Dual-Purpose Lenticular Locking Hinges for Actuation and Stiffening of Deployable Origami Arrays

Abstract

Deployable origami arrays have been used to increase the aperture areas of spacecraft instruments. Folds within these patterns allow the arrays to fold compactly, but can also cause un-desired folding when in the deployed state. In addition, there is a need to deploy them with mechanisms that are light and small. This paper introduces a strain-energy storing joint that can be used to deploy and stiffen foldable origami arrays, called the Lenticular Lock (LentLock). The LentLock hinge design includes compliant flexures with geometry based on the Euler spiral. When panels are folded, the flexures are deflected flat and lie in-plane with the panels, storing strain energy. During deployment, the panels are released and the stored strain energy in the flexures opens the folded hinge. Simultaneously, the out-of-plane displacement of the deployed flexures is used to create beneficial interference to stabilize the array and prevent undesired refolding of the mechanism. In this paper, the geometry of the LentLock is introduced and performance of the joint is shown. The Lent-Lock is integrated into several folding mechanisms including a single fold, a single origami vertex, a Z-fold, and a multi-vertex origami array. Proof-of-concept prototypes of each folding pattern are shown.