Mechanical properties and failure analysis of 3D-printing micron-scale ceramic-based triply periodic minimal surface scaffolds under quasi-static-compression and low-speed impact loads

Abstract

Numerous developments in additive manufacturing have endowed triply periodic minimal surface (TPMS) structures with excellent mechanical properties, providing possibilities for the wide application prospects of such scaffolds in repairing bone defects. However, current studies mainly focus on the basic mechanical and biomedical properties of TMPS with relatively large scale and low precision made from conventional materials such as stainless powder. Therefore, challenges exist in manufacturing ceramic-based TPMS bone scaffolds that stratify the precision requirements for human bones at the micron scale and further investigating their dynamic mechanical properties. Herein, we successfully design and fabricate two TPMS scaffolds named TPMS-B and TPMS-C with microstructures similar to that of human bone utilizing advanced 3D-printing technology. The experiments reveal that TPMS-C outperforms conventional porous scaffold (Normal-A) and TPMS-B for certain parameters such as specific strength and specific energy absorption. Moreover, the numerical simulation analysis illustrates that structural asymmetry and discontinuous boundaries are the main causes of completely destructive disparities in TPMS-C when exposed to given loads. Meanwhile, the cytocompatibility and osteogenic differentiation of the three scaffolds are verified. The objective of this work is to reveal the mechanical properties and failure analysis of novel 3D-printing materials that can be used to fabricate advanced TPMS bone scaffolds for bone defects treatment.