化学物質はその種類や性質が多種多様で，その混合体の膨大な組み合わせを生物にとって有用な情報とすることができます。検知対象は生物由来の代謝物，気候や環境の変動に由来・影響する物質，様々な化学的に生成される物質など，我々の社会生活に密接に関係しています。そのよう

Blood contains volatile biomarkers related to diseases and metabolism. We developed a biofluorometric gas sensor that measures acetone with high sensitivity and confirmed its significance in lipid metabolism and diabetes when applied to breath measurement. Furthermore, regarding transcutaneous gases that permeate through the skin from blood, a biofluorometric gas-imaging system for ethanol vapor as the target chemical was developed and analyzed the secretion dynamics of transcutaneous gases at each skin site, thus showing the stable release of blood-derived volatile markers from the ear canal. Based on the results, we have developed a headphone-type gas sensor and succeeded in continuous and stable transcutaneous gas measurement, thus indicating the future potential of a novel wearable biosensor for blood VOCs.

Detecting and visualizing gas distributed in two dimensions is enabled by the localized surface plasmon resonance (LSPR) gas sensor. This study provides a method for analyzing measurement data that allows component gases to be visualized separately. The degree of decrease in the intensity of the transmitted light (corresponding to the absorbance) due to the effect of the surrounding gas on the sensor was taken as the response of the sensor, and an approximate linear proportionality between the gas concentration and the response of the sensor was assured through measuring the sample of gas sources in different dilutions. Because the responses of gas sensor to mixed gases can be regarded as the sum of the responses to each component gas with respect to its concentration, this proportionality lead the possibility to estimate the concentration distribution of component gases by applying the algorithm of matrix decomposition. We applied matrix decomposition to real measurement data and visualized the component gases spreading over time. Moreover, we discussed the impact of speculating on the number of components in our case by conducting a simulation experiment.

We developed a non-woven polypropylene (PP) SERS substrate using melt-brown PP nonwoven fabric as the base material, which enabled mass production. Ag nanoparticles were physically modified on the PP nonwoven fibers with a particle size of 30 nm by the reduction reaction of the Ag nitrate solution. The fabricated SERS substrate achieved detection of 4-aminothiophenol (4-ATP) within the range of 10^-7 to 10^-3 M. This sensor response was higher than that of a previously developed electroless Ag-plated PP SERS substrate. The results of storage at room temperature and under dark conditions for two weeks showed no decrease in response, but the variability of response increased to CV=23.3%, indicating that the storage method needs to be considered. Thus, the fabricated SERS substrates using melt-brown PP nonwoven fabric are sensitive, easy to fabricate, low cost, and environmentally friendly.

High reliability assembly techniques for miniaturized in-line pressure sensor with diaphragm using a thin strain sensor have been developed to monitor the hydraulic pressure in the pipetting such as dispensing devices. The pressure sensor with a thin strain sensor as a diaphragm has two problems, (i) water leakage and (ii) sensitivity reduction by adding hydraulic pressure. These problems were clarified to generate tensile stress in the adhesive (Ag paste) by adding hydraulic pressure and to peel strain sensor from SUS housing. To overcome these problems, the stress in Ag paste was needed to keep compressive stress even when adding pressure. In this paper, a pressing mechanism is newly proposed to make compressive stress in Ag paste and assemble on the pressure sensor. First, to press the strain sensor to the SUS housing, a cap was bonded on the strain sensor with wafer-level-packaging (WLP) technique. Next, a pressing mechanism was designed to assemble on the miniaturized pressure sensor. The pressing mechanism was composed of a cover, two coil springs, and a spring base with pressing point. The pressing mechanism generates compressive stress to Ag paste even under high hydraulic pressure. The pressure sensor which implements the pressing mechanism has high pressure resistance and high reliability under the repetitive hydraulic pressure of 10 million times, without water leakage and sensitivity decrease.

In this paper, we evaluated generation energy by vibration using piezoelectric longitudinal effect of BaTiO₃ thick film formed on stainless steel substrate with interdigitated electrodes. It was confirmed that the interdigitated electrodes formed on the surface of BaTiO₃ film enables to align the polarization direction to the in-plane direction by forming Al₂O₃ layer on the surface of the stainless steel and generate energy by vibration due to the piezoelectric longitudinal effect.

In this study, we evaluated the sensor sensitivity of bending and torsion sensing MEMS tactile sensors by the sealing depth of the sensor chip in order to improve the sensitivity by changing the sealing method. We succeeded in establishing a fabrication method by controlling the dimensions of the sensor during sealing process. Therefore, we fabricated sensors with different sealing depths, and the experimental results showed the dependence of sensitivity on the sealing depth.

We have developed a Cr-N alloy thin film showing a gauge factor (Gf) of about 10 and a temperature coefficient of resistivity (TCR) of about zero, which is expected as a new strain gauge material in the next generation. In this study, we have investigated the fabrication of polyimide-based Cr-N thin films and the pressure sensor application for very low pressure range using the films. We have found out that the usable crack free Cr-N thin films were obtained on polyimide bases due to using the lower spattering gas pressure, and also enabled to detect the very low range pressure of 1-30kPa sensitively.