Design and fabrication of anisotropic SiO2 gyroid bioscaffolds with tunable properties

Abstract

This paper introduces a mathematical approach and additive manufacturing process to customize the mechanical properties of sheet gyroid bioscaffolds and mimicking the intricate architecture of natural bone. By defining the parameters of the level-set equation, scaffolds with spatially controlled porosity and anisotropic properties can be fabricated though digital light processing and microwave heating. A new susceptor-assisted hybrid pyrolysis-sintering process was developed, resulting in a significant enhancement in quality and mechanical properties of the three-dimensional (3D)-printed ceramic compared to conventional methods. The enhancements are originated from the improved densification, accelerated sintering kinetics, promotion of cristobalite phase transformation, and reduced defect volume under microwave heating. Sheet gyroid scaffolds with radially graded porosity and anisotropic properties were fabricated. Despite the porosity distribution, an increase in the unit cell’s aspect ratio amplified the anisotropic mechanical properties. This was also accompanied by a slight decrease in cell proliferation efficiency possibly due to variations in Gaussian curvatures.