Fundamental Study of Nonlinear Electrokinetic Phenomena in Insulator-based Dielectrophoretic Microdevices

绝缘体介电泳微器件中非线性动电现象的基础研究

• 批准号: 1704379
• 负责人: Xiangchun Xuan
• 金额: $ 29.85万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1704379&HistoricalAwards=false
• 关键词: Fundamental; Study; Nonlinear; Electrokinetic; Phenomena

Dielectrophoresis (DEP) is very useful in manipulating micro/nano-sized particles (e.g., cells, beads, viruses, DNA and protein molecules). Insulator-based dielectrophoresis (iDEP) exploits insulating structures, such as hurdles, posts and ridges, to trap, concentrate, separate and sort particles. Compared to the traditional electrode-based dielectrophoresis (eDEP), iDEP microdevices have the advantages of easy fabrication and robust performance. However, the presence of in-channel insulating structures cause two phenomena that may strongly disturb the flow and either suppress or enhance the particle manipulation in iDEP microdevices. These phenomena are: the electrothermal flow due to the amplified Joule heating in the fluid around the insulators, and the induced charge electroosmotic (ICEO) flow due to the electrical polarization of the insulators. An accurate understanding of either phenomenon is significantly complicated by the thermal diffusion or electric field leakage that occurs in the entire device. This project seeks to develop a generalized depth-averaged model for the fundamental study of nonlinear electrokinetic phenomena in iDEP microdevices. The proposed model will substantially reduce the computational cost for predicting the particle manipulation performance in iDEP devices. It will also serve as an efficient and accurate tool for the optimal design and control of a wide class of electrokinetic microfluidic devices with shallow-channel geometries. This research will be intimately weaved into the undergraduate and graduate educations at Clemson University and the high school outreach in South Carolina. Undergraduate and high school students will be actively involved through various programs available in the department, university, and state with emphasis on the inclusion of women and underrepresented minorities. This project will be the first comprehensive fundamental study of nonlinear electrokinetic phenomena in iDEP microdevices. It is hypothesized that the nonlinear ICEO and electrothermal flows are dominant in low and high ionic concentration fluids, respectively, and can suppress each other in an intermediate ionic concentration fluid. An asymptotic analysis of the temperature-coupled heat, fluid and charge transport equations will be performed for electrokinetic flow in shallow microchannels. A depth-averaged model will be developed based on the asymptotic analysis to simulate the development of temperature, flow and electric fields in typical iDEP microdevices with consideration of both Joule heating and induced charge effects. The fluid temperature and velocity fields will be measured near the insulating structures. The validity of the developed depth-averaged model will be assessed by comparing its predictions with both 3D full-scale numerical simulations and experimental data. The acquired fundamental knowledge of nonlinear electrokinetic phenomena will establish a heat transfer and fluid mechanics framework for iDEP microdevices.

双电泳（DEP）在处理微/纳米级颗粒（如细胞、微珠、病毒、DNA和蛋白质分子）方面非常有用。基于绝缘体的介质电泳（iDEP）利用绝缘结构，如栅栏、柱子和山脊，来捕获、浓缩、分离和分类颗粒。与传统的电极基介质电泳（eDEP）相比，iDEP微器件具有制作简单、性能稳定等优点。然而，通道内绝缘结构的存在会引起两种现象，这些现象可能会强烈干扰流动，抑制或增强iDEP微器件中的粒子操纵。这些现象是：由于绝缘体周围流体的焦耳加热放大而产生的电热流动，以及由于绝缘体的电极化而产生的感应电荷电渗透（ICEO）流动。由于整个器件中发生的热扩散或电场泄漏，对这两种现象的准确理解都变得非常复杂。本项目旨在发展一种广义深度平均模型，用于对iDEP微器件中的非线性电动力学现象进行基础研究。该模型将大大降低预测iDEP器件中粒子操纵性能的计算成本。它也将作为一种高效和精确的工具，用于优化设计和控制一类具有浅通道几何形状的电动微流体装置。这项研究将密切地融入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。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，重点是包括妇女和代表性不足的少数民族。本项目将是首个对iDEP微器件中非线性电动力学现象的综合性基础研究。假设非线性ICEO流和电热流分别在低离子浓度流体和高离子浓度流体中占主导地位，在中等离子浓度流体中相互抑制。本文将对浅微通道中电动力流动的温度耦合热、流体和电荷输运方程进行渐近分析。在渐近分析的基础上，建立了一个深度平均模型来模拟典型iDEP微器件中温度、流动和电场的发展，同时考虑焦耳加热和感应电荷效应。在隔热结构附近测量流体温度场和速度场。通过将所开发的深度平均模型的预测结果与三维全尺寸数值模拟和实验数据进行比较，将对其有效性进行评估。所获得的非线性电动力学现象的基本知识将为iDEP微器件建立传热和流体力学框架。

项目成果

Fluid rheological effects on streaming dielectrophoresis in a post‐array microchannel

阵列后微通道中流体流变学对流式介电泳的影响

• DOI: 10.1002/elps.202100270
• 发表时间: 2021
• 期刊: ELECTROPHORESIS
• 影响因子: 2.9
• 作者: Bentor, Joseph;Raihan, Mahmud Kamal;McNeely, Colin;Liu, Zhijian;Song, Yongxin;Xuan, Xiangchun
• 通讯作者: Xuan, Xiangchun

Joule heating‐enabled electrothermal enrichment of nanoparticles in insulator‐based dielectrophoretic microdevices

• DOI: 10.1002/elps.202000192
• 发表时间: 2020-09
• 期刊: ELECTROPHORESIS
• 影响因子: 2.9
• 作者: Amirreza Malekanfard;Zhijian Liu;Le Song;A. Kale;Cheng Zhang;Liandong Yu;Yongxin Song;X. Xuan

Recent advances in direct current electrokinetic manipulation of particles for microfluidic applications

• DOI: 10.1002/elps.201900048
• 发表时间: 2019-09
• 期刊: ELECTROPHORESIS
• 影响因子: 2.9
• 作者: X. Xuan

Electrothermal enrichment of submicron particles in an insulator-based dielectrophoretic microdevice

基于绝缘体的介电泳微型器件中亚微米颗粒的电热富集

• DOI: 10.1002/elps.201700342
• 发表时间: 2018-03-01
• 期刊: ELECTROPHORESIS
• 影响因子: 2.9
• 作者: Kale, Akshay;Song, Le;Xuan, Xiangchun
• 通讯作者: Xuan, Xiangchun

Revisit of wall-induced lateral migration in particle electrophoresis through a straight rectangular microchannel: Effects of particle zeta potential

重新审视直矩形微通道中粒子电泳中壁诱导的横向迁移：粒子 zeta 电位的影响

• DOI: 10.1002/elps.201800198
• 发表时间: 2019-03-01
• 期刊: ELECTROPHORESIS
• 影响因子: 2.9
• 作者: Liu, Zhijian;Li, Di;Xuan, Xiangchun
• 通讯作者: Xuan, Xiangchun