Dielectric elastomer with excellent electromechanical performance by dipole manipulation of Poly(vinyl chloride) for artificial muscles under low driving voltage application

Dielectric elastomers (DEs) are one of the optimal artificial muscle candidates and featured for their light weight, fast response, and large stroke. However, high operating voltage and prestrain processing are hindering their practical applications. In this work, a remarkable dielectric elastomer, vinyl chloride and ethylene copolymer (P(VC-E)), is developed by a novel strategy of main chain dipole manipulation, which tackles the contradiction between the large permittivity, low modulus, and high breakdown strength. The synthesis of polymer is conducted by a controlled reduction of poly(vinyl chloride), and the chemical composition and glass transition temperature of resultant DE can be simply tuned by varying the reductant dosage. It is found that P(VC-E) bearing 40 mol% vinyl chloride exhibits the highest breakdown strength (85 MV m−1) among high-k (>10) DEs, and much larger strain (38% in the thickness) at 1 kV than DEs without prestrain. Moreover, the actuator fabricated from P(VC-E) demonstrates superior cyclical operability under a relatively low voltage (450 V) and an extremely long lifetime. The facile material preparation and device fabrication present the significant potential of material scaled-up and device production at a low cost, providing a new pathway for DEs in flexible actuator applications.