The strongest natural material known to man might be found in a small shellfish that clings to rocks around British shores . Researchers discovered that limpets – small aquatic snail-like creatures with conical shells – have teeth with biological structures so strong they could be copied to make cars, boats and planes of the future.
Until now, spider silk was considered the hardest material in nature because of its super-strength and potential applications in everything from bullet-proof vests to computer electronics, but scientists from the University of Portsmouth discovered that the teeth of this tiny shellfish contain a hard mineral known as goethite, which forms in the limpet as it grows.
“Limpets need high strength teeth to rasp over rock surfaces and remove algae for feeding when the tide is in. We discovered that the fibers of goethite are just the right size to make up a resilient composite structure. This discovery means that the fibrous structures found in limpet teeth could be mimicked and used in high-performance engineering applications such as Formula 1 racing cars, the hulls of boats and aircraft structures. Engineers are always interested in making these structures stronger to improve their performance or lighter so they use less material”, said Professor Asa Barber, the lead author of the study.
Researchers also explained that a big structure has lots of flaws and can break more easily than a smaller one, while the limpet teeth break this rule as their strength is the same no matter what the size. Because of both the shape of the tooth and the goethite mineral it was found to be the strongest material in nature.
The study examined the small-scale mechanical behavior of these teeth using atomic force microscopy, a method used to pull apart materials all the way down to the level of the atom. The sample that was tested was actually 100 times thinner than the diameter of a human hair.
Finding out about such strong designs in nature and then making structures based on these designs is known as “bioinspiration”.
The research was published in the Royal Society journal Interface.