Next-gen wearable devices might sip your sweat, use it to generate electricity

sweat-powered wearable
Eduard Bonnin Turina/123RF

One of the things that need to improve about wearables is their battery life. A device like the Apple Watch may be the gold standard in its product category, but until users no longer need to take it off at night and remember to charge it, a certain percentage of would-be users will either skip buying it or default on wearing it.

From true wireless charging to wearable battery packs, we have heard about a few possible solutions to the problem. A new piece of research by the University of California, San Diego, may have the best answer yet, however: Charge devices through the sweat of their wearers.

With that in mind, they demonstrated a new sweat-powered wearable that can be used to power a Bluetooth Low Energy (BLE) radio for a couple of days, based on an adhesive wearable strip smart sensor that is just 2cm in width.

“We took conventional biofuel cell technology where enzymatic reactions of a biofuel are used to generate power and translated it to our skin,” Jonathan Wang, Distinguished Professor and Chair of the Department of Nanoengineering, told Digital Trends. “Here we use sweat as source for biofuel and developed a conformal stretchable skin-worn biofuel cell that harvests energy from sweat lactate.”

The proof-of-concept shows off technology that is significantly more efficient than previous demos of similar technology. A paper describing the work, published in the journal Energy and Environmental Science, notes that this research represents the highest power density recorded by a wearable biofuel cell to date.

Wang said that the goal is to power mobile wearable devices on the run. Current work on the project, he said, involves further increasing the power and integration for day-to-day wearable applications.

It’s definitely a neat concept, and we look forward to hearing how it advances. There are, of course, questions —  such as how much sweat would need to be harvested to power a more advanced wearable device that needed more energy than just a BLE radio, and how feasible this is. It would also be interesting to find out whether such this would only be limited to fitness-oriented wearables, whereby users are consciously trying to break a sweat, or whether it would be possible to harvest the necessary sweat from regular physical exertion.