AccScience Publishing / IJB / Volume 7 / Issue 3 / DOI: 10.36922/ijb.v7i3.394

A Systematic Thermal Analysis for Accurately Predicting the Extrusion Printability of Alginate–Gelatin-Based Hydrogel Bioinks

Qi Li1,2† Bin Zhang1,2† Qian Xue1,2 Chunxiao Zhao1,2 Yichen Luo1,2 Hongzhao Zhou1,2* Liang Ma1,2* Huayong Yang1,2 Dapeng Bai1,2
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1 State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310058, People’s Republic of China
2 School of Mechanical Engineering, Zhejiang University, Hangzhou, 310058, People’s Republic of China
Published: 22 June 2021
© 2021 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( )

Three-dimensional (3D) bioprinting has significant potential for addressing the global problem of organ shortages. Extrusion printing is a versatile 3D bioprinting technique, but its low accuracy currently limits the solution. This lack of precision is attributed largely to the complex thermal and dynamic properties of bioinks and makes it difficult to provide accurate estimations of the printed results. It is necessary to understand the relationship between printing temperature and materials’ printability to address this issue. This paper proposes a quantitative thermal model incorporating a system’s printing temperatures (syringe, ambient, and bioink) to facilitate accurate estimations of the printing outcomes. A physical model was established to reveal the relationship between temperature, pressure, and velocity in guiding the printing of sodium alginate–gelatin composite hydrogel (a popular bioink) to optimize its extrusion-based printability. The model considered the phenomenon of bioink die swells after extrusion. A series of extrusion experiments confirmed that the proposed model offers enhanced printing outcome estimations compared with conventional models. Two types of nozzles (32- and 23-gauge) were used to print several sets of lines with a linewidth step of 50 μm by regulating the extrudate’s temperature, pressure, and velocity separately. The study confirmed the potential for establishing a reasonable, accurate open-loop linewidth control based on the proposed optimization method to expand the application of extrusion-based bioprinting further.

3D bioprinting
Pneumatic extrusion
Thermal effects
Temperature control

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International Journal of Bioprinting, Electronic ISSN: 2424-8002 Print ISSN: 2424-7723, Published by AccScience Publishing