title: Filtering microfluidic bubble trains at a symmetric junction.
abstract: We report how a nominally symmetric microfluidic junction can be used to sort all bubbles of an incoming train exclusively into one of its arms. The existence of this "filter" regime is unexpected, given that the junction is symmetric. We analyze this behavior by quantifying how bubbles modulate the hydrodynamic resistance in microchannels and show how speeding up a bubble train whilst preserving its spatial periodicity can lead to filtering at a nominally symmetric junction. We further show how such an asymmetric traffic of bubble trains can be triggered in symmetric geometries by identifying conditions wherein the resistance to flow decreases with an increase in the number of bubbles in the microchannel and derive an exact criterion to predict the same.
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, E5-02-28, Singapore 117576.
authors: Pravien
authors: P
authors: Parthiban
authors: Saif A
authors: SA
authors: Khan
mesh_terms: D005374:Filtration / Q000379:methods*; D005740:Gases; D057446:Hydrodynamics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D044085:Microfluidics / Q000295:instrumentation*; D056004:Molecular Dynamics Simulation; D011312:Pressure; D012680:Sensitivity and Specificity; D013500:Surface Tension
chemical_list: D005740:Gases