Design and Development of an Electromagnetic Micropower Generator for Activity Tracking

This paper goes through the process of designing an electromagnetic Micropower Generator (MPG) to be used for human activity tracking. Finite Element Method (FEM) was employed to simulate the MPG and calculate the power output under different excitations. The MPG was fabricated, tested, and the results compared to the implemented FEM simulations. Good agreement is observed between the two sets of results. The MPG generated 7.7 mW of power under a load of $220\ {\Omega}$ at a natural frequency of 8.9 Hz and acceleration level of 0.24g. The natural frequency is further reduced to 7.2 Hz by removing the top fixed magnet. This achieved higher levels of power output reaching 12 mW at resonance.