Abstract
A spherical electromagnetic energy harvester is designed to harvest omni-directional kinetic energy. A novel spherical Halbach array is proposed, which increases the magnetic field gradient in the coil compared with the traditional permanent magnet array, to increase the output performance. The parameter optimization of the spherical structure is carried out in accordance with the analytical results of the corresponding physical model. Finite element analysis and experimental performance test are carried out on the prototype. Experimental results demonstrate that the novel transducer can harvest kinetic energy in any direction, and then transfer to electric power. When the excitation direction is horizontal with frequency of 7.5 Hz, the load resistance is 3.2 Ω, the electric power reaches its maximum value. The maximum load power of a single coil is 0.18 mW. It can meet the needs of some microelectronic devices and has the potential to take the place of chemistry batteries and supply power to wildlife monitoring and positioning systems.