Kinetic energy harvesting from human walking and running using a magnetic levitation energy harvester

For the first time, the power output of an electromagnetic magnetic levitation vibration energy harvester was studied when placed on 10 human participants while walking and running on a treadmill from 2 mph (3.2 km/h) to up to 7 mph (11.3 km/h). The power generated from the device when participants walked at 3 mph (4.8 km/h) averaged 71 μW. When running at 6 mph, the power increased to 342 μW. The testing on participants revealed that due to unique gaits and body structure, acceleration spectrum and damping can vary significantly between participants. Taller participants had a lower step frequency and therefore lower frequency acceleration content, signifying that a single design may not be optimal for all participants. Additionally, the estimated damping force varied largely between participants, from 3 to 8 mN. To minimize the effects of damping, the paper studies the effect of angle of attachment and damping reduction techniques using low friction materials and a guide rail system, which improve power output by over 50% when compared to the sub-optimal design.