High-sensitive hydrogen detection in oxygen-free environment with mems differential thermopiles

We proposed a gas sensor based on MEMS differential thermopiles that can achieve highly sensitive detection of hydrogen (H-2) in an oxygen-free environment, which is a challenge for state-of-the-art detection methods such as semiconducting metal oxide (SMO) based gas sensors. Due to the high-sensitivity of the designed MEMS differential thermopiles as well as the high-activity of the synthesized Pd nanoparticles (NPs) @Al2O3 sensing material, the manufactured thermopile sensor achieves a detection limit as low as 1 ppm H-2 in an oxygen-free environment and exhibits a linear response to H-2 concentration from 1ppm to 400 ppm with a response time of 14 s and a recovery time of 10 s to 400 ppm H-2. In addition, the sensor also shows good selectivity and stability and is expected to be applied to hydrogen leakage monitoring in oxygen-free environments.