Future wearable devices could draw power through your body using background 6G cellphone signals

A photo of a person wearing a smartwatch with a colorful neon background
(Image credit: Oscar Wong via Getty Images)

Your body could become a battery for wearable devices, thanks to a breakthrough in harvesting waste energy from 6G wireless communication.

Researchers from the University of Massachusetts Amherst found that waste radio frequency (RF) energy given off by visible light communication (VLC), if used to deliver 6G, can be harvested with small, inexpensive copper coils and transmitted to power other devices via the human body. 6G is a future wireless communication technology that is currently in development and is set to be deployed before the end of the decade.

As outlined in a 2022 research paper, the crux of this mechanism lies with VLC — which transmits data through extremely fast flashes of visible light from sources such as LEDs. VLC is one method through which 6G signals might hypothetically be transmitted in the future. But LEDs also emit side-channel RF signals, as a form of leaked energy. The researchers found that this could be harvested by a coiled copper wire, whose energy recycling efficiency is boosted when touching human skin.

Related: Scientists could make blazing-fast 6G using curving light rays

According to the study, skin contact boosted efficiency by up to 10 times compared to using the coil on its own. The human body also proved to be better at amplifying the coil’s ability to collect leaked radio energy than wood, plastic, cardboard or steel.

Body batteries

From this, the researchers created "Bracelet+" — a simple copper wire coil that could be worn as a bracket on the upper forearm. The design can also be adapted to be worn as a necklace, anklet, belt or ring, although the scientists found the bracelet occupied a happy medium between power harvesting and wearability.

"The design is cheap — less than fifty cents," said the authors of the study in a statement. “But Bracelet+ can reach up to micro-watts, enough to support many sensors such as on-body health monitoring sensors that require little power to work owing to their low sampling frequency and long sleep-mode duration."

With this in mind, such technology could solve the issue of limited battery life on wearable devices. Even highly rated smartwatches, like the Apple Watch, tend to need charging on a near-daily basis, which can mitigate how useful they are unless charging is part of one’s daily routine. And now that smart rings are growing in popularity, there are even more devices that require regular power top-ups.

The energy harvesting technology that the Bracelet+ facilitates could, therefore, become a form of in-situ charger for next-generation wearable devices, providing of course that such devices come with a way of taking power from the bracelet.

Of course, this relies on 6G networks that use VLC, which are currently far away from deployment, let alone widespread adoption and integration into consumer or industrial devices.

But this could be the advent of turning the human body into a form of battery to power technology, only in a more harmonious fashion than the future envisioned by "The Matrix."

"Ultimately," said lead author of the study Jie Xiong, professor of information and computer sciences at UMass Amherst, in a statement, "we want to be able to harvest waste energy from all sorts of sources in order to power future technology."

Roland Moore-Colyer

Roland Moore-Colyer is a freelance writer for Live Science and managing editor at consumer tech publication TechRadar, running the Mobile Computing vertical. At TechRadar, one of the U.K. and U.S.’ largest consumer technology websites, he focuses on smartphones and tablets. But beyond that, he taps into more than a decade of writing experience to bring people stories that cover electric vehicles (EVs), the evolution and practical use of artificial intelligence (AI), mixed reality products and use cases, and the evolution of computing both on a macro level and from a consumer angle.