Researchers led by Akhlesh Lakhtakia (Pennsylvania State University and Dalian University of Technology) have developed porous plastic sheets for passive building cooling, reducing temperatures by up to 8.4°C.

Made from powdered polymethyl methacrylate (PMMA), the sheets reflect visible and infrared light, cooling spaces both during the day and night through radiative cooling. 

They are fabricated using a method called powder sintering, which creates air pockets in the sheets. Testing showed that these sheets cool spaces more effectively than cardboard. 

Although the sheets degrade over time, they can be recycled, offering an energy-efficient, sustainable solution to combat rising temperatures due to climate change.