Metamaterials enabling multifunctional wave control have long attracted great interest, but remain largely unexplored in ventilation-required settings. Using the space-coiling strategy, we design and fabricate a compact acoustic meta-structure consisting of labyrinth resonators arranged around a central air passage. Such meta-structures provide a promising route to design well-ventilated and simultaneously highly-effective sound-proofing barriers allowing broadband (about one octave band) transmission loss up to almost 30 dB in the range of 660–1200 Hz. More interestingly, due to the interferences between the forward propagating waves and those re-radiated by the surrounding resonators, some asymmetric Fano-like resonances are observed appearing in the transmission gap. This Fano-like resonance is very useful to open a high transmission window at frequencies of interest by changing the length of coiled-up channels. Our findings are both numerically and experimentally verified, which may stimulate multifunctional applications, such as broadband sound insulation with high transmission loss and tunable acoustic communication, especially in ventilation-required environments.

长期以来，能够实现多功能波控制的超常材料引起了人们的极大兴趣，但在需要通风的环境中仍未得到充分的研究。使用空间盘绕策略，我们设计并制造了一个紧凑的声学元结构，该结构由围绕中央空气通道布置的迷宫式谐振器组成。这样的元结构为设计通风良好且同时高效的隔音屏障提供了一条有希望的途径，该屏障可在660–1200 Hz的范围内使宽带（大约一个八度频段）的传输损耗高达近30 dB。更有趣的是，由于正向传播波与周围谐振器再辐射的波之间存在干扰，因此在传输间隙中观察到一些非对称的费诺式谐振。通过改变盘绕通道的长度，这种类似于Fano的共振对于在感兴趣的频率上打开高传输窗口非常有用。我们的发现在数值上和实验上都得到了验证，这可能会刺激多功能应用，例如具有高传输损耗和可调声通信的宽带隔音功能，尤其是在通风要求较高的环境中。