Evolution of static to dynamic mechanical behavior in topological nonreciprocal robotic metamaterials

Abstract: Based on the Maxwell-Beatty reciprocity theorem, static non-reciprocity has been realized by using nonlinearity, but this non-reciprocity has strict restrictions on input amplitude and structure size (number of units). Here, we propose a robotic metamaterial with two components of displacement and rotation, which uses active control to add external forces on the units to break reciprocity at the level of the interactions between the units. We show analytically and simulatively that breaking reciprocity at the level of the interactions directly leads to a strong asymmetric response of displacement in a static system, this displacement-specific characteristic not only has no restrictions on size, input amplitude, and suitable geometric asymmetry, but also can be transmitted to rotation by coupling under large deformation. After the evolution from statics to dynamics, asymmetric transmission and unidirectional amplification of vector solitons are both implemented in this system. Our research uncovers the evolution of static non-reciprocity to dynamic non-reciprocity while building a bridge between non-reciprocity physics and soliton science.