CAREER: Ionic-Type Phononic Metamaterials: Physics and Acousto-Fluidic Applications

心血管疾病是西方世界死亡和残疾的主要原因，是现代社会的巨大负担;估计每年有1750万人死于心血管疾病。最近的一些研究表明，血流中循环内皮祖细胞的水平是心脏病风险的良好预测因子。然而，目前检测这些罕见循环细胞的方法仅适用于设备齐全的研究实验室。对于允许直接从患者血液中快速和可靠地定量内皮祖细胞的即时护理生物医学技术的开发，仍然存在未满足的医疗需求。该研究计划提出开发基于声子（声学）超材料（人工材料）的新型微流体技术，用于血液样本中内皮祖细胞的高效基于尺寸的富集，亲和分离和无标记计数。为了实现这些目标，拟议的研究计划旨在使一个显着的飞跃，在理解和使用压电基板上产生的声学力。与电子学类似，它旨在引入一整套声学微流体组件，这些组件可以组合在一起，在芯片平台上提供完整的实验室功能。除了为研究生提供培训机会外，该计划的教育部分还包括来自多文化工程计划等本科课程的未代表少数民族，并为当地高中生提供暑期研究经验（实习）。此外，该项目还将通过面向中学女生的“Girls in Engineering Program”等项目，以及为大学毕业生提供高级设计项目的机会等，为拓展活动做出贡献。该研究项目旨在介绍具有声子带隙结构新功能的新型声微流体器件。它特别侧重于离子型声子超材料提供单片集成能力的压电基板。这为声子带隙结构与微流体和声波源的平面和可扩展集成打开了大门。在基础层面上将声子能带结构工程和微流体技术结合起来，可能会导致模块化的芯片实验室技术，这些技术可以通过编程以紧凑和高效的方式完成不同的任务。该计划的具体目标是（1）推进我们对二维声子超材料的理解，以引导、捕获和聚焦声学声子，（2）将这些二维声子超材料与微流体相结合，以及（3）展示这些新型声学微流体装置用于内皮祖细胞的分选、分离和计数以检测心脏病的实际用途。拟议的研究计划涉及单片声子超材料的理论分析、声辐射力以及声微流体通道中微生物颗粒的动力学行为。设计的声子超材料器件将使用内部制造设施和Yanik实验室最近开发的强大制造技术制造。声微流控实验将进行测试，完善和推进这些超材料的理论模型和溶液环境中的声辐射力的理解。Yanik实验室还将展示声子带隙器件在生物医学应用微流体通道中基于尺寸/亲和力的分选、操纵和分离微生物颗粒的实际用途。拟议研究的智力价值在于通过声子超材料操纵表面声波的方法的基础知识，以优化其在微流体系统中的使用。了解与采用声子超材料相关的优势和技术问题，将导致更深入地了解其前所未有的潜力，更多涉及的方案声流体粒子操纵。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。

Cardiovascular diseases are the leading causes of death and disability in the western world and are a great burden to modern society; an estimated 17.5 million people every year die from them. A number of recent studies have shown that the levels of circulating endothelial progenitor cells in blood stream is good predictor of the heart disease risk. However, current methods to detect these rare circulating cells are only suitable for well-equipped research laboratories. There remains an unmet medical need for development of point-of-care biomedical technologies allowing rapid and reliable quantification of endothelial progenitor cells directly from patient's blood. This research program proposes to develop novel microfluidic technologies based on phononic (acoustic) metamaterials (artificial materials) for high- efficiency size-based enrichment, affinity-base isolation and label-free counting of endothelial progenitor cells from blood samples. To achieve these goals, the proposed research program aims to make a remarkable leap in understanding and use of acoustic forces created on piezoelectric substrates. Similar to electronics, it aims to introduce a complete set of acoustic-microfluidic components that can be combined to provide full laboratory functions on a chip platform. In addition to providing training opportunities for graduate students, the educational component of this program incorporates unrepresented minorities from undergraduate programs such as Multicultural Engineering Program and offers mentored summer research experiences (internships) to local high school students. Furthermore, the proposed program aims to contribute in outreach activities through programs such as Girls in Engineering Program, a program focused on middle school girls and to provide senior design project opportunities to final year undergraduate students.This research program aims to introduce novel acousto-microfluidic devices with new functionalities using on phononic bandgap structures. It focuses particularly on ionic-type phononic metamaterials offering a monolithic integration capability to piezoelectric substrates. This opens door to planar and scalable integration of phononic bandgap structures with microfluidics and acoustic wave sources. Merging phononic bandstructure engineering and microfluidics at a fundamental level could lead to modular lab-on-chip technologies that can be programmed to do different tasks in a compact and highly efficient way. The specific goals of this program are (1) to advance of our understanding of two-dimensional phononic metamaterials to guide, trap and focus acoustic phonons, (2) to merge these two-dimensional phononic metamaterials with microfluidics, and (3) to demonstrate practical uses of these novel acousto- microfluidic devices for sorting, isolation and counting of endothelial progenitor cells for detection of hearth diseases. The proposed research program involves theoretical analysis of monolithic phononic metamaterials, acoustic radiation forces and dynamic behavior of micro- bioparticles in acousto-microfluidic channels. The designed phononic metamaterial devices will be fabricated using in-house fabrication facilities and the powerful fabrication techniques recently developed in Yanik lab. Acousto-microfluidic experiments will be conducted to test, refine and advance theoretical models of these metamaterials and understanding of acoustic radiation forces in solution environment. Yanik lab will also demonstrate practical uses of phononic bandgap devices for size/affinity-based sorting, manipulation and isolation of micro- bioparticles in microfluidic channels for biomedical applications. The intellectual merit of the proposed research lies in the fundamental knowledge of ways to manipulate surface acoustic waves by phononic metamaterials to optimize their use in microfluidic systems. Understanding advantages and technical issues associated with employing phononic metamaterials will lead to a deeper insight into their unprecedented potential for more involved schemes of acoustofluidic particle manipulation. This will be accomplished by interdisciplinary research combining our expertise from physics, electrical engineering and biological sciences.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.