Enhanced electro-actuation in dielectric elastomers: the non-linear effect of free ions


  Bin Zheng[1]  ,  Xingkun Man[2]  ,  David Andelman[1]  ,  Masao Doi[2]  
[1] Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University
[2] Center of Soft Matter Physics and its Applications, and School of Physics and Nuclear Energy Engineering, Beihang University, China

Here, we present a simple model for the electro-activity of PVC gels, and show a non-linear effect of free ions on its dielectric behaviors. It is found that their particular deformation behavior is due to an electro-wetting effect and to a change in their interfacial tension. In addition, we derive analytical expressions for the surface tension as well as for the apparent dielectric constant of the gel. The theory indicates that the size of the mobile free ions has a crucial role in determining the electro-induced deformation, opening up the way to novel and innovative designs of electro-active gel actuators.Under electric fields of several hundred Volt/mm, PVC gels undergo large deformations. These gels can be used as artificial muscles and other soft robotic devices, with striking deformation behavior that is quite different from conventional dielectric elastomers.Plasticized poly(vinyl chloride) (PVC) is a jelly-like soft dielectric material that attracted substantial interest recently as a new type of electro-active polymers.