Lee Sam Hyeon, Park Choon Mahn, Seo Yong Mun, Wang Zhi Guo, Kim Chul Koo
Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
J Phys Condens Matter. 2009 Apr 29;21(17):175704. doi: 10.1088/0953-8984/21/17/175704. Epub 2009 Mar 30.
We present experimental and theoretical results on an acoustic metamaterial that exhibits a negative effective modulus in a frequency range from 0 to 450 Hz. A one-dimensional acoustic metamaterial with an array of side holes on a tube was fabricated. We observed that acoustic waves above 450 Hz propagated well in this structure, but no sound below 450 Hz passed through. The frequency characteristics of the metamaterial has the same form as that of the permittivity in metals due to the plasma oscillation. We also provide a theory to explain the experimental results.
我们展示了一种声学超材料的实验和理论结果，该超材料在0至450赫兹的频率范围内呈现出负有效模量。制作了一种在管道上带有侧孔阵列的一维声学超材料。我们观察到，频率高于450赫兹的声波在该结构中传播良好，但频率低于450赫兹的声音无法通过。由于等离子体振荡，该超材料的频率特性与金属中电容率的频率特性具有相同的形式。我们还提供了一种理论来解释实验结果。
