Micro-gas-sensor with conducting polymers

In this paper design and fabrication of micro-gas-sensors, the deposition of four different poly(pyrrole) (PPY) thin films as chemoresistor in the micro-gas-sensors by electrochemical processing and chemical oxidation, and characterisation these films by FTIR, SEM, surface test instrument (WYKO NT2000) and optical microscopy, are reported. The effect of anions in PPY thin films, thickness and surface roughness of the PPY films on the response of micro-gas-sensors and the effect of ethanol vapour concentration on the response of polymer films have also been investigated. The experimental results show that a typical sensitivity to ethanol of ca. 5 muVppm was observed at 30 degreesC and the gas sensitivity of the integrated silicon planar micro-sensor depends on the counter ions in the PPY films, PPY film thickness and surface morphologies. The gas sensitive mechanism of the conducting PPY thin films is also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.