Silk-based smart textile converts body heat into electricity

Researchers at Chalmers University of Technology have come up with a new textile that turns body heat into electrical power using specially coated silk threads.

The idea hinges on a conductive silk thread covered in a special plastic polymer that grabs thermal energy from the temperature difference between the body and the air. This brings us closer to wearable gadgets that don't need batteries.

"The polymers we utilize offer unique advantages - they're flexible, lightweight, and can be applied in both liquid and solid forms while remaining non-toxic," says Mariavittoria Craighero, lead researcher and doctoral student at Chalmers.

The team showed off two versions of the tech: a button-sized device and a bigger fabric panel. These devices produce electricity when there is a temperature difference, with output voltage changing based on the temperature difference and amount of conductive material.

The material proved durable, staying effective for over a year and holding up through multiple washes. After seven washes, it still had two-thirds of its conductive strength, though they'll need to improve that for real-world use.

Right now, making these thermoelectric fabrics takes time. In the lab, it's a manual process that involves lots of careful preparation and sewing. One fabric sample took four days of hand stitching.

This breakthrough could change wearable tech, allowing clothes to power devices like fitness trackers and health sensors without regular batteries. The tech uses the natural heat difference between our bodies and the air to keep generating power.

This development is a major step toward self-powered wearables, hinting at a future where smart clothing stays comfortable, washable, and free from battery charging.