Advanced modular rotary triboelectric nanogenerator: Pushing boundaries in peak power density and impedance reduction

Given the advantages of rotary motion over linear motion in various aspects, rotary triboelectric nanogenerators (TENGs) can accommodate a wider range of applications than their linear counterparts. However, the practical applications of rotary TENGs face several challenges, among which exceptionally high output impedance, low current/charge transfer, and a lack of efficient modular design are the most prominent. To tackle these issues, we propose a novel modular rotary TENG that achieves an ultra-high peak power density of 293 kW/m² and an ultra-low output impedance of 39 Ω, surpassing all previously reported rotary TENGs. Additionally, it demonstrates excellent power capacity multiplication by adding more modules, enabling rotary TENGs to meet various power requirements. This work unveils the electromechanical properties of the TENG and demonstrates that, although the wear of triboelectric films leads to some performance reduction, the settled peak power density remains record-breaking. Finally, its performance is validated by powering a thermo-hygrometer and several watt-scale LEDs, highlighting its readiness for practical applications.