Scientists develop cooling film to reflect sun, reduces energy use in hot cities
Scientists have unveiled a biodegradable cooling film that could dramatically reduce global energy consumption, new research has revealed, Xinhua reports.
The innovative bioplastic metafilm can passively cool surfaces by up to 9.2 degrees Celsius during peak sunlight while reflecting nearly 99 percent of solar radiation, according to a release on Wednesday from the University of South Australia (UniSA), which conducted the research in collaboration with Zhengzhou University in China.
Made from plant-based polylactic acid (PLA), the metafilm is a fully biodegradable, power-free alternative to conventional air-conditioning and petrochemical-based cooling systems, the release said.
"The material reflects nearly all solar radiation but also allows internal building heat to escape directly into outer space. This enables the building to stay cooler than the surrounding air, even under direct sunlight," said Hou Yangzhe, a PhD candidate at UniSA and Zhengzhou University.
Field tests in China and Australia showed the film remained effective after extended exposure to acid and ultraviolet light, surpassing the durability of previous biodegradable materials, the researchers said.
Simulations suggest the metafilm could cut building energy use by up to 20 percent in hot cities, reducing air conditioning demand. Researchers are now exploring mass production and broader applications in sectors like transport, agriculture, electronics, and medicine.
"Our film is scalable, durable and completely degradable," said the study's co-author, Ma Jun, a professor of UniSA.
The discovery, published in Cell Reports Physical Science, tackles the challenge of combining effective cooling with eco-friendly degradation, aiming to boost comfort while reducing fossil fuel use and environmental impact, Ma said.
As written before, May 2025 ranks as the second-warmest on record globally, according to the Copernicus Climate Change Service.