High stiffness and strength carbon fibres are commonly used to reinforce epoxy-resin composites. While wild Antheraea pernyi silk fibres exhibit high toughness originating from their α-helix/random coil conformation structures and their micro-fibre morphology, their insufficient strength and stiffness hinders them from being used in similar structural composites. In this work, we use interply hybridization of silk and carbon fibres to reinforce epoxy-matrix composites. With increased carbon fibre content, the quasi-static tensile/flexural stiffness and strength increases following the rule of mixtures while more silk fibre acts to increase ductility and impact strength. This results in a composite comprising equal volumes of carbon and silk fibres achieving an impact strength of 98 kJ m −2 , which is twice that of purely carbon-fibre reinforced composites (44 kJ m −2 ). This work shows tough natural silk fibres and strong synthetic fibres can be successfully integrated into epoxy-resin composites for tailored mechanical properties.

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Lightweight lattice structures engineered at various length scales have attracted considerable research and development (R&D) efforts. Natural silk fibers and their composites have shown great energy absorption potential and impact resistance. Herein, lattice structures are designed and fabricated from silk‐reinforced epoxy resin plastics (SFRPs). Unidirectional SFRPs from prepreg display excellent flexural modulus (6 GPa), flexural strength (194 MPa), and outstanding interlaminar shear strength (155 MPa), which is attributed to the strong physical and chemical affinity between silk and epoxy resin. The silk composite lattices (SCLs) of varied densities with pyramidal cores are fabricated from silk/epoxy resin prepreg. Under compression, combined fracture modes of Euler buckling (EB)/fracture crushing (FC) prolong the failure process of SCLs, and the specific energy reaches 7 J g−1, to surpass most plant fiber–reinforced composite lattices of a similar density. The new lattice structure well integrates the energy‐absorbing feature of natural silks and the lightweight characteristic of lattices for structural composite applications.