Porous Inclined Auxetic Structural Material*

Porous structural materials with well-defined periodicity are ubiquitous not only in nature but also in synthetic structures and devices. These types of materials have been proven to offer various types of auxetic behavior, ranging from negative Poisson's ratio to high energy absorption and excellent acoustic damping. Yet, here we present a novel auxetic behavior harnessed by introducing angled cuts into a periodic porous material. Using this approach, we utilize out-of-plane behavior with the potential to control friction, light emission and reflection, as well as fluid flow properties. Using a combination of physical experiments and non-linear finite element analysis, we study the effects of geometry on creating and propagating this out-of-plane auxetic behavior.