3D Metapaper with unprecedented mechanical properties under water

Paper has been one of the most widely used sustainable materials for millennia. It is fascinating that its two-dimensional (2D) microstructure consisting of randomly stacked plant fibers has not significantly changed. Such laminate structure leads to paper’s limited mechanical strength and vulnerability to water. Here, we report a novel Metapaper architecture with unprecedented mechanical properties and a scalable roll-to-roll manufacturing process. The Metapaper consists of paper fibers tightly knitted with each other in three-dimensions (3D). Compared with conventional paper, Metapaper exhibits ultra-high mechanical properties, even in aqueous environments. A wet tensile strength of 11.2 MPa, fracture work of 797 KJ/m3 and abrasion resistance of 708 cycles have been achieved, which is about 16, 56 and 350 times more than that of regular paper, respectively. It can be folded over 600 times when loaded with 250g weight and bent at 135° under wet conditions, whereas regular paper would break down upon any folding operation. Except superior mechanical properties, Metapaper is completely additive-free, fully degradable and retains regular paper’s pleasurable visual and tactile sensations. We also demonstrate continuous roll-to-roll production of 3D Metapaper up to 45 cm in width with minimal add-on cost. The unprecedented mechanical properties of 3D Metapaper and its easily scalable manufacturing processes enable new prospects for paper’s applications.