Inherently pre-strained elastomers with self-healing property: new generation of freestanding electroactuators (Conference Presentation)

Dielectric elastomers (DEs) are the leading technology for artificial muscles due to a favorable combination of large stroke, fast response, and high energy density. However, at large actuations, DEs are prone to spontaneous rupture from electromechanical instability. This shortcoming is currently circumvented by chemical or physical bracing, which increases bulk and rigidity of the total actuator assembly and leads to significant cutbacks in device efficiency and utility. Now, we present a molecular design platform for the creation of freestanding actuators that allow for large stroke (u003e300%) at low applied fields (u003c10 V μm-1) in unconstrained as cast shapes. This approach is based on bottlebrush architecture, which features inherently strained polymer networks that eliminate electromechanical instability and the need for bracing. Through accurate control of side-chain length and crosslink density, we obtained effective actuation properties on par with commercial actuators with the advantage of lighter weight, lower voltage operation, and ease of fabrication, which open new opportunities in soft-matter robotics. Furthermore, incorporation of dynamic reversible bonds ensures self-healing of rupture actuators.