A new device can use your body heat to increase battery life

Forget batteries. Your wearable electronics, like fitness trackers and watches, could soon be powered by a biological battery — your body.

Researchers at the University of Colorado have recently developed a low-cost wearable device that can turn body heat into energy — improving battery life for your essential devices. This new invention could lead to a renewable, eco-friendly way to power that Fitbit — and, it may even inspire you to exercise more.

“In the future, we want to be able to power your wearable electronics without having to include a battery,” said Jianliang Xiao, an engineer at CU Boulder. “Whenever you use a battery, you’re depleting that battery and will, eventually, need to replace it. The nice thing about our thermoelectric device is that you can wear it, and it provides you with constant power.”

The team built the new battery out of a material called polyimine, embedded with thermoelectric chips that they connected with liquid wires. It is flexible and can bend to fit the curve of your wrist or move with your body. In their study, published in the journal Science Advances, they show the battery as a ring. It looks like a funky computer chip wrapped around the top of the ring finger.

“The thermoelectric generators are in close contact with the human body, and they can use the heat that would normally be dissipated into the environment,” Xiao said.

Battery Life Woes Could Come to An End

Battery life may be the most significant pain point for wearables and personal devices. With the features — like navigation, reminders, fitness trackers, sleep trackers, music, etc., packed into one device — keeping the battery level topped off seems like it should be a given.

Still, I have to charge my devices at least once a day or more. It’s 2021 — personal devices need longer-lasting batteries already.

Companies are trying to find innovative ways to have longer-lasting batteries. Garmin created the solar-powered Garmin Enduro. And there are reports that Apple may be using Mini-LED or Micro-LED to prolong battery life in the upcoming Apple Watch Series 7, reports T3.

The skin-charged battery produces about one volt of energy for every square centimeter of skin space — enough to power a watch or fitness tracker, the researchers claim. But they aim to increase that output. In the future (the team estimates 5 to 10 years), body-powered batteries could resolve the problem of short battery life. The device would essentially be always “plugged in” — endlessly charging and never drained.

We’d love to hear from you! If you have a comment about this article or if you have a tip for a future Freethink story, please email us at [email protected].