RUI: Modeling of electrokinetic flows at large applied voltages

RUI：大施加电压下动电流的建模

• 批准号: 0930484
• 负责人: Brian Storey
• 金额: $ 10.39万
• 依托单位: Franklin W. Olin College of Engineering
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0930484&HistoricalAwards=false
• 关键词: RUI; Modeling; electrokinetic; flows; large

0930484StoreyMicrofluidic devices are critical components of promising future applications including massively parallel drug discovery, integrated sensors for biological and chemical threats, and personalized medicine. Despite their small size, many microfluidic systems currently in use are limited to the laboratory due to large operational voltages. A relatively new class of device that places micron size electrodes inside channels is promising as they operate at relatively low voltage--a key requirement for portability. Most computational models of these devices are based in the classical theory of electrokinetic phenomena which couples fluid flow, ion transport and electric fields in electrolytes. Unfortunately, these models fail to predict some critically important experimental trends, impeding their development. Recent work by the PI and collaborators has started to apply simple corrections to the classical theory of electrokinetics to account for some of the major deficiencies. To date, the corrected models can predict some of the key trends but the agreement between model and experiment is still lacking. The overall objective of this work is to improve modeling capability in these electrically driven microfluidic applications such that one can use relatively simple simulations as a tool for engineering design. While the phenomena of interest is truly at the nanoscale, the strategy put forth is to develop an accurate yet tractable continuum-based formulation that can be applied by other researchers. This study has two main trusts. The first is to study the role of incorporating surface roughness into the model. The second thrust will be to investigate the role that electrochemical reactions at the electrode surface plays in models of these flows. The hypothesis is that inclusion of these two effects can go a long way toward resolving key discrepancies between simulation and experiment. While the field of electrokinetics is very mature, the microfluidic designs of interest operate in regimes where aspects of the commonly used theory do not apply. This study develops several carefully planned research projects to provide Olin undergraduate students with an immersive, modern and successful research experience.

微流控装置是未来应用的关键组成部分，包括大规模并行药物发现，生物和化学威胁的集成传感器，以及个性化医疗。尽管微流体系统体积小，但由于工作电压大，目前使用的许多微流体系统都局限于实验室。一种相对较新的设备，将微米大小的电极放置在通道内，因为它们在相对较低的电压下工作——这是便携性的关键要求。这些装置的大多数计算模型是基于电解液中流体流动、离子输运和电场耦合的经典电动力学现象理论。不幸的是，这些模型无法预测一些至关重要的实验趋势，阻碍了它们的发展。PI和合作者最近的工作已经开始对经典的电动力学理论进行简单的修正，以解释一些主要的缺陷。迄今为止，修正后的模型可以预测一些关键的趋势，但模型与实验之间仍然缺乏一致性。这项工作的总体目标是提高这些电驱动微流体应用的建模能力，以便人们可以使用相对简单的模拟作为工程设计的工具。虽然感兴趣的现象确实是在纳米尺度上，但提出的策略是开发一种精确而易于处理的基于连续体的配方，可以被其他研究人员应用。这项研究有两个主要的信任。首先是研究将表面粗糙度纳入模型的作用。第二个重点将是研究电极表面的电化学反应在这些流动模型中所起的作用。假设包括这两种效应可以在很大程度上解决模拟和实验之间的关键差异。虽然电动力学领域是非常成熟的，但感兴趣的微流控设计是在常用理论不适用的情况下进行的。本研究发展了几个精心策划的研究项目，为奥林大学本科生提供一个身临其境的、现代的和成功的研究经验。