Synchronization driven acoustics: The nonlinear scattering of a self-oscillating meta-atom

TL;DR

This paper demonstrates a self-oscillating acoustic meta-atom that uses synchronization to control sound transmission, with potential for advanced wave manipulation in acoustic metamaterials.

Contribution

It introduces a nonlinear self-oscillating meta-atom that leverages synchronization for tunable acoustic control, bridging nonlinear dynamics with metamaterial design.

Findings

Experimental validation of synchronization-induced transmission control

Nonlinear dependence of acoustic response on incident wave amplitude

Quantitative description using a nonlinear Liénard oscillator model

Abstract

In this study we demonstrate a self-oscillating acoustic meta-atom functioning as an amplifying transistor, where a steady external flow serves as a control signal to switch between reflective (off-state) and transmissive (on-state) regimes. In the on-state, an acoustic limit cycle synchronizes with incident sound waves. This process governs the energy transfer across the device, with a transmission bandwidth dictated by the synchronization region in parameter space (Arnold tongue). Our experimental measurements reveal nonlinear dependence on the incident wave amplitude, enabling perturbation filtering therein and stabilizing downstream acoustic power. All experimentally observed phenomena are quantitatively described by a nonlinear Li\'enard-type oscillator featuring saturable gain and linear loss, where the essential parameters can be estimated by independent measurements. This work may offer a paradigm shift in acoustic metamaterials research by leveraging self-oscillation and synchronization processes. Bridging those key concepts from nonlinear dynamics and complex systems with active metamaterial design in acoustics and related disciplines, may establish a broadly applicable framework of field-independent mechanisms for wave manipulation.