The spider's silk is known as the strongest natural material hailed for its strength and structure but it may now lose its claim after the limpet's teeth made it as the strongest biological material to be tested.
Scientists previously thought that the spider silk was the strongest natural material because of its remarkable strength that can be used in a number of applications ranging from computer electronic to bullet-proof vests but researchers from Britain have discovered that the teeth of limpets, sea snails with shells that are broadly conical in shape, are so strong they can be used in race cars, hulls of boats, planes and devices where strength-to-weight ratio is crucial.
For their report of the material published in the Royal Society journal Interface on Feb. 18, Asa Barber, from the University of Portsmouth's School of Engineering, and colleagues examined the behavior of the limpets' teeth using a method known as atomic force microscopy, which involves pulling materials apart up to the level of the atom.
They found that limpet teeth have strength that is potentially higher compared with spider's silk. They also found that the limpet teeth have the same strength regardless of the size.
"The tensile strength of discrete volumes of limpet tooth material measured using in situ atomic force microscopy was found to range from 3.0 to 6.5 GPa and was independent of sample size. These observations highlight an absolute material tensile strength that is the highest recorded for a biological material," the researchers wrote.
Barber and colleagues discovered that the teeth have a hard mineral called goethite which forms as the limpet grows. Barber pointed out that the aquatic snail needs highly strong teeth to rasp over the surfaces of rocks and remove the algae that they feed on when the tide is in.
"We discovered that the fibres of goethite are just the right size to make up a resilient composite structure," Barber said adding that the fibrous structures that are present in the limpet teeth could be duplicated and find use in high performance engineering applications such as the hulls of the boats, structures of aircraft and racing cars.
Peter Fratzl, from the Max Planck Institute of Colloids and Interfaces, said that the materials comprising the teeth of the limpets show promise for creating better engineering materials. Scientists and engineers alike eagerly eye duplicating the structure of the limpet teeth to come up with higher performance materials.
