Ultra-high sensitive micro-chemo-mechanical hydrogen sensor integrated by palladium-based driver and high-performance piezoresistor

• Published in: International journal of hydrogen energy 2021-01, Vol.46 (1), p.1434-1445
• Main Authors: Li, Hongfang, Li, Yahui, Wang, Kai, Lai, Liyan, Xu, Xiaoxue, Sun, Bin, Yang, Zhuoqing, Ding, Guifu
• Format: Article
• Language: English
• Subjects: High-performance piezoresistor; Hydrogen sensor; Palladium coated microcantilever; Palladium-based driver
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2020.10.013

A novel resistive chemical-mechanical sensor for hydrogen gas detection was designed and manufactured by using MEMS processing technology. The sensor combines a composite piezoresistor of silver nanowires-polyimide and a palladium sputtered microcantilever, and the optimized structure of which has been obtained through theoretical and simulation analysis. With a series of experimental testing, the fabricated sensor achieved the ultra-high sensitivity of 2825, 8071, 28250 and 47083 for hydrogen detection at the concentration of 0.4%, 0.8%, 1.2%, 1.6% and 2.0%, respectively. The ultra-high sensitive detection for hydrogen was enabled from the synergistic function of both the surface resistance effect between the palladium coated cantilever and silver nanowires-polyimide piezoresistor, and the bulk resistance effect of the silver nanowires-polyimide piezoresistor. In addition, the sensor also demonstrates excellent stability, which has high potential for practical hydrogen gas detection. [Display omitted] •A novel MEMS resistive hydrogen sensor of ultrahigh sensitivity was designed.•Sensor integrated palladium-based microcantilever with high sensitive piezoresistor.•Ultrahigh sensitivity of 2825, 47083 at 0.4%, 2.0% H2 is respectively detected.•Sensing mechanism is synergistic function of surface and bulk resistance effect.