Wear-resistant surfaces inspired by scorpions
As any graffiti-removal specialist will tell you, sand-blasting is definitely an effective method of removing substances that have bonded onto hard surfaces. Unfortunately, sand or other abrasive particles suspended in air or liquid also have a way of eroding not just spray paint, but pretty much anything they encounter. As a result, items such as helicopter rotor blades, airplane propellers, rocket motor nozzles and pipes regularly wear out and need to replaced. Interestingly enough, however, scorpions live their entire lives subjected to blowing sand, yet they never appear to ... well, to erode. A group of scientists recently set out to discover their secret, so it could be applied to man-made materials.
Zhiwu Han, Junqiu Zhang, and Wen Li led a team that examined the bumps and grooves on the exoskeleton of the yellow fattail scorpion. They started by scanning the creatures' backs with a 3D laser device, then used that data to create a computer model of the surface. A computer simulation was then applied to that model, to see how sand-laden air would flow over it. The digital model was also used as a template for an actual physical model, which was used in erosion wind tunnel tests.
The scientists subsequently applied what they observed in the scorpions' exoskeletons to man-made surfaces. They determined that the effects of erosion on steel surfaces could be significantly reduced, if that steel contained a series of small grooves set at a 30-degree angle to the flow of abrasive particles.
This isn't the first time that the study of creepy-crawlies' outer shells has had beneficial results for humans. Last year, MIT scientist Shreerang Chhatre devised a dew-harvesting material for people living in arid regions, based on the bumpy back of the water droplet-collecting Namib Beetle.