Design of TPMS-based Uniform and Hybrid Graded Lattice Structures: A Fluid Flow Analysis

Abstract

Each year, more than four million people around the world undergo bone grafts and prosthesis transplants to treat bone defects and injuries by repairing and/or replacing native bone. As a result, the scaffold holds great promise for the regeneration of damaged or diseased bone tissues. One of the key components is the design of scaffolds that can mimic the structure and function of natural bone. Based on unit cell design, triply periodic minimal surface (TPMS) has attracted the attention of researchers for designing porous scaffolds. In current study, uniform and multi-morphology hybrid graded structures were designed based on TPMS, namely, primitive and I-graph-wrapped package (IWP) minimal surfaces. Furthermore, a computational fluid dynamic (CFD) model was designed based on COMSOL Multiphysics to understand the fluidic characteristics (permeability and wall shear stress) of the structures. The results show that structures reported a permeability of 7.4 – 14.3 × 10 -8 m2, meeting the requirements of natural bone. Moreover, the average wall shear stress of 0.5 – 136 mPa was observed, suitable for osteoblast differentiation and proliferation.