Chiralisation of Euclidean polygonal tessellations for the design of new auxetic metamaterials

Chiral honeycombs are one of the main classes of mechanical metamaterials with the potential to exhibit auxetic behaviour. In this work, we propose a new class of chiral metamaterials based on uniform Euclidean tessellations and their dual counterparts. In total, ten new structures were designed and analysed using Finite Element analysis under periodic boundary conditions, with eight of these systems showing the capability of possessing a negative Poisson's ratio. The relationship between the various geometric parameters defining the systems and the resultant mechanical properties was also studied. We show that ‘chiralisation’, i.e. introduction of chirality and rotational elements within the system, has the ability to transform even complex geometries, which in their original state possess a high positive Poisson's ratio, into auxetic metamaterials and hope that this work can act as a blueprint for the design of auxetic structures with novel topologies.