导体微纳米粒子的特殊介电泳行为特征及其形成机理研究

Conductive micro-and nano-particles are excellent conductors, and their precise manipulation is crucial for achieving the core function of the microfluidics. Dielectrophores is an effective means for the accurate control of the micro-and nano-particles. However, the dielectrophoretic behaviour of the conductive particles can not be explained by the traditional theory of the Maxwell-Wagner interface polarisation, which is a bottleneck problem for the application of dielectrophoresis. Therefore, this project will focus on the basic mechanism of the manipulation of the conductive particles by dielectrophoresis. Firstly, mechanism for the polarisation of the double layer at the interface of the conductive particles and electrolytes will be analyzed, and then the PNP equation will be solved. Moreover, the interaction between the AC electric fields and the conductive particles will be demonstrated by considering both the induced-charge electroosmosis and wall friction.The mechanism of the novel dielectrophoretic behaviour will be carried out; Secondly, dielectrophoresis and induced-charge electrosomosis experiments for many kinds of conductive particles will be carrided out in order to verify the accuracy of the theory, and then correct and complete the theoretical work; Finally, some important functions will be achieved by utilizing the novel dielectrophoresis. This project will show the internal mechanism for the manipulation of the conductive micro-and nano-particles by dielectrophoresis, which lays the foundation for the extensive applications of conductive micro-and nano-particles.

导体微纳米粒子具有优异的电学性能，其精确操纵对实现众多微流控系统的核心功能至关重要,介电泳则是对其精确操纵的一种有效手段。然而，导体粒子的介电泳行为特征不能用传统Maxwell-Wagner界面极化理论评价，成为其应用过程中的瓶颈。为此，本项目拟针对介电泳操纵导体微纳米粒子的基础科学问题展开研究。首先，探究交流电场作用下导体粒子与溶液界面区双电层的极化规律，求解PNP方程，综合考虑诱导电荷电渗及壁面摩擦等参数影响，明确交流电场与导体微纳米粒子的相互作用关系，揭示导体粒子特殊介电泳行为特征的产生机理；其次，开展多种导体微纳米粒子的介电泳相关实验及诱导电荷电渗等实验研究，验证理论研究的合理性，进而对理论研究结果进行修正和完善；最后，利用导体微纳米粒子的特殊介电泳行为特征，实现微流控研究中的一些重要功能。本项目旨在揭示介电泳操纵导体微纳米粒子的内部机理，为其在微流控中的广泛应用奠定理论基础。

导体微纳米颗粒具有优异的电学性能，在微纳机械系统以及其它如生命科学等诸多领域发挥重要作用。如何实现导体微纳米颗粒的精确调控是一项重要挑战。本项目基于电场调控导体微纳米颗粒的运动行为展开，揭示了低频条件下诱导电荷电渗（ICEO）对于导体颗粒运动行为的决定性影响，同时以此为出发点对本课题进行了拓展。通过在PDMS中掺杂银粉，成功实现了可塑性强的三维导体电极材料，并将这一技术在颗粒分离中进行了巧妙应用；发现了ICEO技术实现微纳米颗粒的快速团聚现象，并分析了这一现象产生的机理。同时，申请人团队又将ICEO技术应用在了颗粒定比例团聚、单颗粒捕捉以及流体快速混合等多个领域；此外，申请人团队亦通过合理设计，研究了电场调控下流体的循环驱动机制，并将这一技术成功应用于循环流体体系中的细胞培养中。上述研究无疑将为生物化学领域的贵颗粒处理、超低样本分析、细胞学研究以及可控反应等提供重要的新型技术支持，同时也有望在机械学超精密磨削或抛光领域发挥作用。