论文标题
机械模式工程与正交材料的膜
Mechanical mode engineering with orthotropic metamaterial membranes
论文作者
论文摘要
超材料是相对于与它们相互作用的激发的波长进行小规模设计的结构。这些结构作为人造材料的行为，可以通过设计，嘲笑甚至优于天然材料来选择其特性，并使它们成为操纵波系统的典型工具。在这封信中，我们显示了氮化膜的声学特性如何受纳米图案的影响。模式几何形状中的不对称程度诱导人造各向异性弹性，从而导致否则退化的机械模式分裂。我们引入的人工材料的最大LEDBETTER-rigliori各向异性为1.568，与大多数散装天然晶体相比，相比之下。通过模式旋转定义任意不对称轴的额外自由，我们的方法可用于对材料特性的基本研究以及基于微力机械谐振器的光，质量或加速度的改进传感器。
Metamaterials are structures engineered at a small scale with respect to the wavelength of the excitations they interact with. These structures behave as artificial materials whose properties can be chosen by design, mocking and even outperforming natural materials and making them the quintessential tool for manipulation of wave systems. In this Letter we show how the acoustic properties of a silicon nitride membrane can be affected by nanopatterning. The degree of asymmetry in the pattern geometry induces an artificial anisotropic elasticity, resulting in the splitting of otherwise degenerate mechanical modes. The artificial material we introduce has a maximum Ledbetter-Migliori anisotropy of 1.568, favorably comparing to most bulk natural crystals. With an additional freedom in defining arbitrary asymmetry axes by pattern rotation, our approach can be useful for fundamental investigation of material properties as well as for devising improved sensors of light, mass or acceleration based on micromechanical resonators.
