Ultra-wide frequency broadening mechanism for micro-scale electromagnetic energy harvester

This work proposed a hybrid frequency broadening (HFB) mechanism in micro-scale for vibration energy harvesting with ultra-wide bandwidth. A strong HFB behavior is induced by the Duffing stiffening of the clamped-clamped beam stretching and further stimulated continuously by three distributed resonances including out-of-plane mode I at 62.9 Hz, torsion mode II at 82.1 Hz, and twist mode III at 150 Hz. At the acceleration of 1.0g, the microfabricated device with a small area of 6 × 6 mm2 is able to broaden the operating bandwidth from 62.9 Hz to be as wide as 383.7 Hz. This design methodology can be implemented for efficient electromagnetic energy harvesting.