Thesis

Toward the 3D printing of bioinspired heterogeneous structures

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2026
Thesis identifier
  • T17608
Person Identifier (Local)
  • 202485867
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • The development of multifunctional materials inspired by biological systems has gained increasing attention due to their structural efficiency, adaptability, and sustainability. Among these, hydrogels derived from natural polymers such as sodium alginate offer significant potential for use in additive manufacturing, particularly in bioprinting and soft tissue engineering. However, their printability and mechanical performance depend strongly on effective chemical modification and photo-crosslinking behaviour. This study focused on the chemical modification of sodium alginate to create a photocrosslinkable hydrogel precursor using methacrylate reagents suitable for direct light processing (DLP). Three methacrylation routes, using methacrylic anhydride (MA), glycidyl methacrylate (GMA), and 2-aminoethyl methacrylate (AEMA), were compared to evaluate the degree of methacrylation (DOM), effect on hydrogel crosslinking density, and printing performance. The MA route was identified as the most practical and economical method, whereas the AEMA route required costly carbodiimide coupling reagents, and the GMA route was expected to exhibit inconsistent crosslinking. Rheological characterization further revealed that higher DOM in MA-modified gels produced larger storage moduli (G′) and shorter linear viscoelastic ranges, indicating increased crosslink density and brittleness. Cure depth analysis was used to estimate exposure times for DLP, but the theoretical values (0.43 s for AEMA-based and 0.44 s for MA-based resins at 0.05–0.5 mm slice thickness) were impractically short. Printing trials confirmed that these estimates were inadequate, as they did not account for the crosslinking degree required to achieve sufficient mechanical stability. A trial-and-error optimization approach achieved limited success with an AEMA route (DOM = 17%) resin and produced significant defects with lower DOM MA route (DOM = 7%) formulations. Further optimization of printing parameters and resin formulation is necessary to enable the fabrication of complex and mechanically robust DLP-printed structures.
Advisor / supervisor
  • Lau, K. H. Aaron
Resource Type
DOI
Date Created
  • 2025
Funder
Embargo Note
  • This thesis is restricted to Strathclyde users only until 12 February 2031.

Relations

Items

Thumbnail Title Date Uploaded Visibility Actions
file details File 2026-02-23 Embargo