Professor Shanhui Fan and colleagues have modified silk to reflect 95% of sunlight, helping to keep the wearer cooler than other fabrics. 

They were able to engineer the silk fabric by embedding the fibers with aluminum oxide nanoparticles that reflect the ultraviolet wavelengths of sunlight.

The researchers found that the fabric stayed 3.5°C cooler than the surrounding air because of its ability to reflect most sunlight and radiate heat. It is the first fabric to be developed that stays colder than the surrounding air when in sunlight.

Shanhui says the fabric is mainly designed to keep people cool when they are outdoors and exposed to sun, rather than in indoor settings like homes and office buildings.

Scientists have been searching for passive ways of cooling us that don’t require electricity in order to help reduce demands on energy. Approximately 15% of global electricity goes towards keeping us cool. 

Journal reference: Nature Nanotechnology, DOI: 10.1038/s41565-021-00987-0

Excerpted from

• Tribune.com.pk, “Scientists engineer silk that keeps skin cooler than cotton," November 9, 2021
• NewScientist, "Silk modified to reflect sunlight keeps skin 12.5°C cooler than cotton,” November 8, 2021