Micro-chemo-mechanical hydrogen sensor based on contact resistance of carbon nanotubes array

We developed a micro-chemo-mechanical hydrogen sensor with novel sensing mechanism based on contact resistance change of carbon nanotubes array. The sensor is composed of two facing sets of carbon nanotubes (CNT) arrays as the detection material and palladium (Pd)-coated micro-cantilever fabricated on silicon-on-insulator (SOI) wafer. The Pd-silicon bimorph responds toward various concentration of hydrogen gas at room temperature. This micro-chemo-mechanical sensor reacted to 0.5% of hydrogen gas within 12 seconds and showed detection limit as low as 0.05%. It is much lower value than typical resistive-type chemo-mechanical hydrogen sensors.