High-performance cellulose nanofibers, single-walled carbon nanotubes and ionic liquid actuators with a poly(vinylidene fluoride-co-hexafluoropropylene)/ionic liquid gel electrolyte layer

This study describes new actuators with cellulose nanofibers, single-walled carbon nanotubes and ionic liquids (CNFs/SWCNTs/ILs) and examines the electrochemical and electromechanical properties of CNF/SWCNT/IL gel hybrid actuators. Further, the effects of the CNF species present on the electrode and the electrolyte layer species of poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF(HFP)) or CNF/IL on the electrochemical and electromechanical properties of the low-voltage electroactive polymer actuators are investigated. The CNF/SWCNT/IL structure revealed a network of highly entangled CNFs and SWCNTs. The results indicated that the CNF/SWCNT/IL electrodes and the PVdF(HFP)/IL electrolyte actuators can significantly outperform the CNF/SWCNT/IL electrodes and the CNF/IL electrolyte actuators. PVdF(HFP) was considered to be a better polymer electrolyte than CNF. Further, the frequency dependences of the displacement responses of these CNF/SWCNT/IL electrode actuators were successfully simulated using a double-layered charging kinetic model. The equivalent circuit models exhibited by the PVdF(HFP)/IL electrolyte actuators are different when compared to those exhibited by the CNF/IL electrolyte actuators. Based on the results of this study, the CNF/SWCNT/IL electrodes and the PVdF(HFP)/IL electrolyte actuators are promising for application as electrochemical materials that are useful in real-world applications, including wearable and energy-conversion devices.