On design for additive manufacturing (DAM) parameter and its effects on biomechanical properties of 3D printed ceramic scaffolds

Biological and mechanical functions are sometimes two conflicting characteristics in bone tissue scaffolds, whichnecessitates a trade-offbetween these two properties in load-bearing applications. In this article, a systematiccomputational analysis was performed to investigate the effects of controllable fabrication factors (e.g. Designfor Additive Manufacturing (DAM) Parameter) on compressive strength and permeability of ceramic scaffoldsfabricated by robocasting technique, followed by a study on multiobjective optimization to determine the op-timal structural parameters. To evaluate the compressive strength of scaffolds, the eXtended Finite ElementMethod (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 bio-transport capacity. Furthermore, experimental compression tests andfluidflow tests were conducted for somerepresentative scaffolds to demonstrate the effectiveness of both XFEM and CFD simulations. The computationalresults indicated that the anisotropic degree of permeability could be controlled by adjusting particular geo-metric parameters during design and fabrication process, thereby enabling desirable directional permeability ineach of longitudinal and transverse directions. Moreover, the XFEM results demonstrated that compressivestrength of the scaffolds can be improved by at least 70 % while the porosity is kept unchanged, which is ofconsiderable implication to design of robocast ceramic scaffolds for weight-bearing tissue engineering.