|Title||Magnetic Metamaterial Superlens for Increased Range Wireless Power Transfer|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||G. Lipworth, J. Ensworth, K. Seetharam, D. Huang, J.Seung Lee, P. Schmalenberg, T. Nomura, M.S. Reynolds, D.R. Smith, Y. Urzhumov|
The ability to wirelessly power electrical devices is becoming of greater urgency as a component of energy conservation and sustainability efforts. Due to health and safety concerns, most wireless power transfer (WPT) schemes utilize very low frequency, quasi-static, magnetic fields; power transfer occurs via magneto-inductive (MI) coupling between conducting loops serving as transmitter and receiver. At the "long range" regime - referring to distances larger than the diameter of the largest loop - WPT efficiency in free space falls off as (1/d)(6); power loss quickly approaches 100% and limits practical implementations of WPT to relatively tight distances between power source and device. A "superlens'', however, can concentrate the magnetic near fields of a source. Here, we demonstrate the impact of a magnetic metamaterial (MM) superlens on long-range near-field WPT, quantitatively confirming in simulation and measurement at 13-16 MHz the conditions under which the superlens can enhance power transfer efficiency compared to the lens-less free-space system.
|Short Title||Sci. Rep.|