Mechanical behavior of TPMS-based scaffolds: a comparison between minimal surfaces and their lattice structures

Triply periodic minimal surfaces (TPMS) have drawn widespread attention out of their biomimetic features. This work compares skeletal-TPMS lattices with of strut-TPMS lattices in terms of their geometric and mechanical properties. Skeletal-TPMS lattices consist of continually smooth surfaces, while their counterparts, strut-TPMS lattices, are composed of cylindrical beams. These lattices derived from four kinds of TPMS, namely Gyroid (G), Schwarz Diamond (D), Schwarz Primitive (P), and iWp (W), having incremental nodal connectivity of 3, 4, 6, and 8, respectively. The scaling laws of Young’s modulus and yield strength are determined as power functions of volume fraction according to finite volume method (FVM) simulations. Their uniaxial compression behaviors are characterized by FVM simulations and are experimentally validated using additive manufacturing and uniaxial compression tests, showing that skeletal-TPMS lattices exhibit more homogeneous stress distribution. This work would not only broaden the material space for scaffolds, but shed light on the design criteria for tissue engineering.