Nonlinear and Adaptive Acoustic Metamaterials for Novel Wave-Based Devices

该奖项的研究目标是研究具有自适应特性的非线性声学超材料，用于设计下一代基于波的器件。必要的非线性相互作用和自适应将来自两个主要的材料系统：一个基于可控后屈曲晶格，另一个基于压电可调谐超材料。该研究还将利用由结构不稳定引起的大变形作为一种有效的方法来适应结构材料的拓扑结构和周期性。将根据它们对导波特性的影响来研究硬化和软化效应、振幅相关色散和稳定性。对非线性和自适应声学超材料的基本理解，以及对其波传播行为的探索，将支持创新波基器件的概念、制造和实验测试，包括可调谐滤波器、波导、声学二极管、噪声隔离器和定向能系统。如果成功，本研究的结果将显著推进可调谐和自适应非线性超材料的一般领域的知识和理解。这种理解对于用于通信系统（移动电话，GPS单元等），噪声隔离，能量重定向以及声学滤波器，逻辑端口和开关的创新设备的开发非常重要。研究课题的进展将通过佐治亚理工学院的波动力学学术课程和本科生的研究机会广泛传播。通过佐治亚理工学院正在进行的项目，专门与代表性不足的学生合作，扩大参与范围。此外，与佐治亚理工学院GIFT项目合作开发的教育实验室活动和课堂模块，将使代表性不足的高中和初中学生接触到研究的基本结果和潜在的波动力学原理。

The research objective of this award is to investigate nonlinear acoustic metamaterials with adaptive properties for the design of next-generation wave-based devices. The necessary nonlinear interactions and adaptivity will be derived from two primary material systems: one based on controllable post-buckled lattices, and the other based on piezoelectric tunable metamaterials. The research will also exploit large deformations resulting from structural instabilities as an effective way to adapt the topology and the periodicity of a structured material. Stiffening and softening effects, amplitude-dependent dispersion, and stability will be studied in terms of their effect on the wave guiding characteristics. Fundamental understanding of nonlinear and adaptive acoustic metamaterials, and the exploration of their wave propagation behavior, will support the conception, fabrication, and experimental testing of innovative wave-based devices, to include tunable filters, waveguides, acoustic diodes, noise isolators, and directed-energy systems. If successful, the results of this research will significantly advance knowledge and understanding in the general area of tunable and adaptive nonlinear metamaterials. This understanding will be important for the development of innovative devices for use in communication systems (mobile phones, GPS units, etc.), noise isolation, energy redirection, and acoustic filters, logic ports and switches. Advances from the research topics will be disseminated widely through academic courses on wave mechanics at Georgia Tech and in undergraduate research opportunities. Broadening of participation will be achieved by specifically working with underrepresented students through ongoing programs available at Georgia Tech. In addition, educational laboratory activities and classroom modules, developed in partnership with the GIFT program at Georgia Tech, will expose high school and middle school underrepresented students to basic results of the research and to underlying wave mechanics principles.