Using a simple setup–basically, two metal coils–MIT researchers have demonstrated for the first time that it’s feasible to send power wirelessly as far as two meters. The approach might someday make it possible to charge batteries in laptops, cameras, or phones without plugging them in, says MIT physicist Marin Soljaˇci´c, who led the research with physicist John Joannopoulos. The technique involved, magnetic inductive coupling, has long been used to transfer power between transformers a few centimeters apart, but the MIT group extended its range by focusing the energy at a specific frequency. Power in a cable (1) is transferred to a copper coil antenna (2) that includes a disclike capacitor (3). The coil produces a magnetic field of around 10 megahertz. Energy (4) is transmitted by the magnetic field and received by an antenna (5) also resonating at around 10 megahertz. Ultimately, such a receiving antenna could be built into consumer electronics.
Credit: John Macneill
Five poems about the mind
Work reinvented: Tech will drive the office evolution
As organizations navigate a new world of hybrid work, tech innovation will be crucial for employee connection and collaboration.
I taught myself to lucid dream. You can too.
We still don’t know much about the experience of being aware that you’re dreaming—but a few researchers think it could help us find out more about how the brain works.
Is everything in the world a little bit conscious?
The idea that consciousness is widespread is attractive to many for intellectual and, perhaps, also emotional
reasons. But can it be tested? Surprisingly, perhaps it can.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.