Technical Papers

Highly Resonant Wireless Power Transfer: Safe, Efficient, and Over Distance

Highly Resonant Wireless Power Transfer: Safe, Efficient, and Over DistanceWiTricity White Paper


Morris Kesler
This article explores the advances in wireless power technology enabled by the use of highly resonant wireless power transfer, how those advances are being applied across a broad spectrum of applications, and how they address the safety concerns in typical applications..

Wireless Power Transfer via Strongly Coupled
Magnetic Resonances

ScienceScience | Vol. 317. no. 5834, pp. 83 - 86

July 6, 2006 (Published Online June 7, 2007)

Andre Kurs, Aristeidis Karalis, Robert Moffatt, J. D.
Joannopoulos, Peter Fisher, Marin Soljačić

Using self-resonant coils in a strongly coupled regime, we experimentally demonstrated efficient nonradiative power transfer over distances up to 8 times the radius of the coils. We were able to transfer 60 watts with ~40% efficiency over distances in excess of 2 meters. We present a quantitative model describing the power transfer, which matches the experimental results to within 5%. We discuss the practical applicability of this system and suggest directions for further study.

Efficient wireless non-radiative mid-range energy transfer

Annals of PhysicsAnnals of Physics | Vol. 323, Issue 1, pp 34 - 48

April 27, 2007

Aristeidis Karalis, J.D. Joannopoulos and Marin Soljačić
Abstract: We investigate whether, and to what extent, the physical phenomenon of long-lifetime resonant electromagnetic states with localized slowly-evanescent field patterns can be used to transfer energy efficiently over non-negligible distances, even in the presence of extraneous environmental objects. Via detailed theoretical and numerical analyses of typical real-world model-situations and realistic material parameters, we establish that such a non-radiative scheme can lead to “strong coupling” between two medium-range distant such states and thus could indeed be practical for efficient medium-range wireless energy transfer.