CAREER: Scalable Active Metamaterials for Extreme Sound Manipulation in Arbitrary Environments

这一教师早期职业发展（CAREER）资助将使新一代的大规模合成材料与嵌入式活性元素（即，有源超材料），其将提供对声音传播的无与伦比的控制。这项研究有可能推动医疗保健、汽车和航空航天行业的关键领域的发展。例如，所寻求的材料将通过声音引导实现噪音缓解，这将超过吸声性能，这将导致更安静的生活空间。类似地，这些材料将使无像差的可重构声学透镜能够用于改进的医疗超声诊断和治疗方法。最近的研究表明，有源超材料可能是获得这些应用中所需的声学特性的可行方法;然而，需要进行基础研究才能实现有源超材料的好处。该项目将获得必要的知识，以创造超材料与目前无法达到的声学参数需要极端的声音操纵。该项目的教育目标是加强波浪动力学教育，并通过为代表性不足的学生提供实习机会，K-12推广，课程开发，该项目将系统地探索一种全面的超材料合成方法，该方法将所需的材料特性转化为材料的空间分布，极化夹杂物由活性晶胞实现。该方法将利用一个模型，该模型以点状极化源阵列的形式描述物质，并将有助于回答超材料研究中的基本科学问题，包括：1）所需的声学特性分布是否可实现，如果是，什么结构提供这些特性？2)由大量细胞组成的超材料的动态性能和稳定性之间的权衡是什么？这些细胞彼此之间以及与任意的、动态变化的周围环境之间强烈相互作用。3)动态性能和稳定性对理想超材料特性的扰动有多鲁棒？4)在由大量活性细胞组成的超材料中，人们能精确地实现所需的声学参数吗？5)大型超材料是如何在单元格水平上有效地调谐的？该项目将为PI提供一条研究和教学生涯的道路，致力于探索基本的波浪工程原理，以改善人类栖息地和生活条件。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) grant will enable new generations of large-scale synthetic materials with embedded active elements (i.e., active metamaterials) which will provide unparalleled control over the propagation of sound. This research has the potential to advance key sectors in healthcare, automotive, and aerospace industries. For example, the sought materials will enable noise mitigation through sound guiding that will surpass the performance of acoustic absorption, which will lead to quieter living spaces. Similarly, these materials will enable aberration-free reconfigurable acoustic lenses for improved medical ultrasound diagnostic and treatment methods. Recent studies suggest that active metamaterials may be the feasible way to obtain the acoustic properties necessary in these applications; however, fundamental research is required to realize the benefits of active metamaterials. This project will derive the knowledge necessary to create metamaterials with currently unattainable acoustic parameters needed for extreme sound manipulation. The educational objective of this project is to strengthen wave dynamics education and highlight the societal benefits realized by wave engineering through internships for underrepresented students, K-12 outreach, curriculum development, and involvement of undergraduate and graduate students in research and outreach.This project will systematically explore a comprehensive metamaterial synthesis method that translates desired material properties into spatial distributions of polarized inclusions realized by active unit cells. The method will leverage a model that describes matter in terms of arrays of point-like polarized sources and will help answer fundamental scientific questions in metamaterial research including: 1) Is a desired distribution of acoustic properties realizable and, if so, what structures provide these properties? 2) What is the trade-off between the dynamic performance and stability of metamaterials made of large numbers of cells strongly interacting with each other and with the arbitrary, dynamically changing surrounding environment? 3) How robust is the dynamic performance and stability to perturbations from the ideal metamaterial properties? 4) How accurately can one realize desired acoustic parameters in metamaterials composed of large numbers of active cells? 5) How are large metamaterials efficiently tuned at the unit cell level? This project will provide the PI with the path towards a research and teaching career devoted to exploring fundamental wave engineering principles for improved human habitats and living conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.