Elastic metasurfaces with tailored initial phase for broadband subwavelength focusing

International Journal of Mechanical Sciences, Год журнала: 2024, Номер 268, С. 109048 - 109048

Опубликована: Янв. 21, 2024

Язык: Английский

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Mode-entangled resonance for lamb waves in a plate

International Journal of Mechanical Sciences, Год журнала: 2024, Номер 267, С. 108995 - 108995

Опубликована: Янв. 2, 2024

We report a novel resonance phenomenon called the mode-entangled resonance. It can occur at specific frequency in plate carrying both symmetric and antisymmetric Lamb wave modes. show that this resonance, or be fully transmitted with its mode preserved from one to another through matching geometrically misaligned two base plates. This appears counter-intuitive because waves are generally formed reflected fields when is used as plate. Our analysis shows if modes entangled satisfy established phase condition, transmits any across The discovered related classical Fabry-Perot (FPR), but FPR only applicable for single-mode transmission aligned Numerical experimental results were presented validate phenomenon. Furthermore, we super-amplification of amplitude it excited by plate-surface-mounted patch transducers.

Язык: Английский

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Non-Hermitian metagrating for perfect absorption of elastic waves

Materials Horizons, Год журнала: 2024, Номер 11(7), С. 1658 - 1667

Опубликована: Янв. 1, 2024

Beyond the fashion of Hermitian physics, non-Hermiticity has inspired, most recently, a surge nontrivial principles and significant applications in both open quantum classical systems characterized by gain or loss. However, research on elastic wave manipulation is still predominantly focused conservative systems, overlooking energy interaction with environment. The unavoidable loss, originating from inherent material properties, normally ignored. Additionally, existing materials for absorption suffer complex configurations, sophisticated designs, large volumes. Achieving highly efficient properties advanced artificial ultrathin size easy fabrication challenge. This work proposes design strategy based non-Hermitian modulation to address such proposed metagrating (NHMG), featured subwavelength unit cell, achieves perfect waves under specific low-loss conditions. loss-induced effects are theoretically elucidated framework established NHMG irregular arbitrary shapes. robust performance omnidirectional capabilities respect boundary shape, rotation angle, source location numerically experimentally verified. Consequently, cloaking device further designed avoid arbitrary-shaped targets being detected. Our study enriches ways provides an ultra-compact solution engineering applications.

Язык: Английский

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Dynamic Geometric Phase Mechanism for Multi-mode Guided Wave Manipulation

International Journal of Mechanical Sciences, Год журнала: 2025, Номер unknown, С. 110043 - 110043

Опубликована: Фев. 1, 2025

Язык: Английский

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Synthesized dispersion-engineered elastic metasurfaces for achromatic focusing and harvesting across the audible to ultrasound ranges

Proceedings of the National Academy of Sciences, Год журнала: 2025, Номер 122(18)

Опубликована: Май 1, 2025

Metasurfaces have garnered significant attention for unnatural abilities to modulate waves across various physics domains, including elastics. However, existing elastic metasurfaces are limited narrowband operations due chromatic aberrations; moreover, these exhibit highly discrete phase profiles the empty spaces required each meta-atom function as an individual waveguide. Herein, address these, we propose a synthesized dispersion engineering that compensates higher-order wave dispersion, and considers both diffraction refraction. This approach allows design of metasurface with achromatic focusing capability ultrabroadband range, from audible ultrasound frequencies. By exploiting Kirchhoff-Love plate theory, demonstrate quasi-continuous profile. Additionally, harness amplified electrical energy generated by piezoelectric elements attached at confocal point. Our precise yet straightforward strategy can be extended other dynamics, photonics acoustics, applied scenarios.

Язык: Английский

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Redesigning Finite Metasurfaces for Enhanced Energy Harvesting with Lead-Free (K, Na)NbO3 Ceramics

Sensors and Actuators A Physical, Год журнала: 2025, Номер unknown, С. 116663 - 116663

Опубликована: Май 1, 2025

Язык: Английский

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High-efficiency and large-numerical-aperture focusing with subdiffraction resolution using a hybrid elastic metalens

Physical Review Applied, Год журнала: 2024, Номер 21(3)

Опубликована: Март 5, 2024

Metalenses have been widely studied and used because of their high design freedom ultrathin configurations. For various practical applications, such as geological exploration, energy harvesting, structural health monitoring, it is highly desirable to maximize the focusing efficiency elastic waves. However, a great challenge realize both high-efficiency subdiffraction resolution for waves, especially when mode coupling conversion between longitudinal transverse waves ubiquitous inevitable. Here, we adopt hybrid approach an metalens (54.6%) (0.39\ensuremath{\lambda}) performance with large numerical aperture (NA = 0.931). The composed gradient metasurface in central region metagratings peripheral achieve dramatic lensing functionality, where 112.5 times enhancement wave intensity attained at focal spot. high-efficiency, large-NA, superresolution characteristics performance, together planar compact configuration metalens, are expected find potential applications fields.

Язык: Английский

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Tunable flexural waves by piezoelectric metasurface with shunt circuits

International Journal of Mechanical Sciences, Год журнала: 2024, Номер 284, С. 109769 - 109769

Опубликована: Окт. 11, 2024

Язык: Английский

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Anomalous wavefront control of Lamb wave with metasurfaces via superposed prism resonance

Mechanics of Advanced Materials and Structures, Год журнала: 2024, Номер unknown, С. 1 - 11

Опубликована: Окт. 29, 2024

As a special branch of metamaterials characterized by phase discontinuity, elastic metasurfaces have presented extraordinary capacity for wave manipulation. This class has received extensive attention in recent years. In this paper, subwavelength metasurface with locally resonant prisms is employed to steer the propagation A0 Lamb wave. Based on dispersion curve and transmission ratio, we establish that feature influenced diagonal ratio cross section. By gradually tuning prism section, pattern resonance modes mechanism superposition are clarified. regard, two different can be superimposed at certain frequency. A complete 2π shift crucial redirecting therefore realized. To broader working frequency range, influence height superposed effect plate thickness incident flexural explored. generalized Snell's law, negative refraction verified numerically through assembled from unit cells constant change. addition, other wavefront modulations such as eccentric focusing, nonparaxial also demonstrated. novel design introduces new degrees freedom many engineering applications seismic protection, structural health monitoring energy harvesting.

Язык: Английский

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Directional enhancement of triangular holographic acoustic leaky-wave antennas with reflectors

International Journal of Mechanical Sciences, Год журнала: 2024, Номер 273, С. 109216 - 109216

Опубликована: Март 21, 2024

Язык: Английский

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