Wireless energy transfer system based on high Q flexible planar-Litz MEMS coils

Wireless energy transfer system tends to replace the battery for the power supply of implantable prosthetic devices. Coils are the key point of the wireless transfer system and affect the transfer efficiency. In this paper, high Q flexible planar-Litz coil is designed and implemented for the wireless energy transfer system. Theoretical model of planar-Litz coil is given and the measurement result matches the theoretical analysis. The efficiency of wireless transfer system is improved by using the high Q planar-Litz coils. The experiment results show the coupling efficiency can be improved by about 40% as the transfer distance is 0.5cm. At last, resonant coils are added into transfer system to enhance the magnetic resonance, which makes the energy transfer efficiency improved greatly.