Hybrid multi-mode magneto-mechano-electric generator with enhanced magnetic field energy harvesting performance

Magneto-mechano-electric (MME) generator converts magnetic energy into electrical energy via mechanical strain/stress mediated magnetoelectric coupling effect. However, the narrow operating bandwidth and low power density need to be improved for practical applications. In this work, by developing the constitutive equation of MME structure, we propose a hybrid multi-mode MME device with broadened bandwidth and enhanced energy harvesting performance. The designed hybrid generator includes three power generation units, which are piezoelectric energy harvesting (PEH) unit, electromagnetic energy harvesting (EEH) unit, and magnetostrictive energy harvesting (MEH) unit. Moreover, the corresponding energy harvesting management circuit is designed for these three different power generation units to achieve the maximum harvest of magnetic field energy. At the magnetic field of 5.57 Oe, the maximum output power of the three generating units are 0.71 mW (PEH), 1.694 mW (EEH), and 0.27 mW (MEH), respectively. It is experimentally revealed that the proposed hybrid generator can provide a stable power for temperature and humidity sensors integrated with Bluetooth wireless communication technology by harvesting stray magnetic field energy, and has the potential to power wireless sensors.