Polymer electrolytes as humidity sensors: progress in improving an impedance device

Impedance humidity sensors based on a blend of sodium sulphonated polystyrene and a cellulose-based polymer electrolyte, have been improved by carefully refining the construction details. Enhanced performances have been attained with a close investigation on the electrical characteristics of the device as a function of humidity. The best results have been achieved by choosing both exciting frequency and the distance between the electrodes so that electrode redox processes are avoided.