London: Limpet teeth may be the strongest natural material known to humans, with powerful biological structures that could be mimicked and used to make Formula 1 racing cars and aircraft, scientists say.
Researchers from the University of Portsmouth, UK, have discovered that limpets – small aquatic snail-like creatures with conical shells – have teeth with biological structures so strong that they could be copied to make cars, boats and planes of the future.
The study examined the small-scale mechanical behaviour of teeth from limpets using atomic force microscopy, a method used to pull apart materials all the way down to the level of the atom.
“Until now we thought that spider silk was the strongest biological material because of its super-strength and potential applications in everything from bullet-proof vests to computer electronics but now we have discovered that limpet teeth exhibit a strength that is potentially higher,” said Professor Asa Barber from the School of Engineering who led the study.
Barber found that the teeth 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 fibres 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,” Barber said. The research also discovered that limpet teeth are the same strength no matter what the size. The material Barber tested was almost 100 times thinner than the diameter of a human hair so the techniques used to break such a sample have only just been developed.
“The testing methods were important as we needed to break the limpet tooth. The whole tooth is slightly less than a millimetre long but is curved, so the strength is dependent on both the shape of the tooth and the material,” Barber said.
“We wanted to understand the material strength only so we had to cut out a smaller volume of material out of the curved tooth structure,” he said.
The research was published in the Royal Society journal Interface.
