In 2025, researchers built a box from porous PMMA sheets that reflected 96% of sunlight; 80°F outdoor air measured 65.3°F inside without electricity

Innovative materials scientists are exploring passive cooling techniques to lessen the demand for air conditioning. They have engineered a porous PMMA material that effectively reflects solar radiation, demonstrating a notable temperature difference compared to outdoor air. This cooling phenomenon is attributed to the scattering of light within the material's tiny pores, with promising future uses in energy-efficient home designs, including roofs and siding.