Gui Lin, Ren Carolyn L
Department of Mechanical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1.
Anal Chem. 2006 Sep 1;78(17):6215-22. doi: 10.1021/ac060553d.
Precise design and operational control of the polymerase chain reaction process is key to the performance of on-chip DNA analysis. This research is dedicated to understanding the fluid flow and heat transfer mechanisms occurring in continuous flow PCR chips from the engineering point of view. In this work, a 3-dimensional model was developed to simulate the electrical potential field, the flow field, and the temperature field in an electroosmosis-based continuous flow PCR chip. On the basis of the simultaneous solution to this model, the effects of the channel/chip size, the chip material, and the applied voltage difference on the temperature distribution and control are discussed in detail. The importance of each heat transfer mechanism for different situations is also discussed. It was found that if a larger chip thickness or a material with a lower heat conductivity was used, the temperature in the microfluidic PCR chip would decrease dramatically. The effects of the applied electrical field strength and flow velocity on the temperature distribution, however, are negligible for microchannels with a small cross-sectional area. With bigger channels, the flow direction will affect the temperature distribution in the channel because heat convection will dominate heat transfer.
聚合酶链反应过程的精确设计和操作控制是芯片上DNA分析性能的关键。本研究致力于从工程学角度理解连续流动PCR芯片中发生的流体流动和传热机制。在这项工作中，开发了一个三维模型来模拟基于电渗的连续流动PCR芯片中的电势场、流场和温度场。基于对该模型的联立求解，详细讨论了通道/芯片尺寸、芯片材料和施加的电压差对温度分布和控制的影响。还讨论了不同情况下每种传热机制的重要性。结果发现，如果使用更大的芯片厚度或导热率较低的材料，微流控PCR芯片中的温度将显著降低。然而，对于横截面面积较小的微通道，施加的电场强度和流速对温度分布的影响可以忽略不计。对于较大的通道，流动方向将影响通道中的温度分布，因为热对流将主导传热。
