Micro-contacted self-assembled tungsten oxide nanorods for hydrogen gas sensing

Electron beam lithography was used to fabricate platinum μ-contacts over tungsten oxide nanorods formed on a mica substrate. This made possible the measurement of sensorial response of these self-assembled tungsten oxide nanorods to hydrogen gas for the first time. The nanorods were prepared by thermal evaporation from an oxide source. Consequently, two types of conductometric sensors were assembled: a) percolating network of nanorods and b) set of individually contacted WO₃ nanorods. The preparation procedures are described in detail and the comparison of response of both types of assemblies is given. The first sensorial measurements revealed a good response of the b) type of sensor and the minimum repeatedly detected concentration of H₂ was 50 ppm.