Bridging electrode gaps with conducting polymers around the electrical percolation threshold

Abstract

The conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) is grown electrochemically using cyclic voltammetry between the gaps of interdigitated Au electrodes with separations of 10, 20, and 50 μm. Three electrical conductivity regimes are identified through resistance measurements and SEM imaging. The first is the insulating region where there are no complete conducting pathways between the electrodes. The second is the percolation region where a few localised conducting polymer bridges have formed. The third is the thin film region where a continuous conducting polymer film connects the electrodes. The demonstration of the ability to reliably generate conducting polymer electrical percolation networks is important for their future use in high sensitivity devices.