介电泳和界面效应耦合作用下颗粒运动机理研究

介电泳颗粒操控技术是一门多学科交叉的新兴课题。不同于悬浮颗粒的介电泳，液面漂浮颗粒的介电泳存在着介电力—毛细力—浮力耦合作用复杂和颗粒相对运动规律未知的问题。本项目针对这些问题，拟采用模型建立、数值计算和实验结果对比的方法，开展介电泳和界面效应耦合作用下颗粒运动机理研究。研究内容：（1）考虑外部电场参数、颗粒参数、溶液参数、原有液面曲率、雷诺数等因素，计入极化颗粒表面电荷形成的偶极电场引起交界面的变形，以及介电力—毛细力—浮力的耦合作用，建立介电漂浮颗粒运动模型，并采用有效的计算方法进行求解；（2）研究介电力-毛细力-浮力耦合特性和一般规律，并分析不同间距浮粒的相互作用特点；（3）研究介电漂浮颗粒相对运动的机理，开展相关实验以对比验证计算结果，并深入分析各因素对介电漂浮颗粒相对运动的影响规律，以揭示其复杂的力学规律。本项目将为相关微流系统的设计和性能分析提供理论依据和技术支持。

Particle manipulation of dielectrophoresis in microfluidics is one of newly multidisciplinary research fields. Different from suspended particle manipulation of dielectrophoresis, for floating particle manipulation of dielectrophoresis, the coupling of dielectric force, capillary force and buoyancy is complex and the mechanism of interaction motion of neighbouring particles is unknown. This project will study the mechanism of motion of particles by dielectrophoretic-interfacial coupling effect by aid of modeling, numerical computation, and comparison with experimental measurements. This project includes: (1) Firstly, to build the model of motion of floating dielectrophoretic particles by considering the deformation of meniscus due to the dipolar electric field of the polarized particle and coupling the dielectric force, capillary force and buoyancy, with the inclusion of the factors such as the parameters of electric field, particles and solution, the curvature of free surface and Reynolds number, and use an effective computational procedure to solve the equations of the model. (2) Secondly, to study the general rule and characteristics of coupling of the dielectric force, capillary force and buoyancy and the interaction force among neighbouring particles with different spacings. (3) Thirdly, to study the mechanism of interaction motion of neighbouring particles, do relevant experiments to verify the simulation results, and deeply study the effect of the main parameters to the interaction motion of neighbouring particles. This project will provide theoretical foundation for the microfluidic system’s design and performance analyses.