3D-braided-electrode-based liquid-solid triboelectric nanogenerator for high-efficiency low-frequency mechanical energy harvesting and angle monitoring

As an emerging energy harvesting approach, the liquid-solid triboelectric nanogenerator (LS-TENG) has attracted extensive attention. However, the near-wall laminar flow effect of fluids limits the output performance of the LS-TENG. Herein, we proposed a braided-electrode-based LS-TENG (BLS-TENG) for mechanical energy harvesting and angle monitoring. The three-dimensional (3D) structure of the electrode effectively intensifies fluid disturbance within the tube, enabling the BLS-TENG to generate an open-circuit voltage of 44.6 V and a transferred charge of 31.3 nC at a frequency of 0.16 Hz. These values represent an enhancement by 1.84 times and 3.77 times compared to the conventional LS-TENG, respectively. Meanwhile, the influence of some critical parameters such as liquid column height (h), number of braided electrode laps, swing frequency, and angle (α) on the output performance of the BLS-TENG was systematically investigated. Furthermore, the BLS-TENG can successfully harvest mechanical energy to power microelectronic devices. And a sensing system was designed based on the BLS-TENG for angle monitoring of tilted objects. This work proposes a novel approach for efficient mechanical energy harvesting and self-powered angle monitoring.