A study on the performance of a novel hybrid triboelectric-dielectric elastomer generator based on PDMS composites

Dielectric elastomer generators (DEGs) have been developed to harvest mechanical energy from various sources, such as human motion, water and wind. In particular, DEGs possess potential in wearable applications since they are light, flexible, and have high energy density. However, the requirement of an external circuit with high bias voltage that is used to polarize the dielectric elastomer limits their applications. On the other hand, triboelectric devices gained particular attention in the area of wearable electronics recently due to their good flexibility, portability and cost effectiveness. In addition, triboelectric devices can generate relatively high voltage, which could potentially polarize the dielectric elastomer in the DEG. In this study, a novel hybrid triboelectric-DEG structure is proposed to take advantage of the positive attributes of both. The triboelectric device part of the triboelectric-DEG, which is composed of a single-wall carbon nanotube (SWCNT)-ionic liquid (IL)-PDMS composite and a Teflon film, was fabricated and tested experimentally. The SWCNT-IL-PDMS composite is flexible and its electrical conductivity is high enough to transfer charges without an electrode, which makes the novel hybrid triboelectric-DEG a completely soft and independent energy harvester. The open-circuit voltage of the triboelectric device part reached to 114V, which is high enough to prime a DEG in a self-priming circuit configuration. Based on the experimental results of the triboelectric device part, the configuration and connection of the novel triboelectric-DEG were designed and the energy density was predicted. The resulting triboelectric-DEG can offset the shortcoming of conventional DEGs and greatly increase the feasibility of such device in wearable and mobile applications, to make polymer-based self-powered wearables a reality.