Soutenance de thèse de Wei-Chih Tseng

Wei-Chih TSENG soutiendra sa thèse intitulée "Analysis of Flow Rate Impact in Extrusion-based Bioprinting to Improve Printing Quality", le mercredi 19 mars 2025 à l'université NCU à Taïwan. Un lien visioconférence sera disponible (envoyer un mail à barthelemy.cagneau@uvsq.fr ou luc.chassagne@uvsq.fr)

Titre : Analysis of Flow Rate Impact in Extrusion-based Bioprinting to Improve Printing Quality

Abstract:
Extrusion-based bioprinting is an efficient, simple, and cost-effective technique in bio-
printing, it capable of fabricating porous and complex three-dimensional scaffold struc-
tures widely used in tissue repair and regeneration. However, most biomaterial inks are
non-Newtonian fluids, and the rheological and thermal properties of different inks vary
significantly. The diversity and complexity of these fluids often result in the scaffold
manufacturing process relying on several trial-and-error approaches to determine suitable
printing parameter configurations, raising concerns about the quality and reproducibility
of the printed scaffolds.
In this study, we integrated flow sensing into an extrusion-based bioprinting (EBB) sys-
tem and replaced the conventional approach with fixed printing parameters by capturing
time-series data of all printing parameters, enhancing the monitorability of the printing
process. To improve the adaptability of EBB, we conducted experiments using three
different biomaterial inks with various parameter configurations and developed multiple
deep-learning models to evaluate their adaptability to different inks during the printing
process. This approach enabled ink-insensitive predictions of the scaffold linewidth.
To improve the transparency of black box models and enhance the credibility of their
prediction results, we employed two explainable artificial intelligence methods to analyze
the decision-making process of the deep learning model. This analysis aimed to identify
key features of the printing parameters and time series during the scaffold printing process.
The results enhanced the reliability of the model, and the identification of these key
printing parameters also provides new insights into the bioprinting process, laying the
foundation for improving the efficiency and quality of future bioprinting applications.

Flow rate was identified as a critical parameter that significantly influenced the quality
of scaffolds during the bioprinting process. By assessing the specifications of flow meters
used in bioprinting, we developed a novel flow application based on Particle Image Ve-
locimetry (PIV) technology to measure the flow rate of biomaterial ink during printing.
The reliability of PIV in measuring biomaterial ink was validated by comparing mathe-
matical theoretical models, precision scales, and PIV measurement results. This provided
new approaches and applications for enhancing the quality of bioprinting.