Parametric design and mechanical performance analysis of hierarchical porous structures

In recent years, hierarchical porous structures have garnered extensive attention across multiple disciplines, inspired by their natural counterparts. While structural hierarchy significantly affects overall performance, the mechanistic influence of multiple hierarchical parameters on scaffold mechanical properties remains insufficiently systematized. In this study, a series of hierarchical porous scaffolds (with macro-to-micro pore size ratios of at least 10) featuring different hierarchical parameters were designed and fabricated. The presence of hierarchical structures and the effects of varying hierarchical spacing and pore size parameters on macroscopic structural performance were analyzed through experimental and computational methods. Results indicate that the introduction of hierarchical structures has a significant impact on the mechanical properties of scaffolds. As hierarchical pore size increases or spacing decreases, the mechanical properties of the structure exhibit a decreasing trend, and the maximum reduction in the compressive modulus reaches 25.82% and 45.62%, respectively. Moreover, a coupling mechanism exists between pore size and spacing, and the trend of simulation and experimental results aligns. These findings demonstrate that synergistic tuning of hierarchical parameters enables effective control over scaffold mechanical behavior. This offers new insights and lays a solid theoretical and experimental foundation for developing ideal bone scaffolds with tunable mechanical properties.