The Poisson's ratio of a material characterizes its response to uniaxial strain. Materials normally possess a positive Poisson's ratio - they contract laterally when stretched, and expand laterally when compressed. A negative Poisson's ratio is theoretically permissible but has not, with few exceptions of man-made bulk structures, been experimentally observed in any natural materials. Here, we ...

<span lang="EN-US">This study reviews and analyzes the different auxetic materials that have been developed in recent years. The search for research articles was carried out through one of largest databases such as ScienceDirect, where 845 were collected, which several filters to a base 386 articles. There are variety depending on their structure, composition, industrial application, high...

Graphene is an active element used in the design of nano-electro-mechanical systems (NEMS) owing to its excellent in-plane physical properties on mechanical, electric and thermal aspects. Considering a component requiring negative Poisson's ratio in NEMS, a graphene kirigami (GK) containing periodic re-entrant honeycombs is a natural option. This study demonstrates that a GK with specific auxet...

Auxetic behavior in low porosity metallic structures is demonstrated via a simple system of orthogonal elliptical voids. In this minimal 2D system, the Poisson's ratio can be effectively controlled by changing the aspect ratio of the voids. In this way, large negative values of Poisson's ratio can be achieved, indicating an effective strategy for designing auxetic structures with desired porosity.

Buckling is exploited to design a new class of three-dimensional metamaterials with negative Poisson's ratio. A library of auxetic building blocks is identified and procedures are defined to guide their selection and assembly. The auxetic properties of these materials are demonstrated both through experiments and finite element simulations and exhibit excellent qualitative and quantitative agre...

Auxetic cellular structures offer improvements in some mechanical properties due to their negative Poisson’s ratio response when loaded. This study investigates and compares the effect of using multiple materials within three well researched geometries, two auxetic: re-entrant anti- tetrachiral, one non-auxetic: hexagonal honeycomb. For each geometry, different material configurations were used...

In this paper, a new kind of hierarchical tube with a negative Poisson's ratio (NPR) is proposed. The first level tube is constructed by rolling up an auxetic hexagonal honeycomb. Then, the second level tube is produced by substituting the arm of the auxetic sheet with the first level tube and rolling it up. The Nth ( ) level tube can be built recursively. Based on the Euler beam theory, the eq...

Auxetic structures have been produced using 3D printing and knitted textile materials. A review of other auxetic textiles is presented along with the new range configurations were developed, prototyped, tested to demonstrate significant response, including Poisson’s ratio up negative one. The concept 4D was employed create environmentally responsive hinges in some structures, allowing material ...

Atomistic simulations are carried out for zeolite with ABW framework. The structure is modeled and force field simulations are preformed to investigate its elastic properties, bulk, shear modulus and auxeticity. Bulk moduli (Ks), Shear moduli (G), and Poissons ratios (ν) were found to be Ks=79.71725 GPa, G=16.93265 GPa, νxy = -0.2207, νxz= -0.5730, νyx= -0.71717, νyz=0.87013, νzx= -0.33097 and ...