Sharkskin-Inspired Magnetoactive Reconfigurable Acoustic Metamaterials
Sharkskin-Inspired Magnetoactive Reconfigurable Acoustic Metamaterials
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DOI：
10.34133/2020/4825185
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发表时间：
2020-02-05
期刊：
影响因子：
11
通讯作者：
Wang, Qiming
中科院分区：
文献类型：
--
作者：
Lee, Kyung Hoon;Yu, Kunhao;Wang, Qiming
大多数现有的声学超材料依赖于具有固定配置的架构结构，因此，一旦结构被制造，它们的特性就不能被调制。新兴的有源声学超材料突出了按需切换属性状态的有希望的机会;然而，它们通常需要拴系负载，例如机械压缩或气动致动。使用不受约束的物理刺激来主动切换声学超材料的属性状态仍然是未探索的。在这里，受鲨鱼皮denominator的启发，我们提出了一类主动声学超材料，其配置可以通过不受约束的磁场按需切换，从而实现声学传输，波导，逻辑操作和互易性的主动切换。关键机制依赖于磁可变形Mie谐振器柱（MRP）阵列，其可以在分别对应于声学禁止和传导的垂直和弯曲状态之间进行调谐。MRPs由磁致弹性体制成，并具有波浪形空气通道，以在设计的频率范围内实现人工Mie共振。米氏共振引起的声学带隙，这是关闭时，柱选择性地弯曲一个足够大的磁场。这些磁致MRPs被进一步利用来设计刺激控制的可重构声学开关、逻辑门和二极管。能够创建第一代无束缚刺激诱导的有源声学元器件，本范例可以找到广泛的工程应用，从噪声控制和音频调制到声音伪装。
Most of the existing acoustic metamaterials rely on architected structures with fixed configurations, and thus, their properties cannot be modulated once the structures are fabricated. Emerging active acoustic metamaterials highlight a promising opportunity to on-demand switch property states; however, they typically require tethered loads, such as mechanical compression or pneumatic actuation. Using untethered physical stimuli to actively switch property states of acoustic metamaterials remains largely unexplored. Here, inspired by the sharkskin denticles, we present a class of active acoustic metamaterials whose configurations can be on-demand switched via untethered magnetic fields, thus enabling active switching of acoustic transmission, wave guiding, logic operation, and reciprocity. The key mechanism relies on magnetically deformable Mie resonator pillar (MRP) arrays that can be tuned between vertical and bent states corresponding to the acoustic forbidding and conducting, respectively. The MRPs are made of a magnetoactive elastomer and feature wavy air channels to enable an artificial Mie resonance within a designed frequency regime. The Mie resonance induces an acoustic bandgap, which is closed when pillars are selectively bent by a sufficiently large magnetic field. These magnetoactive MRPs are further harnessed to design stimuli-controlled reconfigurable acoustic switches, logic gates, and diodes. Capable of creating the first generation of untethered-stimuli-induced active acoustic metadevices, the present paradigm may find broad engineering applications, ranging from noise control and audio modulation to sonic camouflage.