revolutionary significance in the clinical targeted treatment of brain tumors. Imaging and tracking miniature robots can provide feedback for precise magnetic field control. The cooperation among micro-nano robots, magnetic field control system, and imaging system is a significant challenge for transitioning micro-nano robots from laboratory research to clinical applications. This study explores the control and spatial localization of magnetic nanorobot swarms in a highly realistic, human-sized vascular phantom which is manufactured using the raw CT scan images. The cerebral arterial vessels are the key focus area with four main inlets and twenty-six branch outlets. The simulation results show that, under the influence of a magnetic field, the nanorobots can accumulate at the target tumor site. The Kernelized Correlation Filter (KCF) algorithm was employed to achieve single-plane tracking of nanorobots. Furthermore, based on a biplanar imaging system, three-dimensional spatial trajectory tracking of nanorobots was realized. This study provides a reference for in vivo spatial localization and imaging of magnetic nanorobot swarms (MNRS) transported through vascular system.

This study proposes an optoelectronic navigation strategy leveraging Ag-SiO2microspheres as “microtruck” to overcome the limitations of traditional optoelectronic tweezers (OET) in manipulating negative dielectrophoresis (nDEP) particles. By dynamically adjusting electric field frequency and optical parameters, we regulate particle-induced dielectrophoretic forces (PiDEP) to achieve efficient adsorption, high-speed transport, and site-specific unloading of nDEP-responsive cargo. Experimental results demonstrate a seven times enhancement in manipulation velocity compared to conventional direct optical methods, along with the capability for simultaneous multi-particle transport. In addition, we utilized finite element simulations to analyze the optimal electric field frequency and optical parameters for the microtruck’s loading and unloading processes. Furthermore, a systematic analysis of critical velocities and failure modes under varying cargo loads further validates the robustness of this approach. Demonstrated within a labyrinthine microenvironment, this strategy enables programmable navigation, sequential cargo handling, and micrometer positional accuracy. This study provides an efficient solution for biomedical applications, including precise single-cell manipulation and targeted drug delivery.

Microfluidic technology is currently a popular approach in the field of single-cell research, which is used to reveal the heterogeneity among cells. However, most of the existing microfluidic technologies for single-cell research lack the ability to control the microenvironment of single cells after isolating them. In this work, a technology that combines lateral-field optoelectronic tweezers (LOET) with electrowetting-on-dielectric (EWOD) is used to separate cells into single cells and then encapsulate each single cell within an individual droplet, generating single-cell droplets. More importantly, it also enables the control of the microenvironment of the separated single cells. The driving control of the single - cell droplets is achieved through the EWOD, which has good application prospects in the field of single- cell research.

Neck lymph node detection is crucial for early cancer metastasis detection and treatment, influencing treatment success and patient survival rates. It also aids in disease staging, monitoring, and treatment selection. It requires the expertise of professional senior radiologists, as the accuracy of current automated detection methods is not sufficiently high. In this study, the neck lymph node detection network (LymoNet) based on YOLOv8 is proposed to detect and classify normal, inflammatory, and metastatic neck lymph nodes from ultrasound images. The advanced attention mechanism modules are utilized to enhance performance of the model, including the Coordinate Attention (CA) which helps the network focus on learning key features in the images, and the Multi-Head Self-Attention (MHSA) which captures global information at different scales. Meanwhile, the medical knowledge embedding which introduces prior knowledge from the medical domain is used to improve the classification performance. By integrating these elements, the YOLOv8 network can achieve better performance in neck lymph node detection tasks. Finally, LymoNet surpassed the benchmark model YOLOv8 by 6.6% in the [email protected], achieving the state-of-the-art (SOTA). This model provides a promising solution for automated neck lymph node detection in clinical environments. The proposed methods can also serve as a reference for applying deep learning algorithms in other fields. The source codes, trained weights, and validation data are available on GitHub.

Optoelectronic tweezers (OET) has shown great promise in various applications, especially in the precise manipulation of microparticles and microorganisms on a micron and nanometer scale. This technology significantly enhances the efficiency of single-cell sorting and the development of antibody-based drugs. However, conventional OET platforms are limited by issues such as low autofocusing accuracy, restricted imaging field of view, and uneven illumination. To overcome these limitations, we have innovatively developed a dynamic adaptive imaging system. By incorporating peak-finding and in situ Gaussian blur compensation algorithms, we achieved rapid automatic focusing and illumination shadow compensation across an expanded field of view. At the same time, the system can also dynamically adjust compensation parameters under different lighting conditions. Our system has successfully completed comprehensive scanning of the optoelectronic tweezers chip, achieving a 60% reduction in autofocus time and a 15.8% improvement in lighting uniformity. Moreover, this imaging system demonstrates robust versatility and can serve as a reference for other optical systems.

