Huang Yao, Wang Xiaoyu, Gong Xun, Wu Haodong, Zhang Dong, Zhang De
Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Sci Rep. 2020 Feb 13;10(1):2564. doi: 10.1038/s41598-020-59270-2.
Nonlinear implementations of acoustic diodes are inherently nonreciprocal and have received continuous attention from the beginning of the research boom for acoustic diodes. However, all the reported nonlinear schemes usually have the shortcomings such as low transmission ratio, action threshold, lack of stability and cumbersome setups. In the present design, we take advantage of extraordinarily large contact acoustic nonlinearity which is several orders of magnitude stronger than material nonlinearity. It is theoretically found that the spectra of the transmitted wave depend on the contact time. It is proven experimentally that the contact nonlinearity can be tamed by adjusting the driving amplitude, the static stress and the elastic constants of the materials. In order to build a compact acoustic diode, a sub-wavelength filter with a sandwich structure is designed. The total length of the acoustic diode is only three eighths of the incident wavelength. The amplitude-dependent behavior of the device exhibits similarities with electronic diodes. A more than 50% transmission ratio is obtained. A robust, stable, compact, highly efficient and solid-state acoustic diode is realized.
声学二极管的非线性实现方式本质上是非互易的，自声学二极管研究热潮伊始就一直受到持续关注。然而，所有已报道的非线性方案通常都存在诸如传输比低、作用阈值、缺乏稳定性以及设置繁琐等缺点。在当前设计中，我们利用了比材料非线性强几个数量级的超大接触声学非线性。理论上发现，透射波的频谱取决于接触时间。实验证明，可以通过调整驱动幅度、静态应力和材料的弹性常数来控制接触非线性。为了构建一个紧凑的声学二极管，设计了一种具有三明治结构的亚波长滤波器。该声学二极管的总长度仅为入射波长的八分之三。该器件的幅度依赖行为与电子二极管表现出相似性。获得了超过50%的传输比。实现了一种坚固、稳定、紧凑、高效的固态声学二极管。
