Gear Train Triboelectric Nanogenerator (TENG) System for Enhancing Power Conversion Efficiency (PCE)

Abstract

Triboelectric nanogenerators (TENGs) have great potential to produce electrical energy by harvesting environmental energy from air flow, wind, waves, vibrations and even human motion. Many studies for developing high performance TENGs have been performed and are still on-going. The surface morphology plays a significant role in enhancing output power. Therefore, many studies have focused on the design and synthesis of novel materials to improve the performance of TENGs. Previously, high output power from TENGs has been achieved using high-speed rotating systems, multi-stack systems, and sliding systems. In those TENG systems, high output power was achieved if a high input energy was captured via high contact frequencies or high contact loads. However, it is difficult to constantly supply high energy because the environmental energy depends on region, weather, population and other factors. Furthermore, obtaining high output power based on high input energy can result in low power conversion efficiency (PCE), which is defined as the ratio of output energy to input energy. Therefore, our goal is to improve the output energy using the same materials and the same input energy to provide a high PCE for future TENG systems. In this study, we report such a gear-based kinematic design for a TENG system to enhance output energy at a given input energy. We connect a small gear (i.e., a working gear, r w) with a moving TENG element, and the working gear meshes with a larger gear (i.e., an input gear, r in), which is connected to an input source. The frequency of the working gear increases beyond the frequency of the input gear by controlling the gear ratio (r in/r w), thus providing enhanced output energy from our TENG system. Finally, we demonstrate the enhanced performance of our gear-based TENG system through the behaviors of capacitor charging. Our results may offer an effective design for TENG systems to generate enhanced PCE for traditional TENGs. Figure 1