Abstract:
In this talk, I will present two strategies consisting in programming slender morphing inflatables structures. A 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. Playing with both the orientation and density of channels, the direction and intensity of the in-plane homogenized “growth” may be programmed, in general incompatible with a flat geometry. The structure spontaneously buckles and adopts a shape, which minimizes its elastic energy. In the case of very thin plates, an analytic method is proposed to solve the general inverse problem. In a second part, I will present structures made of two superimposed inextensible thin sheets, sealed together along a specific line network. Starting with flat curved ribbons, i.e the case of the popular mylar balloon letters, we observe and rationalize the surprising overcurvature upon inflation, as well as the wrinkle pattern. Extending the system to two-dimensional patterned structures, the local in-plane contraction upon inflation may be oriented along a director field, similarly to liquid crystal elastomers. We program the morphing of such stiff inflatable structures and investigate their mechanics.