Robust catalytic gas sensing using a silicon carbide microheater

Abstract

This paper reports the first use of a silicon carbide (SiC) microheater for stable low-power catalytic gas sensing. Catalytic combustion of hydrocarbon gases often requires high operating temperatures, which leads to instability in a previously developed low-power polycrystalline silicon (polysilicon) microheater. A silicon carbide microheater has been developed with low power consumption (20 mW to reach 500 °C) and improved stability, exhibiting an order of magnitude lower resistance drift than the polysilicon microheater after 100 hrs of continuous heating at 500 °C and during temperature increases up to 650 °C. When loaded with a high performance catalytic nanomaterial, the SiC microheater-based catalytic gas sensor exhibits fast response and recovery time (<1 s) and improved long-term stability for propane detection. The results show that a simple change of material from polysilicon to polySiC leads to a significant performance improvement of the microheater and the resulting sensor element.