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

摘要

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 microcanti-lever, 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. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.