Composite acoustic medium with simultaneously negative density and modulus

Area of Science:

• Acoustics
• Materials Science
• Metamaterials

Background:

• Acoustic metamaterials offer unique wave manipulation properties.
• Designing metamaterials with broad functional frequency ranges is a key challenge.

Purpose of the Study:

• To fabricate and characterize a novel acoustic composite metamaterial.
• To investigate its acoustic properties, including transmission, effective density, and phase velocity.
• To explore the potential of this metamaterial for white light applications.

Main Methods:

• Fabrication of a periodic acoustic composite structure with interspaced membranes and side holes.
• Experimental measurement of acoustic transmission, effective density, and phase velocity.
• Analysis of the system's behavior around critical frequencies omega{SH} and omega{c}.

Main Results:

• The metamaterial exhibits distinct frequency ranges with unique properties.
• A wide double-negative (negative permittivity and permeability) spectral range was observed below omega{SH}.
• The system demonstrated transparency below omega{SH} and above omega{c}, with opacity and negative density in between.

Conclusions:

• The fabricated acoustic metamaterial possesses a broad double-negative spectral range.
• This wide operational bandwidth suggests potential applications in advanced optical and acoustic devices, including white light manipulation.