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International Journal of Bioprinting Stress prediction in 3D-printed scaffolds

Figure 7. Mechanical data of sintered scaffolds at different angles. (a) Stress–strain curve of the actual scaffold. (b) Stress–strain curve of the simulated
scaffold. (c) Mechanical performance of the simulated versus actual scaffolds (n = 3); the compressive strength of reconstructed and theoretical scaffolds was
generally higher than that of the actual scaffold. (d) Accuracy of simulation versus experimental finite element analysis (FEA) data (n = 3); reconstructed
scaffold FEA data exhibit higher accuracy; ***p < 0.001.

(Figure 10) to explore the changes in stress distribution distribution. Specifically, the stress of the scaffold in both
during the preparation process of the same scaffold. states was mainly concentrated at the edges and corners. In
The states “after printing,” “after drying,” and “after contrast, the correspondence of stress distribution for the
sintering” correspond to the state of the same scaffold 60° scaffold in the three states was relatively low. For the
right after printing, after freeze-drying to remove 45° scaffold, there was only partial correspondence in stress
moisture, and finally after sintering, respectively. We distribution among the three states, and the distribution
performed P-OCT/micro-CT scans on the scaffolds in range of stress concentration points in the sintered scaffold
these states, reconstructed the scaffold morphology based was wider.
on the scan data, and then performed FEA analysis on During the drying and sintering processes,
the reconstructed images. If the scaffold structure did significant morphological changes occurred, introducing
not change during the preparation process, the predicted uncertainties in the regulation of the scaffold’s mechanical
FEA stress distribution of the model should be consistent properties. The internal moisture and organics in the
in all states. If it couldn’t correspond, it indicated that the scaffold were gradually removed, leading to scaffold
structure of the scaffold had undergone non-uniform shrinkage and warping phenomena. These significant
changes. According to the results of the equivalent stress changes in the macroscopic morphology resulted in
nephograms of the scaffolds, there was a correspondence notable differences in its stress distribution compared to its
between the initial state (after printing) and the final post-printing state. The 60° and 45° scaffolds, due to their
state (after sintering) of the 90° scaffold in terms of stress structural complexity, exhibited more printing defects

Volume 10 Issue 6 (2024) 465 doi: 10.36922/ijb.4460