In 2021, researchers built a two-layer polymer film that cools like skin; under direct sun, it stayed about 7°C below ambient with 150 W/m² cooling power

Researchers have created an advanced cooling film comprising two innovative layers that harmoniously integrate both radiative and evaporative cooling technologies. The bottom layer, made of hydrogel, captures moisture from the atmosphere, aiding in daytime cooling. Meanwhile, the porous top layer serves to block sunlight and conserve moisture, resulting in a notable drop in temperature below the surrounding environment.