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International Journal of Bioprinting CFD analysis for multimaterial bioprinting conditions

Figure 9. Shear stress profiles as a function of the cylindrical nozzle outlet radius at different inlet pressures. (A) 1 bar, (B) 2 bar, and (C) 3 bar.

4. Conclusion Challenges Research Fund (CRF), grant number EP/
R01513/1.
The CFD model presented in this study enables to
investigate the fluid flow of two different biopolymers in Conflict of interest
a KSM-integrated printing head during the extrusion
process. The volumetric flow rate, pressure gradient, shear- The authors declare no conflict of interest. The funders
thinning behavior of the alginate–gelatin mixture, and the had no role in the design of the study; in the collection,
shear stress that occurs in the fluid domain were successfully analyses, or interpretation of data; in the writing of the
predicted using numerical results, allowing to optimize manuscript; or in the decision to publish the results.
the bioprinting process and to reduce the laborious trial-
and-error experimental approach. The spatial distribution Author contributions
of the biomaterials was analyzed at each successive cross- Conceptualization: Paulo Bartolo
sectional planes along the mixing chamber. Due to the Investigation: Gokhan Ates
presence of chaotic advection, the proposed printhead Methodology: Gokhan Ates
exhibited high mixing performance, regardless of the Writing – original draft: Gokhan Ates
applied pressure from the inlets. The volumetric flow rate Writing – review & editing: Paulo Bartolo
and velocity field were deeply investigated for cylindrical
and conical shaped nozzles, with different diameters under Ethics approval and consent to participate
varying dispensing pressures. Results suggest that, if high
bioprinting velocities are required, conical nozzles seem to Not applicable.
be the most suitable option. It was also observed that the
obtained maximum shear stress values were sufficiently Consent for publication
low to sustain high cellular viability. Not applicable.
Future work will focus on the extrusion of
multimaterials in the printing platform using a numerical Availability of data
model to further investigate operating parameters, such Data can be provided by request.
as the nozzle tip-build plate distance, relative velocity
between nozzle and substrate, and morphological analysis References
of the fibers after the deposition process.
1. Emmermacher J, Spura D, Cziommer J, et al., 2020,
Acknowledgments Engineering considerations on extrusion-based bioprinting:
Interactions of material behavior, mechanical forces and
The first author acknowledges the support received from cells in the printing needle. Biofabrication, 12(2):2–16.
the Turkish Ministry of National Education.
https://doi.org/10.1088/1758-5090/ab7553
2. Jiang T, Munguia-Lopez JG, Flores-Torres S, et al., 2019,
Funding Extrusion bioprinting of soft materials: An emerging
This project has been partially supported by the University technique for biological model fabrication. Appl Phys
of Manchester and the Engineering and Physical Sciences Rev, 6(1).
Research Council (EPSRC) of the UK, the Global https://doi.org/10.1063/1.5059393

Volume 9 Issue 6 (2023) 22 https://doi.org/10.36922/ijb.0219