Miniature thermal analysis device with a micro-air-bridge heater which has been proposed by authors is more miniaturized to analyse more small amount of the sample, and an automatic heating-rate measurement system having no need of the reference sample is developed and evaluated by using the water sample. This ultraminiature thermal analysis device consists of monolithically integrated components of an air-bridge microheater (about 500μm × 100μm × 3μm), an Au-Ni thin film thermocouple and a sample-holder (100μm × 100μm × 3μm). Melting and boiling points of water sample are clearly observed in the heating curve and the heating-rate curve.

抄録全体を表示

This paper describes the design, the fabrication, and the characterization of a micro mechanical acoustic sensor modeling the basilar membrane of human cochlea. This work aims at the implementation of human cochlear system on a silicon chip. The acoustic sensor is an array of resonators whose frequency selectivity is associated with the one-way flow of vibration energy. The mechanical structure of the sensor is designed using FEM analysis to have a particular geometrical structure looking like a fish bone that consists of cantilever ribs extending out from a backbone. The skeleton of the sensor is fabricated using silicon micromachining technology. We observed the frequency response of each resonator to pure tones to verify fairly sharp frequency selectivity. The present results encourage us in our trials to integrate human auditory system on a silicon chip toward the goal of artificial cochlea.

抄録全体を表示

The preparation method of multistep Si(100) terraced structure by one photo mask has been proposed. Firstly, silicon nitride or oxide is deposited on the Si(100) substrate as the etching mask of Si(100) in KOH solution. Then, the pattern of the photo mask is transferred to the etching mask by the standard lithography and etching process. The pattern design is very important for the formation of multistep Si(100) terraced structure. In the application of n-step diffractive lens with the same step height, the widths [b_n] and intervals [a_n] of the masked areas of the photo-mask pattern are decided under an arithmetic relation. Finally, the multistep Si(100) structure is formed during the KOH anisotropic etching process. Eight-level Si(100) terraced structure has been achieved. It will simplify the conventional process, in which m masks are necessary for 2^m-step microlens, and reduces the cost.

抄録全体を表示

This paper presents improved capacitive readout type sensor interface circuits designed for CMOS integrated chemical sensors. The sensor is fabricated using a 0.8μm CMOS IC process technology. Volatile organic compounds (VOCs) are detected by measuring the capacitance change of polymer coated interdigital capacitors due to analyte absorption. The delta-sigma modulation sensor interface uses a sensor capacitor and a reference capacitor as those for the input of the frontend switched capacitor integrator. An improved capacitance sensing scheme is proposed to improve the sensitivity.

抄録全体を表示

A multichannel taste sensor can respond to many kinds of chemical substances simultaneously with high sensitivity. It has a possibility to measure various substances that remain in used food packages. The purpose of the present research is to detect chemical substances which were dissolved to aqueous solution from three materials such as raw materials of PET bottles (poly (ethyleneterephthalate)), used PET bottles and recycled egg packages. We found that there is no metalic ions in these samples and hydrophobic substances were dissolved from used PET bottles and recycled egg packages. Additionally, we used near-infrared spectroscopy to analyze the substances; however, no significant spectrum was not found. This result implies that the multichannel taste sensor can be used to evaluate the quality of recycled food packages.

抄録全体を表示

Cataluminescence (CTL) is a kind of chemiluminescence emitted during catalytic oxidation. A new method for analytical detection of mixed organic vapors in air is proposed using a new CTL-based gas sensor made of γ-Al₂O₃, catalyst doped with Dy phosphor. The CTL spectra of ethanol and acetone on γ-Al₂O₃ catalyst consist of two components of λ_L(550nm) and λ_s (420nm). The CTL spectra for the same sample gases on γ-Al₂O₃, doped with Dy have extra spectrum components peaking at λ_D1 (580nm) and λ_D2 (480nm), so that the sensor sensitivity is increased. As the CTL intensities at λ_D1, λ_s and λ_L show different temperature and gas concentration dependence respectively, these may result from different reaction processes. Two CTL intensities of 530 and 580 run are measured for air containing ethanol and acetone of concentrations of C_E and C_A. As the CTL intensities are the different single valued function of C_E and C_A, we can obtain the constituent concentrations of mixed organic vapor of ethanol and acetone by measuring the CTL intensities of two wavelengths of 530 and 580 nm.

抄録全体を表示

The simultaneous detection method for both an electric field and a small quantity of decomposition products is proposed by using a sensor head which consists of a twisted nematic (TN) liquid crystal (LC) cell sandwiched between a pair of cholesteric LC cells and a corner cube prism coated with dye films. The electric field can be detected as changes of optical retardations induced in the TN LC cell at the wavelength of a selective reflection band of the cholesteric LC. The ppm concentration of the decomposition products generated from an electric discharge in SF₆ can also be optically detected as spectrum changes of dye films deposited on the prism at the other wavelength outside the selective reflection band. The optical sensing system using the several sensor heads and an OTDR (Optical Time Domain Reflectometry) method can be applied to monitor and detect simultaneously the electric field and the decomposition products at two different wavelengths. In addition, their locations can also be determined.

抄録全体を表示

Magnetic sensors are used to detect relatively low frequency range of magnetic field. The sensors are expected to have higher resolutions as well as possible. The resolution are being improved until now, and he theoretical limits of SQUIDs and Hall devices have been investigated with specific methods of each sensor. In this paper a general principle has been investigated to evaluate the resolution of any kind of magnetic sensors. On the principle, theoretical limits of resolutions of a fluxgate magnetometer, a proton magnetometer, a SQUID and a Hall device have been evaluated.

抄録全体を表示

A new integration scheme using spot-size converted waveguide devices is presented for use with highly tunable opto-micromechanical devices. A typical application would be for use with an external cavity laser: tunability can be greatly improved by employing a spot-size converted laser diode (SS-LD) with large beam divergence. The feasibility was confirmed theoretically for a typical SS-LD with spot size of 3μm, and its experimental verification was performed with a device fabricated on a comb-drive micromirror.

抄録全体を表示