This paper describes a newly developed ultrasound ring array probe. The probe has one ceramic ultrasound transducer with a convex surface to transmit ultrasound wave with low directivity and eight polymer hydro-phones surrounding the transducer to receive reflected wave with high sensitivity. Firstly, we measured acoustic pressure distribution of a ceramic transducer and confirmed that the transducer can transmit ultrasound with low directivity. Secondly, we performed experiments to reconstruct a 3D image of a metal ball using this probe. The experimental results indicated that this probe enable to present the image with higher resolution.

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We have demonstrated the fabrication and operation of the RICA for application of SPM. The torsional resonator for electromagnetic excitation and detection is successfully fabricated using EB lithography and micromachining technology. The fabricated torsional resonator in a vacuum has the resonance frequency of 3.4MHz and the cantilever is successfully deflected by electromagnetic force in vertical direction. By using DC non-contact mode, deposited charges were observed by the electrostatic force between silicon surface and conductive tip. The fabricated RICA with a high resonance frequency is expected to have extremely potential capability for a quick response and a high speed SPM operation.

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Active polarizers that consist of parallel metal wires are fabricated by silicon micromachining techniques. If wavelength of incident radiation is larger than the period of the wire grid, the wire grid reflects incident radiation with the electric field parallel to the grid line, while transmits the other. Polarization of infrared light can be succussfully modulated by changing the period of the grid or changing the geometrical configuration. Two kinds of silicon structures are fabricated and demonstrated. One of them is electrostatic driven structure composed of mechanically flexible grid. The period of the grid can be modulated by itself with electrostatic actuation. The other is piezo driven structure, which consists of a pair of fingers (wire grid) and a torsional resonator. It changes the geometrical configuration of the wire grid. These mechanical behaviors and optical characteristics for infrared modulation are presented.

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Pb (Zr_0.52Ti_0.48)O₃(PZT) thin films with thickness of 1.8-2.0μm were fabricated using laser ablation onto Pt/Ti/SiO₂/Si substrate. Crystalline phases in the PZT films were investigated by X-ray diffraction analysis (XRD). The microstructure and composition of the films were studied by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA), respectively. The PZT films with well-crystallized perovskite phase were obtained by 20% excess PbO to the target and annealing at 750°C for 90min. The remnant polarization and the coercive field of this film were 23.6μC/cm² and 60.0kV/cm, while the dielectric constant and loss values measured at 1kHz were approximately 935 and 0.04, respectively. The device of micro scanning beams and micro mirrors were successfully fabricated through the PZT film deposition, lithography, electron cyclotron resonance (ECR), reactive ion etching (RIE) and inductively coupled plasma (ICP) releasing processes. The scanning performed by applying AC voltages at resonance frequencies to the actuating bimorph beams.

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We have developed a new thin film pyroelectric IR sensor with micro cavity structure, which consists of infra-red absorption layer using carbon-modified resin membrane on the infra-red detecting azea. And we were able to find the best sensor design rule or thermal conductance: G for micro cavity size, and Pt electrode width and thickness. The developing sensor has realized a high-performance of sensing characteristic that responsivity: Rv, and detectivity: D^* were 2400V/W, and 6.6×10⁷cm√Hz/W at 20Hz, respectively.
In the future, the developing sensor is expected the wide applications for high accurate human detection and non-contact temperature detection.

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A capacitance detection CMOS ASIC has been developed for three-axis common electrode type capacitive accelerometers. The ASIC contains an analog output switched capacitor circuit and a digital output 2nd order deltasigma modulator. The circuits were driven by three or six phase clocks for three-axis detection. The characteristics of the circuits were evaluated by a variable capacitor and a three-axis capacitive accelerometer. A novel compensation method was proposed to reduce the sensitivity dependence on Z-axis acceleration. The three-axis output voltages of the switched capacitor circuits were proportional to three-axis accelerations. The offset and sensitivity of the 2nd order delta-sigma modulator can be calibrated by outer voltages. The sensitivities of 1.5V/G and 20kHz/G were obtained respectively when the circuits were combined with a commercial available three-axis capacitive accelerometer.

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A perfluorocarboxylic acid membrane chemically-plated with gold bends under electric stimili in water. Using the composites, it is made a biomimetic micro actuator having large displacement and uniquely controllable motion. Complex biomimetic motion can be simulated and controlled by type of electrical stimulation, and have great flexibility in motional response depending on the incorporated cation. The principle is currently being extended to a tubular form with quadrupolar directional control for medical applications. Using a simple joystick, this arrangement may serve as a superior active catheter for in-vivo surgery, e.g., in treating brain aneurysm.

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A pulse drive semiconductor gas sensor which has a multi layer structure has been developed. In this study, we investigated gas sensing properties of the sensor composed of SnO₂ to NH₃ and H₂S. As a result, the sensor exhibited high sensitivity to the both gases, and the NH₃ sensitivity was superior to the C₂H₅OH. In addition, this sensor was effective to detect offensive odors, such as kitchen garbage, toilet smells and so on.

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