As a medical microrobot, magnetic-controlled capsule robots (MCRs) are pivotal in internal diagnostics and therapeutic interventions. Achieving high-precision localization of MCRs is essential for the successful execution of medical procedures. This paper introduces a novel Dung Beetle Optimizer (DBO)-based localization method for MCR, demonstrating high localization accuracy and flexibility in static magnetic field environments and under the control of existing magnetic control systems. With the aid of an FPGA-based parallel measurement system, it can effectively eliminate measurement distortion. The average position and orientation errors could achieve 0.53 mm and 0.60° when performing 600 iterations per computation, and further increasing the number of iterations reduces the errors, which is superior to existing methods. Experimental validations underscore the method’s robust performance and compatibility with existing magnetic control systems.

This work presents a novel electrical method, implemented in the form of a microfluidic device, for cell arraying and target cell lysis. The microfluidic device contains a micro-well array on the photoconductive layer based on the optoelectronic tweezers (OET) method, where parallel cell manipulation is performed. As cell suspension flows over the micro-wells, cells can be actively captured in the micro-wells by light-induced dielectrophoresis (DEP) forces, form the designed pattern array in less than 120 s. The single-cell capture rate is over 83 % in the patterned cell array, and about 94% of micro-wells are occupied by cells. Then, the target cell in the specific micro-well is illuminated and lysed by electroporation in 5 seconds. The micro-well barriers and DEP forces block the influence of the flow, and a relatively closed space is critical to preserve the cell lysates. Through experiments, light-induced DEP force cell capture and target cell electroporation can be modulated by changing the light patterns and the applied signal. This device, based on the OET and dynamic electroporation, allows the rapidity in the cell capture and target lysis at the single-cell level and can enable single-cell-based studies, such as molecular diagnostics and disease detection.

Magnetic microrobots exhibit enormous potential in targeted drug delivery owing to the remote wireless manipulation and minimum invasion for medical treatment. High degree of freedom offers the magnetic propelled robots extraordinary application prospect since they can be controlled precisely when different magnetic fields sources working cooperatively. However, the biocompatibility of microrobots have attracted sustained and general concern. Therefore, it is highly necessary to develop a promising carrier with high biocompatibility and investigate the mechanism of drug loading-release triggered by special microenvironment in the targeted region. In this paper, we proposed a magnetically controlled cell robots (MCRs) based on macrophages propelled by a rotating magnetic field. The innovative MCRs exhibit good biocompatibility and low toxicity by optimizing the concentration of polylysine-coated Fe nanoparticles (PLL@FeNPs) to 40 µg/mL. These MCRs loaded with murine interleukin-12 (IL-12), murine chemokine (C-C motif) ligand 5 (CCL-5), and murine C-X-C motif chemokine ligand 10 (CXCL-10) which can stimulate T cell differentiation and recruitment of monocytes, respectively. The macrophages showed an obvious M1-polarization tendency of macrophages to phagocytose intracellular pathogens and resist the growth of tumor cells. Under the control of a magnetic propelling system composed of 3 pairs of Helmholtz coil, the cell robot can be propelled wirelessly and moved along a predefined path with high accuracy. Moreover, the MCRs could approach to cancer cells and stop at places of interest in vitro. In conclusion, we have accomplished the preliminary construction of a targeted drug delivery system which displays great immune-enhancing potential for targeted drug delivery.

The untethered microrobots driven by multiple external physics fields have promising ability in minimally invasive disease treatments. One common type of the driving fields is gradient magnetic field, which can provide microrobots with adequate driving force in complicated environment. In this study, a control method of microrobot through gradient magnetic field system is presented, which is realized by moving the field free point (FFP) to produce an alterable magnetic driving force. A confirmatory experiment of the robot reciprocating motion control is undertaken in a 1D gradient magnetic robot system. The control method could be applied to further studies on in vivo applications of targeted microrobot drug delivery system.

