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International Journal of Bioprinting 3D-printing silicone patient-specific soft-tissue expander

swellable tablets from the other open end. Consequently, silicone membrane thickness could be reduced to allow the
the silicone expander required a longer time to seal to use of smaller expanders and incisions during surgery to
facilitate heat-sealing of the open end using a heat-sealing minimize the risk of wound dehiscence.
clamp. However, this approach could have led to errors The FE mesh model is displayed in Figure 11. The
in the volume expansion test, as it was observed that the simulation revealed that the maximum stress in the soft
actual expansion volume was only 80% similar to the tissue after expansion was 0.06 MPa, which was significantly
predicted volume. Nonetheless, the heat sealing created lower than the tensile strength stress of the soft tissue, that
flat surfaces at both ends of the expander, allowing it to is, 3.81 ± 0.94 MPa. 12,13 Therefore, it could be inferred that
be secured onto the mandibular bone with fixation screws. the stress induced by the soft-tissue expander on the soft
For future automatic sealing processes, we suggest also tissue could withstand tension and did not damage the
including a modified program in the silicone 3D printer soft tissue of the skin flap, thereby effectively preventing
to incorporate specialized fixtures into the expander. For complications associated with excessive expansion.
the present study, the XY-axis positioning accuracy of
the silicone 3D printer was ±0.04 mm, while the Z-axis This study utilized Carbopol 940 as the polymer
positioning accuracy was ±0.04 mm. The layer thickness material to produce swellable tablets and integrated
was 0.2 mm, and the silicone membrane thickness was silicone 3D-printing technology to develop a novel soft-
0.6 mm. With advancements in printer technology, the tissue expander. The feasibility and precision of the

Figure 11. A 2D plane strain finite element (FE) model of the soft-tissue expander silicone membrane and simulated results: (a) FE mesh model; (b) global
stress distribution with displacement control; (c) local stress distribution of soft-tissue.

Volume 10 Issue 4 (2024) 578 doi: 10.36922/ijb.2918