Fumihito Arai

Group behavior control for MARS (micro autonomous robotic system)

We present the design of our small robot MARS (micro autonomous robotic system) and basic experiments of group behavior pattern. MARS is small mobile autonomous robot. The robot has sensors, battery and infrared light communication device. In addition, the robot can get programs from the host computer (programmable). We focus on group behavior design (cooperation, competition coordination etc.) to use real robot MARS and we try to realize the phase change of the group behavior pattern. One of our ultimate dream is designing life-like robotics systems, such as ant or fish societies.

A New Robotic Manipulator in Construction Based on Man-Robot Cooperation Work

This paper deals with the mechanism and the control method of a new robotic manipulator in construction based on man-robot cooperation work. Because of the coming labor shortage of the aging society in the near future, robots will be used in construction fields more and more. To support robot operation, this study aims to develop a cooperation work type of robot to be controlled easily by the direct teaching. The robot has the following features: (1) It has 4 D.O.F. and a parallel link mechanism. (2) It has a operation control sensor and a force control sensor to cooperate with the human operator and to control the contact force between robot and object. (3) The end effector of this robot has a vacuum system to carry payloads. With these features, this robotic system makes it possible to carry heavy payloads easily and this system can be used for various kinds of tasks.

3D attitude control system for bio-micromanipulation

Bio-micromanipulation is important for biology and bio-engineering field. However, operation is very difficult, since the object is very small, kept in the liquid, and observed by the optical microscope. We have been developing a new 3D attitude control system for observation of the micro object such as an embryo, cell, and microbe. The image of the microscope is two-dimensional, so it is hard to observe the target in the 3-D space. To improve the work of the biological experiment, we proposed the 3-D bio-micromanipulation system combined with the virtual reality (VR) space. In this paper we propose the 3-D modeling method of the object to present the 3-D visual information to the operator and improved the observation environment. In this system, we still have difficulty to change the orientation of the microscopic object. The bio-aligner, we propose, is a micro device for the attitude control of an object. We develop a three-dimensional bio-aligner by microfabrication. We show its fabrication process and basic rotating experiment with yeast cells.

Posture control of 6-leg walking robot

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 its 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.

On-chip Method to Measure Elastic Property of Single Cell Using Large Compressive Deformation Model

This paper proposes a method to measure cellular elasticity on a microfluidic chip using large compressive deformation model. In our previous researches, we succeeded in improving accuracy and sensitivity of measurement devices using piezoelectric actuator and sampling moire method. However, there still were some problems on the analysis of mechanical properties of cell. Conventional studies employed Hertzian Contact Theory, which could be utilized in quite limited area of cell compression. Therefore, this theory could not be adaptive to on-chip measurement system based on uniaxial large compression mechanism. In this research, we introduce a large compressive deformation model to illustrate elastic behavior of single cell in detail. This is naturally extended model of Hertzian Contact Theory, and in good accordance with the experimental data. Using iterative least square estimation method, we succeed in demonstrating elasticity measurement based on the new model.

Circulation Type Blood Vessel Simulator Made by Microfabrication

Recently, Japanese have causes of the death. Figure 1.1 was reported by Ministry of Health, Labour and Welfare in 2008 in Japan and which shows the cause of the death. As you can see, the causes of death are cancer, cardiac disease, cerebrovascular disease and etc.. We can categorize cardiac disease and cerebrovascular disease as blood vessel disease. Blood vessel disease is the second highest cause of the death. To treat the cancer and blood vessel disease, many engineering approaches have been studied about tissue engineering, medical treatment tools, rehearsal systems and synthetic vascular prostheses. For treatment of cancer, there are researches of endoscope and abdominoscope for less-invasive surgical operation. For treatment of blood vessel disease, there are researches of endoscope which can use in blood vessels and synthetic vascular prostheses for replacement operation. These researches have the common identity that is improvement of quality of life (QOL). But, these lessinvasive operations are poor in extracting the organ size and controlling the posture of medical tools. To solve these problems, many researches from the other approaches are proposed. One of them is research about surgical simulators for rehearsal, practice and evaluation of real surgical operation. Generally, VR simulator and CFD analysis are famous as computer surgical simulator (Fig.1.2 (a) and (b)). These simulators enable to simulate surgical operation easily, and analyze fluid condition easily, however, these are poor in simulating pulsative system and not suitable to evaluate new treatment method using narrow vessels. Our surgical simulator (Endo Vascular Evaluator: EVE) has threedimensional (3D) blood vessel models fabricated in tailor-made (Fig.1.2 (c)) (Ikeda et al., 2005). And, EVE enables to simulate pulsative system and catheter operation easily, but, not suitable to evaluate new treatment method using narrow vessels. There are two famous methods using narrow vessels. One is a method of necrotizing cancer cells in the part of liver as shown in Fig.1.3 (a) (trancecatheter arterial chemoembolization: TACE, TAE). The other is a method of administering medicine as shown in Fig.1.3 (b) (drug delivery systems:DDS). TAE method protocol is to release anticancer drug and gelatin sponge in blood vessels for stack, then stop the blood flow and the supply nourishment. Stacking gelatin sponge has a possibility of effect to normal cells. Thus, gelatin sponge are needed to release from catheter, and it is very difficult to selectivity stack the only arteriole and capillary vessels which rink to cancer cells. However, blood fluidic condition is very complicated, and catheter’s position, amount of anticancer drug and gelatin sponge, fluidic and pressure condition, environmental condition changed by catheter and effects to other

