A bubble-driven microfluidic transport element for bioengineering
Philippe Marmottant* and Sascha Hilgenfeldt
Department of Science and Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
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.
Source: Proc Natl Acad Sci U S A. 2004 June 29; 101(26): 9523–9527.