Synchrotron X-ray nanomechanical imaging of mineralized fiber composites

In situ synchrotron X-ray scattering and diffraction, in combination with micromechanical testing, can provide quantitative information on the nanoscale mechanics of biomineralized composites, such as bone, nacre, and enamel. Due to the hierarchical architecture of these systems, the methodology for extraction of mechanical parameters at the molecular and supramolecular scale requires special considerations regarding design of mechanical test apparatus, sample preparation and testing, data analysis, and interpretation of X-ray structural information in terms of small-scale mechanics. In this chapter, this methodology is described using as a case study the deformation mechanisms at the fibrillar and mineral particle level in cortical bone. Following a description of the sample preparation, testing, and analysis procedures for bone in general, two applications of the method-to understand fibrillar-level mechanics in tension and bending in a mouse model of rachitic disease-are presented, together with a discussion of how to relate in situ scattering and diffraction data acquired during mechanical testing to nanostructural models for deformation of biomineralized composites.