Abstract
Electrochemomechanical strain (ECMS) under tensile stress up to 5 MPa in polypyrrole films doped with dodecylbenzene sulfonate (PPy/DBS) has been studied in aqueous LiCl electrolytes. The ECMS of about 2% showed cation-driven behavior and decreased with increasing tensile stress. At higher tensile stresses than 2 MPa, a nonlinear deformation against the injected charges was observed, as well as creeping associated with conformation change, slipping and/or breaking of polymer chains. Upon removal of high tensile stresses, the creeping recovered in some extent. The results are discussed in terms of the relaxation of anisotropic strain and memory effect introduced during the creeping. The conversion efficiency from electrical to mechanical energies was 0.04%, being the maximum at approximately 3 MPa.