Baroud Charles N, de Saint Vincent Matthieu Robert, Delville Jean-Pierre
LadHyX and Department of Mechanics, Ecole Polytechnique, 91128, Palaiseau cedex, France.
Lab Chip. 2007 Aug;7(8):1029-33. doi: 10.1039/b702472j. Epub 2007 Jun 8.
The use of microfluidic drops as microreactors hinges on the active control of certain fundamental operations such as droplet formation, transport, division and fusion. Recent work has demonstrated that local heating from a focused laser can apply a thermocapillary force on a liquid interface sufficient to block the advance of a droplet in a microchannel (C. N. Baroud, J.-P. Delville, F. Gallaire and R. Wunenburger, Phys. Rev. E: Stat., Nonlinear, Soft Matter Phys., 2007, 75(4), 046302). Here, we demonstrate the generality of this optical approach by implementing the operations mentioned above, without the need for any special microfabrication or moving parts. We concentrate on the applications to droplet manipulation by implementing a wide range of building blocks, such as a droplet valve, sorter, fuser, or divider. We also show how the building blocks may be combined by implementing a valve and fuser using a single laser spot. The underlying fundamentals, namely regarding the fluid mechanical, physico-chemical and thermal aspects, will be discussed in future publications.
将微流体液滴用作微反应器取决于对某些基本操作的主动控制，如液滴形成、传输、分裂和融合。最近的研究表明，聚焦激光产生的局部加热能够在液体界面上施加热毛细力，足以阻止微通道中液滴的前进（C.N.巴鲁德、J.-P.德尔维尔、F.加莱尔和R.武嫩贝格尔，《物理评论E：统计、非线性、软物质物理》，2007年，75(4)，046302）。在此，我们通过实施上述操作证明了这种光学方法的通用性，无需任何特殊的微加工或活动部件。我们通过实施一系列构建模块，如液滴阀、分选器、融合器或分离器，专注于液滴操纵的应用。我们还展示了如何通过使用单个激光光斑实现阀和融合器来组合这些构建模块。关于流体力学、物理化学和热学方面的基本原理将在未来的出版物中进行讨论。
