The ability to tune the resonant frequency of a self‐assembled ultrasonic metamaterial with mesoscale spatial resolution, after fabrication, by up to 250% is demonstrated. This tunability is achieved by the microlensing‐enabled modification of nanocontact features, wherein the metamaterial resonant elements “dig in” to the substrate. In addition to tunability exceeding prior MHz–GHz frequency ultrasonic metamaterial examples, the system presented herein can be tuned after assembly at a spatial resolution commensurate with the laser spot's diameter. It is posited that these aforementioned advantages will enable a new class of ultrasonic gradient index devices, such as ultrasonic elastic wave cloaks, that can be manufactured in a scalable manner and then rapidly tuned. Finally, it is expected that this large tunability at ultrasonic frequencies will have broader application to areas including optomechanics, acoustoplasmonics, quantum‐mechanical oscillators, and adhesion control.

中文翻译：

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通过微透镜进行纳米接触裁缝，可以在自组装的超声超材料中进行大型的后加工介观调谐。

证明了在制造后能够以中尺度的空间分辨率将自组装超声超材料的共振频率调整至250％的能力。这种可调谐性是通过对纳米接触特征进行微透镜改性而实现的，其中超材料共振元件“挖入”了基板。除了超过以前的MHz-GHz频率超声超材料示例的可调性之外，本文介绍的系统还可以在组装后以与激光点直径相对应的空间分辨率进行调谐。假设这些前述优点将使得能够以可缩放的方式制造然后快速调谐的新型超声梯度指数装置，例如超声弹性波斗篷。最后，