A Study on the Selectivity of Gas Sensors by Sensing Pattern Recognition

Abstract

We report on the building of a micro sensor array based on typical semiconductor fabrication processes aimed at monitoring selectively a specific gas in ambient of other gases. Chemical sensors can be applied for an electronic nose and/or robots using this technique. Microsensor array was fabricated on the same chip using 0.6<TEX>${\mu}m$</TEX> CMOS technology, and unique gas sensing patterns were obtained by principal component analysis from the array. <TEX>$SnO_2$</TEX>/Pt sensor for CO gas showed a high selectivity to buthane gas and humidity. <TEX>$SnO_2$</TEX> sensor for hydrogen gas, however, showed a low selectivity to CO and buthane gas. We can obtain more distinguishable patterns that provide the small sensing deviation(the high seletivity) toward a given analyte in the response space than in the chemical space through the specific parameterization of raw data for chemical image formation.