Electrostrictive Fiber with High Electromechanical Properties Using a Styrene–Ethylene–Butylene–Styrene-Based Dielectric Elastomer

Dielectric elastomers (DEs) are smart materials that can transform electrical energy to mechanical energy. Compared with commonly reported two-dimensional membrane-structured DE actuators (DEAs) that can generate biaxial displacement, fiber-based DEAs are able to generate uniaxial displacement through internal contraction or relaxation forces, mimicking the working mechanism of human muscles. In this work, high-dielectric barium titanate (BTO)-encapsuled carboxylated multiwalled carbon nanotubes (MWCNTs) (BTO@MWCNTs) were prepared and incorporated into a styrene–ethylene–butylene–styrene copolymer (SEBS) to fabricate flexible hollow fiber-based DEs through coaxial wet spinning. By filling the hollow fiber with liquid metal and coating the surface with a flexible carbon grease electrode, a kind of hollow fiber-based actuator (HFDEA) was acquired. The HFDEA achieved a 19.76% actuated elongation at an excitation electric field strength of approximately 49 V/μm and exhibited reliable durability in 100 repeated actuation tests. The fabricated HFDEA has great application potential in the artificial muscle field.