On the permeability of TPMS scaffolds

This study presents an experimental evaluation of permeability of triply periodic minimal surfaces (TPMS). Permeability is widely used to characterize scaffolds for Tissue Engineering (TE) applications as it gives information about the structure porosity, pore size, tortuosity and pore interconnectivity which have an important impact in cell seeding and proliferation. Three different TPMS structures were used: Schwartz Diamond (SD), Gyroid (SG) and Schwartz Primitive (SP), in four different porosity levels (50, 60, 70 and 80%). Overall, the SG scaffold type was determined to be the most permeable one while the SD was the least permeable. Furthermore, the presence of microscopic inertial pressure losses was verified and the Forchheimer's law proved to be a good mathematical tool as a Darcy's law expansion for the calculation of the structure's permeability while the weak-inertia regime was hard to detect or quantify.