Dual-shaft counter-rotating triboelectric nanogenerator for efficient wind energy harvesting

Wind-driven triboelectric nanogenerators (TENGs) exhibit strong potential for sustainable and distributed energy harvesting; however, they are still limited by critical barriers, including structural complexity, low efficiency under weak winds, and instability in fluctuating airflows. In this study, we introduce a dual-shaft counter-rotating TENG (CR-TENG) that achieves breakthroughs in both performance and practicality. By employing two Savonius–Bach rotors rotating in opposite directions, the CR-TENG maximizes the relative angular velocity while dynamically canceling the lateral aerodynamic forces, thereby delivering exceptional output enhancement and mechanical stability. A direct dual-electrode wiring scheme eliminates sliding contacts, providing reliable signal extraction and long-term durability. Comparisons with single-rotor and stator–rotor devices reveal striking improvements: at 3 m/s, the CR-TENG generates 77 % higher voltage and 145 % higher current, and its frequency advantage increases further at higher wind speeds. A systematic evaluation of contact versus non-contact operating modes identifies the non-contact configuration as providing the optimal balance of output stability, efficiency, and operational range. Real-world demonstrations underscore the practical impact of this design, including stable powering of LED arrays, wireless environmental sensors, and commercial electronics such as digital wristwatches and hygrometers. Collectively, these results position the dual-shaft CR-TENG as a scalable and sustainable solution with broad potential for self-powered Internet of Things, smart sensing, and future distributed energy systems.