Thermocapillary control of microfluidic transport with a stationary cyclic heat source
Thermocapillary control of microfluidic transport with a stationary cyclic heat source
复制标题
使用固定循环热源对微流体传输进行热毛细管控制
DOI：
10.1088/0960-1317/15/12/002
复制
发表时间：
2005
影响因子：
2.3
通讯作者：
G. Naterer
中科院分区：
文献类型：
--
作者：
P. Glockner;G. Naterer
本文提出了一种外热源循环流量控制的新方法，用于封闭微通道内微滴的热毛细管泵送。与过去在液滴后退边缘有一个移动热源的研究不同，这项新技术涉及到一个嵌入相邻硅衬底的固定循环热源。用数值方法(有限体积法)和理论方法(弹状流近似)研究了微滴的热毛细抽吸过程。与以往的研究不同，本文考虑了液滴内完整的N-S方程和能量方程的解。此外，固定热源的温度边界条件被施加在衬底与其周围环境之间的界面上，而不是沿着微通道壁。有限体积格式在液体中采用滑动网格，在压缩空气和衬底区域采用自适应网格。沿液滴/空气界面施加压力和速度耦合边界条件。数值预测表明，在静止热源的作用下，液滴的循环位移可以得到。数值预测和理论预测之间的密切一致为这些公式提供了有用的验证。
In this paper, a new method of cyclic flow control with an external heat source is developed for thermocapillary pumping of a micro-droplet in a closed microchannel. Unlike past studies with a moving heat source at the receding edge of the droplet, this new technique involves a stationary cyclic heat source embedded within an adjoining silicon substrate. Thermocapillary pumping of the micro-droplet is examined numerically (finite-volume method) and theoretically (slug-flow approximation). In contrast to past studies, this paper considers the solution of the full Navier–Stokes and energy equations within the droplet. Additionally, temperature boundary conditions for a stationary heat source are applied at the interface between the substrate and its surroundings, rather than along the microchannel wall. The finite-volume formulation is developed with a sliding grid in the liquid phase and an adaptive grid along the compressed air and substrate regions. Coupled pressure and velocity boundary conditions are applied along the droplet/air interface. Numerical predictions suggest that cyclic droplet displacement can be obtained with the stationary heat source. Close agreement between numerical and theoretical predictions has provided useful validation of the formulations.