Swinging electromagnetic power generation device based on arm swing

Due to the rapid growth of wearable devices, including quartz watches, there is a great demand for environmentally friendly and wearable power sources. This work successfully designed an electromagnetic energy collector based on the natural swing of the arm, which is used to collect the energy generated by human movement. The energy collector refers to the brachistocentre problem in the structural design to provide the maximum descent velocity of the spherical magnet along the curved path, thereby increasing the cutting rate of the spherical magnet on the magnetic flux. This paper uses the finite element analysis method to investigate and confirm the energy harvester. The overall structure is simple and has effective scalability. The best output performance can be obtained by selecting the optimal combination of the thickness and width of the coil. The simulation data indicate that the energy harvester can operate under low-frequency motion with an excitation frequency of not more than 5 Hz. At an excitation frequency of 5Hz, the maximum peak power of the energy harvester is 93.98mW and the average power output is 5.34 mW. At the same time, a simplified kinetic model based on liquid density is constructed, revealing the enhancement mechanism of a high-density liquid medium for boosting the acceleration of spherical magnets, which increases the power generation efficiency of coils and has the potential to power wearable devices.