Passive wireless marine Internet-of-Things buoy based on hybrid nanogenerator with omnidirectional water-wave energy harvesting

Efficient harvesting of any directional wave energy by the omnidirectional, anti-overturning and high-output floating water-wave energy harvesting device is the cornerstone of developing passive wireless Marine Internet-of-Things (MIoT) buoy. However, the previous researches on water wave energy collection cannot simultaneously meet the above requirements. Here, we reported a triboelectric-electromagnetic hybrid nanogenerator (OHNG), which can efficiently harvest any directional water-wave energy by the omnidirectional working mode. The performance of OHNG for capturing water-wave power was greatly improved through applying the large-mass coil and magnet of electromagnetic generator (EMG) to fabricate the tumbler and simple pendulum structure, which also endow the excellent anti-overturning performance of OHNG. Furthermore, the OHNG can obtain the floating function without the other auxiliary devices by combining with the light-weight triboelectric nanogenerator (TENG) and the output performance of OHNG was improved by optimizing the structure design of TENG and EMG. Finally, based on the OHNG, a passive wireless MIoT buoy with real-time sensing signal transmission was achieved by combining energy storage device, voltage regulator circuit, sensing and wireless signal transmission modules. Our findings provide important technical support for the efficient development of water-wave energy and the development of smart MIoT buoys.