Future smartwatches could get battery life boost from an unusual source

By Georgina Torbet Published March 19, 2025

Wearable devices like smartwatches and smart glasses have gradually become a regular part of daily life, but there’s still an ongoing annoyance with many of them: battery life. While devices like smartwatches can do a few days per charge, larger devices like smart glasses have a history of shoddy battery life that makes them impractical for many people.

Now, though, new technology could help make wearables last for longer and make them lighter weight. A team from the Korea Electrotechnology Research Institute has developed a new method for creating the functional wires which form the basis of smart wearables.

The newly developed wires are made from carbon nanotubes, a material which is 100 times stronger than steel but can conduct electricity as well as copper. The tubes are created from atoms connected into hexagonal rings, making them both strong and flexible.

However, it is hard to work with carbon nanotube material because it has a tendency to bunch up and tangle. The researchers managed to address this by adding acid and other additives to the material and then kneading it similar to the way you make bread.

The result is carbon nanotube wires which were tested out in textile supercapacitors, of the sort used in smart clothing.

The tubes had excellent energy storage meaning they can help wearables operate in a more efficient way, which would reduce weight and lets the devices last for longer. Another research group found that they could add sensors using these wires to clothing, which could detect harmful gases — making them ideal for use in fields like firefighting.

“This is the world’s first achievement of dispersing functionalized CNTs in organic solvents for solution spinning. It will drive the development of lightweight and long-lasting wearable electronic devices,” said lead researcher Han Joong Tark. “Through continuous research, this technology could replace copper wires in future mobility fields, such as electric vehicles and drones, greatly improving both lightweight design and energy efficiency.”

The research is published in the journal ACS Nano.