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International Journal of Bioprinting CFD analysis for multimaterial bioprinting conditions

Figure 8. Shear stress distribution results for 1 bar of dispensing pressure. (A) Heat map of the shear stress along the KSM-inserted mixing channel. (B)
Conical nozzle with a diameter of 0.4 mm.(C) Long cylindrical nozzle (12mm) with 0.4 mm outlet diameter.(D) Variation of shear stress as a function of
applied pressure and nozzle diameter. (E)Contour plot of shear stress for short needle (5 mm).

stresses in the range of 5–10 kPa and >10kPa. Results needles with small outlet diameters (0.25 and 0.40 mm)
revealed that the viability of cells decreased from 96% at applied pressures of 1 bar. These results suggest that
to 91% for moderate shear stresses (5–10 kPa), whereas our printing heads will induce negligible cell damage.
a significant decrease was observed for the shear It should be noted that the rheological data, considered
stresses over 10 kPa (76% of cell viability). Based on our in our CFD simulations, was related to alginate and
simulation results, the maximum shear stress observed in gelatin solutions without cells. However, several results
the mixing channel was around 66 Pa. The highest shear demonstrated that, even in the case of high cell densities,
stress for straight nozzles was below 5 kPa in all cases, no significant changes were observed on the bioink
whereas the peak stress values were obtained for conical rheological characteristics [1,31,66,67] .

Volume 9 Issue 6 (2023) 21 https://doi.org/10.36922/ijb.0219