Impact of active solids

Active mechanical metamaterials have recently completely changed our ability to manipulate mechanical waves via, e.g., chiral edges modes, unidirectional transmission and self-amplification. However, little is known on how these properties could be translated to active metamaterials capable of large deformations. Here, we study 1D and 2D active metamaterials capable of large deformations by measuring their mechanical responses to dynamic impacts. We show that activity can be used to tune the bouncing angle and bouncing coefficient of active solids independently of their geometry and demonstrate that these specific properties can be rationalised by general odd elastic and non-hermitian skin waves models. This work opens avenues for novel active materials and devices with new mechanical properties based on out-of-equilibrium interactions such as antisymmetric shear coupling, self-oscillations, locomotion, etc.