Factors governing the dimensional accuracy and fracture modes under compression of regular and shifted orthogonal scaffolds

Direct ink writing allows controlling the structure of tissue engineering scaffolds. The aim of this work was to study the effects of the in silico pattern design on the dimensional accuracy of tricalcium phosphate scaffolds and of the loading direction on the compressive strength and fracture modes. Regular and shifted scaffolds showed anisotropic shrinkage during drying and isotropic shrinkage during sintering. Shifted layers induced bending stresses when compressed longitudinally, resulting in lower compressive strength. The transverse Young's modulus and compressive strength were higher than the longitudinal ones for both regular and shifted structures. Strand deflections were more pronounced in shifted structures. Finite element modelling suggested that such deflections considerably increased the effective transverse modulus of the shifted scaffolds, thus increasing the related compressive strength. In conclusion, shifted scaffolds performed similarly to regular ones in the transverse direction but were less mechanically reliable under the longitudinal direction.

Keywords

Direct ink writing, Scaffold design, Tricalcium phosphate, Compression, Fracture mode

Citation

Journal of the European Ceramic Society. 2020, vol. 40, issue 14, p. 4923-4931.
https://www.sciencedirect.com/science/article/pii/S0955221920302260

Document version

submittedVersion

Language of document

en

Document licence

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/