Electrical properties of polymer humidity sensor based on polyethyleneimine

Abstract

In the paper the amperometric properties of polymer humidity sensor based on polythyleneimine are presented. Usually properties of this sensor are examined by means of impedance spectroscopy. The new approach is proposed. It is shown that the current flow in the investigated sensor is a result of the electrode reaction at the anode. The quasi-static diffusion current is a linear function (in the log-lin scale) of relative humidity, so this sensor can be used as an amperometric. An equivalent circuit, containing the elements representing diffusion effect, has been proposed. The shape of impedance plots show diffusion related process.