Large-Volume Stable Bubble-Sliding Triboelectric Nanogenerator for High-Efficiency Low-Frequency Mechanical Energy Harvesting

Abstract

Efficiently harvesting low-frequency mechanical energy remains a pivotal challenge in renewable energy. Although droplet sliding-based liquid-solid triboelectric nanogenerators (LS-TENGs) show potential, their practical application is limited by high triggering thresholds, three-phase contact line pinning, and trail residue. Meanwhile, existing bubble-driven LS-TENGs are mostly focused on sensing, with modest energy-harvesting performance (most outputs <100 V and <1 μA) and challenges such as the splitting of large bubble and high trigger angles. Inspired by the ultra-low inclination sensitivity of bubble levels (0.1°), this work proposes a large-volume stable bubble-sliding TENG (BS-TENG). Bubbles sliding on the lower FEP film exhibit advantages of low sliding trigger angle (1.5°), larger effective contact area, and superior structural integrity during motion. Through systematic optimization of bubble volume and other key parameters, the BS-TENG achieves 1155 nC transferred charge, 670 V open-circuit voltage, 40 μA short-circuit current, and 184 μJ energy output per cycle, significantly surpassing most reported droplet- and bubble-based TENGs. Furthermore, it demonstrates excellent capacitor charging, multi-device collaboration, and practical power supply capability, providing a new strategy for high-performance LS-TENGs.