A startup called FINsix has developed laptop power adapters that are 75 percent smaller than their conventional counterparts. The technology employed could also be used to improve the efficiency of a wide variety of devices and appliances, including washing machines and air conditioners.

FINsix’s first product, which the company will unveil next month at the Consumer Electronics Show in Las Vegas, replaces a conventional charging brick with a device just a little bigger than an ordinary plug. The 65-watt power adapter—which delivers more power than many laptops use—can charge multiple devices at once. It will be available by the middle of next year...

...The researchers at MIT and FINsix developed a way to recycle much of the energy that’s normally lost inside a power adapter, improving efficiency and making it practical to use frequencies 1,000 times higher than those used in conventional power adapters. “The rest of the field is making incremental changes and getting diminishing returns,” says Charles Sullivan, a professor of engineering at Dartmouth, who is not involved with the company. But FINsix, he says, is “leaping past that barrier.”