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Assembly and Characterization of an External Driver for the Generation of Sub-Kilohertz Oscillatory Flow in Microchannels
Published on: January 28, 2022
Velocity oscillations in microfluidic flows of concentrated colloidal suspensions
Lucio Isa1, Rut Besseling, Alexander N Morozov
1SUPA, School of Physics & Astronomy, The University of Edinburgh, James Clerk Maxwell Building, The Kings Buildings, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom.
Physical Review Letters
|March 5, 2009
Summary
Concentrated colloids in microchannels exhibit flow fluctuations at lower confinements, transitioning to regular oscillations at higher confinements (2a/D ≈ 20). This behavior links particle-solvent flow and shear thickening effects.
Area of Science:
- Colloid science
- Fluid dynamics
- Microfluidics
Background:
- Understanding concentrated colloidal suspensions is crucial for various industrial applications.
- Confined geometries significantly alter fluid behavior compared to bulk flow.
- Single-particle resolution is key to elucidating complex flow dynamics.
Purpose of the Study:
- To investigate pressure-driven flow of concentrated colloids in glass microchannels.
- To analyze the impact of confinement on colloidal particle flow behavior.
- To correlate observed flow patterns with solvent-particle interactions and shear thickening.
Main Methods:
- Utilized fast confocal microscopy for single-particle tracking.
- Employed glass microchannels with controlled confinement ratios (2a/D).
- Analyzed particle flow rates and patterns under pressure-driven conditions.
Main Results:
- Observed flow rate fluctuations for lower confinement ratios (2a/D ≤ 30).
- Identified regular oscillations in particle flow at higher confinements (2a/D ≈ 20).
- Provided evidence linking oscillations to solvent permeation and confinement-induced shear thickening.
Conclusions:
- Confinement ratio is a critical parameter governing colloidal flow in microchannels.
- Flow oscillations are a signature of coupled particle-solvent dynamics and shear thickening.
- Single-particle analysis offers valuable insights into microscale fluid mechanics.
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