Investigations on the response to humidity of an interdigitated electrode structure coated with iodine doped polyphenylacetylene

The sensitivity to relative humidity of a sensor based on I2-doped polyphenylacetylene thin film membranes has been investigated. The sensor geometry allows its application in miniature devices. The response to humidity variations (20%–80%) is fast and reproducible for long times (months). V characteristics suggest that ionic type conductivity is prevailing. Current intensity measurements performed on films of different thicknesses show that surface conductivity is mainly responsible for the sensorʹs electrical response.