Chemical Sensors

Vol. 22, No. 2(2006)



藤本 悟

潟_イキン環境・空調技術研究所 取締役

Chemical Sensors for Air Conditioning




玉置 純

〒525-8577 滋賀県草津市野路東1-1-1

High Sensitivity Semiconductor Gas Sensors Using Novel Sensing Materials
and Nano-design of Electrode Structure


Department of Applied Chemistry, Faculty of Science and Engineering Ritsumeikan University
1-1-1 Noji-higashi, Shiga 525-8577, Japan

   High sensitivity semiconductor gas sensors have been developed by using novel sensing materials (mixed oxides) and nano design of electrode structure. It was found that the mixed oxides having trirutile (ZnSb2O6), spinel (CdFe2O4, CdGa2O4), and perovskite (BaSnO3) structure showed significantly high sensor responses to dilute volatile sulfides such as H2S and CH3SH. On the other hand, the WO3 thick film sensor exhibited extremely high response to dilute NO2 and had potential for environmental NO2 monitoring.
The high performance was contributed to the usage of the disk-shaped WO3 particles and the Au comb-type microelectrode. In order to elucidate the effect of microelectrode, the micro-gap electrodes with gap size of 0.1-1.5o were fabricated by means of MEMS techniques(photolithography and FIB) and the WO3 film was deposited on it to be micro gas sensor. The sensor response was increased with decreasing gap size less than 0.8o. The micro-gap effect was contribution of interface with decreasing gap size. The similar micro-gap effects were observed for the Cl2 sensing using In2O3 sensor and the H2S sensing using SnO2 sensor.
It was found that the oxide-electrode interface played an important role in the semiconductor gas sensor and that the nano design of electrode structure was one of clues to get high sensitivity semiconductor gas sensor.


伊藤 成史

株式会社タニタ TU開発部・次長
〒174-8630 東京都板橋区前野町 1-14-2

Commercialization of a Micro Chemical Sensor and its Application to
a Non-Invasive Blood Constituent Monitoring System

Narushi ITO

B&D Department, TANITA Corporation
1-14-2 Maeno-cho, Itabashi-ku, Tokyo 174-8630, Japan

    The goal of this project was to build a non-invasive blood constituent monitoring system. It combined the use of a suction effusion fluid (SEF) collecting technique with an ion sensitive field effect transistor (ISFET) glucose sensor. The system directly collected the SEF by a weak vacuum aspiration through skin where the stratum corneum has removed beforehand. The ISFET glucose sensor performed successfully results, when tested for the monitoring of blood glucose levels in human subjects. On the other hand, we have developed a quantitative urine sample measurements, this urinary glucose meter has been proven to have superior supecifications; wide measurement range (0-2000 r/dL), rapid response (6 seconds), long shelf time (60 days) and enough removal of interferents effect. Furthermore, the meter offers exceptional performance in the quantification of urinary glucose, given its “palm-top” 200o size.

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