Tailored elastic surface to body wave Umklapp conversion
Abstract
Elastic waves guided along surfaces dominate applications in geophysics, ultrasonic inspection, mechanical vibration, and surface acoustic wave devices; precise manipulation of surface Rayleigh waves and their coupling with polarized body waves presents a challenge that offers to unlock the flexibility in wave transport required for efficient energy harvesting and vibration mitigation devices. We design elastic metasurfaces, consisting of a graded array of rod resonators attached to an elastic substrate that, together with critical insight from Umklapp scattering in phonon-electron systems, allow us to leverage the transfer of crystal momentum; we mode-convert Rayleigh surface waves into bulk waves that form tunable beams. Experiments, theory and simulation verify that these tailored Umklapp mechanisms play a key role in coupling surface Rayleigh waves to reversed bulk shear and compressional waves independently, thereby creating passive self-phased arrays allowing for tunable redirection and wave focusing within the bulk medium.
Keywords
Cite
@article{arxiv.1912.05373,
title = {Tailored elastic surface to body wave Umklapp conversion},
author = {Gregory J. Chaplain and Jacopo M. De Ponti and Andrea Colombi and Rafael Fuentes-Dominguez and Paul Dryburg and Don Pieris and Richard J. Smith and Adam Clare and Matt Clark and Richard V. Craster},
journal= {arXiv preprint arXiv:1912.05373},
year = {2020}
}
Comments
5 pages of text with 3 figures plus 3 pages of supplemental text with 5 supplemental figures