Abstract

This paper describes a new method for carrying out flow cytometry, which employs optical gradient forces to guide and focus particles in the fluid flow. An elliptically shaped Gaussian beam was focused at the center of a microchannel to exert radiation pressure on suspended nanoparticles that are passing through the channel, such that these particles are guided to the center of the channel for efficient detection and sorting. To verify the efficiency of this optical-gradient-flow-focusing method, we present numerical simulations of the trajectories of the nanoparticles in both electroosmotic flow (EOF) and pressure-driven flow (PDF).

© 2007 Optical Society of America

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  1. M. A. Van Dilla, Flow Cytometry: Instrumentation and Data Analysis (Academic, London, 1985).
  2. M. R. Melamed, T. Lindmo, and M. L. Mendelsohn, Flow Cytometry and Sorting (New York, Wiley, 1991).
  3. S. L. Anna, N. Bontoux, and H. A. Stone, "Formation of dispersions using "flow focusing" in microchannels," Appl. Phys. Lett. 82, 364-366 (2003).
    [CrossRef]
  4. P. Garstecki, I. Gitlin, W. DiLuzio and G. M. Whitesides, "Formation of monodisperse bubbles in a microfluidic flow-focusing device," Appl. Phys. Lett. 85, 2649-2651 (2004).
    [CrossRef]
  5. M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
    [CrossRef] [PubMed]
  6. M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
    [CrossRef] [PubMed]
  7. C. Simonnet and A. Groisman, "Two-dimensional hydrodynamic focusing in a simple microfluidic device," Appl. Phys. Lett. 87, 114104 (2005).
    [CrossRef]
  8. J. B. Knight, A. Vishwanath, J. P. Brody, and R. H. Austin, "Hydrodynamic focusing on a silicon chip: Mixing nanoliters in microseconds," Phys. Rev. Lett. 80, 3863-3866 (1998).
    [CrossRef]
  9. S. Takeuchi, P. Garstecki, D. B. Weibel and G. M. Whitesides, "An axisymmetric flow-focusing microfluidic device," Adv. Mater. 17, 1067-1072 (2005).
    [CrossRef]
  10. W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
    [CrossRef] [PubMed]
  11. H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
    [CrossRef]
  12. S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
    [CrossRef]
  13. G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
    [CrossRef]
  14. D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
    [CrossRef]
  15. D. P. Schrum, C. T. Culbertson, S. C. Jacobson, and J. M. Ramsey, "Microchip flow cytometry using electrokinetic focusing," Anal. Chem. 71, 4173-4177 (1999).
    [CrossRef] [PubMed]
  16. E. Altendorf, D. Zebert, M. Holl, and P. Yager, "Differential blood cell counts obtained using a microchannel based flow cytometer," in Proceedings of IEEE Conference on Solid-State Sensors and Actuators, Chicago, IL, 531-534 (1997).
  17. G. Goddard, J. C. Martin, S. W. Graves, and G. Kaduchak, "Ultrasonic particle-concentration for sheathless focusing of particles for analysis in a flow cytometer," Cytometry Part A,  69A, 66-74 (2006).
    [CrossRef]
  18. C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
    [CrossRef]
  19. C. H. Lin, G. B. Lee, L. M. Fu, and B. H. Hwey, "Vertical focusing device utilizing dielectrophoretic force and its application on microflow cytometer," J. Microelectromech. Syst. 13, 923-932 (2004).
    [CrossRef]
  20. A. Ashkin, "Trapping of atoms by resonance radiation pressure," Phys. Rev. Lett. 40, 729-732 (1978).
    [CrossRef]
  21. A. Ashkin, J. M. Dziedzic, J. E. Bjorkholm, and S. Chu, "Observation of a single-beam gradient force optical trap for dielectric particles," Opt. Lett. 11, 288-290 (1986).
    [CrossRef] [PubMed]
  22. R. Applegate, Jr., J. Squier, T. Vestad, J. Oakey, and D. Marr, "Optical trapping, manipulation, and sorting of cells and colloids in microfluidic systems with diode laser bars," Opt. Express 12, 4390-4398 (2004).
    [CrossRef] [PubMed]
  23. C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
    [CrossRef] [PubMed]
  24. T. Tlusty, A. Meller, R. Bar-Ziv, "Optical gradient forces of strongly localized fields," Phys. Rev. Lett. 81, 1738-1741 (1998).
    [CrossRef]
  25. A. Rohrbach, "Stiffness of optical traps: quantitative agreement between experiment and electromagnetic theory," Phys. Rev. Lett. 95, 168102 (2005).
    [CrossRef] [PubMed]
  26. G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
    [CrossRef] [PubMed]
  27. P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
    [CrossRef] [PubMed]
  28. C. Coirault, J. C. Pourny, F. Lambert, Y. Lecarpentier, "Optical tweezers in biology and medicine," Med.Sci. 19, 364-367 (2003).
  29. Y. Harada and T. Asakura, "Radiation forces on a dielectric sphere in the Rayleigh scattering regime," Opt. Commun. 124, 529-541 (1996).
    [CrossRef]
  30. R. M. Simmons, J. T. Finer, S. Chu, and J. A. Spudich, "Quantitative measurements of force and displacement using an optical trap," Biophys. J. 70, 1813-1822 (1996).
    [CrossRef] [PubMed]
  31. D. L. Ermak and J. A. McCammon, "Brownian dynamics with hydrodynamic interactions," J. Chem. Phys. 69, 1352-1360 (1978).
    [CrossRef]
  32. J. G. Knudsen and D. L. Katz, Fluid dynamics and heat transfer (McGraw-Hill Book Co. Inc., New York 1958).
  33. N. M. Natarajan and S. M. Lakshmanan, "Laminar Flow in rectangular ducts: prediction of velocity profiles and friction factor," Indian J. Technol. 10, 435-438 (1972).
  34. P. Vasseur and R. G. Cox, "The lateral migration of a spherical particle in two-dimensional shear flows," J. Fluid Mechanics 78, 385-413 (1976).
    [CrossRef]
  35. U. S. Agarwal, A. Dutta, and R. A. Mashelkar, "Migration of macromolecules under flow: the physical origin and engineering implications," Chem. Eng. Sci. 49, 1693-1717 (1994).
    [CrossRef]

