Analysis of Metamaterials-Based Acoustic Sensing Enhancement

Acoustic sensing is a non-destructive technology that plays an essential role in condition monitoring. For high-quality data collection, condition monitoring relies on various sensing methods that further complicate the wiring of the system. Moreover, weak signals such as evanescent waves carrying valuable information are usually hard to capture. With the emerging field of metamaterials, such issues could be optimized and solved. This paper presents a metamaterial that is designed by two kinds of typical unicells, purely geometrically, with the aim to enhance the acoustic signal without any external power source. As a result of transmission through the designed metamaterials, the acoustic pressure level at a particular range of frequency is efficiently enhanced. Furthermore, the frequency shift of the enhancement is achieved by altering specific structural parameters, which demonstrates its tunable characteristics. This study intends to provide ideas for the design of acoustic metamaterials for applications such as remote sound measurement, energy harvesting, fault diagnosis, etc.