title: Ethanol microsensors with a readout circuit manufactured using the CMOS-MEMS technique.
abstract: The design and fabrication of an ethanol microsensor integrated with a readout circuit on-a-chip using the complementary metal oxide semiconductor (CMOS)-microelectro -mechanical system (MEMS) technique are investigated. The ethanol sensor is made up of a heater, a sensitive film and interdigitated electrodes. The sensitive film is tin dioxide that is prepared by the sol-gel method. The heater is located under the interdigitated electrodes, and the sensitive film is coated on the interdigitated electrodes. The sensitive film needs a working temperature of 220 °C. The heater is employed to provide the working temperature of sensitive film. The sensor generates a change in capacitance when the sensitive film senses ethanol gas. A readout circuit is used to convert the capacitance variation of the sensor into the output frequency. Experiments show that the sensitivity of the ethanol sensor is 0.9 MHz/ppm.
authors.affiliation: Department of Mechanical Engineering, National Chung Hsing University, Taichung 402, Taiwan. d099061005@mail.nchu.edu.tw.
authors.forename: Ming-Zhi
authors.initials: MZ
authors.lastname: Yang
authors.affiliation: Department of Mechanical Engineering, National Chung Hsing University, Taichung 402, Taiwan. cldai@dragon.nchu.edu.tw.
authors.forename: Ching-Liang
authors.initials: CL
authors.lastname: Dai