Robust one-way transport in Maxwell-lattice mechanical metamaterials

In this talk, we introduce a 2D mechanical system based on Maxwell lattices with low-frequency topological edge waves and demonstrate direction-selecting energy transfer through phase control. In particular, these edge states are at acoustic frequency, in direct contrast to existing devices based on quantum Hall and valley Hall physics, where edge/interface modes exist only at high frequencies in the gaps between bulk phonon bands. Although this system is achiral and the edge modes contain both left- and right- moving components, we demonstrate that directed energy transfer can be achieved via using multiple sources, where the energy distribution between the left and right moving modes are dictated by the relative phase between the sources. This new design opens the opportunity for directional transport of mechanical waves at previously inaccessible frequencies.