  Controlling the electromagnetic properties of materials beyond those
achievable with natural substances has become a reality with the advent of
metamaterials, artificially designed materials offering a wide range of unusual
physical phenomena. The extreme properties that metamaterials provide can
protect optical and electromagnetic systems from surrounding ordinary materials
and substances - a feature never explicitly used yet. Wireless energy transfer,
i.e., the transmission of electromagnetic energy without physical connectors,
demands reliable and stable solutions for charging high-power systems like
electric vehicles with no effect on people, animals, plants, etc. Here we
tackle this challenging problem and suggest a novel approach of using
metamaterials with extreme parameters to enable targeted and protected wireless
energy transfer. We design and experimentally implement epsilon-near-zero (ENZ)
and epsilon-and-mu-near-zero (EMNZ) metamaterials that provide an energy
transmission if and only if both the transmitter and the receiver are equipped
with these metamaterials. The fact of absence of materials with such extreme
parameters protects the system against surrounding objects, which cause neither
noticeable change in the system operation nor experience any detrimental
effect. The system behind the proposed approach can be realised in virtually
any frequency band by appropriate scaling and suitable choice of material. This
technology will find applications in targeted wireless energy transfer systems,
especially where high power is needed, including electric vehicles.
