Fundamental investigation of transport phenomena in convectively actuated biochemical reactors

发展医疗诊断仪器的一个主要机会是传统的聚合酶链式反应(PCR)热循环硬件的高度低效设计。这种硬件的操作缓慢、昂贵，并且要消耗相当大的电力来反复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聚合酶链式反应进行快速DNA扩增。建议的设计利用自然对流，本质上简单，消耗的电力最少，非常适合便携式应用。这项研究的目的是了解对流流场中热驱动生化反应的基本过程。这些流动的基本结构具有丰富的复杂性，因为它们是在与浮力驱动的湍流开始相关的过渡区域中运行的。由于与固有的混乱运动相关的挑战，这一制度尚未得到广泛调查。这项研究包括使用协调粒子图像测速仪和分散的热致变色种子粒子的激光诱导荧光来详细地三维表征聚合酶链式反应反应器内的速度和温度场。计算流体力学研究将确定观察到的现象可以被捕捉到的程度。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)为超快速PCR设计新的对流热循环设备。智力上的优点：所开发的实验和计算能力将提供新的见解和创新，通过在微米和纳米尺度上探测复杂的单相流和多相流，其空间和时间分辨率是目前无法获得的。广泛的影响：实现反应速度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。除了使PCR变得更容易负担的商业影响外，这项技术还将通过发展本科生在物理、化学和生命科学之间的教育经验，产生教授物理和分子生物学的新方法。这项技术的基本原理高度相关(例如，流动是以与熔岩灯相同的方式建立的)，因此除了本科生之外，它还可以理想地瞄准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正有效的产品。

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.