Re-programmable non-reciprocal metamaterials

Asymmetric structures of nonlinear elements have been previously shown to break reciprocity in passive metamaterials by utilizing bistability to permit the propagation of transition waves in one direction. The configuration of these metamaterials typically limits the propagation of the wave to a single direction, speed, and occurrence. Here we present a simple design for a repulsive lattice of magnetic dipoles which allow for all of these parameters to be tuned, enabled, or disabled through the use of a simple mechanical switch. We present a theoretical map of geometries that allow for reciprocal and non-reciprocal wave propagation. We verify this using numerical simulations and demonstrate that the constant velocity of the transition waves are dependant on the material geometry regardless of the magnitude of impulse. In experiments we validate our numerical findings in regards to the constant velocity of the wave, reversibility of the switch mechanism, and the ability to direct the wave along a curved path. This result suggests the potential use of our material for tuning wave speed.