Enhanced electrochemical actuation of nanoporous gold-polypyrrole hybrid under load

Abstract

This work examines the actuation strain response of a nanoporous gold-polypyrrole electrochemical actuator under compression. The strain is monitored by in situ dilatometry and dynamic mechanical analysis when the material is wetted by an aqueous electrolyte and subjected to cyclic potential variation under various compressive loads ranging from −0.27 to −22.30 MPa. Contrary to previous studies that report reduced actuation amplitudes under load in the individual constituents of the material—nanoporous gold and polypyrrole, we find the strain amplitudes of the hybrid increase with increasing load and even while being deformed by plastic deformation. In this contribution, we discuss the phenomenon by taking into account the variations of the effective Young's modulus of the material that occur simultaneously with the actuation.