Where Scalar Meets Vector: Acoustic-Elastic Metamaterials and Interfaces

Sound behaves fundamentally differently in fluids and solids. In fluids such as air or water, acoustic waves are commonly described as scalar pressure fields, whereas in solids they manifest as vector elastic waves with directional motion, polarization, and mode conversion. Acoustic and elastic metamaterials, together with metasurfaces, provide engineered platforms for manipulating wave propagation at subwavelength scales, enabling capabilities such as anomalous refraction, cloaking, and vibration suppression. Despite these advances, acoustic and elastic wave control are often pursued separately, even though strong coupling naturally arises at fluid-solid interfaces where wave transmission, reflection, and mode conversion occur. Capturing this coupling and turning it into a controllable degree of freedom remains underexplored, offering rich opportunities for the integrated design and application of hybrid wave-control devices.This Research Topic aims to advance the integrated control of scalar, vector, and coupled wave fields in acoustic-elastic metamaterials and interfaces. Significant progress has been made in metasurface design, structured materials, and inverse design methods for individual acoustic or elastic systems. Building on this, the coupling that arises between scalar acoustic and vector elastic fields at fluid-solid interfaces remains comparatively underexplored as a controllable resource for device design. This Topic seeks contributions that address this opportunity through theoretical analysis, numerical modeling, and experimental validation. Of particular interest are studies on mode conversion, impedance-matched transmission, programmable and reconfigurable interfaces, and hybrid wave-field engineering. The ultimate goal is to establish shared physical insights and design strategies for controlling wave phenomena across acoustic and elastic domains, enabling next-generation applications in underwater acoustics, communication, sensing, vibration control, and biomedical acoustics.• Wave control in acoustic/elastic metamaterials and metasurfaces• Fluid-solid interface physics and interfacial wave propagation• Mode conversion mechanisms and device design between acoustic and elastic fields • Impedance matching and optimized transmission across heterogeneous media• Programmable, tunable, and reconfigurable interfaces for acoustic and elastic wave control• Inverse and intelligent design of acoustic-elastic metamaterials and devices• Numerical and experimental methods for coupled acoustic-elastic systems• Applications in underwater acoustics, vibration control, sensing, biomedical acoustics, and beyond Topic editors: Hong-Tao Zhou, Junfei Li Source: https://www.frontiersin.org/research-topics/84692/where-scalar-meets-vector-acoustic-elastic-metamaterials-and-interfaces