Single-parameter mechanical design of a 3D-printed octet truss topological scaffold to match natural cancellous bones

Designing a suitable scaffold matching the mechanical properties of natural bones to optimize the bone regeneration is required in bone tissue engineering. The present work developed a single-parameter design method for the octet truss topological scaffold to achieve the accurate prediction and flexible adjustment of its Young’s modulus and strength. A theoretical model that formulated the normalized Young’s modulus and normalized yield strength of the octet truss scaffold by the single parameter (d/Ø) was proposed and further validated by uniaxial compression tests and FEA simulations. On the basis of the proposed model, the Young's modulus and yield strength of the octet truss scaffold made of different polymers with different d/Ø were mapped, and the ranges of suitable d/Ø that match the different natural cancellous bones were suggested. The results showed that the design method could accurately predict the porosity, specific area, normalized Young’s modulus and normalized yield strength, and adjust the mechanical properties of the scaffold in a wide range. The present work can be used for the design of scaffolds and the selection of constituent materials to obtain a suitable scaffold with desired mechanical properties, and has application prospects in the fields of bone tissue engineering and regenerative medicine