What connects the highlands of Kyrgyzstan to southern Africa's arid Namib Desert? Answer: the shell of the fog-basking beetle.
UK building manufacturer Sto was asked to make a paint to protect the University of Central Asia's central campus, where temperatures drop to -40°C in winter and soar above 35°C in summer.
To cope with this climate, Sto copied the micro-sized grooves on the beetle's shell, which condense dew and ocean fog into water droplets and direct them to its mouth. In particular, the beetle's wings are covered in microscopic bumps with hydrophilic tips that let the water condense. By contrast, the depressions in between the bumps are hydrophobic.
Sto used a micro-textured paint that is simultaneously hydrophilic and hydrophobic, so it attracts water then immediately repels it. The microtexture of the surface features a binding agent to mimic the hydrophilic tips while a filler material to mimic the hydrophobic depressins. The GIF below shows water droplets being attracted before being repelled.
"The coarse particles attract water and the deeper areas in the texture act to channel the water down and off the façade," explains Gary Bundy, Sto's technical director. The paint, StoColor Dryonic, keeps the campus free of micro-organisms such as fungus and algae. Beaten by beetles.
This article was originally published by WIRED UK
