Defence Zhaohang Zhang: "Programmable Design of Mechanical Metamaterials"

Promotors: 1^st promotor: Prof. Antonis Vakis, 2^nd promotor: Prof. Francesco Picchioni

Abstract: Mechanical metamaterials (MMMs) are engineered materials with unprecedented properties derived from their microstructural design rather than intrinsic material composition. This dissertation explores the programmable design of MMMs, focusing on rose-shaped unit cells with tunable Poisson's ratio and stiffness. The research develops systematic frameworks for designing flat and tubular structures with programmable shape-morphing capabilities. Finite element analysis and experimental validation demonstrate the effectiveness of these designs in achieving precise deformation modes, including expansion, bending, and twisting. The study also investigates the application of MMMs in tissue engineering, utilizing Melt Electrowriting (MEW) to fabricate scaffolds with tailored mechanical properties. Computational models are developed to optimize scaffold architectures, reducing reliance on trial-and-error methods. Additionally, the dissertation explores the potential of MMMs in energy absorption, soft robotics, and biomedical devices, emphasizing their scalable manufacturing and multifunctional applications. By integrating computational design, additive manufacturing, and experimental validation, this work bridges the gap between theoretical concepts and practical applications. Future research directions include leveraging machine learning algorithms for automated and real-time design optimization of mechanical properties, advancing 4D printing for stimuli-responsive metamaterials, and improving manufacturing techniques to enhance precision and scalability. This dissertation contributes to the development of adaptive, cost-effective, and application-driven MMMs, paving the way for their implementation in diverse fields such as aerospace, robotics, and regenerative medicine.

Dissertation