• DOI:10.1039/c3lc41227j
• Corpus ID: 13618514

Microstructure-induced helical vortices allow single-stream and long-term inertial focusing.

@article{Chung2013MicrostructureinducedHV,
  title={Microstructure-induced helical vortices allow single-stream and long-term inertial focusing.},
  author={Aram J. Chung and Dianne Pulido and Justin C Oka and Hamed Amini and Mahdokht Masaeli and Dino Di Carlo},
  journal={Lab on a chip},
  year={2013},
  volume={13 15},
  pages={
          2942-9
        }
}

• Aram J. Chung, D. Pulido, +3 authors D. Di Carlo
• Published 2 July 2013
• Physics, Biology
• Lab on a chip

Fluid inertia has been used to position microparticles in confined channels because it leads to precise and predictable particle migration across streamlines in a high-throughput manner. To focus particles, typically two inertial effects have been employed: inertial migration of particles in combination with geometry-induced secondary flows. Still, the strong scaling of inertial effects with fluid velocity or channel flow rate have made it challenging to design inertial focusing systems for single-stream focusing using large-scale microchannels. Use of large-scale microchannels (≥100 μm) reduces clogging over long durations and could be suitable for non-single-use flow cells in cytometry systems. Here, we show that microstructure-induced helical vortices yield single-stream focusing of microparticles with continuous and robust operation. Numerical and experimental results demonstrate how structures contribute to improve focusing in these larger channels, through controllable cross-stream particle migration, aided by locally-tuned secondary flows from sequential obstacles that act to bring particles closer to a single focusing equilibrium position. The large-scale inertial focuser developed here can be operated in a high-throughput manner with a maximum throughput of approximately 13,000 particles per s.