Dual-Transduction MEMS Gas Sensor for H 2 and CO Identification Across Humidity

Selective discrimination between explosive H2and CO gases while preserving moisture resistance is of paramount importance. Conventional metal–oxide–semiconductor (MOS) gas sensors suffer from poor selectivity, and reliable multigas identification with a single device remains challenging. Here, we report a microelectromechanical systems (MEMS) gas sensor that integrates two transduction mechanisms, enabling single-sensor gas identification. We demonstrate this innovative approach through the simultaneous measurement of chemiresistive response and temperature change of the sensing layer. Due to gas-specific catalytic exothermic reaction and distinct redox rates on the MOS surface, and maintaining stability under humidity, the relatively independent resistive and calorimetric signals allow robust classifications of H2and CO gases across humidity conditions using linear discriminant analysis (LDA). We hope our work could resolve the key bottleneck in multigas identification via a single device and offer guidance for intelligent gas sensor technology with compact MEMS platforms.