Artificial Wooden Nacre: A High Specific Strength Engineering Material

Nacre, an organic-inorganic composite biomaterial that forms an ordered multilayer microstructure after years of slow biomineralization, is known as the strongest and toughest material within the mollusc family. Its unique structure provides inspiration for robust artificial engineering materials. Lignocellulose is ultralightweight, abundant, and possesses a high mechanical performance and has been used for ages as a significant renewable raw material in wooden engineering composites. However, the inherent lack of mechanical properties of current wooden composites associated with the fragile microstructure has limited their applications in advanced engineering materials. Here, we develop a large-size ultralightweight artificial "wood nacre" with an ordered layer structure through a fast and scalable "mechanical/chemical mineralization and assembly" approach. The millimeter-thick artificial wooden nacre mimics the stratified construction of natural nacre, resulting in a bulk hybrid material that can achieve almost the same strength as natural nacre while consisting of only one-sixth of the total inorganic content of natural nacre. The specific strength and toughness of the artificial wooden nacre is even superior to engineering alloy materials (such as Cu and Fe). This approach represents an efficient strategy for the mass production of lightweight sustainable structural materials with high strength and toughness.