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In order to measure the trace amounts electric charge which exists in the atmosphere, we have developed a device of differential type using two magnetically levitated electrode ionization chambers. This device is 100-fold higher sensitivity than the ionization chamber on the market. In the case of ionization volume 1 L and time interval 30 minutes, the detection limit of device is 0.3×10^-16C/s, which corresponds to 0.2 ions/cm³·s. Using this device, we have measured space charge around an insulation board made of Bakelite during low level gamma ray irradiation, and the electric charge originating from several kinds of photocatalyst paint lighted up by ultraviolet rays and a visible ray. As a result of measurement, the amount of space charge collected by Bakelite board is about 10^-16-10^-15C/s, and that of electric charge by photocatalyst paint is about 10^-17-10^-15C/s.

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Glucose-driven decompression device which utilizes conversion of chemical energy (glucose) to mechanical energy (actual pressure) has been developed and applied for a novel chemical controlled artificial pancreas system. The artificial system does not need to require any other power source such as electrical or mechanical energy. Integrated intermittent drug release actions and pressure changes were observed in record with CCD camera. The system was then evaluated in closed loop system setting for feedback control of the glucose concentration. The data revealed that drug release interval was extended causing stabilized constant glucose concentration on feedback effect. Accordingly, glucose concentration can be controlled autonomously similar with natural pattern of interdependent relationship between pancreas insulin secretion and glucose level. Potential applications of the organic engine include intelligent actuators, DDS (drug delivery system) and artificial muscles using biological energies (sugar, acid, lipid, etc.) with a neglibly-small heat loss.

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Sputter-deposited TiNi films had needed for a long time a post-annealing process (about 500°C) in order to have properties for shape memory alloy (SMA). A new deposition process, which incorporated simultaneous ion irradiation with multi-target RF magnetron sputtering, enabled to form crystalline TiNi films directly on a substrate at a temperature lower than 200°C. We have reported in our previous study that an SMA device was successfully fabricated on polyimide substrate without any thermal annealing. In this paper, we reveal how the energy of irradiating ion affects on lowering the optimum crystallization temperature of films. As a result, the threshold of ion energy at which crystallization comes out changes depending on plasma conditions, if the energy of irradiating ion determined only by the pulse bias voltage. However, when the energy of irradiating ion is corrected by adding the plasma potential to the bias voltage, it becomes almost constant.

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By electrically connecting and placing an InAs deep quantum well (DQW) Hall element as a magnetic sensor chip and a Si IC linear amplifier in a small plastic package, a very small sized InAs DQW linear hybrid Hall IC (InAs DQW LHHIC) with a high magnetic field sensitivity was developed. The output voltage of the hybrid Hall IC showed a very small temperature coefficient of 0.02%/°C and the response time was very small at less than 3µsec. By using this InAs DQW LHHIC, practical current sensors having high sensitivity, high accuracy, and temperature stability were developed.

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The dependence of radiophotoluminescence (RPL) and photoluminescence (PL) properties on x-ray irradiation dose and heat-treatment after irradiation was investigated for Ag⁺-activated phosphate glass, which is practically used as glass dosimeter for individual monitoring of ionizing radiation. The RPL intensity was increased with increasing x-ray irradiation dose, while the PL intensity was oppositely decreased with x-ray dose. The glass exhibited the vice versa tendency between the PL and RPL changes for heat-treatment at 250°C after x-ray irradiation, that is, the PL intensity was increased with annealing time, while RPL was decreased with annealing time. These results strongly support that the luminescence center of the PL is Ag⁺ and the centers of yellow RPL and blue RPL are Ag²⁺ and Ag⁰, respectively, which has been proposed in previous report. In addition, annealing temperature at 250°C for 40 min made it possible to save much energy and time required for recovering the used glass dosimeter to initial condition before x-ray irradiation.
It was also found from the dose dependence of the RPL intensity that the RPL intensity was saturated around higher dose region than about 15Gy, which means that there is no linearity between RPL intensity and radiation dose in high dose region.

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A method to characterize superconducting thin films by using scanning SQUID microscopy (SSM) is demonstrated. Magnetic field distribution on a film surface with a square defect was calculated and experimental data is also presented. In this paper, principles to observe at a time quantized magnetic flux, shielding current, and defects by SSM is presented.

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