Wireless energy transfer for stand-alone systems: a comparison between low and high power applicability

The applicability of micro-systems, designed to contain monitoring or actuating devices is often hampered by accessibility. For systems with low power demands, the use of inductive links for wireless energy and data transfer to the remote system is a widely acknowledged solution. Design strategies that optimise towards power transfer efficiency for given geometric constraints, have been proposed. With the introduction of more power consuming components, such as small de motors, in micro-systems, a demand was created for inductive links with high power transfer possibilities combined with a high overall efficiency. This paper describes the design considerations for such high energy inductive links. An inductive link is presented, capable of transferring 20 W of power over a distance of I cin with an overall efficiency of 80%. In addition, ongoing developments will be outlined, such as data-transmission and external voltage regulation. (C) 2001 Published by Elsevier Science B.V.