Development of a hydrogen gas sensor based on a suspended monolithic carbon nanowire platform

We introduce a hydrogen gas sensor based on a suspended monolithic carbon nanowire structure. This structure provides selective and sensitive hydrogen sensing capability and unique advantages overcoming limitation of on-plane nanostructure based sensors. The fabrication of suspended carbon nanowire consists of simple two-step conventional microfabrication processes; photolithography and pyrolysis. The monolithic structure ensures perfect ohmic contact between the nanowire and the electrical contact pads. 20 ppm of hydrogen was successfully detected by a suspended monolithic carbon nanowire (width = 300 nm, thickness = 600 nm, distance between the nanowire and the substrate = 7.3 μm) coated wiht a 10-nm-thick palladium layer.