Abstract
Acoustic fields have been widely used for manipulation of particles and cells within microfluidic systems. In this Letter, we explore a novel acoustofluidic phenomenon for particle patterning and focusing, where a periodic acoustic pressure field is produced parallel to internal channel boundaries with the imposition of either a traveling or standing surface acoustic wave (SAW). This effect results from the propagation and intersection of edge waves from the channel walls according to the Huygens-Fresnel principle and classical wave fronts from the substrate-fluid interface. We demonstrate versatile control over this effect to produce both one- and two-dimensional acoustic patterning from one-dimensional SAW fields and its utility for continuous particle focusing. Uniquely, this channel-guided acoustic focusing permits the generation of robust acoustic fields without channel resonance conditions and particle focusing positions that are difficult or impossible to produce otherwise.
- Received 25 October 2017
DOI:https://doi.org/10.1103/PhysRevLett.120.074502
© 2018 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Acoustic Waves Direct Particles in Microchannels
Published 15 February 2018
Acoustic waves guided by the channels of a microfluidic device can precisely manipulate microscopic particles suspended in the liquid flowing through the device.
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