Transition from Monostability to Bistability via Symmetry Breaking in Mechanical Metamaterials

We observe that symmetry breaking can induce bistability in a two-dimensional circular mechanical metamaterial composed of originally monostable unit cells. Through both numerical simulations and experimental validation, we provide evidence that this circular mechanical metamaterial, initially designed with monostable unit cells that show monostable behavior, can exhibit bistable behavior when symmetry is broken, specifically, by modifying the geometry of certain unit cells. These findings open new avenues for designing highly expandable and deployable mechanical metamaterials.