A team of researchers from the UK has published a new discovery that suggests limpets, the aquatic snails that fasten themselves to the tidal rocks during high tide and feed on seaweed and algae possess the strongest teeth in the world, and this is not unconnected with their abilities to carve out a hollow on the surface of the rocks where they dwell in low tide.
Limpets do not have coiling features in their shells, and they are mollusks categorized as Gastropoda. Their conical shells are often dish-shaped and called patelliform by scientists. They often attach themselves to rocks in high tide, but carve out depressions for themselves on the surface of the rocks when the tide moves out, occupying the hollow surfaces they have dug out – called “home scars.”
Scientists have always wanted to know how limpets manage to carve out a hollow space for itself on the surface of tidal rocks, and now discover that the mollusks use their tongues called radulae and the tiny set of teeth it contains to scrape out the rock until it has a comfortable hollow to occupy for itself. These teeth are made of a protein-mineral composite material that exhibits extraordinary strength, and are stronger than spider silk and all but the very strongest man-made materials.
“Biology is a great source of inspiration as an engineer,” said the study’s lead author Asa Barber, from the University of Portsmouth. “These teeth are made up of very small fibres, put together in a particular way – and we should be thinking about making our own structures following the same design principles.”
Less than one millimeter in length and comprised of an iron-based mineral called goethite, the teeth are threaded in fibers through a protein base. The researchers applied an atomic force microscope to measure the force necessary to pull apart the tooth material filed to 100 times thinner than a human hair. They found the tooth material could withstand up to five times the force necessary to pull spider silk apart.
Barber added that “People are always trying to find the next strongest thing, but spider silk has been the winner for quite a few years now. So we were quite happy that the limpet teeth exceeded that.”
The limpet tooth material is stronger than Kevlar and almost as strong as the highest quality carbon fiber material you can get in the market today.