Magnetoelectric Wireless Power Transfer System for Biomedical Implants

This work presents the design and analysis of magnetoelectric (ME) transducer based wireless power transfer (WPT) system incorporating a suitable interface power management circuit (PMC). ME transducers provide effective means to design high-efficiency power transfer to medical implantable devices at low frequencies addressing the trade-off between size miniaturization, lower skin attenuation and higher power transfer. A tri-layered ME laminated transducer operating at 50kHz is designed and fabricated to study the source characteristics. The proposed ME WPT device produces 2.4V output voltage and 1.75mW output power across a load of 3kΩ when the input magnetic field is 2.5mT. A novel PMC design based on Dickson Charge Pump followed by peak detector, buck regulator, and synchronous electric charge extraction (SECE) switching technique is considered which is implemented using low-cost, off-the-shelf components on PCB. The proposed circuit is characterized by very low current consumption and is specifically designed for operating at an input voltage ranging between 350mV to 15V, which provides a significant flexibility in terms of transducer design specifically towards high efficiency WPT systems.