Electrostatically coupled tunable topological phononic metamaterials for angular velocity sensing

We propose an electrostatically coupled phononic metamaterial for angular velocity sensing, whose sensitivity is immune to external damping and local material defects; furthermore, the coupling strength and frequency range of bands are tunable by the voltages applied to the lattices. The induced Coriolis force could open up the topologically nontrivial band gaps, and the edge band bandwidths increase gradually with respect to the angular velocity. Hence, according to the dispersion relation of edge modes and the difference between edge states and bulk states, an angular velocity sensing method based on the band structure variation of the tunable phononic metamaterial is proposed by using the phase difference and amplitude ratio of edge states. In contrast to traditional amplitude-dependent microelectromechanical system gyroscopes, such a frequency-dependent angular velocity sensing method makes the sensitivity independent of the external damping coefficient. In addition, the topological properties ensure the robustness of the proposed angular velocity sensing method against local defects. The tunable metamaterial-based angular velocity sensing mechanism provides a bridge between physics and engineering applications.