Deep beneath the ocean’s surface lie the “black smokers“, undersea chimneys channelling superheated water from below the Earth’s crust. Completely devoid of sunlight, they are some of the most extreme environments on the planet. Any creature that can survive their highly acidic water, scorching temperatures and crushing pressures still has to contend with assaults from predatory crabs. What better place, then, to look for the next generation of body armour technology?
The scaly-foot gastropod (Crysomalion squamiferum) was discovered just 9 years ago at an Indian black smoker and it may have one of the most effective animal armours so far discovered. Its shell is a composite, made of three layers, each with different properties and made of different minerals. Together, they form a structure that’s completely unlike any known armour, whether natural or man-made. It can protect the animal from the searing heat of its habitat, stop its precious minerals from dissolving away in the acidic water and resist the crushing, penetrating, peeling claw-attacks of predatory crabs.
Animals have been protecting themselves with armour long before humans starting shaping steel and Kevlar. To create a protective covering, human designers must account for a mind-boggling array of physical traits including thickness, geometry, strength, elasticity and more. But evolution can take all of those factors into account without the guiding hand of a designer, putting thousands of structures through the test of natural selection and weeding out the best combinations. The results are the culmination of millions of years of research and development and they are striking in their effectiveness.
Haimin Yao from MIT works in the lab of Catherine Ortiz, a group that has been studying the defences of animals including sea urchins, chitons, a group of marine molluscs, to the Senegal bichir, a type of armoured fish.
Yao discovered the secrets behind the snail’s shell by slicing through it in cross-sections and studying its structure at a nanometre level. He even attacked it with a diamond-tipped probe, to simulate the crushing attacks of the crabs that frequent the black smokers. Using this data, Yao created a virtual simulation of the shell and put it through a digital crash-test, crab claws and all.