Tungsten Oxide Nanowires on Micro Hotplates for Gas Sensing Applications

Tungsten oxide nanowires (NWs) were successfully deposited on the membrane of micro hotplates (ams, Germany) by a very simple and scalable thermal oxidation technique. Synthetized nanostructures were morphologically investigated by mean of a FE-SEM (LEO 1525) and the structure was analysed by X-Ray Diffraction and Raman Spectroscopy. Micro hotplates were mounted on standard TO packages by gold wires by electro soldering in order to fabricate a batch of sensing devices.The performances of the fabricated devices were tested towards some chemical compounds of interest (NO2, Acetone, Ethanol and CO). Firstly a temperature screening was performed, to identify the optimal working temperature in presence of each target compound. Moreover, calibration curves were obtained, and the influence of humidity was taken into account for NO2.