Scientists have suggested that they can beam energy to electronic devices three to five meters away. The BBC explains why ‘resonance' may see the end of (some) wires:
Resonance [is] a phenomenon that causes an object to vibrate when energy of a certain frequency is applied.
“When you have two resonant objects of the same frequency they tend to couple very strongly,” Professor Soljacic told the BBC News website. Resonance can be seen in musical instruments for example. “When you play a tune on one, then another instrument with the same acoustic resonance will pick up that tune, it will visibly vibrate,” he said.