Electromechanical behavior of fibers coated with an electrically conductive polymer

Fibers/fabrics coated with conductive polymers exhibit sensing capacities for external stimuli like strain, temperature, relative humidity, etc. In this paper, we present our recent investigation of the sensing behavior and mechanical analysis of polymer fibers coated with an intrinsically conductive polymer, i.e., polypyrrole (PPy). PPy-coated PA6 fibers and PPy-coated Lycra fibers are prepared by chemical vapor deposition using pyrrole in the presence of an oxidizing agent, and their electromechanical behavior under tensile load is studied experimentally. The mechanism governing the electromechanical behavior of these conductive fibers is investigated, and the effects of various factors that are responsible for variations in the electrical resistance are discussed. An electromechanical model is proposed that correlates the resistance change with the applied strain, the damage level of the conductive fibers, the environmental temperature, and the relative humidity. The model provides a theoretical basis for the analysis and design of electrically conductive fabrics.