Chemical Sensing with Ceramics

Abstract

As industrialization has progressed, many factories have used more and more reactive and toxic chemicals, liquids, and gasses to increase competitively their productivity, which gives a severe worldwide environmental crisis. Partly in response to this development, great improvements have been made in chemical sensors over the past 30 years, especially in the area of electrochemical and surface conductive type sensors. For example, the oxygen sensor (EGO or lambda sensor), adopted for use in automobiles, has contributed to a dramatic decrease in the toxic gases CO, hydrocarbon, and NOx that are exhausted from gasoline engines. Surface conductive gas sensors, mainly made of tin oxide, have successfully served as an explosive gas detectors and alcohol checkers. In this paper, the principles of chemical detection will be presented in terms of electron/ionic property of materials and the interface characteristics between materials. It includes electrochemical and adsorption/desorption properties of materials.