High Power Density Levitation-Induced Vibration Energy Harvester

We report a levitation-induced vibration energy harvester based on a double-repulsion configuration in the moving magnet composite. Computational modeling clearly illustrated the advantages of the double-repulsion configuration over the single-repulsion and no-repulsion configurations. Double-repulsion configuration provided the best dynamics (displacement and velocity) and output response (voltage). Based on the modeling results, an AA battery-sized harvester with the double-repulsion configuration was fabricated. The harvester exhibited high power response at low frequencies (12.9 mW at 1g and 16 Hz) and also exhibited a high normalized power density at low excitations (15.33 mW cm-3g-2 at 0.25g and 13 Hz). The harvester was used to charge a cellphone at 4.7 V DC.