Last modified: 2021-06-15
Abstract
Using artificial structures to manipulate wave propagation at will has been a hot topic. Metasurface, a 2D planar material with sub-wavelength width, provides an efficient method for wave control. With compact footprint, metasurface overcomes the shortcoming of large volume for traditional metamaterials, which can be regarded as the mapping of metamaterial in plane. Elastic metasurfaces have already exhibited various nontrivial wave phenomena, however, most of the existing design methods are based on local resonance, which inevitably causes extremely narrow bandwidth. Therefore, how to design metasurfaces for broadband elastic-wave control is a big challenge. In this work, we develop a new zigzag-shape elastic metasurface. By changing the length of wave propagation path, the metasurface can manipulate transmitted waves efficiently. Experimental and simulated results congruously verify that the proposed metasurface can realize broadband wavefront manipulation including anomalous refraction, energy focusing, source illusion and self-bending beam. Remarkably, compared with locally resonant metasurfaces, our developed metasurface is more robust against frequency and efficient in extraordinary wavefront tailoring. The proposed strategy has potential applications in the fields of vibration and noise control.