title: Bubbling and foaming assisted clearing of mucin plugs in microfluidic Y-junctions.
abstract: Microfluidic Y-junctions were used to study mechanical mechanisms involved in pig gastric mucin (PGM) plug removal from within one of two bifurcation branches with 2-phase air and liquid flow. Water control experiments showed moderate plug removal due to shear from vortex formation in the blockage branch and suggest a PGM yield stress of 35Pa, as determined by computational fluid dynamics. Addition of hexadecyltrimethylammonium bromide (CTAB) surfactant improved clearing effectiveness due to bubbling in 1mm diameter channels and foaming in 500μm diameter channels. Plug removal mechanisms have been identified as vortex shear, bubble scouring, and then foam scouring as air flow rate is increased with constant liquid flow. The onset of bubbling and foaming is attributed to a flow regime transition from slug to slug-annular. Flow rates explored for 1mm channels are typically experienced by bronchioles in generations 8 and 9 of lungs. Results have implications on treatment of cystic fibrosis and other lung diseases.
authors.affiliation: Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, United States. Electronic address: danerabdula@gmail.com.
authors.forename: Daner
authors.initials: D
authors.lastname: Abdula
authors.affiliation: Department of Chemistry, Portland State University, Portland, OR 97201, United States.
authors.forename: Ryan
authors.initials: R
authors.lastname: Lerud
authors.affiliation: Department of Chemistry, Portland State University, Portland, OR 97201, United States.
authors.forename: Shankar
authors.initials: S
authors.lastname: Rananavare
mesh_terms: D000818:Animals; D000077286:Cetrimonium; D002593:Cetrimonium Compounds; D057446:Hydrodynamics; D008168:Lung / Q000502:physiology*; D044085:Microfluidics; D009077:Mucins; D013501:Surface-Active Agents; D013552:Swine; D014867:Water
chemical_list: D002593:Cetrimonium Compounds; D009077:Mucins; D013501:Surface-Active Agents; D014867:Water; D000077286:Cetrimonium
keywords: Bifurcation; Foam; Lung; Mucus; Surfactant