Nonlinear dynamics of ionic liquid enhanced soft composite membrane under electro-mechanical loading

The incorporation of ionic liquids (ILs) into dielectric elastomer composites has attracted significant interest due to their potential applications in soft actuators and optical devices. Their soft and hyperelastic nature make them a distinct dynamic. In this paper, nonlinear dynamics of IL enhanced soft composite (ILESC) dielectric membrane subjected to electro-mechanical loading is investigated. A mixed micromechanical model with the incorporation of an electric double layer (EDL) and Maxwell-Wagner-Sillars (MWS) polarization is developed to estimate mechanical and electrical properties of the ILESC. Governing equations are derived via an energy method with the framework of the hyperelastic membrane theory, Neo-Hookean constitutive model and the couple dielectric theory. These equations are discretized by Taylor series expansion (TSE) and differential quadrature (DQ) methods and are solved by incremental harmonic balance (IHB) method combined with arc-length technique. The developed model and results are verified by comparing to experimental data and previous results. The influence of volume fraction, shape and size of IL fillers, static and dynamic applied electric field and excitation amplitude on forced vibration and resonant response of the ILESC membrane are comprehensively analyzed. It is found that ILESC membrane with slender ellipsoidal ILs displays larger amplitude, lower peak amplitude frequency and more obvious softening behavior.