MIT Working on Broadcast Power
We might be approaching one of the final frontiers in the wireless world as researchers from the Massachusetts Institute of Technology (MIT) say they have developed a wireless power transfer device that would enable wireless charging of consumer-electronic devices, such as mobile phones, MP3 players, and laptops.
While the need for cables and wires to operate notebook PCs and connect to the Internet has slowly disappeared in recent years, with audio and data transmissions being piped through the air, cables have been needed to recharge portable devices.
The concept behind this new device is not new, said Marin Soljacic, an assistant professor in MIT’s Department of Physics and Research Laboratory of Electronics, who co-authored the study.
Scientists have known for nearly two hundred years that energy can be transferred without wires. This wireless transfer of energy, such as light energy from the Sun for solar power or the transfer of microwaves from transmitters for communication, involves relatively low levels of energy.
However, recharging devices like laptops requires a much higher concentration of energy that, if run through the air, could be dangerous.
How It Would Work
“It certainly was not clear or obvious to us in the beginning how well it could actually work, given the constraints of available materials, extraneous environmental objects, and so on. It was even less clear to us which designs would work best,” Soljacic said.
The idea is that the recharge device and the receiver would operate on the same acoustic frequency, similar to how a radio picks up only one channel at a time, so that the energy would mostly go to the intended battery, Soljacic said.
Instead of filling the environment with electromagnetic waves, a power transmitter would fill a limited space with a “non-radiative electromagnetic field,” he said. The energy is only picked up by devices specially designed to “resonate”…
