Engineering particle trajectories in microfluidic flows using particle shape

Recent advances in microfluidic technologies have created a demand for techniques to control the motion of flowing microparticles. Here we consider how the shape and geometric confinement of a rigid microparticle can be tailored for ‘self-steering’ under external flow. We find that an asymmetric par...

Full description

Bibliographic Details
Main Authors: Uspal, William E., Doyle, Patrick S., Eral, Huseyin Burak
Other Authors: Massachusetts Institute of Technology. Department of Chemical Engineering
Format: Article
Language:en_US
Published: Nature Publishing Group 2015
Online Access:http://hdl.handle.net/1721.1/97004
Description
Summary:Recent advances in microfluidic technologies have created a demand for techniques to control the motion of flowing microparticles. Here we consider how the shape and geometric confinement of a rigid microparticle can be tailored for ‘self-steering’ under external flow. We find that an asymmetric particle, weakly confined in one direction and strongly confined in another, will align with the flow and focus to the channel centreline. Experimentally and theoretically, we isolate three viscous hydrodynamic mechanisms that contribute to particle dynamics. Through their combined effects, a particle is stably attracted to the channel centreline, effectively behaving as a damped oscillator. We demonstrate the use of self-steering particles for microfluidic device applications, eliminating the need for external forces or sheath flows.