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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.