Tunable Acoustic Metasurface with High-Q Spectrum Splitting

Area of Science:

• Acoustics
• Metamaterials
• Wave Physics

Background:

• Acoustic metasurfaces offer advanced control over sound waves.
• Tunable acoustic devices are crucial for advanced applications.
• Existing metasurfaces often lack efficient tunability and spectral control.

Purpose of the Study:

• To propose and demonstrate a novel tunable acoustic metasurface.
• To achieve a nearly 2π phase shift using a nested microunit.
• To enable directional control of reflected sound waves with high spectral purity.

Main Methods:

• Design of a microunit with coupled resonators and an adjustable split cavity.
• Full-wave simulations to analyze the metasurface's acoustic response.
• Investigation of phase shift and reflection characteristics based on rotation angle.

Main Results:

• The nested microunit achieves a nearly 2π phase shift by rotating the inner split cavity.
• The metasurface demonstrates tunable directional reflection of sound waves within a narrow bandwidth.
• Sound waves outside the operation frequency are unaffected, resulting in high Q-factor spectrum splitting.

Conclusions:

• The proposed tunable acoustic metasurface offers precise control over sound wave reflection.
• This technology is vital for developing advanced acoustic devices like tunable cloaks and switches.
• The high Q-factor spectrum splitting capability opens new avenues in acoustic filtering and imaging.