Functionalisation of metal–polymer-nanocomposites: Chemoelectromechanical coupling and charge carrier transport

Abstract

a b s t r a c tElectrochemical actuation in nanoporous metals is achieved by impregnation of the material's pore space with a ionic conductor, typically an aqueous electrolyte. These hybrid actuators exhibit fully reversible deformation and mechanical properties that can be controlled by electric signals. Recently, set-ups have been proposed in which the nanoporous metal's surface is additionally coated with a conjugated polymer, resulting in a nanocomposite that exhibits strongly increased actuation strains compared to the pure metal while still retaining the mechanical strength of the metal backbone.In order to exploit the full potential of these nanocomposite actuators, a detailed understanding of the underlying ion transport mechanisms and means to predict the actuator's response are necessary. We present an interface-extended continuum mechanical model to study actuation in pure nanoporous gold and nanoporous gold-polypyrrole nanocomposites. Simulations predict significantly enhanced actuation strains due to the presence of the polymer phase and show that both, the nanocomposite's structure and the ions' mobilities, greatly affect the actuator's response.