PNEULASTICS, pneumatically activated differentiated stretchable membranes

Abstract

The object of this research is the design of pneulastics, initially flat, pneumatically activated stretchable membranes with areas of differentiated thickness- and therefore elasticity- that respond with a different expansion rate and create complex tension conditions on their surface when sealed and pneumatically inflated. Previous work [1],[2],[4] has already shown interest in the analysis and acquisition of control over the geometry of inflatable structures, by introducing tension conditions upon the uniform pressure stresses, by means of additional third members other than air and membrane that raise the complexity of the structure. Other precedents [3] manage to embody constraints in pneumatic activation, laying emphasis on the activation itself rather than the final shape. Pneulastics introduce the integration of active material strategies in order to encode the differentiated activation into one single skin. With a series of physical experimentations that confirm the initial hypothesis, that pneulastics can provide a wide range of doubly curved shapes, we empirically decipher and describe material behaviour into digital simulation. Starting with a target shape input, our design method translates curvature and topology into flat membrane configuration that may lead upon inflation to the best approximation of the initial shape.