Asymmetric Zipper-Coupled Tubes and Smooth Sheet Attachments in the Design of Deployable Space-Filling Mechanisms

Abstract

Zipper-coupled tubes are a unique structure consisting of two tubes with zig-zag walls that, when coupled in a zipper fashion, resist compression in the normal direction. A wider application of zipper-coupled tubes, however, is precluded by their angular form. By focusing on a subset of zipper-coupled tubes with parallel and coplanar creases constructed by repeating asymmetric degree-four vertex cells, we design a smooth sheet attachment that lies flat when the asymmetric zipper-coupled tubes are fully deployed, increasing the utility of the otherwise jagged tubes. Furthermore, we provide an explicit mathematical model of the motion of the resulting mechanism, thereby demonstrating its rigid-foldability.