Study on the Actuation Properties of Polyurethane Fiber Membranes Filled with PEG-SWNTs Dielectric Microcapsules.

Polyurethane dielectric elastomer (PUDE), a typical representative of emerging intelligent materials, has advantages, such as good elasticity and flexibility, fast response speed, high electromechanical conversion efficiency, and strong environmental tolerance. It has promising applications in underwater bionic actuators, but its electromechanical properties should be improved further. In this context, the design of polyethylene glycol (PEG) single-walled carbon nanotube (SWNTs) dielectric microcapsules was adopted to balance the problem of contradictions, which conventional dielectric modification methods face between comprehensive properties (e.g., dielectric properties and modulus). Moreover, the dielectric microcapsule was evenly filled into the polyurethane fiber by coaxial spinning technology to enhance the actuation performance and instability of the electrical breakdown threshold of conventional polyurethane dielectric modification. It was revealed that the dielectric microcapsules were oriented in the polyurethane fiber, and the actuation performance of the composite fiber membrane was significantly better than that of the polyurethane fiber membrane filled with SWNTs, thus confirming that the filling design of the dielectric microcapsules in polyurethane fiber could have certain technical advantages. On that basis, this study provides a novel idea for the dielectric modification of polyurethane.