This one’s for Gil Dodgen:
In “Not a scratch: Scorpions may have lessons to teach aircraft designers” (February 4, 2012), The Economist reports,
The north African desert scorpion, Androctonus australis, is a hardy creature. Most animals that live in deserts dig burrows to protect themselves from the sand-laden wind. Not Androctonus. It usually toughs things out at the surface. Yet when the sand whips by at speeds that would strip paint away from steel, the scorpion is able to scurry off without apparent damage. Han Zhiwu of Jilin University, in China, and his colleagues wondered why.
So he bought a number of scorpions in Shanghai pet shops.
And had a look at their armour plates. (The stuff some people will do for science … ) Anyway,
The team found that Androctonus armour is covered with dome-shaped granules that are 10 microns high and between 25 and 80 microns across. These, they suspected, were the key to its insouciance in the face of sandstorms.
A computer model suggested that the erosion was reduced to about half this way. Then they tried aiming sand grains at steel in a wind tunnel.
The upshot was that the pattern most resembling scorpion armour—with grooves that were 2mm apart, 5mm wide and 4mm high—proved best able to withstand the assault.
Not as good but still better. Han Zhiwu’s advice for aircraft designers is that the right sort of rough surface may be better, overall, than a smooth surface.
If nature is unintelligently designed, how come it has so much to teach us?
Hat tip: AITSE Newsletter