Evaluation of energy harvesting performance of electrostrictive polymer and carbon-filled terpolymer composites

Abstract

Recent trends in energy conversion mechanisms have demonstrated the abilities of electrostrictive polymers for converting mechanical vibrations into electricity. In particular, such materials present advantageous features such as high productivity, high flexibility, and processability. Hence, the application of these materials for energy harvesting purposes has been of significant interest over the last few years. The purpose of this paper consists in evaluating the energy scavenging abilities of electrostrictive terpolymer composite filled with 1 vol % carbon black poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene). For fair comparison, a new figure of merit taking into account the intrinsic parameters of the material is introduced. This figure of merit equals the squared product of the electric field-related electrostrictive coefficient by the Young modulus, divided by the permittivity, relating the electric energy density per cycle per squared strain magnitude and squared bias electric field. Based on this criterion, it is demonstrated that the carbon-filled terpolymer outperforms other investigated compositions, exhibiting a figure of merit as high as 30 mJ cm−3 (m/m)−2 (V/μm)−2 cycle−1, which is 2000 times higher than pure polyurethane. In addition, the comparison of the figure of merit with experimental maximal harvested powers shows that such a criterion allows a very accurate prediction of the energy scavenging performance of electrostrictive composites.