A team from MIT has demonstrated wireless power transfer, which would enable cell phones, MP3 players, laptops, and other portable electronics to charge themselves without being plugged in. Some of these devices may not even need their batteries to operate.
The team was able to light a 60W light bulb from a power source seven feet away with no physical connection between the two. The MIT concept is called WiTricity (wireless electricity) and is based on using magnetically coupled resonant objects. Two resonant objects of the same resonant frequency can exchange energy efficiently, while interacting weakly with off-resonant objects.
This technology is suited to everyday applications because most common materials interact only weakly with magnetic fields, so interactions with extraneous environmental objects are suppressed.
According to MIT Professor John Joannopoulos, the reason no one previously had thought of the idea -- which is based on well-known laws of physics -- is because "there was no great demand for such a system" in the past. "Over the past several years, portable electronic devices such as laptops, cell phones, iPods, and even household robots have become widespread, all of which require batteries that need to be recharged often."
