Vibration Energy Harvester Based on Torsionally Oscillating Magnet

Most of the miniaturized electromagnetic vibrational energy harvesters (EVEHs) are based on oscillating proof mass suspended by several springs or a cantilever structure. Such structural feature limits the miniaturization of the device's footprint. This paper presents an EVEH device based on a torsional vibrating magnet over a stack of flexible planar coils. The torsional movement of the magnet is enabled by microfabricated silicon torsional springs, which effectively reduce the footprint of the device. With a size of 1 cm x 1 cm x 1.08 cm, the proposed EVEH is capable of generating an open-circuit peak-to-peak voltage of 169 mV and a power of 6.9 mu W, under a sinusoidal excitation of +/- 0.5 g (g = 9.8 m/s(2)) and frequency of 96 Hz. At elevated acceleration levels, the maximum peak-to-peak output voltage is 222 mV under the acceleration of 7 g (+/- 3.5 g).

Automated summary

This paper presents a novel miniaturized electromagnetic vibrational energy harvester based on a torsional vibrating magnet, with microfabricated silicon torsional springs effectively reducing the device's footprint. The proposed EVEH is capable of generating stable output voltage and power under various conditions, showing promise for energy harvesting applications in small-scale systems.