Design of bionic porous structure of bone scaffolds and analysis of fatigue and permeability characteristics

Chao Long^1*chao qun²Feng Qiu Yuan³Guo Jian Wei⁴zhang wei⁵zhang yue qin⁵cui jie⁶chen xing⁵zhang ming⁷

• ¹Nanjing Vocational College of Information Technology, Nanjing, China
• ²Jinling Hospital, Affiliated Hospital of Medical School, Nanjing, China
• ³Department of Hematology, Zibo Central Hospital, Zibo, China
• ⁴School of Intelligent Manufacturing, Nanjing Vocational College of Information Technology, Nanjing, China
• ⁵School of Intelligent Manufacturing, Nanjing Vocational College of Information Technology, nanjing, China
• ⁶College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, nanjing, China
• ⁷Suzhou University of Science and Technology, suzhou, China

Bone defects caused by trauma, malignant tumors, and other diseases are common symptoms in orthopedic surgery, and when they exceed the critical size of autologous repair, bone transplantation is required. Artificial bone scaffolds are an effective way to repair large bone defects. An ideal artificial bone scaffold should not only have appropriate mechanical properties and biocompatibility, but also have good osteoinductive properties. This paper proposed a bionic porous structure design method based on Voronoi diagram. In the design process, controlling pore morphology and pore size by adjusting irregularity and porosity. In addition, the designed scaffolds were fabricated through laser powder bed fusion (L-PBF) with Ti-6Al-4V powders. The mechanical characteristics were evaluated by static mechanical simulation with ABAQUS and fatigue tests, and the permeability characteristics were analyzed by fluid simulation with COMSOL and in vitro test. The research results showed that fatigue meet the natural bone implant criteria by controlling the porosity and irregularity. And the mathematical relationship between fatigue characteristics and porosity and irregularity parameters was fitted. It can effectively predict the fatigue characteristics of the scaffold and improve its application in natural bone. At the same time, the designed structure has closer permeability to the natural bone, and was conducive to cell proliferation. Therefore, the porous structure based on Voronoi diagram may have good application potential in the bionic design of bone implants.