Mechanical properties of Nacre

Nacre, also known as mother-of-pearl, is a biocomposite located at the inner layer of seashells, with exceptional mechanical properties such as fracture resistance, toughness and strength. Although its constituents are brittle CaCO3 crystals and ductile biomolecules, the combined structure exhibits extraordinary stiffness and toughness. Currently, artificial nacre-like composites are among the most promising materials for novel industrial applications. The complex hierarchical organization and the interactions at the bio-inorganic interface are critical for the high mechanical stability. The figure presents the internal organization of nacre at different scales.

Our group develops computational and theoretical tools for molecular simulations that are currently used to study nacre’s outstanding stability. We employ realistic nanometer size models, including flaw details, inorganic crystals and organic layers under different stress conditions. Our results are expected to link the macroscopic stability with the atomic structure of the material, unraveling the atomic mechanisms behind the mechanical stability of nacre.