Engineered Living Textiles

Abstract

This thesis explores the development and optimisation of engineered living textiles by integrating microalgae into multilayer woven cotton-hydrogel architectures. The research evaluates the potential of microalgae-textile biocomposites as a novel approach to carbon capture, aiming to support microalgal viability within a textile matrix and to evaluate their capacity for CO₂ sequestration.

The study builds upon prior work demonstrating the feasibility of immobilising Scenedesmus sp. within textile-hydrogel systems. However, key challenges remained regarding long-term viability, structural stability, and quantitative CO₂ uptake. To address these gaps, a research-through-design methodology was employed, combining iterative material development with controlled laboratory experimentation. Multiple variables were systematically investigated, including textile architecture, hydrogel cross-linking methods, cryopreservation conditions, inoculation strategies, and environmental parameters.

Initial pilot studies evaluated baseline immobilisation methods and highlighted moisture retention as a critical factor for sustaining microalgal viability. Plain cotton textiles supported initial microalgae attachment but exhibited rapid drying and reduced long-term viability. The introduction of a multilayer cotton-hydrogel matrix improved hydration but revealed additional challenges, including structural inconsistencies, contamination, and reduced viability following freeze–thaw processing.

The technical characterisation of the study focused on optimising the hydrogel matrix, microalgae viability and preservation methods. Freeze-thaw and freeze-drying techniques were compared for cross-linking performance, showing that both methods produced structurally stable composites, though with limited long-term moisture retention. Cryoprocessing experiments demonstrated that freezing at −80 °C best preserved microalgal viability, while the use of glycerol as a cryoprotectant negatively affected photosynthetic performance. Additionally, subsequent experiments demonstrated that microalgae can be successfully introduced into the textile matrix after hydrogel cross-linking, providing an alternative immobilisation strategy that avoids exposing cells to damaging processing conditions. These findings emphasise the sensitivity of microalgae to processing conditions and the importance of balancing material stability with biological functionality.

CO₂ measurement experiments were conducted using a custom-built sensor system. However, consistent photosynthetic CO₂ uptake was not achieved across experiments. Instead, increases in CO₂ concentration were frequently observed, indicating respiration or loss of metabolic activity, particularly after freezing treatments. Furthermore, the results indicate that the microalgae-textile biocomposite does not yet demonstrate higher CO₂ uptake compared to conventional suspension cultures. This highlights the difficulty of maintaining active photosynthesis within the engineered textile system under the tested conditions.

Overall, the research demonstrates that microalgae can be successfully immobilised within multilayer woven textile matrices, and that material design significantly influences cell attachment and distribution. However, maintaining long-term viability and achieving reliable CO₂ sequestration remain unresolved challenges. The study identifies key factors affecting system performance, including moisture retention, textile structure, preservation conditions, and environmental control.

This work contributes to the emerging field of engineered living materials by providing insights into the integration of biological systems within textile architectures. While the current system does not yet achieve consistent functional performance or outperform conventional cultivation methods, it establishes a foundation for future research aimed at developing scalable, stable, and effective living materials for carbon capture applications.