A review on auxetic structures and polymeric materials

Auxetic polymeric materials are a special kind of materials that exhibit negative Poisson's ratio (NPR) effect. They get fatter when stretched and thinner when compressed. Auxetic behavior is a scale-independent property which can be achieved at different structural levels from molecular to macroscopic levels. The internal structure of material plays an important role in obtaining auxetic effect. Because of NPR effect, auxetic polymeric materials demonstrate a series of particular characteristics when compared with conventional materials. In recent years, a variety of auxetic polymeric materials have been designed and fabricated for diverse applications. This article presents a review on advances in this area. The emphasis is focused on the geometrical structures and models, particular properties and applications of auxetic polymeric materials developed.