1st PhD year report Abstract Skeletal diseases such as osteoporosis affect millions of patients world-wide. In order to engineer patient specific treatment solutions, it is necessary to understand the multiscale structure-mechanics hierarchy and the irreversible behaviour of the fundamental building blocks of those mineralised tissues. While bone’s mechanical behaviour is well characterised at the organ level (Wolfram et al., 2016), the underlying non-linear properties of mineralised collagen fibre (MCF) assemblies remain unclear. Thus, the aim of this study is to investigate the post-yield behaviour of individual MCF assemblies by simultaneous micropillar strength tests and structural measurements using small-angle x-ray scattering (SAXS) and x-ray diffraction (XRD).