Bio-inspired reinforcement of Voronoi lattices via hybridisation with periodic architectures for enhanced scaffold performance

Voronoi lattice structures are known for their close resemblance to the random porous architecture of human trabecular bone. In this study, a butterfly-inspired reinforcement strategy was used to improve the mechanical properties of Voronoi lattice structures. Five design configurations were proposed by incorporating periodic lattice structures as reinforcements, with each design tailored to meet tissue engineering requirements. Manufacturing was carried out using fused deposition modelling (FDM) with polylactic acid (PLA) as the material. The reinforcement strategy resulted in a ∼70% increase in both yield strength and Young's modulus under quasi-static compressive loading. Under impact loading, corresponding improvements of ∼45% and ∼75% were recorded for the same properties, respectively. Importantly, the proposed designs demonstrated mechanical performance among the highest reported for polymer-based Voronoi lattices. Overall, Octet + Voronoi and Weaire-Phelan + Voronoi configurations displayed superior mechanical properties. Permeability performance of these reinforced designs was also considerably better than the base Voronoi. In addition, the bio-inspired scaffolds promoted cellular attachment, growth, and proliferation across their surfaces.