Limpets have 1, 920 teeth on their radula, the tongue-like appendage they use to scrape food off rocky surfaces. These teeth are made from common organic materials – chitin and goethite – but the compounds are arranged in ways that make the overall structure incredibly strong.
Limpet teeth are so strong, in fact, that they can only be cut using diamond saws. In 2015, this is exactly what researchers did to test the physical limits of the material. They cut small pieces of the mollusc’s teeth to exclude the effects of its curvature and observed how much load they could take before breaking. They found that limpet teeth are made from one of the strongest known biomaterials.
In August 2022, limpets once again lit up the material science community. Another group of researchers reported in Nature that they had created a novel biomimetic material based on the limpet tooth’s structure.
Before building the novel material, the scientists delved into the biology that generates these unique organs. They observed the molecular processes behind limpet tooth generation and the developmental stages of the radula, the organ from which the teeth emerge. They also looked at how limpet genes govern chitin and iron processing. Borrowing from the generative processes behind organic materials is a hallmark of biomimetic design.
The new limpet biomaterial consists of electrospun chitin scaffolds mineralised with cultured radula cells. Since chitin is biodegradable, this innovation could inspire biocomposites to replace synthetic materials where extreme strength is required, such as in engineering, automotive manufacture, and construction. (Read more)