“Shrink & Morph: 3D-printed self-shaping shells actuated by a shape memory effect” by Jourdan, Schreck, Hugron, Martínez and Lefebvre
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Title:
- Shrink & Morph: 3D-printed self-shaping shells actuated by a shape memory effect
Session/Category Title: Computational Design
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Abstract:
While 3D printing enables the customization and home fabrication of a wide range of shapes, fabricating freeform thin-shells remains challenging. As layers misalign with the curvature, they incur structural deficiencies, while the curved shells require large support structures, typically using more material than the part itself. We propose a computational framework for optimizing the internal structure of 3D printed plates such that they morph into a desired freeform shell when heated. This exploits the shrinkage effect of thermoplastics such as PLA, which stores internal stresses along the deposition directions. These stresses get released when the material is heated again above its glass transition temperature, causing anisotropic shrinkage that induces curvature. Our inverse design method takes as input a freeform surface and finds an optimized set of deposition trajectories in each layer such that their anisotropic shrinkage deforms the plate into the prescribed surface geometry. We optimize for a continuous vector field that varies across the plate and within its thickness. This lets us obtain both developable and doubly-curved surfaces. The algorithm then extracts a set of deposition paths from the vector field in order to fabricate the flat plates on standard FFF printers. We validate our algorithm on freeform surfaces with non-trivial curvatures and topologies.
