Effect of unit configurations and parameters on the properties of Ti-6Al-4V unit-stacked scaffolds: A trade-off between mechanical and permeable performance.

Scaffolds in tissue engineering can be created or printed nowadays with various structures that consist of a number of three-dimensional (3D) units stacked together periodically. The performance or properties of such scaffolds can be affected by the unit configurations and parameters, which, however, has not been well investigated and elucidated. This paper presents our study on the influence of unit configuration and parameters on the scaffolds performance by taking triply periodic minimal surfaces (TPMS) as the basic unit. The normalized values of elastic modulus, shear modulus and permeability were used to characterize the scaffold performance and analyzed by means of finite element analysis and CFD simulation, with focus on identifying the influence of unit configurations and parameters on the scaffold mechanical and permeable properties. Furthermore, by selective laser melting (SLM) printing technique, the cubic Primitive and IWP scaffolds with an oversize of 12 mm (2 × 2 × 2 units) were created and subjected to compressive tests. Both simulation and experiment results are in agreement to illustrate that unit configuration and parameters have significant influence on the mechanical and permeable properties of TPMS units. The methods and findings in the present work would serve as the base or rationales to regulate the unit configurations and parameters with trade-off solutions for given tissue engineering application.