Gas sensing through thick film technology

We report in our research on semiconductor-based sensing layers deposited via thick-film technique. Particular focus was devoted to achieve nanosized films through proper processing and to study their morphological and structural features. Nanosized powders were prepared by sol-gel method or laser-assisted spray pyrolysis. We also considered some techniques to maintain the stability of a nanostructure for long-term usage of the sensing layers. We detailed the preparation of screen printing pastes Suitable for gas sensing application. Implementation of the sensing film on a low-power-consumption micromachined hotplate has also been addressed. The performance of such devices is presented and compared to that of conventional units. (C) 2002 Elsevier Science B.V. All rights reserved.