In view of the magnetically actuated capsule robot applications in diagnoses of human stomach disease, the challenges that are associated with degrees-of-freedom (DOF), environmental adaptability, and the size of the entire system must be addressed. In this study, a new electromagnetic coil system that is based on adaptive magnetic levitation is presented; it is mainly composed of an independent orientation control electromagnetic coil and a magnetic levitation control electromagnetic coil. The system is designed to perform motion control of the capsule, including 3-DOF levitating translational motion control, and pitch and yaw motion control in levitation. In this manner, it compensates for the lack of previous magnetic levitation systems that were based on electromagnetic coils for the control of the tilt angle of the capsule. With torque-based actuation control, the tilt angle of the capsule can be controlled continuously with an angle increment of no more than 2° (within 30°) during levitation. The capsule under the magnetic levitation control, which is based on the fuzzy proportional-integral -derivative controller, can maintain the stability of levitation; the error between the actual capsule position and the required position did not exceed 0.1 mm when the capsule was out of water or completely immersed in it. Moreover, the experiment of the capsule levitating from air to water further verifies the adaptability of the system with regard to the environment; this provides a new examination method for capsule endoscopy. Note to Practitioners—This work is caused by the motion manipulation problem of a magnetically driven capsule robot. Most of the existing magnetically driven capsule robots use a rolling or sliding method that fits tightly against the stomach wall, and these forms of motion make it possible to risk missing diagnoses in the examination of gastric diseases, and the maneuverability limits its further application. This paper proposes an adaptive control strategy for a magnetically driven capsule robot based on magnetic levitation motion. It allows the magnetically driven capsule robot to levitate to any position in the stomach for photography and observation without external mechanical support, and this levitation motion is sufficiently stable. In addition, the proposed capsule robot has independent orientation and position control, which has the potential to achieve automated inspection.

Macrophage immunotherapy is a promising clinical approach to treat cancer. However, low targeting efficiency severely limits the immunotherapeutic effect of macrophages. Here, we report a unique macrophage robot that can target and kill cancer cells using a combination of external acoustic and magnetic fields. First, the inactive macrophages (Mø) are magnetized by endocytosis of the$\gamma$-Fe2O3nanoparticles (FeNPs). Then, the magnetized M⊘can be moved towards the capillary wall under the influence of an acoustic radiation force generated from a lead zirconate titanate piezoelectric (PZT) transducer. Finally, the magnetized cells rotate forward under the action of alternating magnetic fields (AMF). During the process of magnetizing macrophages, FeNPs activate the anti-tumor immune activity of macrophages (M1) to induce cancer cell death. Overall, the present study highlights a novel cell robot that can target and kill cancer cells. Considering that the nanoparticles, macrophages, magnetic fields, and ultrasound technology have all been FDA approved for clinical settings, our targeted delivery system has tremendous clinical translational potential.

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.

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 innovative design of microrobot, which can achieve donor cell suction, delivery and injection in a mammalian oocyte on microfluidic chip. The microrobot body contains a hollow space that produces suction and ejection forces for injection of cell nuclei using a nozzle at the tip of the robot. Specifically, a controller changes the hollow volume by balancing the magnetic and elastic forces of the membrane, and along with motion of stages in the XY plane. A glass capillary attached at the tip of the robot contains the nozzle is able to absorb and inject cell nuclei. The microrobot provides three degrees of freedom and generates micronewton forces. We demonstrate the effectiveness of the proposed microrobot through an experiment of absorption and ejection of 20 μm particles from the nozzle using magnetic control in a microfluidic chip.

The capability to precisely rotate the cells and other microscale objects is invaluable in biomedicine, bioengineering, and biophysics. We propose a novel on-chip three-dimension (3D) cell rotation method using whirling flows generated by oscillating asymmetrical microstructures. In an acoustic field excited by the vibration of a piezoelectric transducer, two different modes of microvortices are generated around our custom-designed microstructures that are utilized to precisely achieve in-plane and out-of-plane rotational manipulation of microparticles and cells. The rotation mechanism is studied and verified using numerical simulations. We also investigate the effect of various parameters on the acoustically induced flows such as the frequency, the driving voltage and the distance from the microstructure tip to the oocyte center, thus indicating the rotational speed can be effectively tuned on demand for single-cell studies. Finally, by observing the maturation stages of M2 after excluding the first polar body of operated oocytes, the proposed method is proved noninvasive. Comparing with the conventional works, our acoustofluidic cell rotation approach is simple-to-fabricate and easy-to-operate, thereby allowing rotations irrespective of the physical properties of the specimen under investigation.

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.

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.

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, 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.

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.