Negative Poisson's ratio materials: names- anti-rubber, auxetic, dilational
Names of these materials
Materials with a negative Poisson's ratio  have been called anti-rubber , dilational materials , or auxetic materials  or auxetics. The name anti-rubber arises from the fact that negative Poisson's ratio materials become fatter in cross section when stretched. By contrast rubber becomes thinner. The name dilational arises from the fact that solids with negative Poisson's ratio n easily undergo volume changes. By contrast, rubbery materials easily undergo shape changes (shear deformation) but are much stiffer in relation to volume changes. The distinction is shown in a map adapted from Milton. The name auxetic, or auxetics after Evans and co-workers in a later article and subsequent publications, is derived from the root word for growth, alluding to the lateral expansion which occurs under tension. More recently, materials in which interesting properties arise from microstructure rather than composition have been called metamaterials. In many of these, resonant effects in the microstructure are of interest. Such effects were reported in the following, accessible on the main Poisson page. Chen, C. P. and Lakes, R. S., "Dynamic wave dispersion and loss properties of conventional and negative Poisson's ratio polymeric cellular materials", Cellular Polymers, 8(5), 343-359 (1989). The word metamaterial was not used at that time.
Novel materials are presented, which exhibit a negative Poisson's ratio.
Such a material expands laterally when stretched, in contrast to ordinary
materials. The original negative Poisson's ratio foam was developed by Rod
Foam materials with a negative Poisson's ratio as small as n = -0.7 were developed  in which an inverted or re-entrant cell structure was achieved by isotropic permanent volumetric compression of a conventional foam, resulting in microbuckling of the cell ribs.
The cause of the negative Poisson's ratio is non-affine deformation.
In a recent advance  , conceptual laminate structures have been presented by Milton . These laminates give rise to intentional negative Poisson's ratios combined with mechanical isotropy in two dimensions or in three dimensions . These laminates have structure on several levels of scale; they are hierarchical. By appropriate choice of constituent properties one can achieve Poisson's ratios approaching the lower limit of -1. The laminate Poisson's ratio is close to the rigorous lower bound which is independent of the microstructure, therefore it will not be possible to find microstructures with much lower Poisson's ratio
for given constituent stiffnesses
Review articles on auxetic materials, auxetics, anti-rubber, or dilational materials are given by Lakes in  and by Evans and Alderson in .
 R. S. Lakes, "Foam structures with a negative Poisson's ratio", Science , 235 1038-1040, 1987
 J. Glieck, The New York Times, 14 April 1987.
 G. Milton, "Composite materials with Poisson's ratios close to -1", J. Mech. Phys. Solids, 40, 1105-1137, 1992
 B. D. Caddock, and K. E. Evans, "Microporous materials with negative
Poisson's ratio: I. Microstructure and mechanical properties", J. Phys. D., Appl. Phys. , 22, 1877-1882, 1989.
 R. S. Lakes, "
Advances in negative Poisson's ratio materials", Advanced Materials (Weinheim, Germany), 5, 293-296, 1993.
 K. E. Evans and A. Alderson, "Auxetic materials: functional materials and structures from lateral thinking", Advanced Materials (Weinheim, Germany), 12, 617-628, 2000.
This is a more recent review on auxetic materials / auxetics .
More references are given in the following, and even more in the link to work by others below.
K. W. Wojciechowski, 'Constant thermodynamic tension Monte Carlo studies of elastic properties of a two-dimensional systems of hard cyclic hexamers', Molecular Physics 61, 1247-125 (1987).
K. W. Wojciechowski and A. C. Branka, 'Negative Poisson ratio in a two-dimensional "isotropic" model', Physical Review A40, 7222-7225 (1989).
Bowick, M. , Cacciuto, A., Thorleifsson, G. , and Travesset, A., "Universal negative Poisson ratio of self-avoiding fixed-connectivity membranes", Phys. Rev. Lett.87, 148103, (2001).
A. Alderson and K. E. Evans, "Molecular origin of auxetic behavior in tetrahedral framework silicates", Phys. Rev. Lett.89, 225503, (2002).