Abstract
Light, strong, and ductile materials (LSDMs) are desired in many emerging fields, such as biomedicine, aerospace industries, and structural engineering materials. However, producing such materials remains a significant challenge because their structures cannot confer the desired mechanical properties. In this study, we developed a silk fiber "welding" strategy to construct bioinspired LSDMs. The key to the welding process is to etch the surface of silk fiber through a partial dissolution process. The dissolved silk proteins further serve as welding materials or glues to bond the silk fibers together. Remarkably, these silk-LSDMs are not only lightweight (with the densities of around 0.28 g cm(-3)) but also strong and tough. Their compression strength reaches up to 13.8 ± 3.4 MPa, which is higher than those of most natural and engineered porous materials. These favorable structural and mechanical characteristics, together with outstanding biocompatibility of silk proteins, render these silk-LSDMs applicable in regenerated engineered tissues and water treatment materials.