Fabrication of Fluorosilicone Rubber/MXene/ag Dielectric Elastomer Composites With Enhanced Electromechanical Performances for Flexible Actuator Applications

Dielectric elastomer has attracted much attention for its promising application in soft robots, actuators, and generators. Nevertheless, fluorosilicone rubber (FSR), as a typical dielectric elastomer matrix, possesses inherently low dielectric permittivity, severely limiting its electromechanical actuation performance. To address this issue, two-dimensional (2D) MXene nanosheets and zero-dimensional (0D) Ag nanoparticles were incorporated into FSR via mechanical mixing and hot-pressing to prepare FSR/MXene/Ag composites. Results show that MXene and Ag were dispersed well in the FSR matrix and the composites were thermally stable up to 390°C. A relatively high dielectric permittivity of 16.63 (2.49 times of pure FSR) was achieved at 10 3 Hz for the composite with 1.2 phr (parts per hundred of rubber) MXene and 3.2 phr Ag, while the loss tangent remained below 0.012. This can be attributed to the synergistic effects of the hybrid fillers where the 0D Ag nanoparticles effectively suppress the agglomeration of 2D MXene nanosheets, while the heterogeneous interfaces between MXene/Ag and FSR significantly enhance interfacial polarization. Furthermore, the FSR/MXene/Ag composites not only show improved tensile strength and elongation at break with decreased elastic modulus, but also exhibit enhanced electromechanical sensitivity, achieving a large electromechanical strain of 16.05% (205% increment of pure FSR) under an electric field of 40 kV mm −1 . This work provides a feasible strategy for designing dielectric elastomers with enhanced electromechanical performances.