Effects of large bending deformation on the electromechanical performance of a soft capacitor

Abstract

Many capacitive devices based on flexible materials with low Young’s modulus have great potential for sensing or energy storage, and the study of their performance changes under large deformations is of great significance for their application prospects. In this study, a bendable soft capacitor was prepared and its capacitive response was found to be extraordinarily stable under large bending deformations. Our experiments and simulations showed that the capacitance change was less than 3% when the bending strain varied from 16% to 40%, showing stable capacitance retention. We also developed a theoretical model to explain the mechanism of the effect of geometric changes on the capacitance of soft capacitors subjected to large bending deformation. Our work provides new ideas for addressing the high nonlinearity and weak repeatability present in bending devices of elastomers. The stable soft capacitor can be harnessed to design supercapacitors in wearable devices and wireless micro-robots.