Effect of micro-electrode geometry on response of thin-film poly(pyrrole) and poly(aniline) chemoresistive sensors

Abstract The response of four different electrochemically prepared resistive conducting polymer sensors to ethanol vapour has been investigated. A theoretical model is developed relating the effect of the micro-electrode geometry on both the steady-state and transient responses. Our theory is compared with experimental results gathered when exposing the sensors to different concentrations of ethanol vapour in air at different relative humidities. The information gained from this comparison is finally used to determine the nature of the polymers using the diffusion-reaction case diagram originally proposed by Gardner et al. [J.W. Gardner, P.N. Bartlett, K. Pratt, Modelling of gas-sensitive conducting polymer devices, IEE Proc.: Circuits, Devices and Systems 142 (1995) 321-333].