Effect of temperature on the stability of dielectric elastomers

Dielectric elastomer (DE) is a kind of electroactive polymer material,
capable of large deformation up to 380%. However, under conservative
operating conditions, DE is susceptible to instability with a small
deformation due to various modes of failure, including electrical
breakdown, electromechanical instability (EMI), loss of tension and
rupture by stretch. This paper proposes a free energy model in the
thermodynamic system of DE involving thermoelastic strain energy,
electric energy and purely thermal contribution energy to obtain the
stability conditions of all failure modes. The numerical results
indicate that the increase in temperature can markedly contribute to
improving the entropy production, the actuation stress and the critical
nominal electric field of the DE. The increase in temperature could
modify the failure modes of loss of tension and the EMI, which
consequently enhances the stability of DE. Simultaneously, estimations
on the maximal energy to be converted can be made from the theoretical
formulation of the stability states. These conclusions may guide the
exploration for high-performance DE materials under thermo, mechanical
and electrical loads.

This paper is now published by Journal of Physics D: Applied Physics 44 365406 doi: 10.1088/0022-3727/44/36/365406