An on-line micro system for the analysis of blood gases was developed. It consists of a reference electrode module and a sensing module with integrated pO₂, pCO₂, and pH electrodes. The thin-film Ag/AgCl element used in these electrodes features a polyimide protecting layer and AgCl layers grown from pinholes formed in the polyimide layer. The structure was particularly advantageous in constructing the reference electrode module with concentrated internal KCl solution. The electrodes provided linear calibration plots both in batch-style and flow-style measurements. The indicator electrode potential of the pH combination electrode was very close to that obtained with a macroscopic commercial reference electrode. A linear region could be observed in a wide range of partial pressure or pH for the respective electrodes. The output current of the oxygen electrode was slightly affected by flow rate due to the depletion of dissolved oxygen by the electrode reaction. However, the difference was smaller as the flow rate increased. On the other hand, no influence of the flow rate on the other electrodes was observed.

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The ferroelectric and piezoelectric properties of Pb(Yb_1/2Nb_1/2)O₃-PbTiO₃ (PYbN-PT) and BiScO₃-PbTiO₃ (BiScO₃-PT) epitaxial films were investigated. The PYbN-PT(50/50) and BiScO₃-PT(50/50) films showed a curie temperature near 380 and 450 °C, respectively. For 1 μm-thick PYbN-PT epitaxial films, the highest remanent polarization (29 μC/cm²) and effective piezoelectric coefficient e_31,f (-14 C/m²) were observed in the (001) PYbN-PT (50/50) film. A 3 μm-thick (001) PYbN-PT (50/50) film exhibited a higher e_31,f coefficient of -19 C/m². (001) BiScO₃-PT epitaxial films also had well saturated hysteresis loops with a remanent polarization of 36 μC/cm². The e_31,f piezoelectric coefficient was -9 C/m². The obtained piezoelectric properties of BiScO₃-PT films were comparable to that of Pb(Zr, Ti)O₃ or relaxor ferroelectric-PbTiO₃ films.

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A method for evaluating transverse piezoelectric coefficient of a thin film on a bulk substrate has been proposed. The measurement method is simple and independent on elastic constants of both the film and the substrate when the film is thinner enough than the substrate. Piezoelectric properties of sol-gel derived PZT (Pb(Zr, Ti)O₃) thin films before and after electrical poling were evaluated using this method. The piezoelectric coefficient h₃₁ of the film of 2.2μ thickness is -400MV/m after a poling of -200kV/cm, which is about a half of that of poled ceramic. Improvement of piezoelectric property by poling was confirmed to be caused by increase of retained polarization with clear proportionality.

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We have developed a fabrication technique of micro-dies made of titanium super plastic alloy. Shapes of micro silicon structures, which are formed on a silicon substrate by micromachining technique, were imprinted to titanium super plastic alloy using a vacuum press machine at a temperature of 720 °C. We investigated the method to flatten the sidewall of dry-etched silicon structures, and obtained the surface roughness of less than 10 nm. A graded layer of TiN/Ti film, which is deposited on the silicon microstructures by sputtering, was also examined to prevent titanium diffusion into the silicon microstructures during the high temperature pressing. Using the developed technique, a concave titanium super plastic alloy mold for an optical wave-guide was successfully produced, exhibiting filling factor of 99.58%.

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A practical method for the full-wafer integration of wafer-bonded uni-traveling carrier photodiodes (UTC-PDs) with gold multilevel interconnections on a Si substrate is described with the focus on the fabrication process. The aim of this work is to show how to produce high-performance Si-based optical-to-electrical conversion modules that will operate in the millimeter-wave region. A damascene process produced multiple levels of thick gold interconnections with a feature size in a range over 10 μm. It involved processing a photosensitive organic polymer as the interlayer dielectric and chemical mechanical polishing that removed the electroplated gold at a high rate. This was achieved by restricting the area to be polished and adding hydrogen peroxide to the conventional KIO₃-based slurry. The mechanism responsible for this acceleration was analyzed by x-ray photoelectron spectroscopy. The coplanar waveguide produced with this damascene process achieved low-loss transmission of millimeter-waves generated by each wafer-bonded UTC-PD. An electro-optic sampling technique confirmed its excellent low-loss millimeter-wave transmission characteristics.

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Micro sonic sensors using piezoelectric diaphragm and cantilever have been developed in order to detect a weak specific sonic wave that is emitted from rotary machinery with anomalous behavior under a large background noise. A piezoelectric PbZr_0.52Ti_0.48O₃ film was prepared on a micromachined SOI wafer by sol-gel method. The sonic wave response for the both diaphragm- and cantilever-sensors was investigated. The both sensors showed resonant peaks which are proportional to the reciprocal of the diaphragm-area and to the power of -2 of the cantilever-length in the frequency region over 5 kHz. The sensitivity and Q-value were estimated to be on the order of 10 mV/Pa and 100, respectively. It is also shown that a specific sonic wave can be detected by choosing several sensors with different diaphragm-area or cantilever-length.

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A micro-analysis system that imitates a mosquito was fabricated by incorporating an electrochemical micro-sampling mechanism that uses an electrochemically generated or shrunk hydrogen bubble. The rates of growth and shrinkage of the bubble could be controlled by applying a potential. An external standard solution could be successfully withdrawn through a syringe needle using the sampling mechanism. A distinct current increase was observed in the on-chip glucose sensor following the withdrawal of the standard solution. The calibration curve was linear for glucose concentrations up to 10 mM.

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In this paper, the waveform of an ultrasonic wave with frequency of approximately 5 MHz propagating through various taste solutions was measured. Furthermore, these solutions were investigated by using surface plasmon resonance (SPR). As a result, differences among solutions were clearly observed. Therefore it was found that the possibility of taste sensing using ultrasonic wave and SPR was obtained from taste solutions.

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It is not easy to supplement the signal from a sensor with that from the other sensors. In this study, a basic method for signal supplementation is proposed using S-System. The function for signal supplementation is found by the method. The validity is conformed by the use of three sensors.

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