PZT-hydrogel integrated active non-Hermitian complementary acoustic metamaterials with real time modulations through feedback control circuits

PZT-水凝胶集成有源非厄米互补声学超材料，通过反馈控制电路进行实时调制

• 批准号: 2423820
• 负责人: Chengzhi Shi
• 金额: $ 40万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2423820&HistoricalAwards=false
• 关键词: PZT; hydrogel; integrated; active; non

This grant will support research that will generate new fundamental knowledge on the dynamic and acoustic properties of a PZT-hydrogel based active complementary acoustic metamaterial. Such acoustic metamaterials will enable high energy transmission at high frequency through sound barriers, including those with strong intrinsic loss like skull for brain imaging and brain-machine interface. Transcranial ultrasound (i.e. ultrasound transmission through skull) has many applications including noninvasive surgeries and drug delivery. However, current transcranial ultrasound techniques are all based on sound waves with relatively low frequency and poor spatial resolution, and the energy transmission through the lossy skull is low even for such low frequency sound waves. Brain imaging and brain-machine interfaces require better spatial resolution, which can be realzied by enabling transmission of high frequency ultrasound through skulls, which is not achievable with existing technologies. Active non-Hermitian complementary acoustic metamaterials (NHCMM) are promising compensation media to complement with the strong transmission loss through skull for high frequency acoustic waves. This project explores the acoustic and material properties of PZT-hydrogel composites integrated with feedback control circuits for the experimental realization of NHCMM that can compensate the high frequency ultrasound transmission loss through a real skull. This experimental realization will set the foundation for high resolution ultrasound brain imaging and brain-machine interface. This research will have broader impacts in science, defense, industry and general society by satisfying the critical need for high performance brain imaging and brain-machine interface. In addition, this research will promote the progress of fundamental acoustics, soft matter physics, and metamaterials. This multi-disciplinary research will broaden the participation of underrepresented groups in science and engineering and positively impact STEM education.The objective of this research is to design, fabricate, and experimentally characterize an active NHCMM by integrating PZT elements, hydrogel, and feedback control circuits that can be used to complement sound barriers, including those with strong intrinsic loss such as skull, to achieve optimal energy transmission for brain imaging and brain-machine interface. The NHCMM has effective density and bulk modulus with negative values of that of the barrier to suppress the strong impedance mismatch and material gain that balances the intrinsic loss in the barrier. The NHCMM will be realized by integrating piezoelectric elements and hydrogel with electrical circuit components. The integrated feedback control circuit will actively modulate the effective acoustic properties of the metamaterials to realize the desired parameters of NHCMM and compensate impedance mismatch and loss simultaneously. This fundamental research project will pave the road for the realization of noninvasive ultrasonic brain imaging, high intensity focused ultrasound treatments, brain stimulation, and brain-machine interface. To achieve the proposed objective, the two PIs will utilize their complemented expertise in acoustics, metamaterials, and soft matter to accomplish the following research tasks: 1) Identify the dynamic properties of different types of hydrogels in a wide ultrasonic frequency band; 2) Design and fabricate hydrogel-based active NHCMMs with feedback-circuit-controlled piezoelectric elements to realize any desired effective density and bulk modulus with acoustic gain; 3) Characterize and optimize NHCMMs to enhance acoustic energy transmission through lossy skull for brain imaging and brain-machine interface.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.

该赠款将支持研究，该研究将产生有关基于PZT-H​​YDREGEL的动态和声学特性的新基本知识。这样的声学超材料将通过声音屏障在高频以高频传递，包括具有强烈内在损失的颅骨（例如用于脑成像和脑部机器接口的头骨）的高能传播。经颅超声（即通过头骨的超声传播）具有许多应用，包括无创手术和药物输送。但是，当前的经颅超声技术都是基于频率相对较低且空间分辨率较差的声波，即使对于如此低频率的声波，通过有损颅骨的能量传递也很低。脑成像和脑机界面需要更好的空间分辨率，这可以通过使高频超声通过头骨传播来实现，而现有技术是无法实现的。主动非热互补的声学超材料（NHCMM）是有前途的补偿介质，可以补充高频声波通过头骨的强透射损失。该项目探讨了与反馈控制电路集成的PZT-H​​YDREGEL复合材料的声学和材料特性，以实现NHCMM的实现，从而可以通过真实的头骨补偿高频超声传输损失。这种实验性实现将为高分辨率超声脑成像和脑机界面奠定基础。这项研究将通过满足对高性能脑成像和脑机界面的关键需求，对科学，国防，工业和一般社会产生更大的影响。此外，这项研究将促进基本声学，软物质物理和超材料的进步。 This multi-disciplinary research will broaden the participation of underrepresented groups in science and engineering and positively impact STEM education.The objective of this research is to design, fabricate, and experimentally characterize an active NHCMM by integrating PZT elements, hydrogel, and feedback control circuits that can be used to complement sound barriers, including those with strong intrinsic loss such as skull, to achieve optimal energy transmission for brain imaging and brain-machine 界面。 NHCMM具有有效的密度和散装模量，其负值的屏障值是抑制强阻抗不匹配和材料增益，以平衡屏障中固有损失。 NHCMM将通过将压电元件和水凝胶与电路组件集成在一起来实现。集成的反馈控制电路将积极调节超材料的有效声学特性，以实现NHCMM的所需参数，并同时补偿阻抗不匹配和损失。这个基本的研究项目将铺平道路，以实现非侵入性超声脑成像，高强度聚焦的超声处理，脑刺激和脑摄像机界面。为了实现拟议的目标，两个PI将利用其在声学，超材料和软物质方面的补充专业知识来完成以下研究任务：1）确定在广泛的超声波频带中不同类型水凝胶的动态特性； 2）设计和制造基于水凝胶的活性NHCMM，并使用反馈电路控制的压电元件，以实现具有声学增益的任何所需的有效密度和散装模量； 3）表征和优化NHCMM，以通过有损的颅骨来增强声学能量传播，以进行大脑成像和脑机界面。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的审查标准通过评估来通过评估来支持的。