Collaborative Research: Probing the hydrodynamic resistance and traffic of confined droplets in microfluidic networks for the rational design of two-phase fluidic processors

合作研究：探讨微流体网络中受限液滴的流体动力学阻力和流量，以合理设计两相流体处理器

• 批准号: 0932796
• 负责人: Siva Vanapalli
• 金额: $ 9.18万
• 依托单位: Texas Tech University
• 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: 2009-09-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0932796&HistoricalAwards=false
• 关键词: Collaborative; Research; Probing; hydrodynamic; resistance

0932796/0933090 Vanapalli/WongThe notion of using tiny nanoliter-scale water droplets in an oil phase as reaction vessels for applications in chemical and life sciences is turning into a reality due to rapid progress in the science and engineering of microfluidics. Despite such progress, fundamental challenges remain to transform current droplet-based devices to next generation fluidic processors capable of characterizing large-scale biological complexity. Two scientific challenges exist in the realization of such an integrated two-phase fluidic processor. First, the transport of a large number of confined droplets in microchannels leads to prohibitively excess pressure drop. Second, due to collective hydrodynamic resistive effects, it is difficult to control the position and timing of droplets for reactions on a device. To address these challenges requires a thorough understanding of hydrodynamic resistance introduced by the motion of confined droplets. The PIs will combine experiments and modeling to quantify the hydrodynamic resistance due to a confined droplet and its dependence on system parameters. Novel aspects of the work include the use of a sensitive microfluidic comparator technique to measure hydrodynamic resistance at the level of individual droplets. Experimental methods and models will be developed to quantify the currently unknown contribution of end-cap, thin film and corner flows to the hydrodynamic resistance of a droplet in rectangular microchannels, with the ultimate goal of achieving predictive capability of pressure drop for enhanced device performance. This study will enable rational design of two-phase fluidic processors that could be potentially autonomous and passively driven. This work will also impact other engineering areas that rely on fundamental understanding of multiphase flows in confined media such as tertiary oil recovery and fuel cells. Educational component of the project includes drawing minority graduate and undergraduate students to the visually striking research on microfluidics and providing state-of-the-art training in microfluidics, microfabrication, microscopy and numerical modeling. The PIs will pursue outreach activities at their respective institutions such as developing a weeklong hands-on-activities and lectures on the theme "Bubbles on Chips".

0932796/0933090 VANAPALLI/WONG在石油相中使用微小的纳米尺度水滴作为化学和生命科学应用的反应容器，这是由于微流体的科学和工程的快速发展而变成了现实。尽管取得了这样的进展，但仍在将基于液滴的设备转变为能够表征大规模生物学复杂性的下一代流体处理器的基本挑战。在实现这种综合的两相流体处理器的实现中，存在两个科学挑战。首先，微通道中大量限制的液滴的运输导致过量的压降。其次，由于集体流体动力学效应，很难控制设备上反应的液滴的位置和时间。为了应对这些挑战，需要对受限液滴运动引入的流体动力耐药性有深入的了解。 PI将结合实验和建模，以量化由于液滴及其对系统参数的依赖性而导致的流体动力阻力。这项工作的新方面包括使用敏感的微流体比较器技术在单个液滴水平上测量流体动力学性。将开发实验方法和模型，以量化端胶，薄膜和角流对矩形微通道中液滴的流体动力耐药性的当前未知贡献，其最终目标是实现预测能力的预测能力，以提高设备性能。这项研究将使可能是自主且被动驱动的两相流体处理器的合理设计。这项工作还将影响其他依赖对繁殖媒体（例如第三级石油回收和燃料电池）的基本了解的工程领域。该项目的教育组成部分包括吸引少数群体研究生和本科生，以进行有关微流体的视觉研究，并提供微流体，微型制作，显微镜和数值建模的最先进培训。 PI将在各自的机构中进行外展活动，例如在“筹码上的泡沫”主题上开发为期一周的动手活动和讲座。