Wearable Wireless Power Transfer using Direct-Write Dispenser Printed Flexible Coils

Direct-write dispenser printing represents a simple solution to rapid flexible and printed electronics prototyping and low-volume manufacturing. This work presents the design, fabrication and evaluation of magnetic resonance wireless power transfer (WPT) coils fabricated using dispenser printing. A double-sided inductor is designed and printed on a flexible polyimide substrate using a commercial dispenser printer. The dispenser printer is used to realize the single-sided coils which are heat pressed to form double-sided inductors using a conductive epoxy via. It is demonstrated that the proposed double-sided coils achieve over 53.8% higher quality factor than a single-sided coil, and 67% higher inductance than two series-connected coils. The coils are tuned to resonate at 6.78 MHz using lumped-matching. The proposed coils achieve a peak WPT efficiency of 50%.