Researchers at the University of Chicago in the US developed a wearable fabric that can cool down its wearers, but can also be applied in building and car design, and food storage.

With global temperatures in the rise, cities have become “urban heat islands”, where stony materials like concrete buildings and pavements trap heat and increasing it. As 68 per cent of the population will live in cities by 2050, this poses a great and deadly problem.

Existing cooling fabric works by reflecting the sun’s light in a diffuse pattern, so it doesn’t blind onlookers. However, in an urban heat island, the sun isn’t the only source of heat, with thermal radiation emitted from buildings and pavement. Sunlight is visible light, whereas radiation is infrared, so they have different wavelengths.

Therefore, the new material was designed in such a way, that it reflects both types of heat, In tests in Arizona, the material kept 2.3 degrees Celsius (4.1 degrees Fahrenheit) cooler than the broadband emitter fabric used for outdoor endurance sports and 8.9 degrees Celsius (16 degrees Fahrenheit) cooler than the commercialized silk commonly used for shirts, dresses and other summer clothing.

The applications for the fabric go further than clothing. A thicker version of the fabric protected by an invisible layer of polyethylene could be used on the sides of buildings or cars, lowering internal temperatures and reducing the cost and carbon impact of air conditioning. Similarly, the material could be used to transport and store milk and other foods that would otherwise spoil in the heat, cutting refrigeration’s impact.

Photos: University of Chicago