Development of a high solid loading β-TCP suspension with a low refractive index contrast for DLP -based ceramic stereolithography

Digital light processing (DLP)-based ceramic stereolithography has recently been regarded as a promising method to produce bioceramic scaffolds because of its high processing accuracy. However, this process suffers from light scattering that can reduce its resolution. This study shows that a reactive monomer OPPEA (2-([1,1′-biphenyl]-2-yloxy) can weaken the light scattering in β-tricalcium phosphate (β-TCP) suspensions and increase the broadening depth by decreasing the refractive index contrast. Moreover, a β-TCP suspension with a low viscosity (5.76 Pa·s at 100 s−1), high solid loading (52 vol%) and high cure depth (>200 μm) without any broadening was developed by investigating the rheological behavior and cure behavior of the β-TCP suspensions. β-TCP scaffolds with a triply periodic minimal surface structure were also fabricated and exhibited a submicron-scale structure and low shrinkage rate (8%) after sintering. This suspension holds great promise for fabricating controllable β-TCP scaffold structures for bone tissue engineering by ceramic stereolithography.