On Design for Additive Manufacturing (DAM) Parameter and Its Effects on Biomechanical Properties of 3D Printed Ceramic Scaffolds

Abstract Biological and mechanical functions are sometimes two conflicting characteristics in bone tissue scaffolds, which necessitates a trade-off between these two properties in load-bearing applications. In this article, a systematic computational analysis was performed to investigate the effects of controllable fabrication factors (e.g. Design for Additive Manufacturing (DAM) Parameter) on compressive strength and permeability of ceramic scaffolds fabricated by robocasting technique, followed by a study on multiobjective optimization to determine the optimal structural parameters. To evaluate the compressive strength of scaffolds, the eXtended Finite Element Method (XFEM) was adopted to model fracture behavior in the scaffolds. Computational Fluid Dynamics (CFD) simulations were also conducted to analyze the permeability of the scaffold structures to quantify their biotransport capacity. Furthermore, experimental compression tests and fluid flow tests were conducted for some representative scaffolds to demonstrate the effectiveness of both XFEM and CFD simulations. The computational results indicated that the anisotropic degree of permeability could be controlled by adjusting particular geometric parameters during design and fabrication process, thereby enabling desirable directional permeability in each of longitudinal and transverse directions. Moreover, the XFEM results demonstrated that compressive strength of the scaffolds can be improved by at least 70% while the porosity is kept unchanged, which is of certain implication to design of robocast ceramic scaffolds for weight-bearing tissue engineering.