Study on Stretch-dependent Permittivity of Dielectric Elastomer and Evaluation of its Power Generation Output

Dielectric elastomer (DE) can be used as a small-scale energy harvester due to its remarkable flexibility, lightweight and output power density. However, the key characteristic of DE, the permittivity, decreases when the DE is stretched. Meanwhile, the influence of the stretch-dependent permittivity on the power generation output performance of DE is unclear. In this study, the stretch-dependent permittivity and its effect on DE's power generation output were clarified. Then a DE's power generation output prediction method considering the stretch-dependent permittivity was proposed. The comparison between the measured and predicted values of power generation output, charge and voltage for the DE revealed that the stretch-dependent permittivity causes a reduction in charge during the charge-discharge cycle, leading to decreased power generation output. Therefore, it is necessary to consider the stretch-dependent permittivity for predicting the power generation output of DE.