A Cuttable Wireless Power Transfer Sheet

Abstract

We propose a cuttable wireless power transfer sheet which allows users to modify its size and shape. This intuitive manipulation allows users to easily add wireless power transmission capabilities to everyday objects. The properties of the sheet such as thinness, flexibility, and lightness make our sheet highly compatible with various configurations. We contribute a set of technical principles for the design of circuitry, which integrates H-tree wiring and time division power supply techniques. H-tree wiring allows the sheet to remain functional even when cut from the outside of the sheet, whereas time division power supply avoids the reduction in power transfer efficiency caused by the magnetic interference between adjacent transmitter coils. Through the evaluations, we found that our time division power supply scheme mitigates the degradation of power transfer efficiency and successfully improves the average efficiency. Furthermore, we present four applications which integrates our sheet into daily objects: wireless charging furniture, bag, jacket, and craft; these applications confirmed the feasibility of our prototype.