Elastic properties of nanocomposite structure of bone

As a nanocomposite material consisting primarily of mineral and protein, bone exhibits superior mechanical properties and complex hierarchical structures. It remains a major challenge to relate the macroscopic properties of bone to its hierarchical microstructures which start from the nanoscale and span over several orders of length scales up to macroscopic bone tissue. Here we show that the elastic properties of bone can be highly anisotropic at the nanoscale. FEM calculations and simple analytical models are used to evaluate the Young’s moduli, shear modulus and Poisson’s ratio of the mineral–protein nanostructure of bone. An open question is how these nanoscale properties are related to the macroscopic properties of bone tissue via many levels of structure hierarchies.