Session: 16-02-01: Poster Session: NSF Research Experience for Undergraduates (REU), NSF Posters

Paper Number: 96531

96531 - Ring Origami for Deployable Structures and Foldable Devices 

Foldable structures have been of great interest due to their ability to reduce in size from deployed to folded state, enabling easier storage in scenarios with space constraints such as aerospace and medical applications. These structures are commonly based on tessellations of structural components, which involves the patterning of panels and components without gap to enable efficient packing and structural design. State-of-the-art examples of tessellation-based structures involve the tessellated hexagonal mirrors of the reconfigurable James Webb Telescope, as well as various origami-inspired deployable solar arrays and medical devices. Of the common shapes capable of tessellation, hexagons have the greatest area to perimeter ratio, allowing a material-saving strategy for these structures. Thus, hexagonal structural components for foldable structures are of intrigue. However, the study on effective folding strategies of the hexagon geometry itself to enable extreme packing of these structures is limited. Here, we report a strategy of snap-folding of hexagonal rings when bending or twisting loads are applied to their edges, to result in reliable folded states of the rings to only 10.6% of their initial area. Motivated by this significant packing, we utilize a combination of experiments and finite element analysis to study effective folding strategies and packing abilities of various 2D and 3D hexagonal ring assemblies, with structures that can be folded to as little as 1.5% and 0.4% of their initial areas and volumes, respectively. Hexagonal rings made of steel are used to experimentally study the folding mechanism of single rings, as well as to develop foldable assemblies such as trusses of hexagonal rings with significant packing abilities. Finite element analysis is utilized for parametric study of the stability and foldability of hexagonal rings as well as for validation of experimental results. Geometric parameters of hexagonal rings can be varied to tune the mechanical stability of individual rings as well as their assemblies. Additionally, instabilities of rings can be utilized to facilitate automatic deployment of folded ring assemblies under small perturbations. Furthermore, integration of rigid functional components such as solar panels with the folding of the hexagonal ring is demonstrated, for a path to deformability of conventionally rigid, non-foldable elements. Future work can also take advantage of the incorporation of soft electronics with rings for foldable and wearable multifunctional devices. With demonstrated structures and devices that exhibit extreme area and volume changes upon snap-folding, it is anticipated that hexagonal ring assemblies could inspire future aerospace or biomedical designs, where reconfiguration and large packing are required.

Presenting Author: Sophie Leanza Ohio State University

Presenting Author Biography: Sophie Leanza is an undergraduate senior at The Ohio State University, where she is pursuing a degree in chemical engineering. Sophie started working on NSF-funded research on foldable and deployable origami devices in the Soft Intelligent Materials Lab in summer 2021 and has since lead and co-authored papers on related topics. Sophie plans to pursue a graduate degree in mechanical engineering after she graduates from Ohio State.<br/>Contact: leanza.13@osu.edu

Authors:

Sophie Leanza Ohio State University
Shuai Wu Stanford University
Renee Zhao Stanford University