Pressure amplification and directional acoustic sensing based on a gradient metamaterial coupled with space-coiling structure

• Published in: Mechanical systems and signal processing Vol. 181; p. 109499
• Main Authors: Chen, Tinggui, Wang, Chengyong, Yu, Dejie
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2022
• Subjects: Acoustic sensing; Coupled acoustic metamaterials; Directivity; Pressure amplification; Directivity; Coupled acoustic metamaterials; Acoustic sensing; Pressure amplification
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2022.109499

The detection and localization of weak sound sources are a topic of great interest in a wide range of applications, but generally require a pressure amplification and directivity acoustic system. Although acoustic technologies have been advanced in recent years, the realization of pressure amplification and directivity acoustic systems remains a slippery subject. Here, we propose a gradient acoustic metamaterial (GAM) coupled with space-coiling structure (GAM-SCS) for the detection and localization of weak sound sources. The GAM-SCS is evaluated both numerically and experimentally. Compared with the GAM without space-coiling structure, the GAM-SCS has a better pressure amplification performance which enables the sound signals to be pre-amplified. Meanwhile, the induced space-coiling structure, making use of subwavelength features, also enables the GAM-SCS to work in a lower frequency. Furthermore, the directivity of the GAM-SCS also shines lights on directional acoustic sensing to resist noise interference. We believe that this work opens up a new vista to realize the detection and localization of weak sound sources based on acoustic metamaterials.