Low Power Thermo-Catalytic Gas Sensor Based on Suspended Noble-Metal Nanotubes for H2 Sensing

Abstract

A thermo-catalytic gas sensor has been constructed based on the local synthesis of high wt% Pt nanotubes (>70 wt%), as the catalytic layer, onto a strip-type, double anchored SiO2 beam with an embedded Resistive Temperature Detector (RTD). This is in contrast to the traditional 10-30 wt% Pt nanoparticle-loaded Alumina used as catalyst, which limits miniaturization. The reported method provides precise synthesis control over small areas as localized Joule heating is used for the synthesis. The sensor operates at a power of 10 mW, an order of magnitude lower than most commercial thermo-catalytic gas sensors and the RTD exhibits resistance changes greater than 3% to 1.6% H2 from the local combustion of the gas.