A Multi-Pole Magnetic Generator with Enhanced Voltage Output for Low-Frequency Vibrational Energy Harvesting

This paper presents a vibrational energy harvesting approach using an array of alternating magnetic poles to enable frequency up-conversion and high-amplitude voltage output under low-frequency mechanical excitation. This approach is intended to overcome the low voltages typically found in magnetically-based energy harvesters. A mesoscale (4.6 x 5.4 x 1.5 cm3) prototype device was tested under low frequency (< 15Hz) excitation to mimic human-induced motions. At an excitation of 0.8 g at 9.25 Hz, an electrical frequency quadrupling was achieved along with a nonlinear voltage boost up to 2 Vpk (0.87 Vrms). These results demonstrate the potential for voltage enhancement using multi-pole magnetic generators.