Membrane-type acoustic metamaterials with tunable frequency by a compact magnet

Area of Science:

• Acoustic Metamaterials
• Vibrational Mechanics
• Magnetism

Background:

• Acoustic metamaterials offer unique sound manipulation capabilities.
• Frequency-tunable acoustic devices are crucial for adaptive noise control.
• Controlling acoustic properties via external forces remains an active research area.

Purpose of the Study:

• To present a novel membrane-type acoustic metamaterial with a compact magnet (MAMM).
• To investigate the frequency-tunable properties of the MAMM by considering magnetic force effects.
• To validate the theoretical model with experimental measurements.

Main Methods:

• Development of a theoretical model incorporating static and dynamic magnetic force effects.
• Analytical investigation of magnetic force influence on transmission loss peaks.
• Experimental validation using impedance tube measurements to determine anti-resonance frequencies.

Main Results:

• Tuning the magnetic force on the central iron platelet shifts the MAMM's transmission loss peaks.
• Experimental anti-resonance frequencies closely match theoretical predictions.
• The MAMM demonstrates continuous tunability over a wide frequency range.

Conclusions:

• The presented MAMM exhibits effective frequency-tunable acoustic properties.
• The theoretical model accurately predicts the MAMM's behavior.
• This tunable metamaterial shows promise for adaptive noise insulation in diverse applications.