Investigations by impedance spectroscopy on the behaviour of poly(N,N-dimethylpropargylamine) as humidity sensor

A thin film of poly(N,N-dimethylpropargylamine) (PDMPA), deposited by spin coating over a SiO2 substrate covered by an interdigitated array of chromiu m electrodes, was characterised by impedance spectroscopy at different rela tive humidity levels, ranging from similar to0 to similar to 90% relative h umidity (RH). The logarithm of the film conductance exhibits a linear behav iour from very low RH contents up to more than 70% RH. The dynamic range of the variation of the conductance is extremely high (similar to6 orders-of- magnitude) and it allows a promising use of the film as a humidity sensor. (C) 2000 Elsevier Science B.V. All rights reserved.