Soft acoustic metamaterials that embed soft materials in a host media have promising applications in aqueous environments. However, the preparation of soft metamaterials under water and realization of low‐frequency soft acoustic metamaterials remains a challenge. By combining 3D printing technology and surface hydrophobic properties, this work presents a general approach to construct 3D soft acoustic metamaterials using bubbles as resonator units. Low‐frequency broadband locally resonant metamaterials can be realized using patterned bubbles with bandgaps that are orders of magnitude wider than other locally resonant metamaterials. In addition, a water‐to‐air ultratransmission metasurface is prepared by patterning a layer of bubbles beneath the water surface, which allows for the ultratransmission of sound across an air–water interface. This strategy opens up promising avenues for many applications based on locally resonant metamaterials such as deep subwavelength acoustic superlenses or negative‐refraction metamaterials.

中文翻译：

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局部共振声超材料的气泡结构

将软材料嵌入宿主介质中的软声超材料在水环境中具有广阔的应用前景。然而，水下软超材料的制备和低频软声超材料的实现仍然是一个挑战。通过结合3D打印技术和表面疏水特性，这项工作提出了一种通用方法，即使用气泡作为谐振器单元来构造3D软声超材料。低频宽带局部共振超材料可以使用带隙比其他局部共振超材料大几个数量级的带图案的气泡来实现。此外，通过在水表面下形成一层气泡来制备水对空气超传输超表面，从而允许声音在空气-水界面之间超传输。