Mechanics of dielectric elastomer structures: A review

In the past decade, the development of theory has deeply revealed the electromechanical coupling deformation mechanism of dielectric elastomer (DE). Many theoretical predictions on highly nonlinear deformation of dielectric elastomer have been verified by experiments. With the guidance of theory, the voltage-induced areal strain of dielectric elastomer has been increased from 100% in the pioneering work to the current record of 2200% and the energy density of a dielectric elastomer generator has reached 780 mJ/g. Much more developments have been realized on the applications of DE transducers in the fields of bioinspired artificial muscles, soft robotics, tunable lenses, and haptic interfaces. However, there is a gap between theory and application. Great potentials of developing DE transducers with the aid of a systematic theory have yet to be explored. This paper reviews the recent advances in the theory of dielectric elastomer and demonstrates some examples of using theory to design DE transducers. 9 boundary value problems of DE structures are analyzed from the simplest homogeneous deformation of a flat membrane to the highly complex bifurcations of a tube. Comparisons between theory and experiment are discussed. The viscous effect and the vibration of dielectric elastomer are reviewed. The developments of DE transducers and new dielectric materials are also reviewed. We summarize the performance of existing DE transducers with different configurations and make some discussions. It is hoped that the mechanics of DE structures can help to develop high-performance DE transducers in the future.