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Acoustic reciprocity, which is widely observed in linear time-invariant systems, refers to the property that wave transmission pattern remains the same when the source and receiver are switched. Non-reciprocity, on the other hand, violates this symmetry and can be used to control wave propagation and manufacture desired propagation patterns. To break reciprocity, multiple approaches (active and passive) have been studied recently. While active manner often relies on odd-symmetry field or time-variant parameters, passive manner achieves non-reciprocity by combining geometric asymmetry and nonlinearity in the structure. In this field, researchers have studied a number of acoustic devices that allow one-way propagation1, 2. However, these devices either change the frequency content of the sending signal, or have a strict restriction on the range of sending frequency. In this paper, we propose a passive, nonlinear, periodic structure, which achieves giant non-reciprocity for a range of input frequency and energy with minimal distortion of the sending frequency.
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Wave redirection, localization, and non-reciprocity in a dissipative nonlinear lattice by macroscopic Landau–Zener tunneling: Experimental results
Nonlinear lattices and the nonlinear acoustics they support have a broad impact on shock and vibration mitigation, sound isolation, and acoustic logic devices. In this work, we experimentally study wave redirection, localization, and non-reciprocity in an asymmetric network of two nonlinear lattices with weak linear inter-lattice coupling. We report on the design, fabrication, and system identification of coupled lattices with essentially nonlinear next-neighbor intra-lattice coupling and on their unusual nonlinear acoustics. By weakly coupling the lattices and introducing structural disorder in one of them, we experimentally prove the realization of irreversible breather redirection between lattices governed by a macroscopic analog of the quantum Landau–Zener tunneling effect. In the experiments performed, the input energy is applied by impulse (broadband) excitation, and the resulting acoustical mechanism for wave redirection is in the form of propagating breathers, that is, localized oscillating wave packets formed by the synergy of nonlinearity and dispersion. Moreover, we study the non-reciprocal acoustics of the experimental lattice system by applying separate impulses at each of its four terminals and investigate the tunability with the energy of the resulting acoustic non-reciprocity by systematically varying the impulse intensity. The reported experimental results show that the weakly coupled, disordered, and nonlinear lattice system has wave tailoring properties that are tunable with energy. Altogether, the experimental results agree well with theoretical predictions reported in a companion work based on reduced-order numerical models and prove the efficacy of the system for applications, providing a path for applying these advanced concepts in future structures and devices.
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- Award ID(s):
- 1741565
- PAR ID:
- 10597511
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- AIP Advances
- Volume:
- 11
- Issue:
- 6
- ISSN:
- 2158-3226
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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