Design and Fabrication of a MEMS-Based Gas Sensor
In this study, the micro gas sensor for NOx gas was fabricated by using a MEMS technology and sol-gel process. The sensing electrode and micro heater were designed to be a co-planar typed structure in the Pt thin film layer. The fabricated micro platform had a low power consumption of 67 mW at 2.0 V of heater voltage and 300°C of operating temperature. Indium oxide as a sensing material for NOx gas was synthesized by a sol-gel process with indium isopropoxide. The particle size of synthesized In2O3 was identified as about 50 nm. The maximum gas sensitivity as relative resistance (Rs = Rgas / Rair) occurred at 300°C with the value of 8.0 at 1 ppm NO2 gas. The present study shows that a MEMS-based gas sensor is a potential candidate for the automobile AQS (air quality system) gas sensor with many advantages of small dimension, high sensitivity, short response time and low power consumption.
Selin Teo, A. Q. Liu, H. Li and B. Tarik
J. H. Yoon and J. S. Kim, "Design and Fabrication of a MEMS-Based Gas Sensor", Advanced Materials Research, Vol. 74, pp. 255-258, 2009