3D printed epoxy composite microsandwich with high strength, toughness, and EMI shielding performances

Abstract

Materials with exceptional mechanical and electromagnetic interference (EMI) shielding properties are urgently needed due to the growing demand for multifunctional protection layers in aviation and new energy vehicles. Herein, we fabricate an epoxy-based composite microsandwich composing of solid and lattice layers via 3D printing. The rationally assembled layered architecture together with high manufacturing accuracy give the microsandwich high strength, toughness, and fracture toughness, exhibiting 92%, 140%, and 18.5% improvement compared to its solid counterpart, respectively. The solid layers bear most of the loadings, while the cellular lattice layers can prevent quick crack propagation, resulting in simultaneously high strength and toughness. Besides, the synergetic effect of the solid and lattice layers also effectively promotes the multiple reflection of the incident electromagnetic waves, giving rise to a high EMI shielding effectiveness. The above findings might offer insights into the achievement of highly tunable multifunctional properties for epoxy-based composites through properly controlled architectures.