Electromechanical analysis and simplified modeling of dielectric elastomer multilayer bending actuator

Dielectric elastomers can generate large voltage-induced deformation and have been widely used as soft actuators. Dielectric elastomer multilayer structures function as bending-type actuators, enhancing their stiffness and ability to resist external loads. Modeling a dielectric elastomer multilayer bending actuator allows analyzing its bending performance, and obtaining the stress and strain distributions in each layer of the actuator. It is of practical importance to develop a simple, yet accurate model. This work develops a model to analyze the electromechanical behavior of the dielectric elastomer multilayer bending actuator with various pre-stretch, material, and structural parameters. We also propose a simplified model for a bilayer slender beam, which is a typical multilayer structure. The simplified model describes the relation between the beam bending curvature and the applied voltage, achieving fast calculation with little accuracy sacrificed. Both the model for the dielectric elastomer multilayer and the simplified model for the bilayer beam agree well with the experiment results, validating the models for practical applications in soft robots, flexible sensors, and smart structures.