Development of Helical circular coils for wireless through-metal inductive power transfer

We present the design and fabrication of Helical circular coils for an inductive power transfer (IPT) system through a sealed metal container. By co-axially aligning a pair of the Helical coils, the wireless IPT channel is formed for energy transfer without any physical penetrations. Power measurement results demonstrate that the helical coil-IPT system achieves a measured power efïîciency of ~4 % that is eight times better than conventional IPT system using solenoid circular coils.