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Synchronization driven acoustics: The nonlinear scattering of a self-oscillating meta-atom.
Alexander K Stoychev1, Xinxin Guo1, Ulrich Kuhl1,2
1ETH Zürich, CAPS Laboratory, Department of Mechanical and Process Engineering, 8092 Zürich, Switzerland.
Physical Review. E
|May 16, 2026
Summary
Researchers developed a self-oscillating acoustic meta-atom that acts as an amplifying transistor. External flow controls the device, enabling it to switch between reflective and transmissive states, demonstrating novel wave manipulation.
Area of Science:
- Acoustics
- Nonlinear Dynamics
- Metamaterials
Background:
- Acoustic metamaterials offer unique wave manipulation capabilities.
- Active metamaterials integrate gain or loss for tunable properties.
- Self-oscillation and synchronization are key concepts in nonlinear dynamics.
Purpose of the Study:
- To demonstrate a self-oscillating acoustic meta-atom functioning as an amplifying transistor.
- To investigate the control of acoustic wave transmission using external flow.
- To explore the application of nonlinear dynamics principles in acoustic metamaterial design.
Main Methods:
- Fabrication and characterization of a self-oscillating acoustic meta-atom.
- Experimental investigation of device response to incident sound waves under external flow.
- Quantitative description using a nonlinear Liénard-type oscillator model.
Main Results:
- The meta-atom functions as an amplifying transistor, switching between reflective and transmissive states.
- An acoustic limit cycle synchronizes with incident waves in the transmissive state, governing energy transfer.
- Nonlinear dependence on incident wave amplitude enables perturbation filtering and stabilizes acoustic power.
Conclusions:
- The study presents a paradigm shift in acoustic metamaterials by leveraging self-oscillation and synchronization.
- The developed framework offers field-independent mechanisms for wave manipulation.
- This work bridges nonlinear dynamics and active metamaterial design for broad applicability.
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