Emerging material strategies for enhanced dielectric elastomer actuation

Abstract

Dielectric elastomers (DEs) are currently the most promising classes of electroactive polymers for actuation application due to their high deformability, quick response, lightweight, and mechanical compliance. Over the last two decades, extensive research efforts have been made to address the inherent limitations of conventional DE materials, such as high actuation voltage, low dielectric permittivity, and electromechanical instability during prolonged use. This review provides a comprehensive overview of recent development and optimization of DE material for actuation applications. The most critical subjects of discussion are the optimization of key parameters in dielectric elastomer actuator (DEA) material design that decides its performance and the mitigation of common failure modes observed in existing dielectric elastomers. In this regards, key strategies such as molecular design and chemical modification of elastomer backbones, addition of suitable fillers, creation of soft nanocomposites, block copolymer design and interpenetrating polymer network designs are reviewed. Also, dielectric, mechanical, and interfacial properties and their synergistic effects on actuation performance are addressed elaborately. In addition, novel electrode material research towards actuation strain improvement is reviewed. Finally, current issues and future research directions are outlined for the development of the next generation of high-performance, low-voltage dielectric elastomer actuators.