Engineering news
Researchers have discovered that limpets have teeth with biological structures so strong they could be copied to make stronger and lighter bodies for cars, boats and aircraft in the future.
Engineers at Portsmouth University examined the small-scale mechanical behaviour of teeth from limpets, small aquatic snail-like creatures, using atomic force microscopy, a method used to pull apart materials down to the atomic level.
The teeth were found to contain a hard mineral known as goethite, which forms in the limpet as it grows.
Professor Asa Barber, leader of the study from Portsmouth University’s School of Engineering, said: “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.”
The material 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 research also discovered that limpet teeth are the same strength no matter what the size.
Barber said: “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. 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.”
“Generally a big structure has lots of flaws and can break more easily than a smaller structure, which has fewer flaws and is stronger. The problem is that most structures have to be fairly big so they’re weaker than we would like. Limpet teeth break this rule as their strength is the same no matter what the size.”
Spider silk was thought to be the strongest biological material and has had potential applications mooted in everything from bullet-proof vests to computer electronics but the research reveals that limpet teeth exhibit a strength that is potentially higher.
The research was published today in the Royal Society journal Interface.