Modulated operating temperature for MOSFET gas sensors: hydrogen recovery time reduction and gas discrimination
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- 作者：Briand ; Danick ; Wingbrant ; Helena ; Sundgren ; Hans ; van der Schoot ; Bart ; Ekedahl ; Lars-Gunnar ; et. al.
- 关键词：Gas sensor ; Low-power ; MOSFET ; Temperature modulation
- 刊名：Sensors and Actuators B: Chemical
- 出版年：2003
- 出版时间：August 1, 2003
- 年：2003
- 卷：93
- 期：1-3
- 页码：276-285
- 全文大小：234 K
文摘
This communication presents a modulated mode of operation for MOSFET gas sensors. A low-power micromachined device allows pulsing the temperature of MOSFET gas sensors with a time constant less than 100ms. Modulating the temperature during the gas exposure modifies the kinetics of the gas reactions with the sensing film. The way the sensor response is modified by the temperature modulation depends on the sensor “history”, on the nature of the surrounding gaseous atmosphere, and on the type of materials used as catalytic sensing film. Pulsing the temperature up just after the gas exposure can reduce the recovery time for specific applications, such as for hydrogen detection. Cycling the temperature can allow the discrimination between different gas mixtures. Discrimination was shown for gaseous mixtures of hydrogen and ammonia in air. The results obtained indicate that a “smart” combination of sample and temperature profile could be used to expand the information content in the sensor response.