Effect of Liquids on the Electrical Resistance of Polypyrrole-Coated Fabrics

Polypyrrole (PPy)-coated fabric can be produced by means of chemical vapour deposition using pyrrole in the presence of an oxidizing agent. This electrically conductive fabric can be used as a strain sensor, and has high potential for producing wearable sensors that can detect the movements of the wearer. Since direct contact between this conductive fabric and human body will be involved, an investigation of the effect of different types of liquids such as sweat, rain water, drinking water, etc. on the electrical conductivity of fabric sensors is critical. Changes in the conductivity and surface morphology of the PPy-coated textile were analysed by placing few drops of liquid onto the fabrics. The results showed that the electrical resistance of the PPy-coated fabrics was different when the fabrics came into contact with different types of liquid. The phenomenon can be explained by both the fibre/fibre contact and yarn/yarn contact models as well as by the uniformity of the PPy-coating layer on the surface of the fibre.