Ultra‐Strong and Transparent Biomimetic Nanocomposite through Orientation Effects and In Situ Biomineralization

The fascinating mechanical property of biomaterials in nature to support living organisms largely relies on their hierarchical and ordered structures. However, for the current biomimetic materials, their organic–inorganic heterostructures typically exhibit poor uniformity, weak interfacial bonding, and various defects, limiting the breakthrough in strength and toughness. Herein, an ultra‐strong and transparent biomimetic nanocomposite is presented by combining orientation effects and in situ biomineralization to precisely engineer each level of the hierarchy. The orientation of nanofiber provides long‐range and order matrix to remarkably eliminate defects, promote multi‐scale interfacial bonding and increase the crystalline degree and size of organic matrix; while the in situ mineralization of amorphous inorganic oligomers firmly welds the organic–inorganic interface together to form a continuous and homogeneous monolithic structure. Due to the unique structural features, the nanocomposite exhibits a tensile strength of up to 1168.1 ± 10.2 MPa and a toughness of 34.1 ± 0.8 MJ m−3. Furthermore, the nanocomposite film is imparted with high transparence and anisotropic optical properties. This work is expected to provide insights into the design of high‐performance biomineralized materials from structural coupling to precisely controlling interfaces and microstructure.