Particle migration and sorting in microbubble streaming flows

Raqeeb Thameem, Bhargav Rallabandi, Sascha Hilgenfeldt

Research output: Contribution to journalArticle

Abstract

Ultrasonic driving of semicylindrical microbubbles generates strong streaming flows that are robust over a wide range of driving frequencies. We show that in microchannels, these streaming flow patterns can be combined with Poiseuille flows to achieve two distinctive, highly tunable methods for size-sensitive sorting and trapping of particles much smaller than the bubble itself. This method allows higher throughput than typical passive sorting techniques, since it does not require the inclusion of device features on the order of the particle size. We propose a simple mechanism, based on channel and flow geometry, which reliably describes and predicts the sorting behavior observed in experiment. It is also shown that an asymptotic theory that incorporates the device geometry and superimposed channel flow accurately models key flow features such as peak speeds and particle trajectories, provided it is appropriately modified to account for 3D effects caused by the axial confinement of the bubble.

Original languageEnglish (US)
Article number014124
JournalBiomicrofluidics
Volume10
Issue number1
DOIs
StatePublished - Jan 1 2016

ASJC Scopus subject areas

  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics
  • Fluid Flow and Transfer Processes
  • Colloid and Surface Chemistry

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