Programmable Elastic Metamaterials

We introduce a novel concept for the design of programmable‐elasticity metamaterials; materials whose elastic properties can be modified instantaneously and reversibly on demand. Real‐time tunable linear and nonlinear elastic moduli are obtained in lattice materials by adjustment of strut connectivity via actuation of embedded electromagnetic locks. The Young's modulus and Poisson's ratio of prototype 2D materials are varied instantaneously by more than 2 orders of magnitude and between 0.15 and 0.9, respectively. The buckling strength of the structure is altered by an order of magnitude between two bifurcation states associated with a centrosymmetric and an anti‐chiral buckling pattern.