Heating power-controlled micro-gas sensor array

A new type micro-gas sensor array and its operating mode were proposed in this paper. Sensor array has a heater, and three sensing electrode and temperature sensor pairs. Three different sensing materials, Fe2O3 + V2O5, SnO2/Au + Pd and nanocrystalline SnO2, were synthesized by coprecipitation method and used for selective gas sensing. Even though fabricated sensor array has three sensing materials, 12 sensing responses in an array were implemented by using heating power-control method as a sensor operating mode. The gas-sensing characteristics were investigated as a function of the heating powers (35, 40, 45, and 50 mW). Principal component analysis (PCA) was employed to discriminate the various kinds of gases, which is known as one of the most effective sensing signal analysis methods. From the PCA result, we could confirm that the gas sensor array with excellent gas discriminating ability could be obtained by using a heating power-controlled method. (C) 2001 Elsevier Science B.V. All rights reserved.