Mechanical properties of graded scaffolds developed by curve interference coupled with selective laser sintering.

In bone tissue engineering, a scaffold requires not only facilitating cell activity but also providing adequate mechanical support. One feasible approach to ensure it is to use modeling tools to design such a scaffold which is then built by additive manufacturing. In this study, curve interference was introduced to design porous scaffolds with gradient structures based on three lattice units (cubical, circular and spherical) which were then manufactured by selective laser sintering (SLS) with PA12/HA material. The mechanical properties of both uniform and graded porous scaffolds were analyzed based on numerical and experimental tests. The results show that the uniform cubical-pore scaffold as well as the gradient spherical-pore scaffold has the optimal mechanical property. Further, uniform and graded scaffolds exhibit distinct failure mechanism. The graded scaffold has a layer-by-layer failure feature while each layer of the uniform structure almost has the same degree of deformation. Additionally, the comparison between the numerical and experimental results shows a good agreement, validating that the proposed curve interference method coupled with SLS technology is suitable for implementing the design of scaffolds following expected performance.