Deformation Measurement of Dielectric Elastomer using Slide Ring Material on a 2-D Plane

Abstract

Dielectric elastomer actuator (DEA) is a soft actuator with low manufacturing cost and high energy efficiency; it expands when an electric field is applied. The structure of DEA comprises a dielectric material interlayered with elastic electrodes similar to a sandwich. The performance of DEA is determined by the material of the dielectric layer, which is generally silicon or acrylic rubber. This study focused on investigating the characteristics and various applications of slide ring material (SRM) as a dielectric. SRM is more suitable for use as a dielectric of DEA as compared to silicone and acrylic rubbers in terms of the dielectric constant and hysteresis loss. Several measurement methods of existing DEAs measure only uniaxial deformation. However, the actual DEA strain distribution is not completely uniform. In addition, obtaining the two-dimensional (2D) strain distribution leads to a better understanding of the lifetime and performance of DEA as DEA deforms in 2D practical applications. Therefore, this study measured the strain on the DEA, while changing the load, applied voltage, and number of layers, using the image correlation method, which is a 2D planar measurement method. This measurement confirmed the two-dimensionally spreading strain distribution. The relationship between the stress, strain, and number of DEA layers was also obtained.