Multi-objective optimization for designing porous scaffolds with controllable mechanics and permeability: A case study on triply periodic minimal surface scaffolds

Design of tissue scaffolds in terms of multiple objectives such as mechanical and biological performances simultaneously remains challenging. In this paper, we present the development of a topology optimization approach that enables to design porous scaffolds with consideration of both mechanical and fluid properties simultaneously. The relationship between structural parameters, mechanical and mass transport properties was investigated, and then the scaffolds were optimized under the constraint of given pore size, porosity and specific surface area. Case studies on the optimized design of triply periodic minimal surface (TPMS) scaffolds were performed to illustrate the effective of our approach. Simulation and experimental results demonstrated that the proposed optimization approach fully decouples the mechanical and mass transport properties, specifically, under given porosities, the elastic modulus and permeability of optimized scaffolds ranged from 1.33 GPa to 16.7 GPa and 0.07 × 10⁻⁸ m² to 1.62 × 10⁻⁸ m², respectively. Three types of optimized gradient scaffolds were designed and they all exhibited significant functional gradients and high adjustability. The proposed approach decouples synergy and enables individual customization of multi-physics properties, providing practical guidance for gradient scaffolds with desired performance.