Figures-of-Merit for Rolling-Friction-Based Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) have emerged as a highly effective and easily scalable technology for harvesting mechanical energy. Recently, standards and figure-of-merits have been defined to quantify the performance of TENGs. In this work, the figure-of-merits of rolling-friction-based TENGs are investigated through a theoretical model based on the rolling freestanding mode, including the conductor-to-dielectric and dielectric-to-dielectric cases. By combining finite-element simulations and semi-analytical derivations, the basic properties and resistive load output characteristics of rolling TENGs are calculated for various structural parameters, such as the electrode gap or rod diameter. The average output power is optimized by maximizing the structural figure-of-merit, which depends on the structural parameters. The results gained in this work could provide useful guidance for optimizing the performance of rolling-friction-based TENGs toward practical self-powered systems.