Fundamental investigation of transport phenomena in convectively actuated biochemical reactors

医疗诊断仪器发展中的一个主要机会是传统聚合酶链反应（PCR）热循环硬件的非常低效的设计。这种硬件的操作是缓慢的、昂贵的，并且消耗相当大的电力来重复地加热和冷却试剂混合物。另一种热循环方法是利用自然对流通过PCR进行快速DNA扩增。所提出的设计利用自然对流，本质上是简单的，并且消耗最小的电力，使得其非常适合于便携式应用。这项研究的目的是了解的基本过程，热驱动的对流场中的生化反应。这些流动的基本结构的特点是丰富的复杂性，因为在过渡制度与浮力驱动的湍流的发病相关的操作。由于与固有的混沌运动相关的挑战，该机制尚未被广泛探讨。该研究涉及详细的三维表征的速度和温度场的PCR反应器内使用协调粒子图像测速和激光诱导荧光分散的热致变色种子颗粒。计算流体动力学研究将确定所观察到的现象可以被捕获的程度。这些结果将（1）指导改进的计算技术和本构模型的开发，这反过来又将（2）使得能够设计用于超快速PCR的新的对流热循环装置。开发的实验和计算能力将提供新的见解和创新，通过探测复杂的单相和多相流在微米和纳米尺度的空间和时间分辨率的水平，更广泛的影响：实现反应速度的数量级增加的潜力将刺激便携式、廉价和坚固的DNA分析仪器的发展。 除了与使PCR更实惠相关的商业影响外，该技术还将通过在物理，化学和生命科学之间的界面上为本科生开发教育经验来产生教授物理学和分子生物学的新方法。这项技术的基本原理是高度相关的（例如，流量是以与熔岩灯相同的方式建立的），因此除了本科生之外，它还非常适合针对K12受众。这将为学生提供一种创新的方式，让他们了解如何将基础知识应用于生产真实的工作产品。

0933688UgazA major opportunity in the development of medical diagnostic instrumentation is the highly inefficient design of conventional polymerase chain reaction (PCR) thermocycling hardware. Operation of such hardware is slow, expensive, and consumes considerable electrical power to repeatedly heat and cool the reagent mixture. An alternative thermocycling approach is to harness natural convection to perform rapid DNA amplification via the PCR. The proposed design makes use of natural convection, is inherently simple, and consumes minimal electrical power making it well suited for portable applications. This research is aimed at understanding the fundamental processes that underlie thermally driven biochemical reactions in convective flow fields. The underlying structure of these flows is characterized by rich complexity because of operation in a transition regime associated with the onset of buoyancy driven turbulence. This regime has not been extensively probed owing to challenges associated with the inherently chaotic motion. The research involves detailed 3D characterization of velocity and temperature fields inside PCR reactors using coordinated particle image velocimetry and laser induced fluorescence of dispersed thermochromic seed particles. Computational fluid dynamic studies will determine the extent to which the observed phenomena can be captured. These results will (1) guide development of improved computational techniques and constitutive models which in turn will (2) enable the design of new convective thermocycling devices for ultra rapid PCR.Intellectual Merit: The experimental and computational capabilities developed will deliver new insights and innovations by probing complex single and multiphase flows at the micro and nanoscales with a level of spatial and temporal resolution that is currently unavailable.Broader Impacts: The potential to achieve an order of magnitude increase in reaction speed will spur development of portable, inexpensive, and rugged DNA analysis instrumentation. In addition to the commercial impact associated with making PCR more affordable, this technology will spawn new ways to teach physics and molecular biology through the development of educational experiences for undergraduates at the interface between the physical, chemical, and life sciences. The underlying principles of this technology are highly relatable (for example, the flow is established in the same way as in a lava lamp), making it ideal to target K12 audiences in addition to undergraduate students. This will provide an innovative way for students to see how fundamental knowledge can be applied to produce real, working products.