Particle Electrophoresis in Curved Microchannels: Fundamentals and Applications

从传统的凝胶电泳到基于微流控技术的芯片实验室设备，局限微通道中的颗粒电泳问题在涉及有界电动流动的各种应用中具有实际意义。然而，迄今为止，对颗粒电泳的研究主要局限于简单几何形状的直微通道的理论或数值分析。在真实的微通道中，粒子电泳运动的研究很少，这些微通道通常由一个或多个转弯组成，以适应例如玻璃载玻片的小足迹。我们的目标是获得弯曲微通道中颗粒电泳的基本知识，并探索微通道转弯作为微流体系统中颗粒传输的被动控制元件的应用。我们将理解并实现微粒子在其通过弯曲微通道的电泳运动期间的连续聚焦，过滤和分离。所有这些过程都源于旋转引起的介电泳力，它使粒子在电动流的流线上偏转。博士生将采用实验、数值和理论相结合的方法进行三项研究：1)单微通道匝中粒子电泳的基础研究；2)粒子聚焦在蛇形微通道中的应用研究；3)螺旋微通道颗粒分离的应用研究。智力优势：提出的回合内粒子电泳的基础研究将填补目前在实际微通道中电泳运动知识的空白。所提出的蛇形微通道中粒子的无电极介电泳聚焦消除了鞘层流和通道内或片上电子元件的使用，从而大大简化了制造和操作并降低了设备污垢的可能性。所提出的螺旋微通道中粒子的无电极介电泳分离可以快速连续地工作，而不需要外力场或机械或电气部件，因为外加电场会同时产生粒子的泵送、聚焦和分离。更广泛的影响：在回合内获得的颗粒电泳知识将从本质上有利于微流控装置中这种传输的每一个工程应用。如本文所述，在弯曲微通道中连续聚焦、过滤和分离颗粒的能力将刺激惰性微结构（例如，转弯、脊状和柱状等）作为大型微流体系统中的被动控制元件的探索和开发。我们设想在生物、医学和工业领域的广泛技术解决方案中，所提出的无电极介电泳聚焦方法在连续生物颗粒分离、高通量流式细胞术和连续过滤系统中的直接近期应用。教育：这项提议的研究将紧密结合到克莱姆森大学的本科和研究生教育以及南卡罗来纳州的高中推广中。本科生和高中生将通过系、大学和州提供的各种项目积极参与这项研究，重点是包括妇女、未被充分代表的少数群体和残疾人。这项研究的结果将通过期刊出版物和专业会议传播，并将在一个自行维护的网站上公布，供世界各地的学生、研究人员和教育工作者开放获取。

0853873XuanThe problem of particle electrophoresis in confined microchannels has practical significance in a variety of applications involving bounded electrokinetic flows, which range from traditional gel electrophoresis to those occurring in microfluidics-based lab-on-a-chip devices. To date, however, studies on particle electrophoresis have been limited to primarily theoretical or numerical analyses in straight microchannels of simple geometries. Very little work has been done on the particle electrophoretic motion in real microchannels which usually consist of one or multiple turns in order to fit them into the small footprint of, for example, a glass slide. Our goals in this proposal are to obtain a fundamental knowledge of particle electrophoresis in curved microchannels, and to explore the applications of microchannel turns as passive control elements of particle transport in microfluidic systems. We will understand and implement the continuous focusing, filtration, and separation of microparticles during their electrophoretic motions through curved microchannels. All these processes stem from the turn-induced dielectrophoretic force that deflects particles across the streamlines of electrokinetic flow.Three research thrusts will be carried out by a PhD student using a combined experimental, numerical, and theoretical method: 1) fundamental study of particle electrophoresis in single microchannel turns; 2) application study of particle focusing in serpentine microchannels; and 3) application study of particle separation in spiral microchannels.Intellectual merit: The proposed fundamental study of particle electrophoresis within turns will fill the blank in the current knowledge of electrophoretic motion in real microchannels. The proposed electrodeless dielectrophoretic focusing of particles in serpentine microchannels eliminates the use of sheath flows and in-channel or on-chip electrical components, and thus substantially simplifies the fabrication and operation and reduces the probability of device fouling. The proposed electrodeless dielectrophoretic separation of particles in spiral microchannels can work in a rapid continuous manner without the need for external force fields or mechanical or electrical parts as the applied electric field generates the concurrent pumping, focusing and separation of particles.Broader impacts: The acquired knowledge of particle electrophoresis within turns will essentially benefit every engineering application of this transport in microfluidic devices. The ability to continuously focus, filtrate and separate particles in curved microchannels as described here will stimulate the exploration and exploitation of inert microstructures (e.g., turns, ridges, and posts, etc.) as passive control elements in larger microfluidic systems. We envision direct near-term applications of the proposed electrodeless dielectrophoretic focusing approach in continuous bioparticle separation, high-throughput flow cytometry, and continuous filtration systems for a wide range of technological solutions in biology, medicine and industry.Education: This proposed research will be intimately integrated into the undergraduate and graduate education at Clemson University and the high school outreach in South Carolina. Undergraduate and high school students will be actively involved in this research through various programs available in the department, university, and state, with an emphasis on the inclusion of women, underrepresented minority groups, and persons with disabilities. The results of this research will be disseminated through journal publications and professional conferences, and will also be posted on a self maintained website for open access to students, researchers and educators around the world.