Analyzing deformation factors in six-segment dielectric elastomer actuator grippers: a finite element method-based numerical simulation

Dielectric elastomer actuators (DEAs) are increasingly recognized as pivotal components in flexible robotic actuators due to their substantial displacement, high energy density, rapid response times, and adaptable design characteristics. Nonetheless, the widespread adoption of DEAs is impeded by challenges such as elevated manufacturing costs and inherent nonlinear characteristics, which obscure a comprehensive understanding of the interplay between dielectric elastomer (DE) related material properties and voltage stimuli governing DEA operation. This study introduces a sophisticated finite element model that integrates Maxwell stress principles with the hyperelastic behavior inherent in DEs, enabling the numerical elucidation of DEA gripper dynamics. Utilizing this model, the minimum energy structure of DEs and their nonlinear actuation behavior under diverse electric field conditions are analyzed. The model's efficacy is validated through a meticulous comparison of simulated angular deflection and displacement with experimental results obtained from a six-segment DEA gripper across varying electric field intensities. Additionally, the impact of dielectric coefficients on the electro-actuated deformation of the DEA gripper is rigorously assessed, revealing a noteworthy enhancement in electro-actuation efficiency with increasing dielectric constants, particularly under high electric field conditions. Furthermore, the deformation differences of multi-segment DEA grippers under different voltage control strategies were investigated. The causes of these differences are discussed through stress analysis, and a sequential voltage application strategy is designed to optimize the gripping effect. The insights gleaned from this study offer valuable guidance for the design and optimization of DEAs tailored to diverse deformation requirements within the field of flexible robotic actuators.