Sun Kangyao, Zhang Fuli, Chen Shuang, Fu Quanhong, Zeng Yali, Fan Yuancheng
MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710129, China.
Shaanxi Huayan Aero-instrument Co. Ltd, Xi'an 710129, China.
iScience. 2024 Jul 14;27(8):110504. doi: 10.1016/j.isci.2024.110504. eCollection 2024 Aug 16.
Acoustic metasurface with rationally distributed phase manipulating characteristic provides a promising platform to reshape the wavefront of scattering wave. Such acoustic illusion carpet suffers from limitation of narrow bandwidth and relatively large volume to contain the object to be hidden. Here, we propose and experimentally demonstrate broadband conformal acoustic illusion coatings composed of subwavelength-thick metacells that are designed by two types of modified Helmholtz resonators with 2π reflection phase. By deliberate design of reflection phase distributions of illusion coating, the reflected wavefront can be reshaped between trapezoid and triangles and vice versa. Furthermore, an enlarged illusion is obtained by this methodology. More importantly, the illusion behaviors are verified both numerically and experimentally from 3000 Hz to 4500 Hz, resulting in relatively broad bandwidth up to 40.5%, which is definitely of extreme importance for potential applications.
具有合理分布相位操纵特性的声学超表面为重塑散射波的波前提供了一个很有前景的平台。这种声学幻象地毯存在带宽窄和容纳待隐藏物体的体积相对较大的局限性。在此，我们提出并通过实验证明了由亚波长厚度的超胞组成的宽带共形声学幻象涂层，这些超胞由两种具有2π反射相位的改进型亥姆霍兹谐振器设计而成。通过精心设计幻象涂层的反射相位分布，反射波前可以在梯形和三角形之间重塑，反之亦然。此外，通过这种方法获得了放大的幻象。更重要的是，从3000赫兹到4500赫兹，通过数值和实验验证了幻象行为，产生了高达40.5%的相对宽带宽，这对于潜在应用绝对至关重要。
