Harnessing instabilities for design of soft reconfigurable auxetic/chiral materials

Shim, Jongmin; Shan, Sicong; Košmrlj, Andrej; Kang, Sung Hoon; Chen, Elizabeth R.; Weaver, James C.; Bertoldi, Katia

doi:10.1039/c3sm51148k

Cited by 179 publications

(128 citation statements)

References 25 publications

Supporting

Mentioning

128

Contrasting

Order By: Relevance

“…Building on these initial results, a library of 2D [21,174,180,181] and 3D [164] porous structures and structured porous shells [22,169,182] in which buckling induces pattern transformations has been identified (see Fig. 11).…”

Section: Instability-driven Pattern Formationmentioning

confidence: 99%

Exploiting Microstructural Instabilities in Solids and Structures: From Metamaterials to Structural Transitions

Kochmann

Bertoldi

2017

Applied Mechanics Reviews

Self Cite

196

View full text Add to dashboard Cite

Instabilities in solids and structures are ubiquitous across all length and time scales, and engineering design principles have commonly aimed at preventing instability. However, over the past two decades, engineering mechanics has undergone a paradigm shift, away from avoiding instability and toward taking advantage thereof. At the core of all instabilities-both at the microstructural scale in materials and at the macroscopic, structural level-lies a nonconvex potential energy landscape which is responsible, e.g., for phase transitions and domain switching, localization, pattern formation, or structural buckling and snapping. Deliberately driving a system close to, into, and beyond the unstable regime has been exploited to create new materials systems with superior, interesting, or extreme physical properties. Here, we review the state-of-the-art in utilizing mechanical instabilities in solids and structures at the microstructural level in order to control macroscopic (meta)material performance. After a brief theoretical review, we discuss examples of utilizing material instabilities (from phase transitions and ferroelectric switching to extreme composites) as well as examples of exploiting structural instabilities in acoustic and mechanical metamaterials.

show abstract

Section: Instability-driven Pattern Formationmentioning

confidence: 99%

Exploiting Microstructural Instabilities in Solids and Structures: From Metamaterials to Structural Transitions

Kochmann

Bertoldi

2017

Applied Mechanics Reviews

Self Cite

196

View full text Add to dashboard Cite

show abstract

“…Currently established functionalities include negative Poisson's ratio [2], vanishing shear modulus [3][4][5], negative compressibility [6,7], pattern transformation [8][9][10][11][12], switchable multistability [13], and topological insulation [14,15]. The building blocks for these materials are typically quasi-1D rods or springs, but recently, origami-inspired metamaterials made from folding planar structures have gained interest.…”

mentioning

confidence: 99%

“…Mechanical metamaterials are elastic media with extraordinary properties that arise from their microstructure [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Currently established functionalities include negative Poisson's ratio [2], vanishing shear modulus [3][4][5], negative compressibility [6,7], pattern transformation [8][9][10][11][12], switchable multistability [13], and topological insulation [14,15].…”

mentioning

confidence: 99%

Origami Multistability: From Single Vertices to Metasheets

et al. 2015

View full text Add to dashboard Cite

We show that the simplest building blocks of origami-based materials-rigid, degree-four vertices-are generically multistable. The existence of two distinct branches of folding motion emerging from the flat state suggests at least bistability, but we show how nonlinearities in the folding motions allow generic vertex geometries to have as many as five stable states. In special geometries with collinear folds and symmetry, more branches emerge leading to as many as six stable states. Tuning the fold energy parameters, we show how monostability is also possible. Finally, we show how to program the stability features of a single vertex into a periodic fold tessellation. The resulting metasheets provide a previously unanticipated functionality-tunable and switchable shape and size via multistability. [14,15]. The building blocks for these materials are typically quasi-1D rods or springs, but recently, origami-inspired metamaterials made from folding planar structures have gained interest. This represents an important departure for a variety of reasons. First, the deformations of folding-based materials can be highly nonlinear owing to the complex constraint space imposed by the fold network. Second, their energetic landscapes do not arise from central-force linear springs but instead through torsional spring interactions [16][17][18][19].Most recent attention has been focused on the Miura-Ori, a fold tessellation well known for its negative Poisson's ratio. Silverberg et al. recently used Miura-Ori to create a metamaterial with tunable stiffness by introducing a reversible "pop-through" defect [18]. This local defect, permitted via plate bending, is one of a few specific examples of bistability in folding planar structures-others include the symmetric water bomb vertex [20] and the hypar [21]. Such multistability is a desirable property for the design of metamaterials as it allows reprogrammable reconfiguration of shape and bulk properties.Here, we reveal how folding planar structures offer a platform for globally multistable metamaterials-structures capable of multiple stable shapes and sizes. Our building block is the degree-four vertex, i.e., four rigid plates connected by four folds (or hinges) that meet at a point. This is the simplest building block for origami metamaterials because it is a one-degree-of-freedom mechanism (lower n-vertices are rigid [22]). We show that the interesting physical properties arise from complexity in the physical configuration space, to which we now turn our attention.Generic configuration space.-We first consider generic four-vertices, i.e., those without collinear folds, symmetry, or flat foldability [23]. We specify the flat-state geometry by the set of sector angles fα i g, where each α i < π and

