It’s already become common wisdom that silk is Earth’s strongest material, however, recent discoveries tend to contradict that claim. Stronger than spider-silk and as tough (if not tougher) than Kevlar vests, snail teeth are even stronger than what scientists considered the toughest material on our planet.
Stemming from a limpet species known as the Patella vulgata, the teeth of these common snails are, as researchers report, the big contender for silk. Published on the 18th of February in The Royal Society journal interface, the study explains how the limpet teeth finally emerged victorious in this curious battle.
Granted, the teeth are so tiny that researchers could only examine them under a microscope, but strong essences are often found in small vials, or so they say. As scientists explain, the teeth are approximately 100 times thinner than human hair. Their particular composition is what grants them the title of toughest material on earth. Exceptionally thin, goethite coated, tightly-packed fibers run through the teeth, so that limpets are able to scrape whatever food they can find off of rocks. The goethite, which is a mineral, is formed by the tiny snail as it grows.
Lead study author, Asa Barber, was thrilled to make the discovery, noting that we could now adapt these findings in order to build anything from aircrafts and boats to dental fillings.
In order to precisely determine how strong the snail teeth were, scientists from the University of Portsmouth tested the tensile strength of the teeth by using an atomic force microscope. Tensile strength measures the amount of force that a particular material can withstand before it breaks. When the results were in, the team was pleased: while the majority of spider silks has a tensile strength of approximately one gigapascal, the teeth had a strength of five.
“Until now we thought that spider silk was the strongest biological material because of its super-strength and potential applications.”
Professor Barber said, while mentioning that limpet teeth are now a top contender, stronger and with endless possibilities.
Another noteworthy aspect when investigating the tiny teeth was that, no matter their size, it seemed that their strength remained the same. This is normally not the case for most materials, especially since, with bigger structures, more flaws tend to occur, causing the material to break more easily.
“Limpet teeth break this rule as their strength is the same no matter what the size.”
So why shouldn’t this material be used for a variety of other purposes, from race cars to aircrafts, especially in those cases where the strength-weight ratio is of the utmost importance?
The advantage for only making the discovery now is that the technology is also available so that this material found in nature can be properly split and used. As Prof. Barber explains, if they would attempt to use the material, small volumes would have to be cut out of the snail teeth and these volumes are less than 1 mm long.
Image Source: IO9