Your new smartwatch or fitness tracker might be powered by your sweat

Honor Band 5 Sport
Honor Band 5 Sport (Image credit: Future)

When people talk about renewable power, sweat isn't exactly something that springs to mind, but it sounds like that natural bodily process is actually capable of powering fitness trackers and maybe even smartwatches too.

Researchers at the University of Glasgow in Scotland have created tech that can use sweat to replace traditional batteries in devices (as reported by Institute of Engineering and Technology).

It works by collecting the sweat you naturally produce, and causing the ions in it to react to polymers in the tech, resulting in a reaction which creates electricity.

The researchers tested the tech by strapping a small version of the cell to runners and having them exercise - the cell powered a load of LEDs, showing that it works, and would theoretically work on a larger scale too.

How could this work in real life?

Judging by the results of the experiment, the sweat-powered tech works, but it doesn't seem like it generates enough power to allow you to completely forgo charging your wearable device in a traditional way.

Instead, the sweat tech could supplement standard charging, meaning you'd have to charge your fitness tracker or smartwatch far less frequently than you currently have to. 

The tech seems perfect for fitness trackers, as typically you wear them when you're active (and producing sweat), but it's possible the tech would work in smartwatches too.

It's not clear if or when we'll actually see this tech pop up in real wearables, but it likely won't be for a few years - we frequently hear of scientists creating tech that could revolutionize your products, like super-thin smartphone camera lenses or super-long-lasting graphene batteries, but they don't always make their way into products you can buy.

Saying that, sweat-powered smartwatches and fitness trackers could be hugely useful, both for day-to-day use to save you charging your device frequently, and for the environmental ramifications of reducing our power use and battery consumption. Hopefully we'll see the tech soon, then.

Tom Bedford

Tom Bedford was deputy phones editor on TechRadar until late 2022, having worked his way up from staff writer. Though he specialized in phones and tablets, he also took on other tech like electric scooters, smartwatches, fitness, mobile gaming and more. He is based in London, UK and now works for the entertainment site What To Watch.

He graduated in American Literature and Creative Writing from the University of East Anglia. Prior to working on TechRadar, he freelanced in tech, gaming and entertainment, and also spent many years working as a mixologist. He also currently works in film as a screenwriter, director and producer.