According to the lead researcher of the study, Asa Barber, the fascinating structure of this organism came to the fore after Barber saw its picture in a textbook. A little further research into the subject revealed to her that the teeth are composed of small, extremely closely packed fibers of goethite, a mineral. It then struck Barber that the structure of the limpet’s teeth was almost identical to the structures that are used for aerospace components and parts, except on a much compressed scale.
A team of researchers at the University of Portsmouth in the United Kingdom has found that limpet teeth surpass the strength of any other material known to man, trouncing materials such as titanium, spider silk and Kevlar. Limpets are essentially snails that dwell in the sea. These vegetarian creatures grow to reach about 5cms in diameter, and feature conical shells. The movement of sea limpets is similar to that of garden snails – they usually latch on to a rock and move using a foot beneath their shell.
These snails do not move their bodies when they need to feed themselves – they simply extend an organ called the ‘radula’ that is lined with rows of minute teeth that help scrape food from various surfaces and move the food back to their mouth.
Barber was aware that such materials exhibit exceptional degrees of strength and lightness of weight, decided to further test the strength of this material against other similar biological materials.
From a tensile strength test that was carried out on limpet teeth, it emerged that about 6.5 gigapascals (GPa) of pressure were required to pull tooth material apart. In comparison, the same figure for spider silk stands at 4.5 GPa whereas for Kevlar it is only 3 to 3.5 GPa.
Now, the team will focus on translating the design principles of limpet teeth to create structures that are not only remarkably strong, but also exceedingly light. This process could take another five to ten years, Barber said.