Nano-mechanical variations in chamber units of dry cuttlebone

Natural hierarchical structures have evolved to exhibit tailored mechanical properties, such as those found in various seashells. Due to their high impact-resisting mechanical properties, these structures have been widely investigated and form the basis of bio-inspired composite materials. This approach requires an accurate understanding of their mechanical properties at the level of individual micro- and nanoscale structural components, which are formed out of a mainly inorganic mineral with biopolymer inclusions in a layered arrangement. Here, we present an AFM study of the mechanical properties of cuttlebone and quantify the elastic modulus of its main micro-nanoscale constituents. The obtained results reveal the detailed mechanical properties of the hierarchical structure of cuttlebone and provide a strategy for accurately testing nanoscale mechanical properties of advanced composite materials.