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

这项学院早期职业发展(Career)补助金将使新一代具有嵌入活性元素(即活性超材料)的大规模合成材料成为可能，这将对声音的传播提供无与伦比的控制。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行业。例如，所寻找的材料将通过声音引导实现噪音缓解，其性能将超过声学吸收，从而使生活空间更加安静。同样，这些材料将实现无像差可重构声学透镜，以改进医学超声诊断和治疗方法。最近的研究表明，活性超材料可能是获得这些应用中所需的声学性能的可行方法；然而，要实现活性超材料的好处，还需要进行基础研究。这个项目将获得创造超材料所需的知识，这些材料目前无法获得极端声音处理所需的声学参数。该项目的教育目标是加强波浪动力学教育，并通过为未被充分代表的学生进行实习、K-12推广、课程开发以及本科生和研究生参与研究和外出活动来突出波浪工程实现的社会效益。该项目将系统地探索一种综合的超材料合成方法，将所需的材料特性转化为由活跃的单元细胞实现的极化夹杂物的空间分布。该方法将利用用点状极化源阵列来描述物质的模型，并将帮助回答超材料研究中的基本科学问题，包括：1)声学特性的期望分布是否可实现，如果是，什么结构提供这些特性？2)由大量相互强烈相互作用的细胞制成的超材料的动态性能和稳定性之间的权衡是什么，动态变化的周围环境？3)理想超材料特性的动态性能和稳定性有多强？4)如何准确地在由大量活动细胞组成的超材料中实现所需的声学参数？5)如何在单位细胞水平上有效地调谐大型超材料？该项目将为PI提供通向致力于探索基本波浪工程原理以改善人类栖息地和生活条件的研究和教学生涯的道路。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.