Auxetic Behavior and Other Negative Thermomechanical Properties from Rotating Rigid Units

Auxetics display the anomalous property of expanding laterally when uniaxially stretched, that is, a negative Poisson's ratio, arises from 1) presence specific geometric features within nano/macrostructure material and 2) amenable deformations in response to applied stimulus. Herein, how ancient symmetrical esthetic artifacts have been transformed functional auxetics through mechanisms ripened field “mechanical metamaterials” “architected materials” last decades is explored. In particular, important role various implementations, both 2D 3D, “rotating rigid units,” which range squares” much more complex renditions at scales structure, are looked at. The rotating units generate thermal expansion compressibility also delved into.