Multi‐Domain Energy Harvesting with Mode‐Dependent Magneto‐Mechano‐Electric Coupling

ABSTRACT Magnetic field energy harvesting based on the magneto‐mechano‐electric (MME) principle offers a promising approach for realizing self‐powered Internet of Things systems. However, the magnetic fields in daily environments are stray and weak (<0.1 mT), greatly limiting the output power and practicality of conventional MME harvesters. Given the frequent coexistence of distinct‐frequency magnetic field and vibration excitations in real‐world scenarios, there is an urgent need for a compact and designable dual‐mode harvester to unlock performance limits. Here, we present a mode‐split MME harvester that leverages the first symmetric and second antisymmetric bending modes to most efficiently capture vibration and magnetic field, respectively. Mode‐dependent internal couplings are integrated, where dual magnetic coupling enhances the magnetic field harvesting power density by 292%, and multi‐stage internal resonance provides a 19‐fold gain for vibration harvesting. The integration of the synchronous electric charge extraction technique further boosts the actual charging power by 493%, achieving a system‐level charging power density of 36.59 mW/cm 3 /mT 2 . Finally, a wireless self‐powered sensing system is developed and deployed in a representative trackside dual‐excitation scenario. Dual‐mode synergy shortens the cold start time by 56% and sensing interval by 50%. This work demonstrates a promising solution for efficient multisource energy harvesting in practical field deployments.