Broadband impedance modulation via non-local acoustic metamaterials

作     者：Zhiling Zhou Sibo Huang Dongting Li Jie Zhu Yong Li Zhiling Zhou;Sibo Huang;Dongting Li;Jie Zhu;Yong Li

作者机构：Institute of AcousticsSchool of Physics Science and EngineeringTongji University Department of Mechanical EngineeringThe Hong Kong Polytechnic University The Hong Kong Polytechnic University Shenzhen Research Institute 

出 版 物：《National Science Review》 (国家科学评论(英文版))

年 卷 期：2022年第9卷第8期

页      面：47-54页

核心收录：

学科分类：08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0811[工学-控制科学与工程] 

基　　金：supported by the National Natural Science Foundation of China (12074286 and 11774297) the Shanghai Science and Technology Committee (21JC1405600,20ZR1460900 and 20DZ1207200) 

主　　题：impedance modulation acoustic absorption non-local metamaterials 

摘      要：Causality of linear time-invariant systems inherently defines the wave-matter interaction process in wave physics. This principle imposes strict constraints on the interfacial response of materials on various physical platforms. A typical consequence is that a delicate balance has to be struck between the conflicting bandwidth and geometric thickness when constructing a medium with desired impedance, which makes it challenging to realize broadband impedance modulation with compact structures. In pursuit of improvement, the over-damped recipe and the reduced excessive response recipe are creatively presented in this work. As a proof-of-concept demonstration, we construct a metamaterial with intensive mode density that supports strong non-locality over a frequency band from 320 Hz to 6400 Hz. Under the guidelines of the over-damped recipe and the reduced excessive response recipe, the metamaterial realizes impedance matching to air and exhibits broadband near-perfect absorption without evident impedance oscillation and absorption dips in the working frequency band. We further present a dual-functional design capable of frequency-selective absorption and reflection by concentrating the resonance modes in three frequency bands. Our research reveals the significance of over-damped recipe and the strong non-local effect in broadband impedance modulation, which may open up avenues for constructing efficient artificial impedance boundaries for energy absorption and other wave manipulation.