title: Velocity oscillations in microfluidic flows of concentrated colloidal suspensions.
abstract: We study the pressure-driven flow of concentrated colloids confined in glass microchannels at the single-particle level using fast confocal microscopy. For channel to particle size ratios 2a/D[over ] less, similar30, the flow rate of the suspended particles shows fluctuations. These turn into regular oscillations for higher confinements (2a/D[over ] approximately 20). We present evidence to link these oscillations with the relative flow of solvent and particles (permeation) and the effect of confinement on shear thickening.
authors.affiliation: SUPA, School of Physics & Astronomy, The University of Edinburgh, James Clerk Maxwell Building, The Kings Buildings, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: Lucio
authors.initials: L
authors.lastname: Isa
authors.forename: Rut
authors.initials: R
authors.lastname: Besseling
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Morozov
authors.forename: Wilson C K
authors.initials: WC
authors.lastname: Poon