Page 417 - v11i4

International

Journal of Bioprinting

RESEARCH ARTICLE
Investigation of humidity-driven swelling–

shrinking behavior of filaments in
material extrusion of medical-grade

biodegradable hydrogel

Kaicheng Yu 1,2† , Yifeng Yao 1,2† , Qiang Gao * , Le Xu , Wei Zhang , Min Zhu ,
4
3
1,2
1,2 id
Peng Zhang , Swee Leong Sing * , and Lihua Lu *
1,2
1,2
5 id
1 School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, China
2 Chongqing Research Institute of HIT, Chongqing, China
3 Key Laboratory of Data Analytics and Optimization for Smart Industry, Northeastern University,
Shenyang, Liaoning, China
4 School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin,
Heilongjiang, China
5 Department of Mechanical Engineering, College of Design and Engineering, National University
of Singapore, Singapore
† These authors contributed equally
to this work. (This article belongs to the Special Issue: Advances in 3D Bioprinting)
*Corresponding authors:
Qiang Gao (gaoq@hit.edu.cn)
Swee Leong Sing (sweeleong.
sing@nus.edu.sg) Abstract
Lihua Lu (lihual@hit.edu.cn)
Material extrusion using medical-grade biodegradable hydrogel demonstrates
Citation: Yu K, Yao Y, Gao Q, significant potential for manufacturing biocompatible scaffolds in regenerative
et al. Investigation of humidity-
driven swelling–shrinking medicine. However, unpredictable geometric variations in the fabricated models, such
behavior of filaments in material as swelling or shrinking, impede the development of complex three-dimensional (3D)
extrusion of medical-grade hydrogel architectures for in vitro-functionalized tissues and organs. A primary cause
biodegradable hydrogel.
Int J Bioprint. 2025;11(4):409-425. of structural deformation, such as wrinkling or even collapse, is improper humidity
doi: 10.36922/IJB025220222 control during the 3D printing process. Therefore, there is a need to investigate the
Received: May 27, 2025 swelling–shrinking behavior of hydrogels under varying ambient humidity and to
Revised: June 18, 2025 determine optimal humidity levels for the printing process. This study established a
Accepted: June 29, 2025 thermal–humidity–multiphase flow coupling field simulation model to numerically
Published online: June 30, 2025 investigate the humidity-driven swelling–shrinking behavior of hydrogel filaments.
Copyright: © 2025 Author(s). The optimal 3D printing humidity levels were determined for hydrogel filaments
This is an Open Access article with diameters of 0.2, 0.3, and 0.4 mm, which were found to be 90, 80, and 60%,
distributed under the terms of the
Creative Commons Attribution respectively. Using these humidity settings, several structures were fabricated,
License, permitting distribution, demonstrating moderated moisture loss of 3D architecture. Notably, a human ear
and reproduction in any medium, model was successfully printed, achieving an effective size of 20 mm (length) × 10 mm
provided the original work is
properly cited. (width) × 10 mm (height). Our research can benefit the future development in tissue
engineering and regenerative medicine.
Publisher’s Note: AccScience
Publishing remains neutral with
regard to jurisdictional claims in
published maps and institutional Keywords: 3D printing; Coupling field simulation; Humidity control;
affiliations. Medical hydrogel

Volume 11 Issue 4 (2025) 409 doi: 10.36922/IJB025220222