A Self-Clearing Electrode Concept for Dielectric Elastomer Applications Using Single-Wall Carbon Nanotubes Line

Abstract

For the electronic components made of electroactive polymer (EAP) materials, a breakdown between the compliant electrodes is the main cause of failure. Similar to high-voltage capacitors, a self-clearing mechanism is needed to minimize the probability of a single defect leading to complete failure. In order to meet compliance and self-clearing needs, single-wall carbon nanotube (SWCNT) films are widely used. However, the complex and expensive process of manufacturing of large-area SWCNT film hinders its application in industry. To reduce the usage of SWCNT while maintaining self-clearing properties, a novel stretchable and self-clearing electrode configuration is proposed in this article, using a patterned electrode consisting of carbon black (CB) connected by SWCNT line. A criterion was established for a successful self-clearing process of the SWCNT line electrode. Some key factors affecting the self-clearing properties were investigated. It was found that high breakdown voltage and thin and narrow SWCNT line electrodes are beneficial to the self-clearing success rate. Besides the self-clearing properties, the effect of the size and number of the CB patterns on capacitance retention was studied. After a self-clearing event, part of the active area of the dielectric is lost. The objective is to maximize capacitance retention after a self-clearing event, which was analyzed experimentally and theoretically. Finally, it is suggested how to select the number and area of the patterned CB, making optimal use of the electrode area. This study provides a theoretical and experimental basis for further mass production of carbon-based self-clearing electrodes.