Park Hong Woo, Seung Hong Min, Choi Wonjae, Kim Miso, Oh Joo Hwan
Department of Mechanical Engineering, Ulsan National Institute of Science and Technology, UNIST-Gil 50, Eonyang-eup, Ulju-gun, Ulsan, 44919, Republic of Korea.
Department of Science of Measurement, University of Science and Technology (UST), Gajeong-ro 207, Yuseong-gu, Daejeon, 34113, Republic of Korea.
Sci Rep. 2022 Jun 11;12(1):9714. doi: 10.1038/s41598-022-13453-1.
Metamaterial cavity has gathered much attention recently due to its capability of localizing vibration energy. Despite the active research, however, there are still big technical challenges not solved yet. Especially, there has been no approach to maximize the wave localization performance of metamaterial cavity; therefore, there has been a possibility that obtained cavity mode does not show sufficiently high performance. Also, there is a tunability issue that whole metamaterials should be re-designed to tune the cavity frequency. Here, we present the metamaterial cavity system that can control its cavity mode frequency from 589 to 2184 Hz by adjusting the cavity length from 140 to 60 mm without re-designing the whole metamaterial based on the broad bandgap. Also, the performance of the obtained cavity mode can be improved by adjusting the length of the side beam attached to the metamaterial; the displacements are amplified more than 18-110 times. Consequently, one may easily obtain the highly localized vibration energy at the desired frequency by adjusting two geometric parameters based on the proposed metamaterial cavity system. Numerical and experimental supports are provided to validate our new metamaterial cavity system. This metamaterial cavity system is expected to provide a guideline for localizing vibration energy in various applications, such as energy harvesting, sensing or vibration dissipation.
超材料腔由于其能够将振动能量局域化，近年来备受关注。然而，尽管进行了积极的研究，但仍存在一些尚未解决的重大技术挑战。特别是，目前还没有一种方法能够使超材料腔的波局域化性能最大化；因此，所获得的腔模有可能无法展现出足够高的性能。此外，还存在一个可调谐性问题，即要调整腔频率就需要重新设计整个超材料。在此，我们提出一种超材料腔系统，该系统基于宽带隙，无需重新设计整个超材料，通过将腔长度从140毫米调整到60毫米，就能将其腔模频率控制在589至2184赫兹之间。此外，通过调整连接到超材料的侧梁长度，可以提高所获得腔模的性能；位移放大了18至110倍以上。因此，基于所提出的超材料腔系统，通过调整两个几何参数，人们可以轻松地在所需频率下获得高度局域化的振动能量。我们提供了数值和实验支持来验证我们的新型超材料腔系统。这种超材料腔系统有望为在诸如能量收集、传感或振动耗散等各种应用中局域化振动能量提供指导。
