Chemical warfare agent sensor using MEMS structure and thick film fabrication method

Recently, many researchers have been attempted to reduce the power consumption in the sensor system and to increase the sensitivity for toxic gases. Most metal oxide sensing films are deposited on an alumina substrate which is easy process but needs high power consumption. Moreover, thin film sensor deposited on the Si substrate shows low sensitivity. Accordingly, this study investigated the fabrication of thick film gas sensors based on tin oxide on a Si substrate. Two heater shapes using a micro electro mechanical system (MEMS) are designed and simulated, and their gas response characteristics to test gases were examined. The sensing materials are SnO₂ mixed with Al₂O₃, and test gases are CH₂Cl₂, CH₃CN as simulant chemical warfare agents. Consequently, high sensitivity is acquired by using a thick sensing film and low power consumption is achieved by using MEMS technology.