This video presents a microfluidic phenomenon called “Virtual Vortex Gear (VVG)” and an application of it. The video contains 4 parts and is described as follows: The 1st part shows an application of VVG as a controllable valve in a micro fluidic system and the on and off of the valve are controlled by different flow speeds. The valve is turned on when the flow speed is high enough, and vice versa. The 2nd part shows the generation of VVG and its mechanism. When the flow speed, which is proportional to Reynolds Number, is gradually increased, the flow pattern evolves in the order as (1)parallel streamlines, (2)one vortex, (3)two vortices and eventually (4)three vortices including the last vortex inside the circular chamber. The evolution indicates the transmission of flow energy from the main stream to the inside of the chamber when the flow speed is over a certain range. In addition, every two adjacent vortices rotate in opposite directions which is just like a set of gears, and that is why we named it “VVG”. In the 3rd part, an application of VVG for chemical injection is demonstrated. A colored liquid is represented for the chemical and is surrounded by different sheath flow for the control of injection locations. It is found that only the fluid in a particular pinpoint can be injected into the target chamber. Furthermore, the complex but stable 3D flow patterns are visualized from the video. The last part of the video shows that different amount of chemical injection can be performed in different chambers along the same main stream and the distribution of the color is gradually become uniform by spontaneous diffusing.

This paper reports an ultra-fast manipulation on micro-scale objects in a microfluidic channel. The objects are manipulated in simple harmonic motions and the manipulation speed has been achieved up to 3000 Hz. While the maximum speed was only about 130 Hz in previous works, the speed is advanced with an additional order in this work. Based on the experimental results, we find that the gain decreases along the line of -20 dB/decade in a logarithmic plot. The transfer function based on a theoretical model was employed for interpreting the results. The experimental gain and theoretical gain were well matched. Finally, experiments with red blood cells were performed and it supports the feasibility of applying such ultra-fast manipulation to cell evaluations.

Recently, many studies have been conducted on soft in-pipe robots, which are expected to work in pipes where ordinary rigid robots cannot work. In this paper, we present a new soft in-pipe locomotive device that consists of six braided tubes. The tubes of the device are inflated by pneumatic power whose inflation drives the device. This device can travel forward and backward and can rotate in both directions in pipes with various diameters with periodic pressurization of the six tubes. We have developed bundled-tube locomotive devices where each device consists of three tubes in which the devices can travel in pipes of various diameters without blocking the flow in the pipes. However these devices cannot control the their rotation in a pipe. Therefore, we developed the new bundled-tube locomotive device that can control the rotation in a pipe. This new device is a braid with six tubes that include a right-hand helix and a left-hand helix with three tubes each. The developed braided device can achieve various motions based on the pressurization patterns in each of the six tubes. In this paper, we thoroughly explain the relationship between the motions of the device and the pressurization pattern. We also present the locomotion experiment within a pipe with a variable-diameter part and a part that bends in an elbow shape.

This paper presents the development of a remotely operated brachytherapy system for oral cancer. The purpose of the system is to reduce exposure dose to the operator by keeping him or her at a distance of 1m from radioactive198Au sources. The system is designed to enable the operator to perform the same procedure as for conventional brachytherapy treatment without exposure dose. It consists of an applicator manipulator to implant198Au seeds, a finger device to firmly grasp organs in the mouth, operational parts for both of them, and a base arm. The applicator manipulator and finger device are fixed on the base arm which is fixed on a radiation shield. The applicator manipulator is a serial manipulator with five degrees of freedom (DOF). The finger device is necessary because organs in the mouth are soft and flexible. Its finger and operational parts are identical three DOF parallel manipulators. This paper details preliminary experiments of grasping and insertion with the system. These experiments verify that an operator can grasp a tongue model with the finger device and can insert the applicator into it with the applicator manipulator. In our developed system, we also confirm that rotation of the applicator needle can reduce insertion force.

In laparoscopic surgery large instruments cannot be used because they cannot pass through trocars which are typically smaller than 12mm in diameter. For example, retracting an internal organ with a slender instrument is often a difficult task. To remove this limitation, we have proposed “assemblable instruments”, that is, parts are inserted through trocars and assembled inside the abdominal cavity to become a large instrument and we have developed assemblable hands. However they use two trocars for assembling, which require positioning and alignment of two assembled parts. This paper presents a simple three fingered hand whose function is limited to retracting. We propose a much simpler assembling method “single trocar assembling” for the hand. Experimental results verify that the hand can be assembled easily and that it can withstand a force of 25N enough to rectract a pancreas.

This paper presents Tokyo-TECH 100 N Hand, a three-fingered eight-degree of freedom hand that can generate a large grasp force of 100N. All fingers are 90 mm in length and the weight of the hand is 941 g. The hand can generate a large grasp force with a force-magnification mechanism whereas all joints can perform a high speed motion of over 200 deg/s with a high-speed driving mechanism. The high-speed driving mechanism consists of a feed screw and nut with a low reduction ratio. We propose a simple and small three-dimensional toggle mechanism for the force-magnification mechanism. The toggle mechanism thrusts the feed screw and nut of the high-speed driving mechanism when the finger is in contact with an object. It can maintain a large grasp force without energy consumption. We experimentally verify the force and speed performances.

