GOALI: EFRI NewLaw: Non-reciprocal effects and Anderson localization of acoustic and elastic waves in periodic structures with broken P-symmetry of the unit cell

目标：EFRI 新定律：单胞 P 对称性破缺的周期性结构中声波和弹性波的非互易效应和安德森局域化

基本信息

批准号：
1741677
负责人：
Arkadii Krokhin
金额：
$ 199.72万
依托单位：
University of North Texas
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-11-01 至 2024-10-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1741677&HistoricalAwards=false
关键词：
GOALI EFRI NewLaw Non reciprocal

项目摘要

This award will investigate non-reciprocal metamaterials that arise in periodic media due to viscosity and engineer acoustic wave propagation through it. For light and sound waves, nature ideally follows the reciprocity rule that reversing a wave propagation will return that wave to its original state. This phenomenon is similar to the "undo" action on a computer or device, and is fundamental to the behavior of waves used in conventional communication and our general perception of reality. However, there is a select class of specially designed materials that violate these behaviors called non-reciprocal metamaterials that break reciprocity symmetry. In these materials, the "undo" or reverse action does not ideally return the wave to its initial state. Deeper understanding of non-reciprocity will enhance our knowledge of general acoustics and impact applications like architecture, secure communications, vibration isolation, medical diagnostics and therapeutics. Active phononic structures including tunable lens, filters and acoustic diodes will be designed. Additive manufacturing and micro-electro-mechanical techniques will be utilized to realize active phononic structures. Local high school students, graduates, post-docs, and undergraduates from physics, mechanical and electrical engineering, and material science will be involved in this project. Research experience and mentoring (EFRI-REM) will be offered through this research project to the students from Texas Academy of Math and Sciences. This project also includes close collaboration with the industry for student training and commercialization of the outcome of the research activities.Propagation of waves through a system of scatterers follows the reciprocity theorem which states that the transmission of a wave remains identical if the positions of the emitter and receiver are interchanged. The reciprocity follows from the fundamental property of the wave equation - time reversal symmetry. This project investigates a new mechanism of non-reciprocal or unidirectional propagation of sound in viscous medium. A common viewpoint is that while dissipation breaks time-reversibility, this is not sufficient to induce different transmission along two opposite directions. However, this is not valid in case of a viscous fluid. It will be shown that sound propagating in viscous medium through a phononic crystal with broken P-symmetry does not follow the reciprocity theorem. More specifically, we investigate how differential dissipation arising in the Navier-Stokes equation leads to significant non-reciprocal effects without the requirement of dynamic energy input, and expand that to new classes of non-reciprocal structures including non-reciprocal hyperbolic metamaterials. The transmission through a 2D disordered phononic crystal with non-reciprocity will also be studied. The presence of disorder in an individual scatterer results in localization of sound waves - an effect termed Anderson localization. This effect will be utilized to achieve encryption, which can be used to develop secure communication of acoustic signal both in air and water.

该奖项将调查由于粘度和工程师的声波传播，该奖项在周期性介质中出现的非晶体质材料。对于光线和声波，理想情况下自然遵循互惠规则，即逆转波传播将使该波恢复到其原始状态。这种现象类似于计算机或设备上的“撤消”动作，并且是传统交流中使用的波浪行为以及我们对现实的一般看法的基础。但是，有一类特殊设计的材料，违反了这些行为，称为非近代超材料，它们破坏了互惠对称性。在这些材料中，“撤消”或反向作用理想地将波浪归还其初始状态。更深入地了解非股展度将增强我们对一般声学的了解和影响应用程序，例如建筑，安全通信，振动隔离，医学诊断和治疗学。将设计包括可调透镜，过滤器和声学二极管在内的活动音调结构。添加剂制造和微电机械技术将用于实现主动的音调结构。当地的高中生，毕业生，毕业后以及物理，机械和电气工程以及材料科学的本科生将参与该项目。研究经验和指导（EFRI-REM）将通过该研究项目提供给德克萨斯州数学和科学学院的学生。该项目还包括与该行业的学生培训和研究活动结果的商业化的密切合作。通过散射系统的波浪范围遵循互惠定理，该定理指出，如果发射器和接收器的位置互换，则波浪的传播仍然相同。互惠来自波方程的基本特性 - 时间逆转对称性。该项目研究了粘性培养基中声音的非逆时针或单向传播的新机制。一个普遍的观点是，尽管耗散破坏了时间可逆性，但这不足以沿两个相反的方向诱导不同的传播。但是，在发生粘性流体的情况下，这是无效的。可以证明，通过损坏的p-对称性的语音晶体在粘性介质中传播的声音不会遵循互惠定理。更具体地说，我们研究了无需动态能量输入而在Navier-Stokes方程中产生的差异耗散是如何导致显着的非转向效应的，并将其扩展到新的非近代结构，包括非二型超细增压超材料。还将研究通过2D无序的语音晶体的传播，具有非股展度。单个散射器中疾病的存在导致声波的定位 - 这种效果称为安德森定位。这种效果将用于实现加密，该加密可用于在空气和水中发展声学信号的安全通信。