Dielectric elastomers with large actuation strain and high output force

Dielectric elastomer actuator (DEA) is considered as an ideal artificial muscle with soft and light in nature, widespread application in soft robotics and sensors. Dielectric elastomer (DE), the core component of DEA, with high output force and large actuation strain under relatively low driving electric field is critical for high-performance DEA. However, the widely used VHB series (3M) DE suffered from very large pre-strain and high driving voltage to get their high actuation performance, limiting their scope of application. In this work, the DEs with good mechanical and dielectric properties were prepared via UV curing method consisting of acrylic acid (AA) with strong polar groups as functional monomer, n-butyl acrylate (BA) as soft monomer and urethane acrylate as cross-linker (c-p(BA-AA)). The c-p(BA-AA) DE films obtained the simultaneous increasing of dielectric constant and breakdown strength with the increasing content of AA, which guaranteed the good actuation performance. The c-p(BA-AA) film exhibited excellent actuating performance (44.11% actuation strain at 45 kV/mm) without pre-strain. Besides, a simple linear actuator based on the c-p(BA-AA) film could easily output weight that is tens of times of its own active weight (654.1 mN/g at 30 kV/mm). Acrylate-based dielectric elastomers with enhanced mechanical and dielectric properties were prepared by simple and fast UV curing method. The dielectric constant and breakdown strength of the DEs were decouplingly enhanced with the increasing of acrylic acid. The linear actuator based on the DE film can achieve an output force per unit mass of 654.1 mN/g at 30 kV/mm. image