Folding of thick origami through regionally sandwiched compliant sheets

Abstract

The regional sandwiching of compliant sheets (ReCS) technique presented in this work creates flat-foldable, rigid-foldable, and self-deploying thick origami-based mechanisms. Regional sandwiching of the compliant sheet is used to create mountain-valley assignments for each fold about a vertex, constraining motion to a single branch of folding. Strain energy in deflected flexible members is used to enable self-deployment. This work presents the methods to design origami-based mechanisms using the ReCS technique, including volume trimming at the vertex of the compliant sheet and of the panels used in the sandwich. Three physical models, a simple single fold mechanism, a degree-four vertex mechanism, and a full tessellation, are presented to demonstrate the ReCS technique using acrylic panels with spring and low-carbon steels. Consideration is given to the risk of yielding of the compliant sheet due to parasitic motion with possible mitigation of yielding by decreasing the thickness of the sheet.