Innovative cooling fabric offers hope

Created a new cooling fabric that reflects both direct sunlight and thermal radiation from pavements and buildings in urban heat islands

@John Zich

After months of massive heat waves hitting cities in Mexico, India, and Pakistan with temperatures approaching or exceeding 122 degrees Fahrenheit, a terrible heat wave is now engulfing us.

With the rise in global temperatures and urban populations, cities around the world have become true “urban heat islands,” a whirlwind of thermal radiation emitted by sidewalks and skyscrapers that trap and amplify temperatures. With 68% of all people projected to live in cities by 2050, this is a growing and sometimes deadly problem.

Innovative cooling fabric offers hope

In an article published in Science, researchers from the UChicago Pritzker School of Molecular Engineering (PME) present a unique solution. They detail a new wearable fabric that can help people withstand the worst impacts of extreme heat. This fabric has potential applications not only in clothing but also in building and automobile design, and even in food preservation.

The tests

How does this revolutionary fabric work? It operates on the principle of radiative cooling, a natural process where objects emit heat in the form of infrared radiation. Based on this principle, the newly invented material not only reflects direct sunlight but also the thermal radiation emitted by buildings and pavements.

The fabric is composed of three distinct layers: an inner layer made from common materials like wool or cotton for comfort and breathability; an intermediate layer containing silver nanowires that reflect most thermal radiation; and an outer layer of polymethylpentene, a plastic material that emits a narrow band of infrared radiation, allowing heat to dissipate effectively.

Test results

Outdoor tests showed that the fabric was 16 degrees Fahrenheit cooler than regular silk fabric and 4 degrees Fahrenheit cooler than materials that emit radiation over a broader range. On the skin, the fabric was 3 degrees Fahrenheit cooler than cotton, indicating significant potential to enhance comfort in hot environments.

We need to reduce carbon emissions and make our cities carbon negative or carbon neutral,” concludes Prof. Po-Chun Hsu, who conducted the study. “But in the meantime, people are feeling the impact of these high temperatures.”

We need to reduce carbon emissions and make our cities carbon negative or carbon neutral,” concludes Prof. Po-Chun Hsu, who conducted the study. “But in the meantime, people are feeling the impact of these high temperatures.”