Optimized cross-slot flow geometry for microfluidic extension rheometry

S.J. Haward, Monica Oliveira, M.A. Alves, G.H. McKinley

Research output: Contribution to journal › Article

63 Citations (Scopus)

Abstract

A precision-machined cross-slot flow geometry with a shape that has been optimized by numerical simulation of the fluid kinematics is fabricated and used to measure the extensional viscosity of a dilute polymer solution. Full-field birefringence microscopy is used to monitor the evolution and growth of macromolecular anisotropy along the stagnation point streamline, and we observe the formation of a strong and uniform birefringent strand when the dimensionless flow strength exceeds a critical Weissenberg number Wicrit 0:5. Birefringence and bulk pressure drop measurements provide self consistent estimates of the planar extensional viscosity of the fluid over a wide range of deformation rates (26 s1 "_ 435 s1) and are also in close agreement with numerical simulations performed by using a finitely extensible nonlinear elastic dumbbell model.
LanguageEnglish
Article number128301
Number of pages5
JournalPhysical Review Letters
Volume109
Issue number12
DOIs
Publication statusPublished - 17 Sep 2012

Fingerprint

flow geometry
slots
birefringence
viscosity
stagnation point
fluids
pressure drop
strands
kinematics
simulation
microscopy
anisotropy
polymers
estimates

Keywords

  • flow geometry
  • microfluidics
  • rheometry
  • polymer solutions
  • anisotropy
  • birefringence
  • cross-flow

Cite this

Haward, S.J. ; Oliveira, Monica ; Alves, M.A. ; McKinley, G.H. / Optimized cross-slot flow geometry for microfluidic extension rheometry. In: Physical Review Letters. 2012 ; Vol. 109, No. 12.
@article{da29ce84498645b480298ad2e3829f9a,
title = "Optimized cross-slot flow geometry for microfluidic extension rheometry",
abstract = "A precision-machined cross-slot flow geometry with a shape that has been optimized by numerical simulation of the fluid kinematics is fabricated and used to measure the extensional viscosity of a dilute polymer solution. Full-field birefringence microscopy is used to monitor the evolution and growth of macromolecular anisotropy along the stagnation point streamline, and we observe the formation of a strong and uniform birefringent strand when the dimensionless flow strength exceeds a critical Weissenberg number Wicrit 0:5. Birefringence and bulk pressure drop measurements provide self consistent estimates of the planar extensional viscosity of the fluid over a wide range of deformation rates (26 s1 {"}_ 435 s1) and are also in close agreement with numerical simulations performed by using a finitely extensible nonlinear elastic dumbbell model.",
keywords = "flow geometry, microfluidics, rheometry, polymer solutions, anisotropy, birefringence, cross-flow",
author = "S.J. Haward and Monica Oliveira and M.A. Alves and G.H. McKinley",
year = "2012",
month = "9",
day = "17",
doi = "10.1103/PhysRevLett.109.128301",
language = "English",
volume = "109",
journal = "Physical Review Letters",
issn = "0031-9007",
number = "12",

}

Haward, SJ, Oliveira, M, Alves, MA & McKinley, GH 2012, 'Optimized cross-slot flow geometry for microfluidic extension rheometry' Physical Review Letters, vol. 109, no. 12, 128301. https://doi.org/10.1103/PhysRevLett.109.128301

Optimized cross-slot flow geometry for microfluidic extension rheometry. / Haward, S.J.; Oliveira, Monica; Alves, M.A.; McKinley, G.H.

In: Physical Review Letters, Vol. 109, No. 12, 128301, 17.09.2012.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Optimized cross-slot flow geometry for microfluidic extension rheometry

AU - Haward, S.J.

AU - Oliveira, Monica

AU - Alves, M.A.

AU - McKinley, G.H.

PY - 2012/9/17

Y1 - 2012/9/17

N2 - A precision-machined cross-slot flow geometry with a shape that has been optimized by numerical simulation of the fluid kinematics is fabricated and used to measure the extensional viscosity of a dilute polymer solution. Full-field birefringence microscopy is used to monitor the evolution and growth of macromolecular anisotropy along the stagnation point streamline, and we observe the formation of a strong and uniform birefringent strand when the dimensionless flow strength exceeds a critical Weissenberg number Wicrit 0:5. Birefringence and bulk pressure drop measurements provide self consistent estimates of the planar extensional viscosity of the fluid over a wide range of deformation rates (26 s1 "_ 435 s1) and are also in close agreement with numerical simulations performed by using a finitely extensible nonlinear elastic dumbbell model.

AB - A precision-machined cross-slot flow geometry with a shape that has been optimized by numerical simulation of the fluid kinematics is fabricated and used to measure the extensional viscosity of a dilute polymer solution. Full-field birefringence microscopy is used to monitor the evolution and growth of macromolecular anisotropy along the stagnation point streamline, and we observe the formation of a strong and uniform birefringent strand when the dimensionless flow strength exceeds a critical Weissenberg number Wicrit 0:5. Birefringence and bulk pressure drop measurements provide self consistent estimates of the planar extensional viscosity of the fluid over a wide range of deformation rates (26 s1 "_ 435 s1) and are also in close agreement with numerical simulations performed by using a finitely extensible nonlinear elastic dumbbell model.

KW - flow geometry

KW - microfluidics

KW - rheometry

KW - polymer solutions

KW - anisotropy

KW - birefringence

KW - cross-flow

UR - http://prl.aps.org/toc/PRL/v109/i12

U2 - 10.1103/PhysRevLett.109.128301

DO - 10.1103/PhysRevLett.109.128301

M3 - Article

VL - 109

JO - Physical Review Letters

T2 - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 12

M1 - 128301

ER -

Haward SJ, Oliveira M, Alves MA, McKinley GH. Optimized cross-slot flow geometry for microfluidic extension rheometry. Physical Review Letters. 2012 Sep 17;109(12). 128301. https://doi.org/10.1103/PhysRevLett.109.128301

Access to Document