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International audience; We introduce a new mechanism for self-actuating deployable structures, based on printing a dense pattern of closely-spaced plastic ribbons on sheets of pre-stretched elastic fabric. We leverage two shape-changing effects that occur when such an assembly is printed and allowed to relax: first, the incompressible plastic ribbons frustrate the contraction of the fabric back to its rest state, forcing residual strain in the fabric and creating intrinsic curvature. Second, the differential compression at the interface between the plastic and fabric layers yields a bilayer effect in the direction of the ribbons, making each ribbon buckle into an arc at equilibrium state and creating extrinsic curvature. We describe an inverse design tool to fabricate low-cost, lightweight prototypes of freeform surfaces using the controllable directional distortion and curvature offered by this mechanism. The core of our method is a parameterization algorithm that bounds surface distortions along and across principal curvature directions, along with a pattern synthesis algorithm that covers a surface with ribbons to match the target distortions and curvature given by the aforementioned parameterization. We demonstrate the flexibility and accuracy of our method by fabricating and measuring a variety of surfaces, including nearly-developable surfaces as well as surfaces with positive and negative mean curvature, which we achieve thanks to a simple hardware setup that allows printing on both sides of the fabric.

International audience; Printing-on-fabric is an affordable and practical method for creating self-actuated deployable surfaces: thin strips of plastic are depositedon top of a pre-stretched piece of fabric using a commodity 3D printer; the structure, once released, morphs to a programmed 3Dshape. Several physics-aware modeling tools have recently been proposed to help designing such surfaces. However, existing simulators do not capture well all the deformations these structures can exhibit. In this work, we propose a new model for simulating printed-on-fabric composites based on a tailored bilayer formulation for modeling plastic-on-top-of-fabric strips, and an extended Saint-Venant–Kirchhoff material law for modeling the surrounding stretchy fabric. We show how to calibrate our model through a series of standard experiments. Finally, we demonstrate the improvedaccuracy of our simulator by conducting various tests.

Printing-on-fabric is a recent manufacturing technique which consists in extruding molten plastic into pre-stretched fabric using standard additive manufacturing technologies. Printing-on-fabric recently gained popularity as a low-cost fabrication technique for designing deployable structures which can pop out of shape when the fabric is released. The complex morphing behavior of this composite material can be explained by metric frustration phenomena which are described in this thesis. We leverage these phenomena to build several applications aiding the design of self-actuated, lightweight structures.We first present a (forward) design tool for fabricating lightweight architectural models based on a tiling of star patterns, with the dimensions (and hence physical properties) of the individual pattern elements varying over space. Users of this system design free-form shapes by adjusting the star pattern; our system then automatically simulates the complex physical coupling between the fabric and stars to translate the design edits into shape variations.We then extend the form-finding tool to a general-purpose simulation method that can predict the buckling behavior of a variety of printed-on-fabric designs besides star tilings. We show the importance of modelling the bilayer effect caused by the differential compression at the interface between the plastic and fabric layers, as well as the anisotropic properties of the fabric.Finally, an inverse design tool that is able to reproduce target shapes with printing-on-fabric using a dense pattern of closely-spaced ribbons is introduced. The core of this method is a parameterization algorithm that bounds surface distortions along and across principal curvature directions, along with a pattern synthesis algorithm that covers a surface with ribbons to match the target distortions and curvature given by the aforementioned parameterization.; L'impression sur tissu est une technique de fabrication récente consistant à déposer sur un tissu étiré du plastique en fusion en utilisant des procédés standard de fabrication additive. L'impression sur tissu a récemment gagné en popularité car c'est une technique de fabrication peu coûteuse permettant de créer des structures déployables qui prennent automatiquement une forme en 3D lorsque le tissu est relâché. Le comportement en déformation de ce matériau composite peut s'expliquer par des phénomènes de frustration de métrique que nous décrivons dans la suite de cet exposé. Nous exploitons ces phénomènes pour proposer plusieurs applications aidant à la conception de structures auto-déployables légères.La première application présentée est un outil de design pour fabriquer des maquettes architecturales légères basé sur un pavage de motifs en étoile dans lequel les dimensions (et donc les propriétés physiques) de chaque élément varient dans l'espace. Les utilisateurs de ce système peuvent créer des formes libres en ajustant le motif d'étoiles ; notre système simule ensuite le couplage entre le tissu et les motifs de plastique pour traduire les paramètres en design en variations de forme.L'outil de simulation introduit précédemment est ensuite généralisé pour pouvoir s'appliquer à tous types de motifs imprimés et pas seulement des motifs en étoile. Nous modélisons notamment l'anisotropie du tissu ainsi que l'effet bilame causé par le différentiel de compression à l'interface entre la couche de plastique et la couche de tissu.Pour finir, une méthode de design inverse capable de reproduire des formes cibles en imprimant un motif dense de rubans peu espacés est présentée. Le cœur de la méthode consiste en un algorithme de paramétrisation qui borne les distorsions locales de surface le long des directions principales de courbure, ainsi qu'un algorithme de synthèse de motifs qui couvre la surface de rubans pour respecter les distorsions cibles et la courbure données par la paramétrisation.

International audience; We describe a new meta-material for fabricating lightweight architectural models, consisting of a tiled plastic star pattern layered over pre-stretched fabric, and an interactive system for computer-aided design of doubly-curved forms using this meta-material. 3D-printing plastic rods over pre-stretched fabric recently gained popularity as a low-cost fabrication technique for complex free-form shapes that automatically lift in space. Our key insight is to focus on rods arranged into repeating star patterns, with the dimensions (and hence physical properties) of the individual pattern elements varying over space. Our star-based meta-material on the one hand allows effective form-finding due to its low-dimensional design space, while on the other is flexible and powerful enough to express large-scale curvature variations. Users of our system design free-form shapes by adjusting the star pattern; our system then automatically simulates the complex physical coupling between the fabric and stars to translate the design edits into shape variations. We experimentally validate our system and demonstrate strong agreement between the simulated results and the final fabricated prototypes.