Making plugs obsolete!
BBC: A system that can deliver power to devices without the need for wires has been shown off at a hi-tech conference.
The technique exploits simple physics and can be used to charge a range of electronic devices over many metres.
Eric Giler, chief executive of US firm Witricity, showed mobile phones and televisions charging wirelessly at the TED Global conference in Oxford.
He said the system could replace the miles of expensive power cables and billions of disposable batteries.
"There is something like 40 billion disposable batteries built every year for power that, generally speaking, is used within a few inches or feet of where there is very inexpensive power," he said.
The system is based on work by physicist Marin Soljacic at the Massachusetts Institute of Technology (MIT).
It exploits "resonance", whereby energy transfer is markedly more efficient when a certain frequency is applied.
When two objects have the same resonant frequency, they exchange energy strongly without having an effect on other, surrounding objects.
For example, it is resonance that can cause a wine glass to explode when a singer hits exactly the right tone.
But instead of using acoustic resonance, Witricity's approach exploits the resonance of low frequency electromagnetic waves.
