Auxetic behavior refers to a unique quality in materials where they expand in one or more directions when stretched, and contract when compressed. Unlike typical materials, which behave oppositely, auxetic materials exhibit this counterintuitive response due to their internal structure. This distinctive characteristic is often observed in structures with specific geometric arrangements, leading to intriguing mechanical properties.
Auxetic foam was discovered decades ago with numerous studies showing the spectacolour properties that auxetic polyurethane foams can provide. Till now, due to financial and technological constraints imposed by the original production methods, this material was limited to the academic world and a couple rather niche applications.
The old method to produce auxetic foam was costly as it involved converting a pre-synthesised block of conventional PU foam and subjecting it to a series of heat, chemical and stress cycles. Coupled with the fact that the old method is also limited to small lab scales from a technical point of view, meant this foam could never become commercially available.
At Smart materials we have revolutionised this process. We produce auxetic polyurethane foam in a one-pot reaction in the same way one would produce any other type of polyurethane foam. This means there is no post processing and it can be produced at large, industrial scales.
