Transfer Printing Technology as a Straightforward Method to Fabricate Chemical Sensors Based on Tin Dioxide Nanowires.

Metal oxide multi-nanowire-based chemical gas sensors were manufactured by a fast and simple transfer printing technology. A two-step method employing spray pyrolysis deposition and a thermal annealing process was used for SnO 2 nanowires fabrication. A polydimethylsiloxane stamp was used to transfer the SnO 2 nanowires on two different gas sensing devices-Si-based substrates and microhotplate-based platform chips. Both contained a metallic inter-digital electrode structure (IDES), on which the SnO 2 nanowires were transferred for realization of multi-NW gas sensor devices. The gas sensor devices show a very high response towards H 2 S down to the 10 ppb range. Furthermore, a good response towards CO has been achieved, where in particular the microhotplate-based devices exhibit almost no cross sensitivity to humidity.