Human-powered inertial energy harvesters: the effect of orientation, location and activity on obtainable power

Inertial energy harvesting is an emerging technology that can power electronic devices using energy scavenged from the motion of the human body. Owing to the relatively low frequencies associated with body motion (<3 Hz), the generated electrical power is typically in the range of a few μW; hence transduction must be optimized. Previous studies have investigated the effect of activity and harvester location on the obtained power; this work evaluates how power is also affected by the harvester’s orientation. Ten participants performed walking and running exercises, while tri-axial acceleration data were sampled at five locations on the body. The results show consistency in the optimal orientation of the harvester between people, but this orientation is not aligned with the axes of the body and limbs. During walking, the power harvested from the upper and lower body differs by an order of magnitude; however, this difference is less significant when running. © 2011 Published by Elsevier Ltd.