Mechanically robust and thermally stable mineralized cellulose bulk structural materials via capillarity-assisted densification

Bioinspired design and manufacture based on sustainable raw materials is emerging as a promising way to develop high-performance lightweight structural materials. However, the bottom-up fabrication of bioinspired materials, involving the densification from dispersion systems of heterophase components through conventional evaporation methods, faces significant challenges due to high energy and time consumption. Here we demonstrate a simple and efficient method termed “capillarity-assisted densification” for the facile preparation of high-performance bioinspired structural materials. This versatile method, inspired by the wicking effect, effectively accelerates manufacturing efficiency while maintaining structural stability. The as-fabricated mineralized cellulose bulk structural materials exhibit high specific strength (146 MPa/(Mg m −3 )) and toughness (6.4 MPa m 1/2 /(Mg m −3 )), surpassing those of conventional polymer-based composites and various bioinspired composites. Furthermore, such a unique lightweight structural material bridges the gap between engineering ceramics and light alloys regarding the coefficient of thermal expansion and specific fracture toughness. We propose that green and robust mineralized cellulose bulk structural materials are promising for advanced lightweight structures, and that the capillarity-assisted densification could be easily adapted for various dispersion phases for practical bioinspired production.