Rolled Soft Actuators Based on P(VDF-TrFE-CTFE) Electrospun Nanofibers

Abstract

This study presents a novel rolled dielectric elastomer actuator, based on Poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene), i.e., P(VDF-TrFE-CTFE), nanofibers that are fabricated by means of an electrospinning process. The soft actuator is realized by rolling a mat of two active layers, interleaved with two electrodes. The active layers are mats of P(VDF-TrFE-CTFE)-based nanofibers, embedded in an elastomeric matrix of polydimethylsiloxane (PDMS). The electrodes are made of a mixture of carbon black and PDMS, bonded to the active layers by electrostatic adhesion force. The effects of the nanofibers in the soft actuators are investigated. Specimens of the soft actuator are realized that differ in the thickness of the nanofibrous mats used for the active layers, that is, 60 and 120 μm. An electromechanical characterization is performed to analyze and measure the axial force and axial displacements of the soft actuators when different electric fields are applied to the specimens in the transversal direction. The experimental results show that the presence of P(VDF-TrFE-CTFE)-based nanofibers enhances the force-to-weight ratio of the soft actuators by up to 43.5%, and the energy density by up to 12.9%, compared to a control specimen with the active layer made of PDMS only.