Work

Chemoresistive and Catalytic Dual‐Signal Pd‐WO 3 MEMS Sensor for Reliable H 2 Monitoring

Year: 2025

Type: article

Abstract: The demand for H 2 monitoring in its production and utilization grows rapidly to ensure operational efficiency and safety. Given the high flammability of H 2 , it is crucial to detect levels below the lower flammability limit (4%) in a sensitive, rapid, and reliable manner. Although integrating multiple sensor types can improve selectivity and accuracy, such systems often involve bulky architecture and time‐consuming operation. This study presents a dual‐signal H 2 sensor based on a single microelectromechanical system (MEMS) platform, enabling miniaturization, low power consumption, and robust performance. Pd nanoparticle‐decorated WO 3 nanorods (Pd‐WO 3 NRs) are employed as sensing material and integrated into the MEMS substrate. The catalytic Pd promotes H 2 oxidation, enabling the sensor to simultaneously monitor resistance changes in the Pd‐WO 3 NRs and temperature variations in the microheater. This dual‐signal approach corresponds to concurrent chemoresistive‐ and catalytic combustion‐type gas sensing. The sensor exhibits high sensitivity and selectivity toward H 2 , with detection limits of 0.01%–0.02% for dual signals, and demonstrates excellent reliability under varying humidity levels, repetitive cycles, and static gas exposure conditions. This work provides a practical foundation for the development of single gas sensors with dual output signals, enabling robust and energy‐efficient H 2 detection in diverse environmental and industrial scenarios.

Source: Small

DOI: 10.1002/smll.202509377