Wireless energy transfer between anisotropic metamaterials shells

•Anisotropic metamaterial shells exhibit high quality factors and sub-wavelength size.•Exchange of electromagnetic energy between shells with high efficiency is analyzed.•Strong coupling is supported with high wireless transfer efficiency.•End-to-end energy transfer efficiencies higher than 83% can be predicted.

The behavior of strongly coupled Radial Photonic Crystals shells is investigated as a potential alternative to transfer electromagnetic energy wirelessly. These sub-wavelength resonant microstructures, which are based on anisotropic metamaterials, can produce efficient coupling phenomena due to their high quality factor. A configuration of selected constitutive parameters (permittivity and permeability) is analyzed in terms of its resonant characteristics. The coupling to loss ratio between two coupled resonators is calculated as a function of distance, the maximum (in excess of 300) is obtained when the shells are separated by three times their radius. Under practical conditions an 83% of maximum power transfer has been also estimated.