A Permanent-Magnet Linear Motion Driven Kinetic Energy Harvester

This manuscript presents a double-sided flat-type permanent magnetic linear energy harvester to scavenge kinetic power from linear motions. The dynamic system model of the linear generator is analytically driven and analyzed by an innovative state-based approach. The analytical equations on maximum power generation specific for non-resonant applications such as human foot motion are derived. Both magnetic circuit analysis and the finite-element analysis simulation are carried out on the linear machine to investigate its performance. Under the typical horizontal foot motion velocity of 4.5 m/s, the proposed energy harvester generates 674 mW electric power with the power density as high as 3.4 mW/cm3. A macro-scale proof-of-concept machine is prototyped to verify the performance of the linear machine and validate the analysis, simulation, and the proposed modeling approach.