Advancing Dielectric Elastomer Actuators for Oriented Electroactuation: From Physical Engineering to Material Preparation

ABSTRACT The oriented actuation of biological muscles that relies on the contraction and relaxation of sarcomeres in myofibrils is the foundation of animal movement. Dielectric elastomers (DEs), which are deemed as a kind of promising artificial muscles, can effectively transfer electric energy to mechanical energy within milliseconds under a stimulation of external electric field. Herein, the state‐of‐art in bioinspired oriented electroactuation of dielectric elastomer actuators (DEAs) is reviewed. The oriented electroactuation of DEAs shows directional movement with larger stroke, directional output, and higher energy transformation efficiency. In general, most of the DEs are mechanically isotropic with uniform expansion deformation, yet in practical applications they usually utilize deformation in limited direction, leading to energy waste in other directions. Thus, we have principally reviewed the efforts from physical engineering mainly based upon mechanically isotropic DEs to material preparation for mechanically anisotropic DEs, aimed at achieving oriented electroactuation of DEAs. Meanwhile, the typical bionic applications of DEAs with oriented electroactuation are introduced, the main challenges are summarized, and some perspectives for promoting this area are also proposed. We firmly believe that the development of DEAs with oriented electroactuation can significantly impact the fields of artificial muscles for flexible actuators and soft robotics.