Fig. 1: Structural design and working principle of the MEMS differential thermopile H2 sensor.

a Schematic diagram of the MEMS differential thermopile-based H2 sensor, consisting of a sensing thermopile and a reference thermopile. b Schematic diagram of the H2 sensing mechanism and working principle of the sensor. The differential output signal is proportional to the temperature change due to the H2 catalytic reaction process, while environmental interferences are subtracted