In silico actuation performance investigation of dielectric elastomers with TPMS geometries

Abstract

Dielectric Elastomer Actuators (DEAs) are highly efficient soft actuators widely used in soft robotics and artificial muscles due to their superior actuation capabilities. Introducing two-phase structures to DEAs offers potential benefits, particularly in reducing operational voltages. However, this approach poses significant challenges due to both physical and numerical constraints. This study investigates the distinctive actuation performance of two-phase microstructure DEAs, designed using a class of architected materials known as Triply Periodic Minimal Surfaces (TPMS), and compares them with Random Heterogeneous Microstructures. Six well-known TPMS geometries, including Gyroid, Schwarz-P, and IWP structures, are employed. In addition to actuation performance, localized electric fields and blocking forces are analyzed for all microstructures to provide a comprehensive understanding of their behavior. The quasi-static, fully coupled governing equations of DEAs are implemented in ABAQUS software using a reliable in-silico FEM approach. The results reveal that DEAs based on TPMS geometries exhibit intrinsic advantages over their random counterparts in terms of actuation performance. Notably, the microstructure named Octo demonstrates the highest improvement, showing a 9.9% increase in actuation performance compared to Random Microstructures. However, this trend is reversed with respect to blocking forces, where Random Microstructures exhibit higher values. The analysis of localized electric fields indicates that both TPMS- and Random-based microstructures have the potential to offer relatively low localized fields. These findings represent a preliminary step toward the development of multi-phase DEA composites with architected geometries.