From bubble dynamics to acoustic control: Underwater bubble-based metamaterials for marine sustainability

Marine acoustics is crucial for the sustainable utilization of ocean resources. Researchers have discovered that underwater bubbles can serve as highly efficient acoustic resonators, enabling precise manipulation of sound waves in water. However, understanding the complex dynamics of bubble evolution in fluids is essential to optimize their acoustic characteristics. This review provides theoretical forecasts and practical approaches for studying bubble evolution, along with an overview of recent advancements in underwater bubble metamaterials. It covers classical and modified theoretical equations and explores strategies for modifying acoustic environments through resonant coupling in bubbles. Techniques, such as applying external forces, introducing surfactants, and creating micropatterned designs for structuring bubbles, are discussed. This review evaluates the superior acoustic properties of underwater bubble metamaterials, including their reflection, absorption, and transmission capabilities and their potential applications in marine environments. Finally, this study outlines the challenges that need to be addressed to manage bubble dynamics and enhance acoustic metamaterial technologies for underwater applications. These insights are expected to contribute to the sustainable development of the ocean.