This paper proposes an assemblable hand that can be inserted through trocars for robotic hand assisted laparoscopic surgery (HALS). When it is difficult to perform surgery using only slender laparoscopic surgery instruments, surgeons often apply HALS, which makes an incision about 7-8 cm through which their hand is inserted. This is invasive compared with complete laparoscopic surgery. We proposed robotic HALS to replace a human hand with a robotic hand. We previously developed a three-fingered five-degree of freedom assemblable hand. It is challenging to an assemblable hand with more degrees of freedom (DOF) that can be assembled with a simple assembly procedure. This paper presents an assemblable hand with three fingers and nine degrees of freedom-the 3f9d-hand. Its power transmission mechanisms and assembly procedure are completely different from those of our previous 3f5d-hand. The new hand consists of center, right, and left finger units. The center finger unit connects the operational part at its end and the right and left finger units connect to the operational part outside the abdominal cavity. This facilitates assembly and improves safety, which is a significant improvement compared with the previous hand. Although the hand has no wrist joint, its three finger joints play the role of a wrist joint. A preliminary experiment with a plastic model verified that the proposed assembly procedure was feasible and the hand was easily assembled and disassembled.

In laparoscopic surgery, surgeons perform surgery in the abdominal cavity by using only slender instruments that can be inserted through small diameter trocars. When it is difficult to perform surgery by using only instruments for laparoscopic surgery, they often make a 7–8 cm incision through which their hand can be inserted. Clearly this is invasive compared with complete laparoscopic surgery. This paper proposes an assemblable mechanical hand like a human hand that can be inserted through trocars. We already developed a three-fingered three-degree of freedom assemblable hand. The purpose of this paper is to develop an assemblable hand with more degrees of freedom that can grasp/push aside large internal organs and open membranes. The developed hand has three fingers with a total of five degrees of freedom. Its power transmission mechanisms and assembling method are completely different from those of the previous hand. The hand is assembled from body and finger units with an installation tool. The finger unit is fixed to the body unit with only one screw by using the installation tool. To drive the fingers, power is transmitted with cables, gears and shafts. Experimental results verify that the hand can be assembled in a closed space and that it can grasp and push aside various objects.

We have proposed a novel concept of assemblable instruments for laparoscopic surgery, that is, their parts can be disassembled to pass through trocars and can be reassembled inside the abdominal cavity to become large instruments. By applying this concept, this paper proposes an assemblable pursestring suture instrument (PSI). In gastrectomy, a purse string suture on the esophagus is made preparatory to the anastomosis of the esophagus and the small intestine with a circular stapler. A traditional PSI cannot pass through a trocar because of its T-shaped jaws and a PSI that can be used in laparoscopic surgery is highly desired, which motivates us to develop the assemblable PSI. We have developed two prototypes of the assemblable PSI. The experiment with the first prototype verifies that it can be assembled in the abdominal cavity. However it cannot generate a grip force enough to hold the esophagus. We propose a two-DOF unfolding linkage mechanism for the gripper of the second prototype. The in vivo experiment with the second prototype verifies that it can make a satisfactory purse string suture.

In laparoscopic surgery, surgeons can use only rod-shaped instruments that can be inserted through a trocar and therefore high technique is required. To overcome this problem, much work has been done to develop multi-degree-of-freedom forceps. However they are still inadequate to grasp, manipulate or push aside large internal organs, like a spleen, pancreas, and liver. This paper proposes mechanical hands with detachable fingers that can be assembled in the abdominal cavity, each of whose parts can be inserted through a trocar. Two types of such three-fingered hands are developed. The three fingers of one are dependently driven and those of the other are independently driven. For each hand, we show fixing and power transmission mechanisms. Power of each hand is transmitted from operator's hand to its fingers by connecting wires with a ball and socket. Experimental results verify that both hands can grasp large and oily objects like internal organs. One goal of this study is to develop simple hands that can be used as a retractor. The other goal is to develop skillful hands that can replace surgeons' hands in hand assisted laparoscopic surgery which is still invasive by making a 7-8cm incision to insert a human hand into the abdominal cavity.

We have developed Souryu-I and II, connected crawler vehicles that travel in the rubble. They were developed for the purpose of finding survivors trapped in collapsed buildings. We have identified problems of these machines through experiments and studies, which are shape of the crawler, joint mechanism, dust- and waterproofing and communication system. We developed an improved model called Souryu-III based on these findings. It has unitized crawlers, new joint mechanism, dust proofing and waterproofing mechanism and tethered communication system with a new reel mechanism in order to address those problems. This paper describes Souryu-III, its mechanism and the experiments to test its mobile performance.

There is the possibility to generate a very efficient locomotion strategy for a snake-like robot by introducing full-body helical motion. This paper proposes a new kind of propulsion principle for the underwater active cord mechanism, in which the helical motion is created by distortion of each articulated body segment, while keeping the whole body helically. This paper also discusses about the design of a new mechanical prototype to realize a hermetic underwater 3D active cord mechanism, used to verify the effectiveness of the newly proposed propulsion principle.