3D star-shaped lattice metamaterials exhibiting zero Poisson's ratio

Zero Poisson’s ratio metamaterials are a peculiar class of metamaterial systems which undergo no lateral deformation upon uniaxial loading. In this work, we propose a new 3D star-shaped lattice metamaterial structure which is specifically designed to exhibit this property in all three principal directions. This system, which is highly anisotropic, can have a tailorable stiffness which is dependent on the geometry of the structure and may be altered according to design specifications without influencing the Poisson’s ratio. An analytical model which may be used to predict the mechanical properties of this system was derived and validated through a wide ranging parametric Finite Element simulation run. In addition, a prototype system was produced using additive manufacturing and tested under compressive loading, with Digital Image Correlation techniques confirming the zero Poisson’s ratio of the system, which is retained under relatively high-strain loading. It is envisaged that the large versatility and tuneability of this new metamaterial structure make it ideal for future implementation in applications requiring zero Poisson’s ratio properties. • Lattice metamaterial structures exhibiting zero Poisson’s ratio in all principal directions are designed • An analytical model which may be used to predict mechanical properties is derived and validated with Finite Element Simulations • Anisotropic stiffness of system may be regulated as a function of geometric parameters • An additively manufactured prototype was fabricated and tested, confirming the zero Poisson’s ratio characteristic of this architecture