When using conical needles in bioprinting procedures, mechanical cell injury is a serious risk. Shear pressures and extensional flow are two of the stresses that biological inks loaded with cells undergo during extrusion through these needles, which may jeopardize the bioinks’ viability and functionality. Conical needles are advantageous in some bioprinting applications. This vital application made it our outright target in this study, which is conducted based on the reference paper entitled “ MODELING MECHANICAL CELL DAMAGE IN THE BIOPRINTING PROCESS EMPLOYING A CONICAL NEEDLE”.

Figure 1: Typical bioprinting setup b) cell deformation inside needle (from reference paper)

Simulation Process

The tapered needle geometry is created based on the parameters given in Table 1 (reference paper). It is then discretized by a structured grid inside ANSYS Meshing (100000 cells). The fluid carrying mechanical cells is a cell-alginate mixture.

Post-processing

The contours show how the fluid moves inside a conical needle used in bioprinting. In the first contour, the pressure decreases from the wide end to the tip, pushing the fluid. The third contour displays the speed of the fluid, which increases as it moves toward the narrow exit of the needle. Importantly, the second contour reveals that there is very high stress on the walls of the needle at the center, which could damage cells during the printing process. The high pressure, fast fluid movement, and intense stress at the narrow point of the needle make it difficult for cells to pass through without being harmed. This analysis emphasizes the importance of finding the right balance between efficient bioprinting and maintaining cell health.