A novel high-power density, low-frequency electromagnetic vibration energy harvester based on anti-phase motion. (15th June 2021) - Foong, Faruq Muhammad
Graphical abstract: Highlights: A novel harvester that achieves anti-phase vibration at any frequency. Achieved a power output and power density of 417.8 mW and 765.3 Wm −3 in experiment. Experiment results are comparable or better than recent published works. A 1.0% decrease in friction can increase the power output by 98.7 mW. A theoretical power density of 1708.5 Wm −3 can be achieved after optimisation. Abstract: The paper proposes a novel electromagnetic vibration energy harvester based on the concept of anti-phase vibration. Anti-phase motion is desirable in electromagnetic vibration energy harvesting applications as it results in a higher power output due to the increase in the relative velocity between the coil and the magnet components. The proposed device achieves anti-phase motion at any driving frequency due to a developed new design. The harvester was experimentally tested under a base input of 0.49 g, 0.38 g and 0.36 g, recording a power density of 765.3 Wm −3, 420.8 Wm −3 and 587.2 Wm −3 respectively under a resonant frequency of 11.8 Hz. Although the device has not yet been optimised, these values obtained are already comparable, if not higher than the recent previous works on vibration energy harvesting. In addition, the observed experimental results have well agreed with the results obtained through the mathematical model, derived in this study. The original design was then optimised to determine the optimum load resistance, mechanical arm length and component dimensions that would result in the maximum power output. Considering a base input of 0.36 g and the same friction and damping forces as obtained from the experiment, a power density of 1708.5 Wm −3 could theoretically be achieved under the same natural frequency.