A Piezoelectric‐Electromagnetic Hybrid Energy Harvester With Frequency up‐Conversion for Marine Wave Detection

This study proposes a piezoelectric‐electromagnetic hybrid energy harvester with frequency up‐conversion for marine wave detection (PEEH). This harvester uses a gear set to achieve mechanical frequency up‐conversion. Within a unit time, it increases the excitation frequency of the end magnet. Theoretical and simulation analyses reveal that shortening the magnetic spacing can enhance the magnetic force experienced by the end magnet. Increasing the number of circumferential array magnets increases the excitation frequency of the end magnet. In the experiment, the effect of different magnetic spacings and the number of magnets on the output voltage is discussed. Under the optimal structural parameters, PEH1 and PEH2 generate a maximum output power of 16.152 mW. The PEEH can light 57 LEDs rated at 7.5 mW and simultaneously deliver stable electrical signals under varying wave heights and frequencies. This feature allows for wireless, real‐time wave‐height monitoring in practice by leveraging the correspondence between the output signals and wave heights. The above experiments demonstrate that PEEH possesses the capabilities of self‐powering and self‐sensing. This study introduces a novel approach for harnessing marine wave energy.