When the researchers apply a force on the soft side of the metamaterial, it easily induces rotations of the squares and diamonds within the structure, but only in the near vicinity of the pressure point, and the effect on the other side is small. Conversely, when they apply the same force on the rigid side, the motion propagates and is amplified throughout the material, with a large effect at the other side. As a result, pushing from the left or from the right results in very different responses, yielding a large nonreciprocity even for small applied forces.
Read more at: https://phys.org/news/2017-02-mechanical-metamaterials-block-symmetry-motion.html#jCp
