Buoy-Inspired Hybridized Energy Harvester with Freestanding Dielectric Oscillator Towards Sustainable Blue Energy Harvesting

Although blue energy is the most promising renewable and carbon-free energy source, the blue energy harvesting is disturbed due to the fatal problems such as low-efficiency for the ocean wave frequency, heavy weight and massive structure, and high cost. Herein, the magnetic-levitated blue energy harvesting device (ML-BEHD), which is inspired by buoy shape, is demonstrated to harvest the wave-induced blue energy with low-frequency. The ML-BEHD is composed of the magnetic-levitated triboelectric nanogenerator (ML-TENG) and the electromagnetic generator (EMG), respectively. Due to the levitated freestanding dielectric oscillator (FDO), the friction between FDO and bottom surface of the ML-BEHD is decreased. Then, the electrical output generated from the ML-TENG is increased because the mechanical energy of the FDO can be transferred to its electrode without friction-induced loss. The rectified voltage of 17 V is generated from the ML-BEHD, which is larger than the sum of the rectified voltage generated from the ML-TENG and EMG. Furthermore, with the electrical energy stored in a 4.7 mF capacitor, the electroforming process is successfully conducted without any external power source. This result indicates that the ML-BEHD can generate the high voltage and current. Considering these results, the proposed ML-BEHD is expected to be utilized as a promising sustainable energy harvester in near future because the sufficient electricity to utilize can be generated from the ML-BEHD.