Geometric frustration as a route to shape-morphing inflatables

Shape-morphing structures are at the core of future applications in aeronautics, minimally invasive surgery and smart materials. In this talk, I will present two strategies to program slender morphing inflatable structures. The first strategy consists in manufacturing elastomeric plates embedding a network of channels, which expand when inflated mainly perpendicular to their local orientation, similarly to simple elastic tubes, whereas the second strategy consists in two superimposed inextensible thin sheets, sealed together along a specific line network which contract on inflation. Playing with both the orientation and density of channels, the direction and intensity of the in-plane homogenized “growth” may be programmed and is in general incompatible with a flat geometry. The structure thus spontaneously buckles and adopts a shape which minimizes its elastic energy. Using the framework of non-Euclidean elasticity, we program the morphing of such inflatable structures.