Design and Performance of Bionic Multi-level Porous Structures Generated by 3D Printing

To obtain high-performing biological fixation implants with excellent properties, it is necessary to comprehensively characterize the design method and molding process of new porous structures printed using 3D technology. We adopted parametric modeling to design a bionic multi-level porous structure, evaluated the properties of the porous structure with finite element method, and optimized the design parameters. Finally, the properties of the 3D printed porous structure were characterized by a compression experiment and fractal theory. The results indicate that the porous structure designed by parametric modeling exhibits a good modeling effect. When a traditional porous structure is stressed, the stress mainly concentrates on the longitudinal bar, while the transverse bar is less stressed. In multi-level porous structures, the stress distributions of longitudinal and transverse bars are relatively uniform. No obvious molding defects were detected in the prepared porous structures. The interlaminar fracture mechanism of traditional porous structure is brittle fracture and the fracture mechanism of multi-level porous structure is elastic fracture. The modulus of elasticity and compressive strength increases with the increase of mean pore size and surface-to-volume ratio, and decreases with the increase of porosity. These results present a foundation for 3D printing of high-performing biological fixation implants.