Tuesday, February 14, 2012
Surprisingly the north African desert scorpion, Androctonus australis, unlike other desert animals, does not dig burrows. It is a resistant to sand storms. When the sand whips by at speeds that would strip paint away from steel, this scorpion is able to survive without apparent damage.
Recently, Dr Han Zhiwu of Jilin University, in China, and his colleagues found that Androctonus armor is covered with dome-shaped granules that are 10 microns high and between 25 and 80 microns across. The granules disturb the air flow near the scorpion's surface in ways that appeared to be reducing the erosion rate. Their computer model suggested that if scorpion exoskeletons were smooth, they would experience almost twice the erosion rate that they actually do.
Aircraft engines and helicopter rotor-blades are constantly abraded by atmospheric dust, and a way of slowing down this abrasion would be welcome.
The research team placed samples of steel in a wind tunnel and fired grains of sand at them using compressed air. One piece of steel was smooth, but the others had grooves of different heights, widths and separations, inspired by scorpion exoskeleton, etched onto their surfaces. Each sample was exposed to the lab-generated sandstorm for five minutes and then weighed to find out how badly it had been eroded.
The result was that the pattern most resembling scorpion armor proved best able to withstand the assault. The lesson for aircraft makers, Dr Han suggests, is that a little surface irregularity might help to prolong the active lives of planes and helicopters, as well as those of scorpions.
From this we see another example of remarkable divine wisdom in nature. Human engineers are able to learn from humble little bugs.
Posted by jewish philosopher at 4:35 PM