Collaborative Research: Integrated Experiments and Modeling for Spatial, Finite, and Fast Rheometry of Graded Hydrogels using Inertial Cavitation

合作研究：利用惯性空化对梯度水凝胶进行空间、有限和快速流变测量的综合实验和建模

• 批准号: 2232427
• 负责人: Mauro Rodriguez
• 金额: $ 35.05万
• 依托单位: Brown University
• 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: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2232427&HistoricalAwards=false
• 关键词: Collaborative; Research; Integrated; Experiments; Modeling

Until recently, inertial cavitation—the rapid, unstable growth and collapse of bubbles—has been best known as a damaging agent in environments such as pumps, coatings, and bodily tissues. Current advances in medicine aim to harness inertial cavitation to cut tissues noninvasively using ultrasound, but this goal is limited by available data. A present challenge is that tissues and various soft material systems are complex, with interfaces and stiffness gradients along different internal directions. This award supports characterizing, modeling, and predicting the mechanical response of non-uniform soft materials subject to rapid bubble collapse and oscillation. This knowledge could be used, for example, to speed up assessment during ultrasound-based surgery and provide critical insight into mitigating injury from rapid forces. Thus, the research will not only promote the progress of science but will also advance national health, prosperity, and welfare. This project will further train students working across disciplines of fluid and solid mechanics, and materials science. The team will encourage scientific learning in a broad early-learner audience via the development of two children's books written in multiple languages and outreach activities about soft material mechanics.A single test probing ultra-high-rate and finite deformation regimes of materials simultaneously has been elusive. Prior work has established inertial cavitation rheometry as a promising candidate, but the technique restrictively assumes spherical symmetry. This project aims to leverage quantities surrounding asphericity—regarded as a problem in the original technique—as a critical metric for assessing local material gradients. A multi-perspective, ultra-high-rate microscopy platform for characterizing graded, ultraviolet-light-tunable hydrogels using bubble kinematics, and full-field deformations determined via embedded speckle plane-based digital image correlation comprise the experimental setup. Concurrently, numerical methods leveraging (a) full-field kinematic fields with simulation and (b) bubble shape perturbation information with a modified 1D-perturbation model of the governing equations of motion and conservation will establish a suite of baseline problems. Together, critical measurable quantities in the inverse calibration problem will be used to establish a fast reduced-order model for describing both material behavior and gradients therein. This approach will provide a methodology for producing linearly graded hydrogels, a database of ultra-high-rate, finite viscoelastic hydrogel behavior, upgraded inverse-calibration procedures leveraging spherical perturbations and simulations, and a reduced-order approach for fast rheology without, with, or with-coupled property gradients.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.

直到最近，惯性空化（气泡的快速、不稳定的生长和破裂）一直被认为是泵、涂层和身体组织等环境中的破坏剂，当前的医学进展旨在利用惯性空化来无创地切割组织。超声波，但这一目标受到现有数据的限制，目前的挑战是组织和各种软材料系统非常复杂，具有沿不同内部方向的界面和刚度梯度。例如，这些知识可用于加速超声手术期间的评估，并为减轻快速力造成的损伤提供重要的见解。该项目将进一步培训跨学科的流体和固体力学以及材料科学的学生，并通过该项目鼓励广大早期学习者进行科学学习。开发两本以多种语言编写的儿童读物软材料力学的语言和推广活动。同时探测材料的超高速率和有限变形状态的单一测试一直难以实现。先前的工作已将惯性空化流变测量法确立为有希望的候选者，但该技术限制性地假设球对称。该项目旨在利用非球面量（被视为原始技术中的一个问题）作为评估局部材料梯度的关键指标。使用气泡运动学进行表征分级、紫外光可调水凝胶，以及通过包含实验设置的嵌入式散斑平面数字图像相关确定的全场变形，同时利用（a）全场运动场与模拟和（ b) 气泡形状扰动信息以及运动和守恒定律的修正一维扰动模型将共同建立一系列基线问题，即逆校准问题中的关键可测量量。将用于建立一个快速降阶模型来描述材料行为和其中的梯度，该方法将提供一种生产线性分级水凝胶的方法、超高速率、有限粘弹性水凝胶行为的数据库、升级的逆校准。利用球形扰动和模拟的程序，以及在没有、有或有耦合属性梯度的情况下实现快速流变学的降阶方法。该奖项反映了 NSF 的法定使命，并被认为值得通过以下方式获得支持：使用基金会的智力价值和更广泛的影响审查标准进行评估。