Hybrid Magnetoelectric‐Electromagnetic Generator with Coupled Negative Stiffness for Ultra‐Low Frequency Wave Energy Harvesting

Abstract Marine intelligent sensing equipment is essential for collecting marine resources, and its development has increasingly advanced. However, increasing battery pollution necessitates an urgent search for alternative energy sources. This study proposes a novel compact magnetoelectric‐electromagnetic hybrid energy harvester (MEEM‐HEH) to enhance the low voltage characteristics of traditional electromagnetic generators (EMGs). To adapt to the low frequency characteristics of waves (< 2 Hz), a quasi‐zero stiffness mechanism is designed to address the ultra‐low frequency limitations of parallel magnet mechanisms in the hybrid generator. Additionally, a coupled negative stiffness mechanism is developed to increase the energy density of the generator. The effectiveness of the MEEM‐HEH is verified experimentally. At excitation frequencies ranging from 0.5 to 1.5 Hz, the magnetoelectric generator (MEG) achieves an output power density of 28.67 W m −3 , whereas the EMG reaches 450.19 W m −3 at 50 Ω. The maximum output power of the MEEM‐HEH is 18.05 mW. The effectiveness is also tested in a real marine environment. This work offers a potential solution for hybrid generators that target ultra‐low frequency wave energy.