Highly aligned suspended nanowire array for self-heating type gas sensors

A unique array structure of highly aligned and suspended palladium nanowires was demonstrated for application in self-heating type hydrogen gas sensors. Unlike conventional devices which employ randomly distributed bottom-up grown nanowires, in this study a top-down method which enables controllable and uniform device fabrication was used to produce the highly aligned nanowire array. Moreover, by suspending the array, heat loss through the substrate was eliminated, leading to a more efficient self-heating and rapid gas sensing response. As a result, with only a few milliwatts of power, the self-heated gas sensing device exhibited a considerably faster response time upon exposure to hydrogen gas than the device operating at room temperature.