Compact acoustic bilayer metasurfaces for high-efficiency flexible beamsplittinga)

Area of Science:

• Acoustics
• Metamaterials
• Wave manipulation

Background:

• Tunable acoustic beamsplitting is crucial for flexible control of sound wave radiation.
• Twisted bilayer metasurfaces offer dynamic acoustic wave manipulation via interlayer angle adjustment.
• Existing methods often lack facile adjustability and compactness.

Purpose of the Study:

• To introduce a compact acoustic bilayer metasurface (ABM) for high-efficiency, flexible beamsplitting.
• To demonstrate tunable control over acoustic beamsplitting with multiple far-field radiation patterns.
• To provide a versatile solution for advanced acoustic applications.

Main Methods:

• Design and fabrication of a compact acoustic bilayer metasurface with near-zero interlayer distance.
• Integration of two identical metasurfaces allowing four phase configurations via 90° rotations.
• Numerical simulations and experimental validation of the beamsplitting performance.

Main Results:

• The ABM achieves high-efficiency flexible beamsplitting with four distinct far-field radiation patterns.
• The compact structure ensures stability, while the periodic design allows for scalability.
• Demonstrated tunable control over acoustic beamsplitting through simple mechanical rotation.

Conclusions:

• The developed compact ABM offers a versatile and effective solution for tunable acoustic beamsplitting.
• This work advances the field of acoustic wave manipulation with practical, multifunctional capabilities.
• The ABM design is suitable for scalable and stable integration into various acoustic systems.