EAGER: Understanding and Leveraging Nonlinear Effects in Acoustic Holograms

EAGER：理解和利用声全息图中的非线性效应

基本信息

批准号：
2121933
负责人：
Shima Shahab
金额：
$ 12.74万
依托单位：
Virginia Polytechnic Institute and State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-15 至 2022-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2121933&HistoricalAwards=false
关键词：
EAGER Understanding Leveraging Nonlinear Effects

项目摘要

Ultrasound waves, which can travel through human tissues and fluids, have been used in acoustic sensing, ultrasound therapy, and imaging. The spatial control over the propagation of ultrasound waves can significantly improve noninvasive ultrasound techniques. This EArly-concept Grant for Exploratory Research (EAGER) project will explore acoustic holograms for shaping ultrasound waves in high-intensity fields. Recent studies suggest that passive acoustic holograms can be used for projecting an arbitrary acoustic pattern when illuminated with only a single acoustic source. However, for high-intensity ultrasonic manipulations, where nonlinear effects set in, the hologram technology is in its early stage on untested approaches. This project applies new expertise in volume acoustic holography in nonlinear regimes and contributes to the key elements needed for the novel field of wavefront engineering.The research goal of this EAGER project is to understand how the nonlinear effects influence the general picture of the reflection and transmission phenomena in acoustic holograms, which are characterized by the constructed acoustic fields in the target plane. At higher excitation amplitudes, the nonlinear effects are exhibited by the generation of harmonics, distortion of the acoustic waveform, and possibly the formation of shock fronts. These effects can be responsible for amplitude as well as phase distortions of the primary interfering waves that give rise to extra acoustic images and ambiguity functions of the reconstructed acoustic field. This award will explore an untested nonlinear volume holography approach based on experimental measurements and modeling. The method will help to answer fundamental scientific questions in wavefront engineering research including: (1) What are the dominant origins of nonlinearity in acoustic holograms? (2) Is the enhancement and engineering of nonlinear effects can increase the efficiency of controlling sound waves? (3) What are the effects of the intensity level and frequency of the sound wave as well as nonlinear harmonics on reconstructed acoustic fields?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.

可以通过人体组织和流体传播的超声波已用于声学感应，超声治疗和成像。对超声波传播的空间控制可以显着改善非侵入性超声技术。探索性研究（急切）项目的这项早期概念赠款将探索用于塑造高强度领域超声波的声学全息图。最近的研究表明，仅用单个声源照明时，被动声全息图可用于投射任意声学模式。但是，对于非线性效应的高强度超声操纵，全息图技术正处于未经测试的方法上。 This project applies new expertise in volume acoustic holography in nonlinear regimes and contributes to the key elements needed for the novel field of wavefront engineering.The research goal of this EAGER project is to understand how the nonlinear effects influence the general picture of the reflection and transmission phenomena in acoustic holograms, which are characterized by the constructed acoustic fields in the target plane.在较高的激发幅度下，非线性效应通过谐波的产生，声波形的变形以及可能的冲击前线形成表现出来。这些效应可能导致振幅以及主要干扰波的相变，这些波浪产生了重建的声场的额外声学图像和歧义功能。该奖项将基于实验测量和建模探讨未经测试的非线性全息方法。该方法将有助于回答波兰工程研究中的基本科学问题，包括：（1）声学全息图中非线性的主要起源是什么？（2）非线性效应的增强和工程是否可以提高控制声波的效率？（3）声波的强度水平和频率以及非线性谐波对重建的声学领域的影响是什么？该奖项反映了NSF的法定任务，并通过基金会的智力优点和更广泛的影响来评估NSF的法定任务，并被认为值得支持。