Total Internal Reflection (TIR) Behavior of Heterogeneous Interface Shear Waves in Layered Soft Structure

The total internal reflection (TIR) behavior of interface shear waves is crucial for ensuring the reliability of dielectric elastomer (DE) devices. However, due to the complex force-electric coupling and large deformation of DEs, the TIR behavior of shear waves in heterogeneous force-electric interface models is still unclear. This study modeled an elastic/DE bi-material interface to analyze the trajectory of out-of-plane shear waves. Employing Dorfmann and Ogden’s nonlinear electroelastic framework and the related linear small incremental motion theory, a method has been developed to control the TIR behavior of interface shear waves. It has been found that the TIR behavior is significantly influenced by the strain-stiffening effect induced by biasing fields. Consequently, a biasing field principle involving preset electric displacement and pre-stretch has been proposed for TIR occurrence. By controlling the pre-stretch and preset electric displacement, active regulation of TIR behavior can be achieved. These results suggest a potential method for achieving autonomous energy shielding to improve the reliability of DE devices.