The Breakdown and Self‐Clearing Performance During the Energy Harvesting Process of Dielectric Elastomer Generators Using Single‐Walled Carbon Nanotubes Electrodes

ABSTRACT For dielectric elastomer generators (DEG), electrical breakdown is the main failure mode during their working cycle. The application of self‐clearing electrodes is of great significance to avoid a single breakdown leading to the failure of the entire generator. Electrodes based on single‐walled carbon nanotubes (SWCNT) have proven to have excellent self‐clearing performance and thus are suitable for elastomers. Similar to metal electrodes, Joule heating generated during the breakdown process is used to self‐combust, forming nonconductive regions at the defect location. Because breakdown is a prerequisite for self‐clearing, it is necessary to understand how the dielectric strength of the DEG changes during a working cycle. Therefore, this article investigates the changes in breakdown characteristics and self‐clearing during the dynamic process of the DEG working cycle. The breakdown field strength of the DEG was tested, and it was found that the prominent cause of failure after introducing SWCNT electrodes was buckling instability and uneven deformation due to electrode nonuniformity. A detailed study of the self‐clearing process was conducted. A good self‐clearing performance of SWCNT electrodes during the DEG power generation cycle is related to the energy supplied by the parallel capacitance in the system. To investigate the influence of the parallel capacitance on self‐clearing and to better design the total capacitance in the real DEG device, the energy required for self‐clearing was analysed and clarified. This study provides an experimental basis for the development of reliable DEG devices.