Phononic Metamaterials and Wave Propagation Dynamics

Phononic metamaterials are engineered composites designed to manipulate the behaviour of acoustic and elastic waves beyond the limits of conventional materials. By organising periodic or locally resonant elements at scales comparable to—or smaller than—the wavelengths of interest, these structures can open bandgaps where wave propagation is forbidden, steer energy along tailored pathways and convert between wave modes and polarisations. Control over dispersion relations, group velocity and polarisation states enables novel functionalities such as vibration isolation, subwavelength imaging, non-reciprocal transport and energy harvesting. Emerging approaches harness anisotropy, nonlinearity and dynamic modulation to achieve adaptive or multifunctional responses. The interplay of theoretical models, numerical simulations and experimental realisations has accelerated the translation of phononic concepts into practical devices for applications ranging from ultrasonic sensing and noise control to seismic shielding and mechanical computing.

Research from Nature Portfolio

Recent studies have expanded capabilities for manipulating mechanical waves by exploiting novel resonant mechanisms and polarisation control. A recent investigation has demonstrated the generation of perfect circular polarisation of elastic waves in isotropic solids by designing anisotropic layers that induce coupled Fabry–Pérot and quarter-wave resonances in orthogonal planes. This approach enables detection of defects oriented arbitrarily and offers a new paradigm for nondestructive evaluation. Another work introduced nonlinear chaotic dynamics within phononic lattices to achieve ultra-low-frequency and ultra-broad-band attenuation. By integrating tailored nonlinear elements, metamaterials now suppress vibrations across bandwidth-to-frequency ratios far exceeding those of linear designs. In a geophysical context, a resonant metawedge composed of spatially graded subwavelength resonators has been shown to mode-convert surface Rayleigh waves into shear bulk waves, producing a seismic “rainbow” and demonstrating broadband surface-wave control useful for earthquake engineering.

Phononic Metamaterials and Wave Propagation Dynamics publication trend

The graph below shows the total number of articles in phononic metamaterials and wave propagation dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Phononic metamaterial: A composite material engineered to control the propagation of phonons, or mechanical waves, through its micro- or macro-structure.

Bandgap: A frequency range in which wave propagation is forbidden due to destructive interference or resonance phenomena.

Subwavelength resonance: Resonant behaviour occurring at scales smaller than the wavelength of incident waves, enabling strong local interactions.

Anisotropy: Directional dependence of material properties, used to tailor wave speeds and polarisation states.

Dispersion relation: The functional relationship between wave frequency and wavevector that governs propagation characteristics.

References

1. Perfect circular polarization of elastic waves in solid media. Nature Communications (2024).
2. A seismic metamaterial: The resonant metawedge. Scientific Reports (2016).
3. Ultra-low and ultra-broad-band nonlinear acoustic metamaterials. Nature Communications (2017).
4. Tunable Hypersonic Bandgap Formation in Anisotropic Crystals of Dumbbell Nanoparticles. ACS Nano (2023).
5. Embodying Multifunctional Mechano‐Intelligence in and Through Phononic Metastructures Harnessing Physical Reservoir Computing. Advanced Science (2023).
6. Large scale mechanical metamaterials as seismic shields. New Journal of Physics (2016).