Multiscale Interfacial Engineering Enables Robust Reconstituted Wood

ABSTRACT Development of sustainable, high‐performance structural materials capable of replacing traditional engineering plastics and lightweight alloys is critical to achieving carbon neutrality. However, engineering renewable wood into structural materials intrinsically relies on reconstitution and bonding, during which traditional polymer adhesives introduce compositionally and mechanically heterogeneous interfaces. These discontinuities produce stress concentrations under water‐induced swelling and shrinkage, undermining long‐term stability. Herein, we proposed a synergistic strategy integrating interfacial reconstruction and water‐induced regeneration to reconstruct heterogeneous interfaces into homogeneous ones with compositional and structural continuity. This approach enabled lap joints to achieve a high dry shear strength of 6.2 MPa, exceeding that of natural wood. Notably, this strategy utilized water to facilitate the regeneration and performance retention of the interface, allowing the material to retain 97% of its strength even after two boiling water cycles. Furthermore, the mechanical properties were optimized through pressure control, thereby yielding specific flexural strength (276.2 MPa cm 3 g −1 ) and specific flexural modulus (24 000 MPa cm 3 g −1 ) that were comparable or even superior to those of certain metals, construction materials, and engineering plastics. This work provides useful insights into the design of high‐performance, sustainable wood‐based structural materials suitable for outdoor environments.