基于绝缘结构介电泳微流控器件中的电热流动

Dielectrophoresis (DEP) is a powerful tool that has been widely used to manipulate particles, cells, and biomolecules in microfluidic devices. As compared to the traditional electrode-based dielectrophoresis (eDEP), insulator-based dielectrophoresis (iDEP) microdevices are easier to fabricate, inerter to electro-chemical reactions, and less prone to fouling. However, due to the locally amplified electric field around the in-channel micro insulator(s), Joule heating often becomes an issue in iDEP microdevices. Their effects on fluid flow and particle motion in iDEP microdevices have thus far remained nearly unexplored. Our goal in this proposal is to develop a comprehensive knowledge of the effects of Joule heating on fluid, heat, and particle transport in iDEP microdevices. We will integrate experimental validations and 3D numerical simulations to investigate the electrothermal effects on fluid flow in three types of typical iDEP microdevices. This proposed research will advance our understanding and prediction of particle manipulation in iDEP microdevices, resulting in a better realization of focusing, trapping, concentration, and sorting for particles with various properties. The acquired knowledge will build the fluid mechanics and heat transfer foundations for the design, analysis, control, and optimization of future iDEP microdevices that will avoid electrothermal effects or take advantage of them for cellular and biomolecular applications.

介电泳是微流控器件中广泛用于操控颗粒、细胞和生物分子的一类强大工具。与传统基于电极介电泳相比，基于绝缘结构介电泳（insulator-based dielectrophores,iDEP）微流控器件具有易加工、抗电化学反应能力强、不易失效等优势。然而，由于通道中绝缘微结构附近电场的局部增强，焦耳热效应经常成为iDEP器件应用中难以避免的问题，相关研究迄今仍未开展。本项目将开展iDEP微流控器件中焦耳热效应对流体流动、热传导、颗粒输运影响的系统研究。结合实验测量和三维数值模拟以探索三种典型iDEP微流控器件中的电热流动效应，增强对iDEP器件中颗粒操控的深入了解和精确预测，更有效地实现不同颗粒的汇聚、捕捉、富集、分类等功能。通过建立相关流动和传热规律，避免电热效应的负面效应并能进一步利用电热效应，为iDEP微流控器件的设计、分析、控制和优化提供理论指导，以拓展针对细胞及生物分子的相关应用。

介电泳是微流控器件中广泛用于操控颗粒、细胞和生物分子的一类强大工具。与传统基于电极介电泳相比，基于绝缘结构介电泳（iDEP）微流控器件具有易于加工、抗电化学反应能力强、不易失效等优势。本项目拟开展iDEP微流控器件中焦耳热效应对流体流动、热传导、颗粒输运影响的系统研究。根据项目实施计划，本项目全面完成了研究目标，取得的重要进展包括：1）发展了三维非定常热电流动数值模型；2）研究了基于储液池/微通道复合结构的介电泳微流控器件中的焦耳热效应；3）研究了焦耳热对电渗流入口流动的影响；4）研究了纳米尺度受限空间的离子及颗粒电动输运规律；5）研究了用于微纳生物颗粒的高通量微流动操控机理与应用；6）研究了受限微通道中可变形液滴的动力学行为。发表了15篇SCI论文，1篇EI论文，7篇论文为中国科学院SCI一区论文，其中一篇为ESI高引用论文HCP前3%论文，SCI总引用数135次。