Silk Lattice Structures from Unidirectional Silk Fiber–Reinforced Composites for Breaking Energy Absorption

Abstract

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.