Self-locking degree-4 vertex origami structures

Fang, Hongbin; Li, Suyi; Wang, K. W.

doi:10.1098/rspa.2016.0682

Cited by 54 publications

(30 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It locks the mountain/valley assignment of certain unit cells, but still allows the pattern to fold smoothly as a rigid origami to the flat-folded states. This is different from motion locking [21] where the panels come into contact with each other hindering the rigid foldability and preventing the pattern from reaching the flat-folded state.…”

Section: (C)(d)) the Bending Poisson's Ratio Is Then Obtained As (Smentioning

confidence: 88%

Geometric Mechanics of Origami Patterns Exhibiting Poisson’s Ratio Switch by Breaking Mountain and Valley Assignment

2019

View full text Add to dashboard Cite

Exploring the configurational space of specific origami patterns (e.g. Miura-Ori, Eggbox) has led to major advances in science and technology. To augment the origami design space, we present a pattern, named Morph, that combines the features of its parent patterns. We introduce a fourvertex origami cell that morphs continuously between a Miura mode and an Eggbox mode, forming a homotopy class of configurations. This is achieved by changing Mountain/Valley assignment of one of the creases, leading to a smooth switch through a wide range of negative and positive Poisson's ratios. We present elegant analytical expressions of Poisson's ratios for both in-plane stretching and out-of-plane bending, and find that they are equal in magnitude and opposite in sign. Further, we show that by combining compatible unit cells in each of the aforementioned modes through kinematic bifurcation, we can create hybrid origami patterns that display unique properties such as topological mode-locking (irreversible morphing under stretch by synchronized engagement of aligned panels in the Miura mode) and tunable switching of Poisson's ratio.

show abstract

Section: (C)(d)) the Bending Poisson's Ratio Is Then Obtained As (Smentioning

confidence: 88%

Geometric Mechanics of Origami Patterns Exhibiting Poisson’s Ratio Switch by Breaking Mountain and Valley Assignment

2019

View full text Add to dashboard Cite

show abstract

“…The early study by Schenk and Guest showed that using a nonuniform Miura‐ori crease pattern can ensure that a stacked origami material is locked in a predetermined configuration . Fang et al extended the study by using generic 4‐vertices, and identified several different self‐locking mechanisms that involves facet‐binding either within constituent origami sheets or between adjacent sheets . They further examined the locking‐induced discrete stiffness jumps using both numerical simulations and experiments .…”

Section: Folding Induced Mechanical Propertiesmentioning

confidence: 99%

Architected Origami Materials: How Folding Creates Sophisticated Mechanical Properties

et al. 2018

Self Cite

View full text Add to dashboard Cite

devices, [26,27] to small-scale nano- [28][29][30] and DNA origamis. [31] A common theme in these studies is to exploit the sophisticated shape transformations from folding. For example, an origami robot is typically fabricated in a 2D flat configuration and then folded into the prescribed 3D shape to perform its tasks. The origamis have been treated essentially as linkage mechanisms in which rigid facets rotate around hingelike creases (aka "rigid-folding origami"). Elastic deformation of the constituent sheet materials or the dynamics of folding are often neglected. Such a limitation in scope indeed resonates the origin of this field, that is, folding was initially considered as a topic in geometry and kinematics.However, the increasingly diverse applications of origami require us to understand the force-deformation relationship and other mechanical properties of folded structures. Over the last decade, studies in this field started to expand beyond design and kinematics and into the domain of mechanics and dynamics. Catalyzed by this development, a family of architected origami materials quickly emerged (Figure 1). These materials are essentially assemblies of origami sheets or modules with carefully designed crease patterns. The kinematics of folding still plays an important role in creating certain properties of these origami materials. For example, rigid folding of the classical Miura-ori sheet induces an in-plane deformation pattern with auxetic properties (aka negative Poisson's ratios). [32,33] However, elastic energy in the deformed facets and creases, combined with their intricate spatial distributions, impart the origami materials with a rich list of desirable and even unorthodox properties that were never examined in origami before. For example, the Ron-Resch fold creates a unique tri-fold structure where pairs of triangular facets are oriented vertically to the overall origami sheet and pressed against each other. Such an arrangement can effectively resist buckling and create very high compressive load bearing capacity. [34] Other achieved properties include shape-reconfiguration, tunable nonlinear stiffness and dynamic characteristics, multistability, and impact absorption.Since the architected origami materials obtain their unique properties from the 3D geometries of the constituent sheets or modules, they can be considered a subset of architected cellular solids or mechanical metamaterials. [35][36][37][38][39] However, the origami materials have many unique characteristics. The rich geometries of origami offer us great freedom to tailor targeted Origami, the ancient Japanese art of paper folding, is not only an inspiring technique to create sophisticated shapes, but also a surprisingly powerful method to induce nonlinear mechanical properties. Over the last decade, advances in crease design, mechanics modeling, and scalable fabrication have fostered the rapid emergence of architected origami materials. These materials typically consist of folded origami sheets or modules with intricate 3D geomet...

show abstract

“…Micro-origami structures like these provide a basic building block for microactuators or metamaterials. [40,41] The Miuraori pattern is well known to have one degree-of-freedom kinematics needed for this actuation approach; however, origami simulation methods such as the rigid folding algorithm [42,43] can be used to determine if other origami patterns also have one degree-of-freedom kinematics. For more complicated patterns, kinematic analysis alone may not be sufficient to determine if the system can be folded accurately and the placement of actuators will play a significant role.…”

Section: Toward Complex Origamimentioning

confidence: 99%

Elastically and Plastically Foldable Electrothermal Micro‐Origami for Controllable and Rapid Shape Morphing

Birla

Oldham

et al. 2020

Adv Funct Materials

View full text Add to dashboard Cite

Integrating origami principles within traditional microfabrication methods can produce shape morphing microscale metamaterials and 3D systems with complex geometries and programmable mechanical properties. However, available micro-origami systems usually have slow folding speeds, provide few active degrees of freedom, rely on environmental stimuli for actuation, and allow for either elastic or plastic folding but not both. This work introduces an integrated fabrication-design-actuation methodology of an electrothermal micro-origami system that addresses the above-mentioned challenges. Controllable and localized Joule heating from electrothermal actuator arrays enables rapid, large-angle, and reversible elastic folding, while overheating can achieve plastic folding to reprogram the static 3D geometry. Because the proposed micro-origami do not rely on an environmental stimulus for actuation, they can function in different atmospheric environments and perform controllable multi-degrees-of-freedom shape morphing, allowing them to achieve complex motions and advanced functions. Combining the elastic and plastic folding enables these micro-origami to first fold plastically into a desired geometry and then fold elastically to perform a function or for enhanced shape morphing. The proposed origami systems are suitable for creating medical devices, metamaterials, and microrobots, where rapid folding and enhanced control are desired.

show abstract

Self-locking degree-4 vertex origami structures

Cited by 54 publications

References 44 publications

Geometric Mechanics of Origami Patterns Exhibiting Poisson’s Ratio Switch by Breaking Mountain and Valley Assignment

Geometric Mechanics of Origami Patterns Exhibiting Poisson’s Ratio Switch by Breaking Mountain and Valley Assignment

Architected Origami Materials: How Folding Creates Sophisticated Mechanical Properties

Elastically and Plastically Foldable Electrothermal Micro‐Origami for Controllable and Rapid Shape Morphing

Contact Info

Product

Resources

About