Study on the performance optimization of circular dielectric elastomer membrane actuator by charge compensation methods

Abstract

This study develops a physical model based on the principle of non-equilibrium thermodynamics and the theory of nonlinear dissipative dielectrics to describe the effects of viscoelasticity and charge leakage on the electromechanical coupling behavior of circular dielectric elastomer membrane actuators. Through theoretical analysis and numerical simulations, this study systematically investigates the electromechanical response characteristics of membrane actuators under charge-controlled conditions. The effects of charge leakage and viscoelasticity on the performance of the actuator are mainly discussed. An optimized charge compensation method is proposed to eliminate the limitation of the combined effect of charge leakage and viscoelasticity on the performance of the membrane. The research results indicate that charge leakage causes a gradual decrease in the deformation of the membrane actuator. While compensating for the leaked charge helps maintain a high level of stretching, precise control of membrane deformation is difficult due to the inability to suppress viscoelastic effects. The improved charge compensation method proposed in this study effectively stabilizes the deformation of the membrane by simultaneously suppressing the coupling effects of charge leakage and viscoelasticity, enabling stable deformation control over any specified time period. After charge compensation, the radial stretch of the membrane is maintained at the level corresponding to the compensation moment. The value of the radial viscoelastic stretch gradually approaches and eventually equals the radial stretch, thereby keeping the membrane strain constant. Meanwhile, the surface charge of the membrane tends to stabilize, with the rate of change of the surface charge equal to the leakage current. These research findings aim to provide theoretical guidance for the application of circular dielectric elastomer membrane actuators in soft robotics, artificial muscles, intelligent systems, and other fields, offering optimization insights for their design and control in dynamic environments.