Si-On-Insulator (SOI) structure is an attractive material not only for VLSI but also for sensor applications. In SOI sensors, the top Si layers can be used as a piezoresistor or a hall-sensor, and SiO₂ is used as perfect electric isolation at high temperatures. Epitaxially stacked SOI structures such as Si/Al₂O₃/Si structures can be used as a sensor material, which is formed by epitaxial growth of Al₂O₃ on Si substrates and epitaxial growth of Si on Al₂O₃/Si. By this epitaxial method, the thicknesses of Si and insulator layers are easily controlled and optimized for sensor applications. Multi-SOI structures like a Si/insulator/Si/insulator/Si structure can be formed, which are also interesting structures for micromachining. In this paper, pressure sensors, an accelerometer, and a magnetic sensor using SOI structure for high temperature application are presented. The advantages of SOI structure in sensor applications are also demonstrated showing examples of actual sensor devices and their characteristics.

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In the elderly society, the sensor and transducers are applied to improve quality of life. Sensors are attached to the furniture or inside a room instead of attached to the human.The non-invasive and unconstrained monitoring are performed in the home and less constrained monitoring using portable-small sensor are used. In this paper, recent development of sensor and transducer in the Gerontechnology field is reviewed.

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In this paper, a improved method for detecting odor samples using mono-channel QCM LB film sensor is described. The sensing film deposited on the QCM was DOABr combined by PVSK as an under layer. The odor sensor was able to detect the usual frequency shift, the resistance shift and more the response time related to the boiling point and volatile rate of odor substances. The gradient of the curve for frequency vs. resistance shift decreased as coefficient of viscosity rate. Single odor samples, such as benzene, hexane and chloroform can be detected by these parameters. Mixed odor samples such as three kind of odor substances could be also detected by adding the response time measurement.

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A newly developed linear electrostatic microactuator is described. Thus far, authors have proposed an electrostatic linear microactuator with vibrating motion in order to avoid the influence of friction. Satisfactory characteristics are achieved for low energy consumption, output force, moving speed, and positional accuracy. Low energy consumption is especially to the fundamentals of applying an actuator to moving lens to mobile instruments. However, there are several difficulties for putting it into practical use. The fabrication cost is very high, and it is hard to produce in large quantities. To clear up these problems, a new actuator configuration and process for manufacturing is being developed. The moving part (slider) is sandwiched between the plate whose surface has many comb-electrodes and the plate whose surface has one filmy electrode. This mechanism is advantageous with regard to assembling stators. In this configuration, the distance between two stators is important, but the phase between them needs not to be arranged. The good characteristics of this project are low cost and mass production.

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