微热气泡驱动下的微流控的理论研究

微流控技术是指在微纳米尺度下利用流体的动力学特征，对微粒进行俘获、富集、自组装等微操作的技术.其已发展为一个生物、化学、医学、材料、光学、流体、机械等多学科交叉的崭新研究领域.其中，微热气泡驱动的流体具有优异的可操控性，受到越来越多研究者的关注.本文基于微热气泡的产生机制，结合热力学和流体力学的理论知识，采用COMSOL Multiphysics 4.4数值计算软件，对微热气泡驱动下的流体的流速场进行模拟和定量分析.结果证明，微热气泡表面具有马格兰尼效应，其驱动下的流体以漩涡的方式高效地俘获和富集微粒，与实验现象相符.因此，本文从理论上探究微热气泡驱动下的流速场性质，对提高微流体的可操控性，促进微流控技术的发展都具有重要的意义.

The Theoretical Study of Microfluidics Control Driven by Thermal Microbubbles

Microfluidics control is the technique that takes advantage of the dynamic characteristics of the fluid under the micro/nano scale and makes microoperation on particles such as trapping, aggregating, self-assembling and so on. It has been a novel study filed of hybrid subjects of biology, chemistry, medicine, materials, optics, fluid and machinery. Microfluidics control driven by thermal microbubbles has excellent controllability and receives an increasing significant attention among the researchers. This paper bases on the generation mechanism of thermal microbubbles and combines the theory of thermodynamics and hydrodynamics. Using the Comsol Multiphysics 4.4 to simulate and quantitative analyze the velocity field of fluid driven by thermal microbubbles. The result turns out that the surface of thermal microbubbles exist marangoni effect and the fluid driven by it can trap and aggregate paricles in the way of vortex efficiently, which is consistent with the experimental phenomenon. In consequence, this paper explores the property of velocity field of fluid driven by thermal microbubbles, which is meaningful for improving the controllability of microfluid and the developing of microfluid control technique.