Materials become insensitive to flaws at nanoscale: Lessons from nature

Natural materials such as bone, tooth, and nacre are nanocomposites of proteins and minerals with superior strength. Why is the nanometer scale so important to such materials? Can we learn from this to produce superior nanomaterials in the laboratory? These questions motivate the present study where we show that the nanocomposites in nature exhibit a generic mechanical structure in which the nanometer size of mineral particles is selected to ensure optimum strength and maximum tolerance of flaws (robustness). We further show that the widely used engineering concept of stress concentration at flaws is no longer valid for nanomaterial design.

[1]  R. Owen.  Palaeontology , 2018, Nature.

[2]  P. Fratzl,et al.  Structural development of the mineralized tissue in the human L4 vertebral body. , 2001, Journal of structural biology.

[3]  P. Fratzl,et al.  Graded Microstructure and Mechanical Properties of Human Crown Dentin , 2001, Calcified Tissue International.

[4]  Zhigang Suo,et al.  Deformation mechanisms in nacre , 2001 .

[5]  K. Vecchio,et al.  Quasi-static and dynamic mechanical response of Strombus gigas (conch) shells , 2001 .

[6]  Huajian Gao,et al.  Physics-based modeling of brittle fracture: Cohesive formulations and the application of meshfree methods , 2000 .

[7]  P. Fratzl,et al.  Mineralized collagen fibrils: a mechanical model with a staggered arrangement of mineral particles. , 2000, Biophysical journal.

[8]  R. Ballarini,et al.  Structural basis for the fracture toughness of the shell of the conch Strombus gigas , 2000, Nature.

[9]  Marc A. Meyers,et al.  Quasi-static and dynamic mechanical response of Haliotis rufescens (abalone) shells , 2000 .

[10]  Mario Viani,et al.  Molecular mechanistic origin of the toughness of natural adhesives, fibres and composites , 1999, Nature.

[11]  S. Weiner,et al.  Peritubular dentin formation: crystal organization and the macromolecular constituents in human teeth. , 1999, Journal of structural biology.

[12]  Steve Weiner,et al.  THE MATERIAL BONE: Structure-Mechanical Function Relations , 1998 .

[13]  P Zioupos,et al.  Mechanical properties and the hierarchical structure of bone. , 1998, Medical engineering & physics.

[14]  Huajian Gao,et al.  Numerical simulation of crack growth in an isotropic solid with randomized internal cohesive bonds , 1998 .

[15]  M. Marko,et al.  Mineralization of collagen may occur on fibril surfaces: evidence from conventional and high-voltage electron microscopy and three-dimensional imaging. , 1996, Journal of structural biology.

[16]  P. Hauschka,et al.  Nucleation and inhibition of hydroxyapatite formation by mineralized tissue proteins. , 1996, The Biochemical journal.

[17]  R. Mullen,et al.  A biomimetic example of brittle toughening: (I) steady state multiple cracking , 1996 .

[18]  W. Landis.  The strength of a calcified tissue depends in part on the molecular structure and organization of its constituent mineral crystals in their organic matrix. , 1995, Bone.

[19]  H. Warshawsky.  Organization of crystals in enamel , 1989, The Anatomical record.

[20]  A. P. Jackson,et al.  The mechanical design of nacre , 1988, Proceedings of the Royal Society of London. Series B. Biological Sciences.

[21]  M. Glimcher.  Recent studies of the mineral phase in bone and its possible linkage to the organic matrix by protein-bound phosphate bonds. , 1984, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[22]  John D. Currey,et al.  Mechanical properties of mother of pearl in tension , 1977, Proceedings of the Royal Society of London. Series B. Biological Sciences.

[23]  J. Gilman,et al.  Direct Measurements of the Surface Energies of Crystals , 1960 .

[24]  P. de Gennes,et al.  Why is nacre strong? Elastic theory and fracture mechanics for biocomposites with stratified structures , 2001 .

[25]  Siegfried Schmauder,et al.  Comput. Mater. Sci. , 1998 .