CAREER: Electrokinetic Transport of Fluid, Particles and Macromolecules through Nanochannels and Nanopores

1150590 PI：Saintillan微加工技术的最新进展使微流体领域的发展成为可能。随着这些技术变得越来越复杂，设备现在正在缩小到纳米级，带来了新的丰富的物理现象，例如在芯片实验室设备中被利用。在这些装置中使用电动力学已被证明在广泛的应用中特别有用，特别是操纵流体、颗粒和大分子。然而，在纳米尺度上对这些流动的建模仍然受到限制，这是由于经典模型无法捕获某些非连续效应，以及直接分子模拟的高成本，这只能解决非常短的时间尺度。这些意见强调，需要重新建模的努力，在电动力学领域的高度封闭的环境。在这个项目中，我们建议使用一种新的模拟方法的基础上的Langevin模型和布朗动力学的电解质物种的扩散电荷动力学的电化学和大分子的运输在受限的设备进行研究。这种新方法将结合经典连续模型的功能，但也将允许一个捕捉非连续效应，而无需原子方法的高成本。它可以应用于研究电渗和电泳与任意大小的双电层，并可以很容易地解释复杂的几何形状。一个新的聚合物模型的基础上的细长体理论的波动弹性长丝也将被开发来研究具有任意德拜长度的聚电解质的动力学。这些新的模型和工具将用于研究一些技术应用，包括：（i）寡核苷酸在纳米通道中的电泳分离，（ii）通过纳米毛细管阵列膜的电化学运输，以及（iii）生物聚合物通过纳米孔的电驱动移位。拟议的研究活动将有助于加强对电动流动和大分子的基本理解和建模在高度受限的几何形状中的输运，其中非连续效应可能变得重要。作为研究的一部分实施的新模型和模拟工具将适用于物理，工程和医学领域的广泛问题，其中包括：芯片实验室设备上的生化测定，用于基因组分析的DNA的电流体动力学拉伸，PEM燃料电池中通过聚合物电解质膜的电化学传输等。教育和推广活动也将纳入该方案。一个新的研究生课程的基础和应用的微和纳米流体，包括电动流，将在伊利诺伊大学推出。将设计一个电动力学及其应用教程网站，供学生和非专业人员使用，并将开发一个扩散电荷动力学和电化学输运的可视化软件，并在公共许可证下在线提供给该领域的学生和研究人员。

1150590 PI: SaintillanRecent advances in microfabrication techniques have enabled the development of the field of microfluidics. As these techniques become more sophisticated, devices are now being scaled down to the nanoscale, bringing about a new wealth of physical phenomena to be exploited in lab-on-chip devices for instance. The use of electrokinetics in these devices has proven particularly useful in a wide range of applications, and specifically to manipulate fluid, particles and macromolecules. Yet, the modeling of these flows at the nanoscale still suffers from limitations, owing to the inability of classical models to capture certain non-continuum effects, and to the high-cost of direct molecular simulations, which are only able to resolve very short time scales. These observations emphasize the need for renewed modeling efforts in the field of electrokinetics in highly confined environments. In this project, we propose to study electrochemical and macromolecular transport in confined devices using a new simulation approach for diffuse charge dynamics based on a Langevin model and Brownian dynamics for the electrolyte species. This new method will incorporate features from classical continuum models, but will also allow one to capture non-continuum effects without the high cost of atomistic methods. It can be applied to study both electroosmosis and electrophoresis with electrical double layers of arbitrary sizes, and can easily account for complex geometries. A new polymer model based on slender-body theory for a fluctuating elastic filament will also be developed to study the dynamics of polyelectrolytes with arbitrary Debye lengths. These new models and tools will be applied to study a number of technological applications, including: (i) the electrophoretic separation of oligonucleotides in nanochannels, (ii) electrochemical transport through nanocapillary array membranes, and (iii) the electrically driven translocation of biological polymers through nanopores.The proposed research activities will serve to enhance the fundamental understanding and modeling of electrokinetic flows and macromolecular transport in highly confined geometries, where non-continuum effects may become important. The new models and simulation tools implemented as part of the research will be applicable to a wide range of problems in the fields of physics, engineering, and medicine, among which: biochemical assays on lab-on-chip devices, electrohydrodynamic stretching of DNA for genomic analysis, electrochemical transport through polymer electrolyte membranes in PEM fuel cells, and many others. Educational and outreach activities will also be integrated in this program. A new graduate-level course on fundamentals and applications of micro- and nanofluidics, including electrokinetic flows, will be introduced at the University of Illinois. A tutorial website on electrokinetics and its applications will be designed for use by students and non-specialists, and a visualization software for diffuse charge dynamics and electrochemical transport will be developed and made available online to students and researchers in the field under a public license.