Quantitative analysis of CO-humidity gas mixtures with self-heated nanowires operated in pulsed mode

Self-heating effect in individual metal oxide nanowires can be used to activate their response to gases with power consumptions below tenths of microwatts. The thermal response time of these devices is extremely fast (a few milliseconds) and it makes it possible to observe the kinetics of the interactions between the gas molecules and the metal oxide. In this work we demonstrate that such effects enable an experimental methodology to improve the selectivity of metal oxide-based sensors based on the analysis of their fast response dynamics. Specifically, this work jointly analyzes the magnitude and response time of SnO2 nanowire-based sensors to carbon monoxide (CO) and humidity (H2O) mixtures, proving that a quantitative analysis of CO-H2O gas blends can be achieved by modulating their work temperature through the self-heating effect. (C) 2010 American Institute of Physics. [doi:10.1063/1.3515918]