Only just over 10cm in length, the mantis shrimp scuttles along the sea bed in the near darkness of the ocean floor. Unlike its cousins, the mantis is armed with two snapping pinchers, able to whip its club-like forearms an astonishing 23 metres per second – smashing its prey with the force of a rifle bullet. On first glance, it was thought that such a blow would permanently damage the mantis.
Despite the tremendous impact, however, these ancient crustaceans can throw punch after punch without sustaining a hint of injury.
It has led material scientists at the University of California to discover these small beasts have clubs uniquely designed with a nanoparticle coating that absorbs and dissipates energy.
The finding could prove significant for engineering materials in the automotive, aerospace and sports industries.
Professor David Kisailus, the study’s lead research, explained the peculiarity of the discovery on a human scale.
He told BBC Science Focus magazine: “Think about punching a wall a couple of thousands times at those speeds and not breaking your first.
“That’s pretty impressive, and it got us thinking about how this could be.”
Using transmissions electron microscopes (TEM) and atomic force microscopes (AFM), the team examined the nanoscale architecture and materials that make up the surface layer on the clubs.
From this, they found that the non particles are made of intertwined organic proteins and polysaccharides, as well as inorganic calcium phosphate non crystals.
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“At relatively low strain rates, the particles deform almost like a marshmallow and recover when the stress is relieved.”
Interestingly, at high strain rates, the particles behave differently.
Professor Kisailus explained: “The particles stiffen and fracture at the nanocrystalline interfaces.
“When you break something, you’re opening up new surfaces that dissipate significant amounts of energy.”
The peculiar structure could be imitated and used to engineer similar particles to add enhanced protective surfaces.
These could be used in human-oriented projects, such as cars, aircraft, bicycle helmets and body armours, the researchers say.
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