In-plane measurements and computational fluid dynamics prediction of permeability for biocompatible NiTi gyroid scaffolds fabricated via laser powder bed fusion

Abstract

Laser powder bed fusion (LPBF) is considered a promising technology for manufacturing porous, biomimetic, and patient-specific scaffolds for bone repair. Scaffold permeability is one of the key factors to be considered for acquiring the required mass-transport properties in bone tissue engineering. This study aims to reveal the relationship between the design parameters of gyroid-based porous structure and scaffold permeability. A set of gyroid samples was manufactured from intermetallic NiTi alloy. Nine configurations of porous structures were obtained by varying the main design parameters, namely wall thickness and unit cell size. The in-plane method was employed to measure the permeability coefficient for the gyroid structures. Computational fluid dynamics simulations of the porous structures were performed to predict the targeted properties in an implant at the design stage before LPBF manufacturing. The results of the simulations were validated with the obtained experimental results. Geometrical accuracy and surface morphology of the as-built samples were investigated with various techniques. Biocompatibility assessment of the gyroid scaffolds was performed with human cell culture experiments.