In recent years, a productin of nanoparticles has been required in many fields such as production process for electronic materials, foods and medicine. By using re-crystallization process, nanoparticles can be formed by quenching a solution. We have generated mono-disperse droplets by using an ultrasonic torsional transducer and a micropore plate to form fine nanoparticles by quenching droplets. In this nanoparticle production system, formed nanoparticles have a diameter of 79.9 nm when the applied voltage for the transducer and the diameter of micropore to generated micro droplets were 100 V_p-p and 50 µm. We have successfully obtained fine nanoparticles from mono-disperse droplets generated by using the ultrasonic torsional transducer. This result shows that the proposed system is effective for the miniaturization of the alum particles.

The complex dielectric constant of a polymer piezoelectric sensor was measured to investigate the properties of biopolymers detection of piezoelectric polymer using relaxation behavior. From the measurement of the complex permittivity, relaxation of the polymer piezoelectric sensor was confirmed. In the properties of the detection of the polymer film, the real part (ε') of the relaxation process linearly shifted to the low frequency with loading the polymer films. This showed the same trend as the result that the frequency shifted to the low frequency with loading mass anticipated from Sauerbrey's equation. In the biopolymer detection, the relaxation was shifted to the low frequency with the fluorescently labeled avidin (the host material) immersion time. With accompanying fluorescently labeled biotin (the guest material) adsorption by host-guest reaction, the relaxation shifted to low frequency. It was considered that the biopolymer detection with the polymer piezoelectric sensor is possible by using relaxation behavior.

The development of light modulation element with suspension-free mirror is reported. The feature of the device is that the mirror is not supported by hinges on the substrate. In other words, the mirror is suspension-free. We reported the operating principle and the results in the past as a two-dimensional MEMS (Micro Electro Mechanical Systems) mirror array device. This device has the advantage of being fine and fast because it has no restoring force, so it can be expected to be used in light modulators of holographic displays with 1µm pixel size. Because the mirror is suspension-free and contact somewhere constantly, the main problem of this device is sticking. This time, we changed drastically materials of the device. As a result, it was possible to suppress charging sticking, and a mirror tilt corresponding to light modulation of 52 ° was confirmed at low voltage of 5 V with a mirror having a side length of 10 µm.