Engineering surface waves in flat phononic plates

Abstract

Surface acoustic-wave phenomena span a wide range of length scales going from the devastation of earthquakes down to image reconstruction of buried nanostructures. In solid-fluid systems, the so-called Scholte-Stoneley waves (SSWs) dominate the scene at the interface with their evanescent fields decaying away into both media. Understanding and manipulating these waves in patterned surfaces would enable new applications of sound to be devised for imaging and acoustic signal processing, although this task has so far remained elusive. Here, we report SSW modes displaying directional gaps and band folding in fluid-loaded solid phononic plates. The plates are inhomogeneously patterned with in-plane periodic modulations of the elastic constants, but present flat surfaces free of corrugations. We experimentally demonstrate control of SSWs, which opens a promising route toward acoustic fluid sensing, microscopy, and signal processing.

Negative refraction and backward waves in layered acoustic metamaterials

“…33 Acoustic waves trapped at metamaterial surfaces have been investigated as well. 42,43 Wave phenomena in general find their expression in sound, and even classical analogs of quantum-optics effects such as induced transparency have been realized. 44,45 The ability of perforated plates to negatively refract and focus acoustic waves has already been established.…”

Geometrical isotropy in perforated plates with subwavelength holes decorated with Archimedean patterns

“…The measurements are in close agreement with the calculated results even though there are some differences between them. The measured transmissions show three kinds of modes interacting with the lattice resonances: S 0 Lamb mode, A 0 Lamb mode and Scholte-Stoneley mode [24]. These modes were not predicted by the calculated results due to the fact that they were carried out with a hard-solid model in which the elastic movement of the plate was not considered.…”

Band structure analysis of leaky Bloch waves in 2D phononic crystal plates

“…[9] as well as Finite Element (FEM)-based absorbing regions [10,11,12] and Perfectly Matched Layers [13,14], while the so-called Plane Wave Expansion (PWE) method has been used in [15,16,17].…”