Additively manufactured gradient Voronoi-based structures with enhanced compressive strength and deformability via a bamboo-inspired design strategy

Gradient Voronoi porous scaffolds are promising candidates for bone tissue engineering due to their biomimetic architecture and tunable mechanical properties. In this study, we present a bamboo-inspired gradient Voronoi design strategy that incorporates hierarchical features of bamboo into Voronoi topologies, enabling systematic control over layer number, array number, and iteration number. The effects of these structural parameters on the mechanical and deformation behavior of gradient Voronoi-based structures fabricated via laser powder bed fusion additive manufacturing were investigated using experiments and finite element simulations. The results showed that increasing layer number from 10 to 20 enhances interlayer connectivity and promotes multi-layer cooperative load transfer, leading to a significant increase in compressive strength from 39.84 MPa to 125.57 MPa and fracture strain from 16.46 % to 25.67 %. Lower array numbers and lower iteration numbers enhance local strut stability and connectivity of vertical and horizontal struts, delaying localized buckling and extending the plastic strengthening plateau. Compared with other zinc porous structures, the bamboo-inspired gradient Voronoi structure exhibited higher fracture strains and improved strength–ductility synergy. The findings can provide a valuable reference for the rational design of gradient bone implants.