2A2-L02 Magnetically Driven Robot-on-a-chip (MDRoC) : Part 2: Design and Fabrication of Hybrid MMT

We proposed a polymer-metal hybrid MMT (magnetically driven microtool) which has properties of both elasticity and rigidity. A magnetic metal axle is made by electroplating which is rigid to prevent bending by the unwanted external force. The magnetic metal axle also has a merit to have higher magnetic property which contributes to the powerful actuation. We designed a hybrid MMT for on-demand droplet dispensing on a chip. The displacement of the hybrid MMT was about 300 μm which was 6 times larger than that of the conventional MMT, and on-demand droplet generation was successfully performed. The MMT has potential to be used as micro-nano-robot on a chip which can be defined as Magnetically Driven Robot-on-a-Chip (MDRoC).

2P1-D13 On-chip cell manipulation systems : Part6: On-chip Droplet Dispensing by Magnetically Driven Microtool

References: Experiments: We have investigated an actively size controlled droplet generation system by using magnetically driven microtool (MMT). With this method cellenclosed droplet can be produced on demand to fit the size of each enclosed cell, and which is difficult to be carried out by fluid dynamic force. For the current study, the system has been evaluated in terms of the frequency of MMT actuation and the size of droplets produced and which contribute to the effective transportation of cells in microchannel

Determining Internal Local Corrosion of Screwed Pipes Through Ultrasonic Testing

In diagnosing air-conditioning pipe deterioration, it is especially important to inspect screwed parts because their original thickness is thinner than that of straight parts and it is comparatively easy for leakage to occur if there is local internal corrosion. Usually, a radiographic test is used, but this method requires a licensed person to carry out the inspection. We examined a method of applying an ultrasonic test for the inspection, and proposed a method for detecting internal local corrosions of screwed parts and estimating the size of corrosion with surface SH waves. In this paper, we propose a method for detecting internal local corrosion of screwed parts of air-conditioning pipes with ultrasonic testing. The objective of the first step is to detect artificial corrosion and estimate its size and position. It is impossible to detect corrosion with a normal probe because a joint or valve overlapping the screwed pipe prevents ultrasonic waves from reaching the inside. Therefore, we used an angle probe, specifically a surface SH wave angle probe, because the thickness of the pipes requires a large angle of incidence, close to a right angle. We describe the following in this paper: ・ The results of experimental analysis on the echo from screwed parts of pipes. ・ The method used to detect local corrosion and estimate the size and position by using the pipe-end echo. ・ The results of tests on artificial corrosion pipes and the limitations of this method.

Artificial larynx using PZT ceramic vibrator as a sound source (the characteristic improvement of PZT ceramic vibrator)

Various speech production substitutes which aim to reconstruct speech function have been developed and used practically, for vocalizing handicapped persons. However, conventional speech production substitutes have problems. In order to develop perfect speech production substitutes, we paid attention to the PZT ceramic vibrator as a sound source of an artificial larynx. We produced an artificial larynx using a PZT ceramic vibrator, and we evaluated its performance. The power spectrum of produced artificial larynx users voice is similar to that of an unhandicapped persons voice. The vocalized sound of the produced artificial larynx user shows good characteristics at formant frequency with the role which is important for the vowel discrimination. However, the resonant frequency of the vibrator is high, and it is difficult to generate sound near 125 Hz. Thus, we researched a method for lowering the frequency of the generated sound. In this report, we tried to reduce the frequency of the generated sound by using an added mass.