The teeth of tiny marine molluscs called limpets may be the strongest natural material in the world.
Until now, spider silk was considered the strongest natural material. However, researchers from the University of Portsmouth found that limpet teeth are even stronger than spider silk. The researchers claim that the biological structure of limpet teeth may also be replicated to build cars, planes and boats in the future.
Professor Asa Barber at the University of Portsmouth's School of Engineering, who also led the research, explained that they examined the mechanical behavior of limpet teeth at a very small-scale level. The study used atomic force microscopy, which is a method that pulls apart materials to the atom level.
The researchers found that limpets require teeth that have high strength to scrape over hard rock surfaces to eat algae. Limpet teeth contain a mineral called goethite and their fibers are of the right size, making up the strong composite structure.
The biological structure of the teeth can be mimicked and utilized in engineering applications that require high performance, such as racing cars used in Formula 1, the researchers said.
The study also found that the teeth of limpet have the same strength regardless of their size.
"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," reported Professor Barber.
The researchers also revealed that the sample that they tested was over 100 times thinner than a single human hair. Using an atomic force microscope, the researchers applied a force on the two ends of the material to rip it apart.
The calculations of the experiment showed that limpet teeth are about five times stronger than spider silk.
The study is significant because the strength-providing mineral fibers of limpet teeth are very thin, which is ideal for avoiding flaws that weaken engineering structures.
The study was published in the Royal Society journal Interface.
