AC Complex Impedance Study on the Resistive Humidity Sensors with Ammonium Salt-Containing Polyelectrolyte using a Different Electrode Pattern

摘要

We examined the effect of electrode fingers and gaps of coplanar interdigitated electrode (IDE) structures to characterize the ammonium salt-containing polyelectrolyte film of resistance-based humidity sensors. IDEs designed for this purpose were flexible gold electrodes deposited on a polyimide substrate using a printing process because the geometry presents a potential for tunable sensitivity over other electrode designs. The basic design of the sensors consisted of IDEs with a different number of electrode fingers such as 3,4, and 5 and gap sizes of 310, 360,410, and 460 μm. Details of the AC complex impedance characteristics such as the Nyquist plot, Bode plot, and activation energy based on electrode construction were investigated.