The interplay between symmetry-breaking and symmetry-preserving bifurcations in soft dielectric films and the emergence of giant electro-actuation

TL;DR

This paper presents a novel approach to enhance electro-actuation in soft dielectric films by leveraging symmetry-breaking bifurcations, enabling strains 200% larger at lower electric fields, thus advancing soft robotics and flexible electronics.

Contribution

It introduces a simple method to induce symmetry-breaking bifurcations in dielectric films, surpassing conventional actuation limits while avoiding pull-in instability.

Findings

Electro-actuation strains exceed 200% of conventional limits.

Achieved large deformations at significantly lower electric fields.

Demonstrated control over bifurcation modes to enhance actuation.

Abstract

Soft elastomers that can exhibit extremely large deformations under the action of an electric field are essential for applications such as soft robotics, stretchable and flexible electronics, energy harvesting among others. The critical limiting factor in conventional electro-actuation of such materials is the occurrence of the so-called pull-in instability. In this work, we demonstrate an extraordinarily simple way to coax a dielectric thin film towards a symmetry-breaking pitchfork bifurcation state while avoiding pull-in instability. Through the nonlinear interplay between the two bifurcation modes, we predict electro-actuation strains that exceed what is conventionally possible by 200$\%$, and at significantly lower applied electric fields.