Novel electroactive PVA-TOCN actuator that is extremely sensitive to low electrical inputs

Abstract

A novel electroactive biopolymer actuator was developed based on a cross-linked ionic networking membrane of TEMPO-oxidized bacterial cellulose nanofibers (TOCNs) and polyvinyl alcohol (PVA). Ionic liquids were added to develop an air-working artificial muscle and to enhance the performance of the PVA-TOCN actuator. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) conducting layers were deposited on the top and bottom surfaces of the PVA-TOCN membrane via a simple dipping and drying method. The electroactive PVA-TOCN actuator under both step and harmonic electrical inputs shows much larger tip displacements and faster bending deformation than the pure TOCN actuator. The cross-linking reaction between PVA and TOCN was observed in the Fourier transform-near-infrared (FT-IR) spectrum of the PVA-TOCN networking membrane. Scanning electron microscopy (SEM), x-ray diffusion (XRD), thermogravimetric analysis (TGA) and tensile and ion conductivity testing results for the PVA-TOCN membrane were compared with those of pristine TOCN. Most important, the PVA-TOCN actuator shows much larger bending deformation under even extremely low input voltages, and this could be attributed to the cross-linking mechanism and the greater flexibility resulting from the synergistic effects between PVA and TOCN.