Tailored Natural Fiber Shape Memory Polymer Biocomposites for Sustainable Architecture: Advancing Self-Responsive and Multifunctional Systems
On 4 March 2026, Asmaa Hassan defended her doctoral research titled "Tailored Natural Fiber Shape Memory Polymer Biocomposites for Sustainable Architecture: Advancing Self-Responsive and Multifunctional Systems" with distinction in front of the doctoral committee. The doctoral committee consisted of Prof. Martina Bauer(IEK) as chair, Prof. Dr. Hanaa Dahy (BioMat/ITKE) as supervisor and first examiner, and Prof. Dr.-Ing. Lucio Blandini (ILEK) as second examiner
Congratulations to Asmaa Hassan on her outstanding achievement!
Abstract of Doctoral Research
The growing demand for sustainable building materials calls for innovative solutions that minimize environmental impact while enabling adaptive, high-performance architectural systems. Inspired by nature’s intrinsic capacity for transformation and adaptability, shape memory polymers (SMPs) have emerged as promising candidates for responsive applications that change shape in response to external stimuli. However, despite this adaptability, SMPs suffer from low stiffness and strength, restricting their application to small-scale demonstrations rather than robust architectural contexts.
To address these limitations, Shape Memory Polymer Composites (SMPCs) have been reinforced with fibers, most often synthetic ones such as carbon or glass, which improve mechanical properties but compromise sustainability. Continuous fibers have also been employed, though typically in fabric forms rather than yarns, limiting precise control over alignment and performance. Meanwhile, natural fibers, though environmentally advantageous, have primarily been integrated in short-fiber thermoplastic SMP systems, offering programmability yet mostly with limited scalability and robustness for architectural applications.
This thesis advances the development of Shape Memory Polymer Biocomposites (SMPBCs) reinforced with continuous flax fibers, integrating sustainability, mechanical robustness, and programmable adaptability within a single material system. By integrating the renewability and strength of flax fibers with the responsive behavior of epoxy-based SMPs, and by overcoming fabrication constraints through Tailored Fiber Placement (TFP) for precise fiber yarn deposition, the research establishes comprehensive design-to-application workflows that connect material development, computational design, digital fabrication, and activation strategies.
A bottom-up methodology was adopted, beginning with the development and characterisation of continuous flax fiber-reinforced epoxy SMPBCs. Mechanical, thermomechanical, and shape memory behaviors were systematically evaluated across fiber orientations and patterns. Computational simulations guided adaptive geometries and corresponding fiber placement, including origami-inspired folding strategies and compliant hinges. Fabrication workflows were established through TFP combined with resin infusion, alongside explorations of moldless approaches to enhance efficiency and design freedom. Activation strategies included both direct thermal heating and indirect electro-active methods, with experimental prototypes used to validate scalability, reusability, and performance.
Results were demonstrated through a series of experimental studies and full-scale prototypes that translated the developed material systems into architectural contexts. These outcomes validated the feasibility of SMPBCs as an integrated material system for scalable, self-configurable, and multifunctional architectural applications that integrate sustainability, material intelligence, and design adaptability.
This research contributes a new class of sustainable, programmable, and mechanically robust biocomposites for architecture. By linking material innovation with computational design, digital fabrication, and activation strategies, it demonstrates how SMPBCs can move beyond laboratory novelty to become viable systems for multifunctional, responsive, and reusable applications, offering a pathway toward more sustainable and transformative architectural practices.
Papers of which the doctoral research consisted
Hassan, A., & Dahy, H. (2024). Continuous natural fiber-reinforced shape memory polymer biocomposites: design and fabrication for sustainable self-folding architectural applications. Smart Materials and Structures, 34(1), 015051. https://doi.org/10.1088/1361-665X/ad9c06
Hassan, A., & Dahy, H. (2025). Tailored continuous flax fiber-reinforced shape memory polymer biocomposites: Enhanced thermomechanical and shape memory performance for sustainable structural applications. Composites Part B: Engineering, 112840. https://doi.org/10.1016/j.compositesb.2025.112840
Hassan, A., Karazi, Y., Xie, W., Chau, W. M., Petrš, J., & Dahy, H. (2024). Shape memory polymer biocomposites for thermoresponsive self-configurable sustainable architectural applications. Composites Communications, 53, 102222. https://doi.org/10.1016/j.coco.2024.102222
Hassan, A., Bulut, Y., Sanei, S., & Dahy, H. (2025). Electro-Active continuous flax fiber-reinforced epoxy shape memory biocomposites with enhanced mechanical strength for self-shaping multifunctional architectural applications. Materials & Design, 255, 114203. https://doi.org/10.1016/j.matdes.2025.114203