Maximizing charge transfer efficiency in droplet-driven IDE-TENGs via top electrode engineering

The droplet-based triboelectric nanogenerator (TENG) has attracted widespread attention in the field of energy harvesting due to its simple structure, low cost, and excellent environmental friendliness. By utilizing triboelectric and contact electrification effects, it efficiently converts the kinetic energy of droplets into electrical energy, offering a new technological pathway for the development of sustainable miniature energy systems. To enhance its electrical output performance, this study introduces a dual-layer electrode structure and investigates the impact of the width, number, and position of the top electrode on the electrical output of the interdigital electrode-based triboelectric nanogenerator (IDE-based TENG). The results show that while the width and number of the top electrodes have minimal effect on the output, the optimal position of the top electrode significantly boosts current generation, particularly when the droplet reaches its maximum spread and makes contact with the top electrode, achieving the highest current output. By optimizing the design of the top electrode, charge separation efficiency and charge transfer pathways are improved, leading to maximum increases in short-circuit current (ISC), open-circuit voltage (VOC) and charge amount by 4.2, 1.2 and 2.1 times, respectively. This study offers a theoretical foundation and design guidance for optimizing IDE-based TENG electrical output performance and provides valuable insights for enhancing the performance of droplet energy harvesters and other energy collection devices. Additionally, the optimized design presents new solutions for practical applications in fields like smart homes, environmental monitoring, and green energy technologies, with particular promise in rain droplet detection and automatic window control.