Forget batteries, Apple Watch and Fitbit could soon be powered by your body heat

US researchers have developed a low-cost wearable device that can convert your body into a biological battery. The new study is published in the peer-reviewed journal, Science Advances, and details the ground-breaking innovation that could see the human body replace batteries entirely.

Yes, that’s right: researchers at the University of Colorado have created a climate-friendly, green-focused gadget, which harvests body heat before turning it into masses of energy. The concept – shown as a ring – uses a malleable and flexible material called polyimine. We haven't heard of it either, so read on for more jargon-busting context.

With wearables needing to last longer and longer, companies like Garmin are coming up with increasingly ingenious ways to elongate battery life. This ranges from the solar-powered Garmin Enduro, even reports of Apple using Mini-LED or Micro-LED in the upcoming Apple Watch Series 7 to boost battery life – many brands are focused on energy and maximizing how that energy is used. 

So, a product that lets you tap into your body heat reserves could be the crux of all these efforts: an always-on solution, permanently charging against through your skin, and devoid of any low battery reminders.

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The pioneering invention could let users power their wearables from the internal; heat stores from your body: charge up your Apple Watch from the comfort of your own body, fuel your Fitbit fitness trackers – perhaps even something off our best Fitbit guide – through the technology, which resembles a stretchy bracelet with tiny thermoelectric clips.

It begs the question of whether previous and current iterations of devices from the likes of Apple, such as the Apple Watch Series 5 and Apple Watch Series 6, could somehow be retroactively tweaked to use the body-generated power.

The thermo-gizmos produce around a single volt of energy per square centimeter of skin covered. The project is obviously in its infancy with the researchers looking to increase the overall power yield, but the paper suggests that the gadgets could roll out in the next five to ten years. If you can’t wait that long and want a wearable right sooner, you can check out our best smartwatch guide to help you choose.

The senior author of the study, Jianliang Xiao, says: “Thermoelectric devices can provide continuous power to wearable devices and could potentially replace batteries in the future,” boosting the likelihood of continuously charged wearable devices. 

If the researchers manage to distill the technology into something workable for your mobile handset, it could signal that the days of carrying multiple chargers for a model from our picks of the best iPhone, and best Android phone, could be drawing to a welcome close. 

In the future, all you'll need to remember is to pack a charger for your Apple MacBook Air (M1, 2020), or – who knows – maybe a more powerful skin-sapping charger could use the same mechanism to charge an even bigger device from our best laptop guide, but we're not sure how that would look in public. 

There's definitely something slightly unsettling about a laptop charging from your body heat, but we're definitely on board with these smaller, more covert charging devices that champion self-made green energy from your very own body.

Source: Tom's Guide