Electromechanical instability and snap-through instability of dielectric elastomers undergoing polarization saturation

By applying a voltage, electric charge will be induced on the surface of dielectric elastomers. Generally, the charge increases with the level of voltage. When the voltage reaches to a certain value, the charge would not increase any more due to the polarization saturation of dielectric materials. In this paper, a thermodynamic constitutive model, combined both the nonlinear dielectric and hyperelastic behavior as dielectric elastomers undergoing polarization saturation, has been developed. Analytical solutions have been obtained for situations incorporating strain-stiffening effect, electromechanical instability and snap-through instability. The numerical results reveal the marked influence of the extension and polarization saturation limits of elastomer material on its electromechanical instability and the snap-through instability. The developed constitutive model would be helpful in future research of dielectric elastomer based high-performance transducers.

► Model of dielectric elastomer undergoing polarization saturation has been developed.
► Analytical solutions have been obtained for electromechanical and snap-through instability.
► Numerical results reveal the marked influence of polarization saturation on instability.
► Model would be helpful in future research of elastomer based high-performance transducers.