A mechanical wave switch with tunable frequency output

Abstract

Various acoustic and mechanical wave components have been developed. Most of them focused on the control of energy flow. However, these waves are not only energy flow but also wave signals with a frequency dependence. In this Letter, we propose a mechanical wave switch (MWS) capable of controlling energy flow and output frequency simultaneously. It consists of a difference frequency generation (DFG) unit and a wave filter. The DFG unit consists of two mass blocks and a tension/compression asymmetrical bilinear spring, and the wave filter is a one-dimensional mass-spring lattice. Systematical calculations were carried out to identify the critical condition for the design of MWSs. Both numerical and experimental results demonstrate the capability of the proposed MWS to tune the energy flow and the output frequency of acoustic waves via a small amplitude control wave signal. The scale-independent MWS can be implemented at micro- and nanoscales.

Active control on topological immunity of elastic wave metamaterials

“…These new kinds of structures have many extraordinary properties, e.g. the wave band gaps [9][10][11][12] , negative refraction 13,14 , acoustic/elastic wave cloaks [15][16][17] , etc. These interesting behaviors can be used to tune the wave propagation properties and have a wide variety of potential engineering applications.…”