Integrated Bending Actuation and the Self-Sensing Capability of Poly(Vinyl Chloride) Gels with Ionic Liquids

Soft actuation materials often only perform an actuation function, and do not achieve the function of self-sensing. In this work, the polyvinyl chloride (PVC) gels are prepared with a plasticizer of dibutyl adipate (DBA) and small amount of imidazolium type ionic liquids (ILs), and are demonstrated that the PVC/DBA/ILs gels deliver the integrated bending actuation and capacitance pressure self-sensing capability. The bending actuation performances and sensing behavior of PVC/DBA/ILs are related to the migrability of movable ions from ILs, which are dependent on the dissociation of anions and cations of ILs, and the concentration of ILs. Among the ILs, the PVC/DBA gel with 3.3 wt% 1-allyl-3-methylimidazolium bis ((trifluoromethyl)sulphonyl) imide (P/[AMIM]NTF2 (3.3 wt%)) exhibits best bending displacement of 6.6 mm (corresponding to 24 degrees of bending angle) at 7.2 kV (180 V mm(-1) of nominal electric field). In addition, the P/[AMIM]NTF2 (3.3 wt%) exhibits 0.42 kPa(-1) capacitance pressure sensitive in the pressure range 0 to 2.2 kPa, and a sudden change in capacitance in the pressure range 2.2-2.7 kPa with 47.5 kPa(-1) of sensitivity. The results can provide a new idea for developing integrated sensing and actuation functions of electroactive dielectric polymer gels.