Research on the usability of metallised fabrics as moisture sensor elements

Abstract

This paper presents a generative-type textile humidity sensor made entirely from commercially available electroconductive fabrics. The sensor consists of two woven fabric strips metallised with different metals (copper and nickel), ultrasonically welded to a polyester-woven fabric substrate. In the presence of moisture, the structure forms an electrochemical cell that generates a voltage dependent on relative humidity. Four sensor variants were investigated with respect to their static and dynamic properties. The results show a nonlinear relationship between generated voltage and relative humidity, with effective operation mainly above 50 % RH. Dynamic tests revealed response times of several seconds and recovery times of several minutes, governed by the drying behaviour of the textile substrate. The sensors also respond to artificial acid and alkaline sweat. Temperature tests indicated a positive temperature coefficient. The proposed fully textile sensor offers a simple, flexible solution for textile humidity sensing in smart garments.