show abstract

“…This generic property inspires the identification of origami tessellations with mechanical metamaterials, or a composite whose effective properties arise from the structure of the unit cell. Although originally introduced to guide electromagnetic waves [18], rationally designed mechanical metamaterials have since been developed that control wave propagation in acoustic media [19,20], thin elastic sheets and curved shells [21][22][23][24], and harness elastic instabilities to generate auxetic behavior [25][26][27][28][29].…”

mentioning

confidence: 99%

Lattice mechanics of origami tessellations

2015

View full text Add to dashboard Cite

Origami-based design holds promise for developing materials whose mechanical properties are tuned by crease patterns introduced to thin sheets. Although there has been heuristic developments in constructing patterns with desirable qualities, the bridge between origami and physics has yet to be fully developed. To truly consider origami structures as a class of materials, methods akin to solid mechanics need to be developed to understand their long-wavelength behavior. We introduce here a lattice theory for examining the mechanics of origami tessellations in terms of the topology of their crease pattern and the relationship between the folds at each vertex. This formulation provides a general method for associating mechanical properties with periodic folded structures, and allows for a concrete connection between more conventional materials and the mechanical metamaterials constructed using origami-based design.While for hundreds of years origami has existed as an artistic endeavor, recent decades have seen the application of folding thin materials to the fields of architecture, engineering, and material science [1][2][3][4][5][6][7]. Controlled actuation of thin materials via patterned folds has led to a variety of self-assembly strategies in polymer gels [8] and shape-memory materials [4], as well elastocapillary self-assembly [9], leading to the design of a new category of shape-transformable materials inspired by origami design. The origami repertoire itself, buoyed by advances in the mathematics of folding and the burgeoning field of computational geometry [10], is no longer limited to designs of animals and children's toys that dominate the art in popular consciousness, but now includes tessellations, corrugations, and other non-representational structures whose mechanical properties are of interest from a scientific perspective. These properties originate from the confluence of geometry and mechanical constraints that are an intrinsic part of origami, and ultimately allow for the construction of mechanical meta-materials using origami-based design [1-4, 6, 11-13]. In this paper we formulate a general theory for periodic lattices of folds in thin materials, and combine the language of traditional lattice solid mechanics with the geometric theory underlying origami.A distinct characteristic of all thin materials is that geometric constraints dominate the mechanical response of the structure. Because of this strong coupling between shape and mechanics, it is far more likely for a thin sheet to deform by bending without stretching. Strategically weakening a material with a crease or fold, and thus lowering the energetic cost of stretching, allows complex deformations and re-ordering of the material for negligible elastic energy cost. This vanishing energy cost, especially combined with increased control over micro-and nanoscopic material systems, indicates the great promise for structures whose characteristics depend primarily on geometry, rather than material composition.By patterning creases, hinges, or fold...

show abstract

Harnessing instabilities for design of soft reconfigurable auxetic/chiral materials

Cited by 179 publications

References 25 publications

Exploiting Microstructural Instabilities in Solids and Structures: From Metamaterials to Structural Transitions

Exploiting Microstructural Instabilities in Solids and Structures: From Metamaterials to Structural Transitions

Origami Multistability: From Single Vertices to Metasheets

Lattice mechanics of origami tessellations

Contact Info

Product

Resources

About