Channel-Coupling Fano Resonance and Acoustic Metadamping

TL;DR

This paper presents a novel acoustic metamaterial design that generates multiple Fano-like resonances for broadband sound insulation, enhanced by metadamping, and demonstrates potential for practical ventilation and noise control applications.

Contribution

The study introduces a new metamaterial with multiple Fano-like resonances and integrated metadamping, enabling broadband sound insulation with practical design for real-world applications.

Findings

Achieves over 10 dB transmission loss from 0.6-1.1 kHz

Dampened design maintains over 10 dB loss from 0.32-4 Hz

Demonstrates acoustic negative refraction with coupled channels

Abstract

Fano resonance featuring asymmetric spectral profiles originates from the interference of local resonances and background continuum. Its narrow-band nature looks seemingly adverse to broadband noise cancellation purposes. In this study, we report theoretically on an intriguing acoustic metamaterial capable of generating multiple Fano-like resonances to realize a broadband sound barrier with satisfactory transmission loss performance. Our proposed design involves an effective channel characterized by effective parameters and short channels filled with air. The effective channel support both monopolar and dipolar modes which interact with the continuum state admitted by the short channels to generate a pair of Fano-like resonances. Due to the destructive interference of sound waves, the two resonances result in transmission loss overall exceeding 10 dB over a broad range 0.6-1.1 kHz. In order to further optimize the overall performance, we introduce metadamping by integrating additional viscous foams in the proposed unit cell. Furthermore, for future experimental tests, the dampened design is decoded into a real space-coiling cell which exhibits identical functionality and is assembled into a partition wall to ensure transmission loss over 10 dB across the range 0.32-4 Hz. Lastly, acoustic negative refraction is accessible by deploying two coupled space-coiling channels in a similar fashion. We believe this work paves the way for realizing effective broadband sound insulation devices with efficient ventilation.