Dual-objective customized design of mechanical responses and mass transport characteristics for TPMS bone scaffolds

In bone tissue engineering, balancing mechanical properties and mass transport capabilities is essential for the design of porous scaffolds. This study proposes a dual-objective optimization design method based on triply periodic minimal surface (TPMS) structures, aiming to simultaneously meet the requirements of elastic modulus and permeability. Three types of TPMS structures—Diamond (D), Gyroid (G), and IWP—were constructed in both sheet and rod forms. The effects of structural parameters (both porosity and unit cell size) on the elastic modulus and permeability of the scaffolds were systematically investigated. Finite element analysis and computational fluid dynamics simulations were conducted to establish empirical formulas relating structural parameters to mechanical and transport performance, which were experimentally validated with high predictive accuracy. On this basis, orthogonal experiments and entropy weight analysis were introduced to quantitatively evaluate the influence of structural parameters on the two performance indicators, and a comprehensive performance optimization strategy was proposed. The results show that porosity is the most significant factor affecting elastic modulus, while unit cell size is the dominant factor influencing permeability. Among the structures, the IWP type demonstrates superior performance in both mechanical and transport characteristics. This study provides a theoretical foundation and quantitative tools for the personalized design of TPMS bone scaffolds, offering promising potential for clinical applications.