Marmottant Philippe, Hilgenfeldt Sascha
Department of Science and Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands.
Proc Natl Acad Sci U S A. 2004 Jun 29;101(26):9523-7. doi: 10.1073/pnas.0307007101. Epub 2004 Jun 21.
Microfluidics typically uses channels to transport small objects by actuation forces such as an applied pressure difference or thermocapillarity. We propose that acoustic streaming is an alternative means of directional transport at small scales. Microbubbles on a substrate establish well controlled fluid motion on very small scales; combinations ("doublets") of bubbles and microparticles break the symmetry of the motion and constitute flow transport elements. We demonstrate the principle of doublet streaming and describe the ensuing transport. Devices based on doublet flow elements work without microchannels and are thus potentially cheap and highly parallelizable.
微流体技术通常利用通道，通过诸如施加的压力差或热毛细作用等驱动力来输送微小物体。我们提出声流是小尺度下定向传输的一种替代方式。基底上的微气泡在非常小的尺度上建立了良好控制的流体运动；气泡和微粒的组合（“双联体”）打破了运动的对称性，构成了流体传输元件。我们展示了双联体流的原理并描述了随之而来的传输过程。基于双联体流动元件的装置无需微通道即可工作，因此可能成本低廉且具有高度可并行性。
