CAREER: Fundamental and Applied Studies of Novel Electrokinetic Effects

abstractcbet - 0645097 t。微加工流体装置有可能彻底改变化学、生物学和医学，就像集成电路对计算、科学和技术所做的那样。复杂的设备已经被开发出来，可以执行那些用宏观技术可能会昂贵得多、困难得多、甚至不可能完成的任务。如果微流体流动可以以一种独立的、便携的方式驱动，这种装置就可以从实验室带到现场（或在皮肤下）。电动流动对微流体的可移植性有许多优点；然而，迄今为止，一些基本问题阻碍了它们在实际系统中的应用。本CAREER提案描述了一个理论和实验计划，有两个中心目标：1)对液/液界面上的电渗透流动的基本理解，以及2)利用这些和相关现象开发真正便携式微流体操作系统。为了实现第一个目标，PI将开发并采用一种微流体系统，该系统将首次能够直接测量液/液界面上的电渗透流动，同时提供对胶体研究中前所未有（甚至不可能）的输入“变量”的控制。因此，这将允许对电动理论进行第一次直接和严格的测试。为了实现第二个目标，PI将开发一种低压高压微流体泵，该泵在新型各向异性多孔床中利用横向诱导电荷电动力学现象。智力优势：提出的微流控平台将允许在一个近两个世纪的领域进行开创性的基础研究。以前的胶体研究只是间接地探讨了电动力学流动，并且很少或根本没有控制表面电荷密度、几何形状或双层动力学。所提出的系统可以直接控制所有这些量，并直接测量随之而来的流量。因此，各种物理机制将可用于研究：线性和非线性电动力学，瞬态双层效应和表面电导率。将由此产生的新知识直接应用于微流体操作系统将大大拓宽我们对诱导电荷动力学的理解，无论是在非对称体的测试理论还是在集中集合的统计理论的发展方面。在所有情况下，PI将强调最简单，最直观的系统来阐明关键现象。更广泛的影响：提议的电动泵可以立即集成到现有的弹性体微流体装置中，以实现快速和广泛的影响。这将使一个完全便携式的、强大的、多功能的流体操作系统成为可能，并使手持危险传感器和医疗诊断工具以及植入式生物医学设备成为可能。PI将继续努力弥合微流体“应用”和“基础”社区之间的鸿沟，并设计了这个职业计划，以展示对现实世界挑战的工程解决方案的基本理解的价值，以及在设计基础研究时认真考虑现实世界挑战所能产生的影响。他将以美国物理学会新期刊《生物微流体》编委会“基础专家”的身份推广这一观点。他将继续利用UCSB现有的成功项目（如加州少数民族参与联盟），将本科生和未被充分代表的少数民族纳入他的研究，并将包括高中生和教师。教育：PI试图通过使用微流体作为令人兴奋的动机框架，通过强调物理直觉理解，以及通过解决依赖于这些现象的各种学科和应用，重新激发学生对流体和运输现象的兴趣。他将用他关于微流体物理现象的评论文章作为多学科专题课程的基础，并作为教科书的基础。他将为非科学家/工程师开发并在网上发布一门微流体新生研讨会课程，以扩大研究的影响，并更广泛地培养对微流体中发生的各种有趣，令人兴奋，令人惊讶和美丽现象的欣赏。

AbstractCBET-0645097T. Squires, UC-Santa BarbaraMicrofabricated fluidic devices have the potential to revolutionize chemistry, biology, and medicine, much as the integrated circuit did for computing, science and technology. Sophisticated devices have already been developed to perform tasks that would be vastly more expensive, more difficult, or even impossible with macro-scale techniques. If microfluidic flows can be driven in a self-contained, portable fashion, such devices could be taken out of the lab and into the field (or under the skin). Electrokinetic flows present many advantages towards microfluidic portability; however, fundamental issues have thus far precluded their use in practical systems.This CAREER proposal describes a theoretical and experimental program with two central goals: 1) a fundamental understanding of electro-osmotic flow over liquid/liquid interfaces, and 2) the exploitation of these and related phenomena to develop truly portable microfludic manipulation systems. To achieve the first goal, the PI will develop and employ a microfluidic system that will enable, for the first time, direct measurements of electro-osmotic flow over liquid/liquid interfaces, while providing a control over the input 'variables' that is unprecedented (even impossible) in colloidal studies. As such, this will allow the first direct and stringent test of electrokinetic theories. To achieve the second goal, the PI will develop a low-voltage, high-pressure microfluidic pump that employs transverse induced-charge electrokinetic phenomena within a novel anisotropic porous bed. Intellectual Merit: The microfluidic platform proposed will allow groundbreaking, fundamental studies in a field that is nearly two centuries old. Previous colloidal studies probed electrokinetic flows only indirectly, and allowed little or no control over surface charge density, geometry, or double-layer dynamics. The proposed system allows direct control over all of these quantities, and directly measures the consequent flows. A variety of physical regimes will thus be available for study: linear and nonlinear electrokinetics, transient double-layer effects, and surface conductivity. The direct application of the resulting new knowledge to microfluidic manipulation systems will significantly broaden our understanding of induced-charge electrokinetics, both in testing theories for asymmetric bodies and in developing statistical theories for concentrated collections. In all cases, the PI will emphasize the simplest, most intuitive systems to elucidate key phenomena.Broader Impacts: The proposed electrokinetic pump may be immediately integrated intoexisting elastomeric microfluidic devices for rapid and broad impact. This will enable an entirely portable, robust, and versatile fluidic manipulation system and make possible hand-held hazard sensors and medical diagnostic tools, as well as implantable biomedical devices. The PI will continue his efforts to bridge the divide between the "application" and "fundamental" communities in microfluidics, and has designed this CAREER program to demonstrate the value of fundamental understanding in engineering solutions to real-world challenges, and the impact one can have by seriously considering real-world challenges in designing fundamental research. He will promote this view in his role as the "fundamentals expert" on the editorial board of the new American Institute of Physics journal Biomicrofluidics. He will continue to leverage existing, successful programs at UCSB (such as the California Alliance for Minority Participation) to integrate undergraduates and under-represented minorities into his research, and will include high-school students and teachers. Education: The PI seeks to re-invigorate student interest in fluid and transport phenomena by using microfluidics as an exciting motivational framework, by emphasizing physically intuitive understanding, and by addressing the variety of disciplines and applications that depend on such phenomena. He will use his review article on microfluidic physical phenomena as the basis for a multidisciplinary special-topics course and as the foundation for a textbook. He will develop and web-publish a freshman seminar course in microfluidics for non-scientists/engineers to broaden the impact of the research, and to more generally cultivate an appreciation for the variety of interesting, exciting, surprising and beautiful phenomena that occur in microfluidics.