Applications of Acoustic Metamaterials

This Collection supports and amplifies research related to SDG 9: Industry, Innovation & Infrastructure. 

This Collection aims to advance the understanding and development of acoustic and elastic metamaterials, with a particular focus on wave manipulation, vibration and noise control, and novel functionalities emerging from “architectured” designs. By exploiting geometry, resonance, multiscale structuring, and spatio-temporal modulation, acoustic and elastic metamaterials provide unprecedented control over sound and mechanical waves, enabling responses unattainable in conventional materials.

Relentless progress in recent years in theoretical modelling, numerical design, and experimental realization of metamaterials has established them as a central research frontier in modern acoustics, mechanics, and vibro-acoustics. These advances have opened new opportunities for both fundamental studies of wave phenomena and the development of scalable solutions addressing real-world acoustic and vibration-related challenges.

This Collection brings together fundamental and applied research on acoustic and elastic metamaterials, with an emphasis on physical mechanisms, wave propagation phenomena, and robust design strategies across multiple length and frequency scales. Contributions addressing theoretical, numerical, and experimental approaches are welcome, from sub-wavelength structures to large-scale and infrastructural implementations.

We invite original research articles and review articles addressing, but not limited to, the following topics:

1. Physical mechanisms in acoustic and elastic metamaterials: Fundamental studies of wave-fluid and wave-fluid-structure interactions, including locally resonant systems, band-gap formation, effective medium theories, anisotropy, nonlinearity, multiscale or hierarchical architectures, and spatio-temporally modulated materials for acoustic and elastic waves.

2. Wave propagation, dispersion engineering, and topological protection: Research on advanced wave control strategies such as guiding, focusing, redirection, cloaking, and mode conversion, including symmetry-driven and topologically protected wave phenomena, as well as non-reciprocal and frequency-converting effects enabled by space–time modulation.

3. Noise, sound, and vibration control: Metamaterial-based approaches for sound attenuation, vibration isolation, and noise mitigation across a broad frequency spectrum, including low-frequency acoustics and elastic waves relevant to mechanical systems, the built environment, and transportation.

4. Seismic and large-scale elastic metamaterials: Studies addressing the control of surface and bulk elastic waves at macroscopic scales, including seismic metamaterials, ground vibration mitigation, and metamaterial-inspired solutions for civil, structural, and environmental acoustics.

5. Modelling, numerical methods, and inverse design: Theoretical and computational frameworks for predicting and optimizing metamaterial behavior, including finite-element and multiscale modelling, homogenization techniques, inverse design approaches, and data-driven or machine-learning-based methodologies.

6. Experimental realization and validation: Experimental investigations demonstrating acoustic and elastic metamaterial concepts, including fabrication strategies, active and reconfigurable implementations, advanced measurement techniques, and validation of theoretical and numerical predictions.

7. Emerging applications and interdisciplinary connections: Applications spanning acoustic and ultrasonic devices, sensing, energy harvesting, structural and human health monitoring, medical applications, intelligent or adaptive systems, and hybrid approaches connecting acoustics with mechanics, materials science, applied physics, artificial intelligence, and control theory.

8. Ocean acoustics and metamaterial innovations: Research spanning ocean acoustics, underwater and ultrasound metamaterials, bioinspired acoustic design, metasurfaces for surface acoustic waves, and multi-physics metamaterials.

This Collection aligns with the mission of npj Acoustics by highlighting rigorous, physics-based research that deepens the understanding of sound and elastic wave phenomena while fostering strong links between fundamental acoustics and engineered systems. Interdisciplinary contributions that integrate acoustics with mechanics, materials science, applied mathematics, and data science are particularly encouraged.