New Scientist reports: [edited]
Charging your phone may soon be as simple as sitting down at your desk, thanks to a device called MagMIMO that can charge phones at a distance.
Wireless chargers exist, but they require a phone to be right next to a charging pad. At a distance of 30 centimetres a prototype can charge an iPhone 4s battery from dead to full in just under 5 hours. It doesn't matter what orientation the phone is in – upside down in a pocket or flat on the desk – and the phone needn't be stationary.
MagMIMO borrows a trick from radio communications: advanced Wi-Fi routers can detect when a computer is connecting to them and boost the signal in their direction. MagMIMO does the same thing, but using magnetic fields instead of radio waves. An array of wire coils generates a magnetic field and when a phone disrupts that field, MagMIMO senses it and focuses on the phone by creating a slightly different field with each coil. The magnetic fields reinforce each other so as to maximise the strength of the overall field reaching the phone.