Imagine a world where smartphones, laptops, wearables, and other electronics are powered without batteries. Researchers from MIT and elsewhere have taken a step in that direction, with the first fully flexible device that can convert energy from wi-fi signals into electricity that could power electronics.

Devices that convert AC electromagnetic waves into DC electricity are known as “rectennas.” The researchers demonstrate a new kind of rectenna, described in a study appearing in Nature today, that uses a flexible radio-frequency (RF) antenna that captures electromagnetic waves—including those carrying wi-fi—as AC waveforms.

The antenna is then connected to a novel device made out of a two-dimensional semiconductor just a few atoms thick. The AC signal travels into the semiconductor, which converts it into a DC voltage that could be used to power electronic circuits or recharge batteries.

In this way, the battery-free device passively captures and transforms ubiquitous wi-fi signals into useful DC power. Moreover, the device is flexible and can be fabricated in a roll-to-roll process to cover very large areas.

 …