School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150000, China.
Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A9, Canada.
ACS Biomater Sci Eng. 2022 Apr 11;8(4):1623-1643. doi: 10.1021/acsbiomaterials.1c01438. Epub 2022 Mar 14.
The design of scaffolds for tissue engineering has to consider two trade-off properties: mechanical and mass-transport properties. This is particularly true for additively manufactured scaffolds with the structures of minimal surfaces, and notably, the influence of the surface curvature of the structure on the mechanical and mass-transport properties remains unclear. This work presents our study on the scaffolds designed with the structure of triply periodic minimal surfaces (TPMS), with a focus on discovering the influence of surface curvature on the mechanical response and the mass-transport property or permeability of the scaffolds. Based on the entropy weight fuzzy comprehensive evaluation method, a model representative of both mechanical and permeable properties of scaffolds was developed; scanning electron microscopy (SEM) and finite element analysis (FEA) were also used to reveal the influence mechanism of curvature on structural fracture and deformation behavior. AlSi10Mg samples of scaffolds designed with different surface curvatures were manufactured using selective laser melting (SLM), and their mechanical and permeable properties were examined and characterized by both experiments and simulations. Our results illustrate that at the same porosity, the more concentrated the curvature distribution of the same type of unit, the better trade-off mechanical and mass-transport properties the scaffolds have. Particularly, at the porosity of 55%, the compressive elastic modulus and permeability of the Dte structure are increased by 2.03 times and 1.95 times compared with the Diamond unit, respectively. The fusion structure can greatly improve permeability performance at the cost of mechanical properties. Our results also show that porosity has the greatest influence on mechanical and permeable properties, followed by the surface curvature. The study illustrates that the surface curvature has a significant influence on the mechanical and permeable properties of scaffolds, and that the developed scaffold performance evaluation scheme is an effective means for the optimization and evaluation of scaffold performance.
机械性能和质量传输性能。对于具有最小表面结构的增材制造支架，这尤其如此，并且结构表面曲率对机械和质量传输性能的影响尚不清楚。这项工作介绍了我们对具有三重周期极小曲面（TPMS）结构的支架的研究，重点是发现表面曲率对支架机械响应和质量传输特性或渗透性的影响。基于熵权模糊综合评价方法，建立了一个能够代表支架机械性能和渗透性的模型；还使用扫描电子显微镜（SEM）和有限元分析（FEA）来揭示曲率对结构断裂和变形行为的影响机制。使用选择性激光熔化（SLM）制造了具有不同表面曲率的支架的 AlSi10Mg 样品，并通过实验和模拟对其机械和渗透性进行了检验和表征。我们的结果表明，在相同孔隙率下，相同类型单元的曲率分布越集中，支架的机械性能和质量传输性能的权衡越好。特别是在孔隙率为 55%时，Dte 结构的压缩弹性模量和渗透率分别比金刚石单元提高了 2.03 倍和 1.95 倍。熔合结构可以在牺牲机械性能的前提下极大地提高渗透性。我们的结果还表明，孔隙率对机械和渗透性的影响最大，其次是表面曲率。该研究表明，表面曲率对支架的机械和渗透性有重大影响，并且所开发的支架性能评估方案是优化和评估支架性能的有效手段。
