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: 0933090
• 负责人: Harris Wong
• 金额: $ 8.22万
• 依托单位: Louisiana State 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 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0933090&HistoricalAwards=false
• 关键词: Collaborative; Research; Probing; hydrodynamic; resistance

0932796/0933090 Vanapalli/Wong The 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 由于微流体科学和工程的快速进步，使用油相中的微小纳升级水滴作为化学和生命科学应用的反应容器的想法正在变成现实。尽管取得了这些进展，但将当前基于液滴的设备转变为能够表征大规模生物复杂性的下一代流体处理器仍然存在根本挑战。实现这种集成两相流体处理器存在两个科学挑战。首先，微通道中大量受限液滴的传输导致过高的压降。其次，由于集体流体动力阻力效应，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，需要彻底了解受限液滴运动引起的流体动力学阻力。 PI 将结合实验和建模来量化受限液滴造成的流体动力学阻力及其对系统参数的依赖性。这项工作的新颖之处包括使用灵敏的微流体比较器技术来测量单个液滴水平的流体动力学阻力。将开发实验方法和模型来量化目前未知的端盖、薄膜和角流对矩形微通道中液滴的流体动力学阻力的贡献，最终目标是实现压降的预测能力以增强设备性能。这项研究将使两相流体处理器的合理设计成为可能，该处理器可能是自主和被动驱动的。这项工作还将影响依赖于对受限介质中多相流的基本了解的其他工程领域，例如三次采油和燃料电池。该项目的教育部分包括吸引少数族裔研究生和本科生参与视觉上引人注目的微流体研究，并提供微流体、微制造、显微镜和数值建模方面最先进的培训。 PI 将在各自的机构开展外展活动，例如开展为期一周的实践活动和主题为“芯片上的气泡”的讲座。