The influence of the choice of the cross-linking agent on the electrical properties of polyethyleneimine-based humidity sensors

The results of impedance measurements of thin film polymer humidity sensors are presented in this paper. The sensors were made of chemically modified polyethyleneimine, spread on alumina substrate with comb type gold electrodes. Electrical properties of the sensors are strongly dependent on relative humidity (RH). The influence of the selected cross-linking agents on the properties, measuring range, and technology of preparation of the sensors is discussed.