Page 314 - IJB-9-4

International Journal of Bioprinting Biomechanical properties of 3D printable material

Table 2. Thickness, failure stress, and maximum Young’s modulus values in both longitudinal and circumferential directions
Location Thickness (mm) Failure stress (MPa) Maximum Young’s modulus (MPa)
L C L C
Medial proximal 1.66 0.46 0.45 0.75 0.89
Medial middle 1.72 0.47 0.61 0.72 1.05
1.80 0.46 0.64 0.61 0.98
Medial distal 1.63 0.31 0.36 0.61 0.74
Lateral middle 1.06 0.48 0.55 1.02 1.34
Lateral distal 1.05 0.48 0.56 1.02 1.19
Abbreviations: C, circumferential; L, longitudinal.

Table 3. Biomechanical properties of the NinjaFlex material according to thickness
Expected thickness (mm) Measured thickness (mm) Failure stress (MPa) Maximum Young’s modulus (MPa)
0.8 0.78 1.38 11.90
0.9 0.89 1.33 8.53
1 0.97 1.38 9.75
1.1 1.05 1.13 8.18
1.2 1.11 0.93 8.88
1.3 1.23 1.54 9.87
1.4 1.33 2.49 9.45
1.5 1.40 2.71 10.93
1.6 1.49 2.80 11.24
1.7 1.53 2.83 10.51
1.8 1.67 2.95 10.26

Table 4. Biomechanical properties of the Filastic material according to thickness
TM
Expected thickness (mm) Measured thickness (mm) Failure stress (MPa) Maximum Young’s modulus (MPa)
0.5 0.32 2.39 12.65
0.55 0.37 2.37 13.97
0.6 0.45 2.11 21.06
0.65 0.50 2.64 23.16
0.7 0.57 2.38 18.26
0.75 0.62 2.30 12.63
0.8 0.64 2.61 25.37
0.85 0.71 2.53 8.91

Its failure stress and maximum Young’s modulus similar (within 0.03 mm) to the ones measured during
did not increase with thickness. It displayed a highly the experiment. However, the 50 SH and 40 SH materials
heterogeneous behavior. With a thickness of 0.65 mm, its showed errors up to 0.45 mm. Table 5 displays the
failure stress and maximum Young’s modulus attained the thickness, failure stress, and maximum Young’s modulus
highest value with 2.64 MPa and 23.16 MPa, respectively. in both directions (A and B).
3.1.3. Rubber-like material (RGD450+TangoPlus) As RGD450+TangoPlus was printed for different
Ten samples of RGD450+TangoPlus were tested with values of stiffness, we showed that the 70 SH was the
the biaxial tensile technique. The expected printed stiffest, whereas the 40 SH was the least stiff. Theoretically,
thickness values provided by the manufacturer of materials with the same shore hardness should have the
RGD450+TangoPlus material in the 70 SH and 60 SH were same maximum Young’s modulus value regardless of

Volume 9 Issue 4 (2023) 306 https://doi.org/10.18063/ijb.736