Influence of structural design and electrode configuration on the electrical performance and reliability of polytetrafluoroethylene-based water drop triboelectric nanogenerators

The growing environmental concerns associated with conventional fuel-based energy generation have increased the demand for sustainable and green energy solutions. Among these, nanogenerators have emerged as a promising alternative due to their ability to harvest energy from diverse sources, including light, heat, wind, and temperature variations. This study focuses on the development of a triboelectric nanogenerator (TENG) that utilizes water droplets as the primary energy source. The device generates energy through the interaction between water droplets and the TENG surface, enabling efficient conversion via the triboelectric effect. The objective of this work is to investigate the influence of critical device parameters, including electrode configuration and design, electrode material, electrode size, and the thickness of the polytetrafluoroethylene (PTFE) substrate, on the overall electrical performance. The results reveal that an Al–Cu asymmetric electrode in a sandwich configuration, combined with a 1 mm PTFE thickness and a 2 mm electrode size, achieves the best performance with an average voltage of 8.81 V, current of 11.6 µA, and power of 1.68 µW. Furthermore, the device exhibited good reliability, maintaining stable electrical output for over two hours of continuous droplet impact, which highlights its potential for long-term operation. This study demonstrates that device configuration and structural design directly control charge transfer efficiency and electric field strength, thereby governing the overall energy output. The findings provide valuable insights into water droplet-based TENG design and establish a simple, low-cost, and scalable strategy for developing high-performance devices for sustainable energy harvesting and environmental applications.