Smart electric elastomer based on electronic and ionic operational mechanism

Electric elastomer, a type of an artificial muscle, have been extensively investigated in the last decade. These responsive materials are broadly classified as electronic or ionic according to its operational mechanism. In this report, our group's results are summary. In the ionic group, two kinds of nature polyelectrolyte hydrogels, gelatin hydrogel and gelatin/alginate semi-interpenetrating polymer network membranes, were prepared. It is found that in a neutral NaCl solution, the hydrogels bend toward the cathode under a non-contact DC electric fields. Under a cyclically varying electric field, the hydrogels exhibit a good reversible bending behavior. In addtion, an electric-stimulus-response of the gelatin hydrogel in the medium of silicone oil was also explored. In the electronic group, based on Gelatin and silicone rubber as the matrix, two types of electric elastomers, Barium Titanate/Gelatin and starch/gelatin/glycerin composite Hydrogel Elastomers, were prepared without and with a curing electric field, respectively. The results suggest that the particles were aligned in the matrix under an curing DC electric field. It is suggested that their mechanical property is controlled by an applied electric field and the weight fraction of particles. On the other hand, two types of starch/ silicone oil /silicone rubber electric elastomers were also prepared in the absence and presence of a curing electric field, respectively. Silicone oil reduces the viscosity of the silicone rubber prepolymer, and then the electric field-induced storage modulus becomes larger. Furthermore, a transformer oil keeping a liquid phase in the whole curing process was added, and starch/ transformer oil drop/silicone rubber hybrid elastomer was prepare. The larger storage modulus sensitivity was obtained. Smart electric elastomer will be extensively applied in artificial muscles and electric actuators.