Reconfigurable Elastic Metamaterials: Engineering Dispersion with Meccano${}^{\text{TM}}$

We design, simulate and experimentally characterise a reconfigurable elastic metamaterial with beyond-nearest-neighbour (BNN) coupling. The structure is composed from the popular British model construction system, Meccano${}^{\text{TM}}$. The Meccano${}^{\text{TM}}$ metamaterial supports backwards waves with opposite directions of phase and group velocities. We experimentally verify three distinct configurations and acoustically infer their spatial vibration spectra.