Wireless power transmission for implantable devices using inductive component of closed magnetic circuit

A mechanically flexible wireless power transmission module for implantable systems with enhanced transmission efficiency using a closed magnetic circuit (CMC) is presented. The CMC-based power transmission module consists of a primary inductor for power transmission and a secondary inductor for power reception. The CMC is fabricated by electroplating the Permalloy, composed of 81% nickel and 19% iron, on the inductors. For an open magnetic circuit (OMC), the measured power transmission efficiency was 13% when the distance between the two inductors was 5%mm. However, the efficiency was enhanced to 27% and 34% for the proposed two types of CMCs.