Innovative method of pulverisation coating of prestabilized nanopowders for mass production of gas sensors

A method to coat thin layers of previously stabilised sensing material by p ulverisation is presented, Parameters such as pulverisation timing, substra te temperature and flow of pulverised material are controlled by computer a nd their influence over final layer is explained. SEM characterisation was performed on samples which showed fine homogeneity and good control of thic kness, ranging from 0.2 to 10 mum. Different coatings of SnO2 and other sem iconductor sensing materials were performed over glass, alumina and silicon substrates. Interdigitated sensors were coated with SnO2 and a good sensit ivity to CO, CH4 and NO2 was found. The method is suitable for any gas sens ors based on nanopowders, either for laboratory sample evaluation or mass p roduction using standard substrates or micromachined sensors. (C) 2001 Else vier Science B.V. All rights reserved.