Our goal is to unveil the design rules underlying the unique mechanical properties of protein assemblies, cells and tissues. We are interested in both bottom-up and top-down approaches. In the former, we study the relationship between structure and mechanical properties for peptides and proteins assemblies in vitro. In the latter, we are interested in human pathologies that modify the mechanical properties of cells and tissues through changes in cytoskeletal or extra-cellular matrix architecture. The techniques we use include atomic force microscopy, electron microscopy, X-ray scattering, second harmonic generation microscopy, as well as Infrared and Raman spectroscopy.