Study on mechanical and permeability property of gradient multi-porous scaffold based on triply periodic minimal surface

In order to construct a bone scaffold structure with good biological properties, P-type, FRD-type homogeneous multi-porous scaffolds and P&FRD gradient multi-porous scaffolds with different porosities and unit cell scales were designed based on the triply periodic minimal surface（TPMS）.The effects of unit cell types, porosities and unit cell scales on the mechanical and biological properties of TPMS multi-porous scaffolds were investigated by tests and finite element simulation.The results show that the internal pores of homogeneous and gradient multi-porous scaffolds based on TPMS have good connectivity.The mechanical properties of multi-porous scaffolds decrease with the increase of porosity, but the permeability increases with the increase of porosity.Increasing the unit cell scale can significantly improve the permeability of multi-porous scaffolds.The permeability of the gradient multi-porous scaffold is also affected by the seepage direction.The gradient multi-porous scaffolds can synthesize the performance characteristics of each homogeneous unit cell structure, and show different mechanical and biological properties in different regions of the scaffold, which is closer to the structure and biological properties of human bone.