Microauscultation devices via acoustic coupling with near-field light-matter interactions

通过声耦合与近场光物质相互作用的微听诊装置

• 批准号: 2314118
• 负责人: Donald Sirbuly
• 金额: $ 50万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2314118&HistoricalAwards=false
• 关键词: Microauscultation; devices; via; acoustic; coupling

Sound waves are crucial in communication and imaging, including medical ultrasound, sonar, and seismography. Auscultation—listening to the sounds of the body—is one of the first things a physician does to assess the health of a patient. Heart activity, blood flow, and pulmonary gas exchange all have unique sounds that to a trained physician’s ear can be used to quickly identify problems in bodily functions. It is also conceivable that cells, bacteria, and viruses all generate distinct acoustic signals. Being able to eavesdrop on this acoustic world would not only be a significant scientific breakthrough but would also transform our ability to monitor our health, diagnose disease, particularly at an early stage, and help answer fundamental biological questions. However, detecting the subtle acoustic signatures from small biological objects while surrounded by a cacophony of other sounds will require a new approach to listening: devices that can approach the size of the sound source, have exceptional sensitivity over a broad range of acoustic frequencies, and have a strong directional and distance-limited sensory capability. Current mechanoelectrical stethoscopes and hydrophones are not engineered to push the limits of auscultation nor be scaled down to operate extremely close to acoustic sources. To address these shortcomings, this proposal seeks to engineer small nanoscale fiber optics that can efficiently convert weak sound waves into an optical signal that can be measured with a photodetector or camera. The working principle of the design involves metal nanoparticles decorating a soft polymer coating that moves in response to extremely low amplitude sound waves, creating a modulated optical signal unique to the detected acoustic signature. This project will have a major impact on student learning, achievement, diversity, and inclusion. For example, “Summer of Nano” workshops will be developed to increase underrepresented minority student enrollment numbers in STEM degree programs at UC San Diego, and other higher education institutes, by galvanizing cross-border relationships between UC San Diego and Mexico as well as local San Diego high schools. Through teaching about how diverse, cross-disciplinary science can be used to accelerate scientific discovery and innovation, this project will also be pivotal in recruiting and retaining underrepresented minority students in engineering degree programs at UCSD.This proposal aims to design, fabricate, and evaluate acoustic-to-optical nanoscale transducers that leverage strong near-field plasmon-dielectric coupling effects to detect and interpret sound signatures never heard before by other local nano-ears. Impedance-optimized acousto-compressible polymer nanofiber cladding layers will be synthesized that enable strong, acoustic modulation of plasmonic nanoparticles embedded in, or attached to, the polymer layer. It will be demonstrated that these cladding layers can be tuned to be modulated by weak sound waves in the optical near field with a broad range of frequencies and amplitudes. Through laser Doppler vibrometry and high-speed digital holographic microscopy, the acoustic resonance and response of the plasmomechanical transduction mechanism will be fully correlated to the cladding deformation studies, providing a deep understanding of how to leverage various parameters (light wavelength, nanoparticle size/shape, polymer composition/thickness, etc.) to control the performance and response of the nanofiber microauscultation devices. The directional response pattern and frequency-dependent sensitivity will be quantified using custom lithium niobate transducers, which will help fill the intellectual gap on how the acoustic near field couples to the far field, and it will be demonstrated that the nanofiber microauscultation devices are sensitive enough to detect and transduce acoustic signatures from nanobiomechanical systems (e.g., genome ejection from viral capsids) for the first time.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.

声波在通讯和成像中是至关重要的，包括医学超声、声纳和地震学。听诊--倾听身体的声音--是内科医生评估病人健康状况的首要任务之一。心脏活动、血液流动和肺气体交换都有独特的声音，对于训练有素的医生来说，这些声音可以用来快速识别身体功能的问题。同样可以想象的是，细胞、细菌和病毒都会产生不同的声音信号。能够窃听这个声学世界不仅是一项重大的科学突破，还将改变我们监测健康、诊断疾病、特别是在早期阶段诊断疾病以及帮助回答基本生物学问题的能力。然而，检测微小生物物体的微妙声学特征，同时又被其他声音的刺耳声音包围，将需要一种新的收听方法：设备可以接近声源的大小，在广泛的声频范围内具有非凡的灵敏度，并具有强大的方向性和距离限制的感知能力。目前的机电听诊器和水听器的设计既不能突破听诊的极限，也不能缩小到离声源非常近的地方工作。为了解决这些缺点，这项提议寻求设计一种小型纳米级光纤，可以有效地将微弱的声波转换为可以用光电探测器或相机测量的光学信号。该设计的工作原理涉及金属纳米颗粒装饰软聚合物涂层，该涂层响应极低幅度的声波而移动，产生检测到的声学特征所独有的调制光学信号。这个项目将对学生的学习、成就、多样性和包容性产生重大影响。例如，将开展“纳米之夏”研讨会，通过促进加州大学圣地亚哥分校与墨西哥以及当地圣地亚哥高中之间的跨境关系，增加加州大学圣地亚哥分校和其他高等教育机构STEM学位项目中未被充分代表的少数族裔学生的入学人数。通过教授如何利用多样化、跨学科的科学来加速科学发现和创新，该项目也将在招收和留住加州大学圣地亚哥分校工程学学位课程中未被充分代表的少数族裔学生方面发挥关键作用。该提议旨在设计、制造和评估声光纳米级换能器，这种换能器利用强大的近场等离子体-介电耦合效应来检测和解释其他当地纳米耳朵以前从未听说过的声音特征。将合成阻抗优化的声学可压缩聚合物纳米纤维包层，使嵌入或附着在聚合物层中的等离子体纳米颗粒能够进行强大的声学调制。我们将证明，这些包层可以被频率和幅度范围较宽的光学近场中的微弱声波调制。通过激光多普勒测振仪和高速数字全息显微镜，等离子体机械传导机制的声学共振和响应将完全与熔覆变形研究相关联，从而深入了解如何利用各种参数(光波长、纳米颗粒大小/形状、聚合物组成/厚度等)。以控制纳米纤维微听诊设备的性能和响应。方向响应模式和频率依赖的灵敏度将使用定制的铌酸锂换能器进行量化，这将有助于填补关于声波近场如何耦合到远场的知识空白，并将首次证明纳米纤维微听诊设备具有足够的灵敏度，可以检测和转换来自纳米生物机械系统的声学特征(例如，从病毒衣壳中弹出基因组)。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。