Micro gas sensor assembly of tin oxide nano-particles by a capillary micro-molding process

Abstract

This paper reports a micro gas sensor assembled with tin oxide, SnO 2, nano-powders. The micro gas sensors are fabricated by a modified micro molding in capillary (MIMIC) technique using an ethanol suspension with 2.0 vol% SnO2 nano-powders. A micro pattern is formed as a set of parallel lines 23 μm in width and 1.2 μm in depth. The micro pattern is heat treated at 300°C for 5 h. The micro-sensor was able to detect ethanol gas by measuring the electrical resistance of the tin oxide a glass tube furnace. When ethanol vapor flows through the furnace the resistance decreases and the response time is 1.9 s. The sensor resistance ratio was determined to be 19.5 at 450°C. Our modified MIMIC technique enables easy and simple fabrication of ethanol vapor micro-sensors in a cost-effective way. © 2010 The Ceramic Society of Japan.