Print Email Facebook Twitter Curvature tuning through defect-based 4D printing Title Curvature tuning through defect-based 4D printing Author Moosabeiki, Vahid (TU Delft Biomaterials & Tissue Biomechanics) Yarali, E. (TU Delft Biomaterials & Tissue Biomechanics) Ghalayaniesfahani, A. (TU Delft Biomaterials & Tissue Biomechanics) Callens, S.J.P. (TU Delft Biomaterials & Tissue Biomechanics) van Manen, T. (TU Delft Support Biomechanical Engineering; TU Delft Biomaterials & Tissue Biomechanics) Accardo, A. (TU Delft Micro and Nano Engineering) Ghodrat, S. (TU Delft Emerging Materials) Bico, José (Sorbonne Université) Habibi, Mehdi (Wageningen University & Research) Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics) Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics) Date 2024 Abstract Emerging 4D printing techniques have enabled the realization of smart materials whose shape or properties can change with time. Two important phenomena play important roles in the 4D printing of shape memory polymeric materials. First, the anisotropic deformation of the printed filaments due to residual stresses can be harnessed to create out-of-plane shape transformations. Second, the unavoidable formation of micro-defects during the printing processes often affects the programmability of the printed object. Here, we propose a design approach that harnesses these two effects occurring during fused deposition modeling to create tailor-made curved geometries from initially 2D flat disks. We first determined the size and distribution of the imperfections formed within printed structures by varying two printing parameters namely the printing speed and the number of printed materials. Spatially varying the printing speed and combining polylactic acid filaments with a softer material without shape memory properties allowed us to cover a variety of shapes from negative to positive values of the mean and Gaussian curvature. We propose an analytical model to calculate the magnitude of the maximum out-of-plane deformation from the anisotropic expansion factor of the constituting microstructures. Furthermore, we develop computational models to predict the complex shape-changing of thermally actuated 4D printed structures given the distribution of rationally introduced imperfections and we demonstrate the potential applications of such defect-based metamaterials in drug delivery systems. Subject OA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:ea2d48a7-a455-4ce8-a2a5-632df5764916 DOI https://doi.org/10.1038/s43246-024-00448-w ISSN 2662-4443 Source Communications Materials, 5 (1) Part of collection Institutional Repository Document type journal article Rights © 2024 Vahid Moosabeiki, E. Yarali, A. Ghalayaniesfahani, S.J.P. Callens, T. van Manen, A. Accardo, S. Ghodrat, José Bico, Mehdi Habibi, Mohammad J. Mirzaali, A.A. Zadpoor Files PDF s43246-024-00448-w.pdf 6.06 MB Close viewer /islandora/object/uuid:ea2d48a7-a455-4ce8-a2a5-632df5764916/datastream/OBJ/view