[Lab on a chip] Selective particle and cell capture in a continuous flow using micro-vortex acoustic
Acoustic streaming has emerged as a promising technique for refined microscale manipulation, where strong rotational flow can give rise to particle and cell capture. In contrast to hydrodynamically generated vortices, acoustic streaming is rapidly tunable, highly scalable and requires no external pressure source. Though streaming is typically ignored or minimized in most acoustofluidic systems that utilize other acoustofluidic effects, we maximize the effect of acoustic streaming in a continuous flow using a high-frequency (381 MHz), narrow-beam focused surface acoustic wave. This results in rapid fluid streaming, with velocities orders of magnitude greater than that of the lateral flow, to generate fluid vortices that extend the entire width of a 400 μm wide microfluidic channel. We characterize the forces relevant for vortex formation in a combined streaming/lateral flow system, and use these acoustic streaming vortices to selectively capture 2 μm from a mixed suspension with 1 μm particles and human breast adenocarcinoma cells (MDA-231) from red blood cells.
David J. Collins,ade Bee Luan Khoo,b Zhichao Ma,a Andreas Winkler,c Robert Weser,c Hagen Schmidt,c Jongyoon Hanbde and Ye Ai*a Author affiliations * Corresponding authors a Pillar of Engineering Product Development, Singapore University of Technology and Design, Singapore 487372, Singapore E-mail: email@example.com Tel: (+65) 6499 4553 b BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore 138102, Singapore c SAWLab Saxony, IFW Dresden, PF 270116, 01171 Dresden, Germany d Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, USA e Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA