Energy absorption characteristics of additively manufactured sea sponge-inspired lattice structures under low-velocity impact loading

Our research hypothesizes that bio-inspired lattice structures, modeled after the marine sponge *Euplectella aspergillum*, exhibit superior energy absorption capabilities due to their unique hierarchical architecture. Using low-velocity impact tests conducted with a drop tower, we gathered data on the energy absorption characteristics of these lattices, additively manufactured via digital light processing (DLP). The results reveal that the sea sponge-inspired lattice structure, incorporating double diagonal bracings within a square-grid lattice, enhances stability and promotes a layer-by-layer collapse under impact, achieving an 11-fold increase in energy absorption compared to conventional square-grid lattices. Further, by adjusting the thickness ratio, we observed an additional 87% improvement in energy absorption. The sponge-inspired lattices also outperform traditional energy-absorbing materials like hexagonal honeycombs of equal weight, and the addition of 0.015 phr MWCNTs further amplifies the energy absorption properties, indicating potential for multifunctional lightweight structures. The raw experimental data supporting this paper, titled "Energy absorption characteristics of additively manufactured sea sponge-inspired lattice structures under low-velocity impact loading," is accessible in the repository, with files labeled to correspond to figures in the manuscript and supplementary materials, which include comprehensive analyses of various parameters.