Transversely-isotropic chiral metamaterials based on pentagonal tessellations

Abstract

In continuum-based systems, the design of two-dimensional isotropic metamaterial structures is ensured through the presence of hexagonal symmetry. This principle also holds for the design of auxetic metamaterials and is a considerable limiting factor for the geometric design of systems with tuneable and tailorable mechanical properties since all structural alterations and variations must adhere to this strict condition. Indeed, besides the most well-known example of the hexachiral honeycomb, very few auxetic systems which are strictly (mathematically) transversely-isotropic exist and, those which do, exhibit a restricted range of mechanical properties defined by a small range of changeable variables.