FABRICATION METHODS FOR AUXETIC FOAMS

Auxetic materials have a negative Poisson's ratio, that is, they expan d laterally when stretched longitudinally. Negative Poisson's ratio is an unusual property that affects many of the mechanical properties of the material, such as indentation resistance, compression, shear stif fness, and certain aspects of the dynamic performance. The unusual mec hanical properties of auxetic foams are attributed to the deformation characteristics of re-entrant microstructures. One way of obtaining ne gative Poisson's ratio is by using a re-entrant cell structure. Auxeti c foam was fabricated from a conventional polymeric foam. The fabricat ion method for making both small and large auxetic foam specimens is d escribed.