Fundamental nanoscale studies show that there are adhesive molecules in abalone shell, bone and other materials that use the nanoscale mechanism of sacrificial bonds and hidden length to dissipate energy. These molecules are present in the gel matrix that binds together the mineralized collagen fibrils of bone. Bone fracture begins with the separation of the mineralized collagen fibrils at nanometer length scales. New instruments can now test how well bone resists this nanoscale separation of mineralized collagen fibrils . even in living patients! The results of these tests distinguish between the bone of patients with and without fractures. Thus, these instruments have the potential to diagnose bone fragility and to guide the development of therapies for decreasing bone fragility.