Particulated granular metamaterials with tunable elastic moduli

The mechanical properties of jammed granular materials are qualitatively different from continuum solids and their behavior is especially interesting close to the jamming transition. Most continuum solids have bulk (B) and shear (G) moduli that are within an order of magnitude of each other. In this work, we show that we can create granular metamaterials with bulk moduli that are up to three orders of magnitude larger than their shear moduli. To achieve this, we designed "particulated" granular metamaterials - flexible tessellations filled with a small number of solid particles in each cell. For under-constrained tessellated networks, the dominant contributions to B and G stem from particle-particle and particle-cell interactions. By filling the cells with specific particle configurations, we can tune the material's response, e.g. generating materials with G/B