Light, Strong, and Ductile Architectures Achieved by Silk Fiber “Welding” Processing

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.