Design and properties research of radial gradient controllable biomimetic bone scaffold based on tree-liked fractal structure
Yuxi Liu, Aihua Li, Bing Du, Xiaohui He
Abstract
• A parameterized design method of tree-liked fractal structure biomimetic bone scaffold was proposed. • The Ti6Al4V tree-liked fractal scaffold designed in this work has the properties of high strength and low modulus. • Radial gradient scaffolds with different mechanical properties, porosity and radial gradient parameters can be designed. Inspired by the branching structure of natural trees, a parameterized design method of tree-liked fractal structure biomimetic bone scaffold was proposed. Four porous scaffolds with different fractal parameters were designed and prepared using selective laser melting (SLM) process. The radial porosity gradient distribution, mechanical properties, and permeability of the four biomimetic bone scaffolds were systematically studied. The 2nd-order and 3rd-order fractal structures have a gradient of gradually decreasing porosity from the inner to the outer zone, which is similar to natural bone. The mechanical test results indicate that the Ti6Al4V tree-liked fractal scaffold designed in this work has the properties of high strength and low modulus. The results of permeability measurement and analysis declare that the radial and axial permeability of the 2nd-order fractal structure are better than those of the other three structures. Therefore, the biomimetic bone scaffold with 2nd-order fractal structure has superior radial gradient porosity, mechanical properties and permeability. Radial gradient scaffolds with different mechanical properties, porosity and radial gradient parameters can be designed to meet the personalized needs of patients for bone implants in clinical practice.