Ionic Liquid/Polyurethane/PEDOT: PSS Composite Actuators

Abstract

The transparent ionic liquid/polyurethane (IL/PU) gels were synthesized by addition reaction of polyol and diisocyanate in the presence of 1-ethyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide. With increasing the IL content from 0 to 40 wt%, both ionic conductivity and electric-double-layer capacitance increased from 3.1×10-5 S/cm and 9.6 pF/cm2 to 8.8×10-5 S/cm and 277 pF/cm2, respectively, while the compression modulus slightly decreased from 0.49 to 0.44 MPa. The IL/PU/PEDOT:PSS composites were fabricated by sandwiching the IL/PU gel between two conductive polymer films made of poly (3, 4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) as soft and flexible electrodes. Upon application of an electric field, the IL/PU/ PEDOT:PSS composite showed quick and intensive bending toward anode, where the bending displacement attained 3.8 mm at IL=40 wt% and 2 V, corresponding to the strain of 0.32 %.