A Research Of Micro Wireless Magnetic Resonant Energy Transfer System And Its Application

Implantable medical devices have been used more widely in the field of modern medicine with the development of microelectronics technology. However, the ensuing problem about implantable device’s power supply becomes the bottleneck of the technology. As implantable devices get smaller, battery size and replacement problem will restrict the development of implantable devices. Wireless magnetic resonant energy transfer system shows more superiority in energy transfer efficiency and relative position parameters than that of inductive coupling system. It has been recognized as the best power supply method for implantable medical devices. The dimension and performance of the resonant coil is the key point that has great effect on the transfer efficiency and implantable applications.Flexible planar and roll Litz coil is designed to make a further optimization on size and efficiency of wireless energy transfer system. Wireless energy transfer system based on two and four resonant coils is build up. As the experimental results, the roll-Litz four coil system shows priority in higher transfer efficiency with smaller size comparing with planar-Litz coil system. The efficiency of four-coil transfer system based on roll-Litz coils gets48%higher than the two-coil system with1.0cm transfer distance, and10%higher than the four-coil transfer system based on planar-Litz coils with1.5cm transfer distance.A kind of dual inductor overlapping structure3D MEMS coil is proposed in this paper. The cross diagonal line structure makes higher area utilization and further improves the reliability of the coil.At last, a wireless charging system is built based on flexible3D coils. A Class-E amplifier with inverter driver is designed using power tube and used as a transmitter. Discrete components are used to set up the rectifier and regulator circuit which comprise receiver to provide a regulated output. Experimental test shows the receiver could get5V regulated output, and the mobile phone can be charging successfully.