Microscale thin-walled acoustic resonators for broadband sound absorption
Phys. Rev. Applied 23, 064044 – Published 18 June, 2025
DOI: https://doi.org/10.1103/qlby-kfwm
Abstract
Extreme sound absorption at the microscale presents significant challenges in acoustic systems. Here, we propose and experimentally validate a theoretical model for extreme-scale sound absorption in microscale thin-walled resonators (MTWR). By leveraging the mechanisms of viscous and thermal losses, the model achieves the minimum cross-sectional dimensions permitted by manufacturing constraints. Specifically, at the microscale, we have designed a resonator with cross-sectional dimensions (≤2 mm) and wall thickness (≤300 µm). Loss equations and analytical models are employed to systematically determine the optimal cross-sectional dimensions for sound absorption and uncover the physical mechanisms in microscale narrow tube resonators. Theoretical analysis and numerical simulations reveal the acoustic performance of single and multiple Fabry-Pérot coupled resonators, achieving broadband, quasiperfect absorption of incident acoustic waves through the mechanism of weakly coupled resonance. Our finding demonstrates the potential of thin-walled resonators to achieve extreme sound absorption at the microscale.
