Harnessing Soft Elasticity of Liquid Crystal Elastomers to Achieve Low Voltage Driven Actuation

Dielectric elastomers (DE) are soft electromechanical transducers that can generate large, rapid, and reversible deformation under an electric field. Despite being one of the leading candidates for soft actuators, the widespread applications of dielectric elastomers are restricted by the high voltage requirement (1-10 kV) for thin film DEs, which increases the system complexity and pose a potential safety threat for humans. In this work, a new class of dielectric elastomer actuators using liquid crystal elastomers (DLCEs) is reported. Soft elasticity of DLCEs and the high dielectric constant are utilized to reduce the actuation voltage. Freestanding DLCE thin film actuators (approximate to 20 mu m) are fabricated, which can generate large actuation strains (approximate to 88%) at 400 V, an input voltage almost one order of magnitude lower compared to typical dielectric elastomers actuators. This allows to develop a soft tunable bilayer DE lens, which can achieve a 21% focal length variation at 500 V.