Harnessing architected stiffeners to manufacture origami-inspired foldable composite structures

Owing to an excellent packaging efficiency and the possibility of jointless folding, origami-inspired composites have attracted great interest in aerospace, flexible electronics, robotics and other applications. Considering the complexity of origami patterns, novel fabrication methods are needed to manufacture the vast array of foldable-composite structures. In this study, a cost-effective compression molding technique is employed to develop origami-inspired fiber-reinforced foldable-composite structures. The manufacturing technique is demonstrated for two typical composite geometries, namely, an origami-inspired triangulated cylinder with a spiral configuration and a single-DOF reverse-folder flat flasher design. The folding operation is achieved through elastic hinges that separate the different architected stiffened regions of the composite. Flexural coupons are fabricated to investigate the behavior of the elastic hinges and establish the practical minimum width of the elastic hinge for rapid recovery after unloading. Mechanical tests on the cylindrical flexible structure show a consistent recovery of 90% of the original length after several loading cycles. The resulting cylindrical structure exhibited easy deployment and collapse properties. Finally, the flasher design (a box-like structure that flattens once deployed), exhibited a deployment radius equivalent to 4 times that of the folded state, as well as 98% recovery of its surface area.