Researchers at the City University of Hong Kong developed a passive radiative cooling ceramic material, which was inspired by a beetle.

Passive radiative cooling (PRC) is one of the most promising green cooling technologies to combat ever increasing temperatures worldwide. However, most current PRC materials are often expensive or lack weather resistance.

The new material has a hierarchically porous structure, and can easily be fabricated using accessible materials. Its design was inspired by the bio-whiteness of the Cyphochilus beetle. With an optimized structure to scatter light, the ceramic material has a solar reflectivity of 99.6 per cent and achieves a high-mod infrared thermal emission of 96.5 per cent.

The material is made of alumina, which has a good resistance to UV degradation and can withstand temperatures of more than 1,000 °C.

Photos: City University of Hong Kong