Collaborative Research: Manipulation of Suspended Microparticles via Localized Fluid Boundary Dynamics: Modeling, Simulation, and Experiments

该项目将通过互补的理论，计算和实验研究，提出一种新颖的，生物启发的方法，用于在微观尺度上操纵悬浮在流体中的固体颗粒。一个全面的数学框架将被开发用于描述在低雷诺数的流体流动的控制，通过局部循环边界变形使用微分几何和动力系统理论的概念。将开发一种高保真数值方法，使用粘性涡粒子法模拟此类问题。将构建一对对比物理尺度的实验平台，每个平台包括一个模仿自然界中观察到的纤毛的可重构共振探针系统，并将收集大量数据以校准理论和计算模型。将设计并通过实验证明用于分离和分选颗粒以及用于定制单个颗粒的空间轨迹的化学方法。该项目的重点是开发和展示一种用于分离和操纵浸入流体中的脆弱微观物体的新技术，该技术的应用范围越来越广，从DNA等大分子的机械测试到人类卵子与不动精子的辅助受精，再到持续激励流体携带的磨料颗粒，用于脆性表面的精密加工。将开发模型来预测包含多个涡流场的流体中的颗粒的轨迹。这些涡流场将使用振荡纤维通过实验产生。将建造一对具有毫米和微米（1/1000毫米）物理尺度的实验平台。对于每一个平台，可重新配置的共振探针系统将用于在含颗粒流体中产生稳定的涡流场。最小的探针将模仿自然界中观察到的微观振荡纤毛。将收集数据以验证理论和计算预测模型。该项目不仅将在应用数学，计算科学和工程方面产生综合进步，而且还将揭示原生动物和人类中存在的生理设计背后的物理学。微操作方法的开发代表了替代技术的简单性，便携性和成本的改进。PI开发这种方法的计划包括多机构合作，包括至少一名博士后研究人员，至少两名博士生和一些本科生的指导指导（以促进多样性为目的），在PI大学的两个跨学科研究生课程和两个本科课程的课程扩展，并向第三所大学的生物学学生和多民族地区的高中生进行宣传。

This project will advance a novel, biologically inspired method for the manipulation of solid particles suspended in fluids on a microscopic scale through complementary theoretical, computational, and experimental research. A comprehensive mathematical framework will be developed for describing the control of fluid flows at low Reynolds number through localized cyclic boundary deformations using concepts from differential geometry and dynamical systems theory. A high-fidelity numerical approach will be developed for simulating such problems using a viscous vortex particle method. A pair of experimental platforms on contrasting physical scales will be constructed, each comprising a system of reconfigurable resonant probes mimicking cilia observed in nature, and extensive data will be collected to calibrate both theoretical and computational models. Algorithmic methods for separating and sorting particles, and for tailoring the spatial trajectories of individual particles, will be devised and demonstrated experimentally. The project focuses on developing and demonstrating a novel technique for separating and manipulating fragile microscopic objects immersed in fluids, which has a growing list of applications ranging from the mechanical testing of macromolecules like DNA to the assisted fertilization of human ova with immotile sperm to the sustained excitation of fluid-borne abrasive particles for the precision machining of brittle surfaces. Models will be developed to predict the trajectories of particles in fluids containing multiple vortex fields. These vortex fields will be produced experimentally using oscillating fibers. A pair of experimental platforms with millimeter and micrometer (1/1000 of a millimeter) physical scales will be constructed. For each platform, a system of reconfigurable resonant probes will be used to generate steady vortex fields in particle-bearing fluids. The smallest probes will mimic the microscopic oscillating cilia observed in nature. Data will be collected to validate the theoretical and computational predictive models. This project will not only engender integrated advancements in applied mathematics, computational science, and engineering, but will also shed light on the physics underlying a physiological design present in protozoa and humans alike. The micromanipulation method to be developed represents an improvement over alternative technologies in simplicity, portability, and cost. The PIs' plan for developing this method incorporates a multi-institutional collaboration involving the directed mentoring of at least one postdoctoral researcher, at least two PhD students, and a number of undergraduates (with a deliberate eye toward promoting diversity), the curricular expansion of two cross-disciplinary graduate courses and two undergraduate courses at the PIs' universities, and outreach to biology students at a third university and to high school students in an ethnically diverse area.