Page 471 - IJB-10-6

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

Figure 5. Reconstructed images of scaffolds at different states and angles on the XY plane. (a) Macroscopic morphology of reconstructed scaffolds in three
states: printed scaffolds (left), dried scaffolds (middle), and sintered scaffolds (right). (b) Average filament diameter of reconstructed scaffolds (n = 3);
filament diameter significantly decreased after drying and sintering. **p < 0.01.

This result was consistent with published research; the pore that the compressive strength and modulus of compression
structure significantly affects the mechanical properties of of the 90° scaffolds were the highest, demonstrating its
the scaffold. Adjacent layers of ink deposition on scaffolds superior compressive ability, followed by the 60° and 45°
with different pore structures resulted in varying numbers scaffolds, indicating that the microporous structure of
of joints, with structures with more intersections exhibiting the scaffold had a significant impact on its mechanical
stronger mechanical properties. The 90° scaffold had properties. However, there was a significant difference in
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the maximum number of joints, whereas the 45° scaffold the numerical predictions between the two models. Taking
exhibited the fewest (Figure 3). The larger number of joints the 90° scaffold as an example, the predicted compressive
might strengthen the mechanical properties of the 90° strength and compressive modulus of the reconstruction
scaffolds when it is compressed.
model were 6.54 ± 2.12 and 42.02 ± 3.74 MPa, respectively,
3.4. Establishment of finite element analysis while in the theoretical model, they were 14.02 ± 1.88 and
prediction methods 80.24 ± 9.88 MPa, respectively. Comparing the predicted
results with the actual test results (compressive strength:
3.4.1. Comparison of simulation and 7.65 ± 1.08 MPa; compressive modulus: 45.96 ± 3.57 MPa),
experimental data it was found that the accuracy of the reconstruction model
In this study, FEA was employed to reveal the stress
distribution within the scaffolds. Given the printing prediction was over 85%, significantly better than that
defects and morphological changes during the scaffold of the theoretical model (less than 60%). This deviation
preparation, the scan-reconstructed model was adopted might be due to simplification during the modeling
to simulate and analyze the mechanical behavior of the process and fluctuations in filament diameter during
sintered HAP scaffold. The results were then compared with actual printing (Figure 5), which prevented the theoretical
those obtained from a commonly used theoretical model. model from accurately reflecting the true structure and
Both models predicted linear stress–strain curves for the performance of the scaffold. Using theoretical models for
sintered HAP scaffolds, consistent with the behavior of analysis and prediction might overestimate the mechanical
brittle materials (Figure 7b), matching the measured trend performance of scaffolds, leading to scaffold failure during
(Figure 7a). The prediction results of both models indicate clinical use. In contrast, the reconstruction model was

Volume 10 Issue 6 (2024) 463 doi: 10.36922/ijb.4460