A free-floating structure triboelectric nanogenerator based on natural wool ball for offshore wind turbine environmental monitoring

Abstract

The marine distributed wireless sensor network system can promote the development of offshore wind turbine environmental monitoring. However, traditional ocean sensors and large power generation equipment are hard to meet the requirements of distributed sensor networks. Hence, we proposed a free-floating structure triboelectric nanogenerator (FF-TENG) based on the all-in-one ocean energy harvesting and sensing device concept for offshore wind turbine environmental monitoring. The FF-TENG device follows the integrated structure design of the sphere and floating body, which brings high wave energy capture efficiency and high wave sensing sensitivity. In this design, the wool ball plays the role of the triboelectric material owning to excellent positive triboelectricity. And the lightweight characteristic of the wool ball endows the FF-TENG device with fine wave-following properties in the ocean environment. In rolling working mode, when the motion amplitude and frequency are 5 cm and 4.5 Hz, the instantaneous open-circuit voltage (Voc) and short-circuit current (Isc) of a single FF-TENG can arrive at 462 V and 15.5 μA, respectively. The transferred charge (Qsc) of a single FF-TENG can reach 107 nC. According to the results, the FF-TENG device can achieve a 4.26 times energy harvesting effect compared with nine-independent spherical TENG. Moreover, the Isc of FF-TENG represents a nicely linear relationship with the swing angle (minimum frequency: 0.2 Hz), which indicates that the FF-TENG can monitor the change of wave frequency and amplitude. This research provides a new path for all-in-one ocean energy harvesting and sensing device in offshore wind turbine environmental monitoring.