The Electromagnetic Vibration Energy Harvesters Utilize Dual-Mass Pendulums for Multidirectional Harvesting

While vibration harvesting shows promise for powering sensors, effectively harvesting low-frequency, multidirectional ambient vibrations remains challenging. This article presents a novel electromagnetic vibration energy harvesting device (EVEHD) with three key innovations: a dual-mode mass-pendulum configuration-dual-mass coupling (series mode) amplifies induced voltage, and dual-mass uncoupled (parallel) mode enables multifrequency harvesting-spring-position-based frequency tuning (4.5-16.7 Hz in series mode; dual-band 3.7-9.3/5-13.3 Hz in parallel mode), and an optimized energy conversion structure, boosting output by 85.2%. The findings were validated through theoretical modeling, FEM simulations, and shaker tests, the EVEHD generating a maximum voltage of 2 V and a power of 769.2 mW under a base excitation amplitude of 0.5 g at 16.7 Hz. This work reveals the potential of this multidirectional EVEHD for power generation and application in self-powered systems.