Ceramic Materials Inspired by Conch Shells
Bioinspired design has the potential to enable the development of far tougher ceramic materials. In particular, the shell of the Queen conch (Strombus gigas) is particularly fascinating to materials scientists in the world of bioinspired materials. This is because this conch shell is made of 95% Calcium Carbonate (CaCO3), but has a toughness that is 1,000 times greater than that of monolithic CaCO3, also commonly known as chalk.
How is this possible? This is because the conch shell is a composite material, which contains:
🐚 Layers upon layers of aragonite crystals (a polymorph of CaCO3) criss-crossed at varying length scales.
🐚 Aragonite crystals small enough to force cracks in the material along tortuous paths
🐚 Aragonite crystals are held together by a tough viscoelastic protein-based matrix (the remaining 5% of the conch shell material)
Both the small size of the aragonite crystals and viscoelastic matrix mean that the conch shell provides a bioinspired design for body armors which are lightweight and tough. The potential impact of this is to improve upon existing body armor designs that rely upon non-composite ceramic materials.
We have much to learn from bioinspired design - and Queen conch shells are just the start!
Image from: https://www.sciencedirect.com/science/article/pii/S1096495913001978
Information from: https://www.researchgate.net/publication/253839782_The_conch_shell_as_a_model_for_tougher_composites