Fundamental investigation of transport phenomena in convectively actuated biochemical reactors

0933688UgazA医疗诊断仪器发展的主要机遇是传统聚合酶链反应（PCR）热循环硬件的设计效率极低。这种硬件的操作缓慢，昂贵，并且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PCR进行快速DNA扩增。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，使其非常适合便携式应用。本研究旨在了解对流流场中热驱动生化反应的基本过程。这些流的底层结构具有丰富的复杂性，因为它们处于一个与浮力驱动的湍流开始相关的过渡状态。由于固有的混沌运动带来的挑战，这种状态尚未得到广泛的研究。该研究涉及使用协调粒子图像测速和分散热致变色种子粒子的激光诱导荧光技术对PCR反应器内的速度和温度场进行详细的3D表征。计算流体动力学研究将决定所观察到的现象能够被捕捉到的程度。这些结果将(1)指导改进计算技术和本构模型的发展，这反过来将(2)使超快速PCR的新对流热循环装置的设计成为可能。智力优势：开发的实验和计算能力将提供新的见解和创新，通过在微观和纳米尺度上探测复杂的单相和多相流动，具有目前无法获得的空间和时间分辨率水平。更广泛的影响：在反应速度上实现数量级增长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技术更经济实惠的商业影响外，这项技术还将通过发展物理、化学和生命科学之间的本科生的教育经验，为物理学和分子生物学的教学带来新的方法。这项技术的基本原理是高度相关的（例如，流动是以与熔岩灯相同的方式建立的），使其成为除了本科生之外的理想目标K12观众。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、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.