Interface elasticity effects in polymer-filled nanoporous metals

- A novel continuum mechanical framework for electromechanical coupling is proposed.
- Interface effects are accounted for by an extension of interface elasticity.
- Model fully couples mechanical, electrostatic and diffusional behaviour.
- Numerical examples illustrate interaction of different electromechanical effects.

A continuum formulation for electroactive composites made from nanoporous gold and ion-conducting polymer is proposed. A novel extension of surface elasticity theory is developed to account for the high surface-to-volume ratio of nanoporous gold, and to capture the chemoelectromechanical coupling that occurs on the interface between the metal and the polymer. This continuum formulation accounts for the fully non-linear behaviour exhibited by the composite.The balance of linear momentum, Gauß's flux theorem and a relation for the transport of charge carriers are introduced in the bulk material as well as on the interface to describe the non-linear multiphysics and highly coupled response of the actuator. The resulting system of non-linear equations is solved using the finite element method. A series of numerical examples is presented to elucidate the theory.