2007

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

2006

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
[CrossRef] [PubMed]

H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
[CrossRef]

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

G. Goddard, J. C. Martin, S. W. Graves, and G. Kaduchak, "Ultrasonic particle-concentration for sheathless focusing of particles for analysis in a flow cytometer," Cytometry Part A,  69A, 66-74 (2006).
[CrossRef]

2005

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

C. Simonnet and A. Groisman, "Two-dimensional hydrodynamic focusing in a simple microfluidic device," Appl. Phys. Lett. 87, 114104 (2005).
[CrossRef]

S. Takeuchi, P. Garstecki, D. B. Weibel and G. M. Whitesides, "An axisymmetric flow-focusing microfluidic device," Adv. Mater. 17, 1067-1072 (2005).
[CrossRef]

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

A. Rohrbach, "Stiffness of optical traps: quantitative agreement between experiment and electromagnetic theory," Phys. Rev. Lett. 95, 168102 (2005).
[CrossRef] [PubMed]

2004

R. Applegate, Jr., J. Squier, T. Vestad, J. Oakey, and D. Marr, "Optical trapping, manipulation, and sorting of cells and colloids in microfluidic systems with diode laser bars," Opt. Express 12, 4390-4398 (2004).
[CrossRef] [PubMed]

P. Garstecki, I. Gitlin, W. DiLuzio and G. M. Whitesides, "Formation of monodisperse bubbles in a microfluidic flow-focusing device," Appl. Phys. Lett. 85, 2649-2651 (2004).
[CrossRef]

C. H. Lin, G. B. Lee, L. M. Fu, and B. H. Hwey, "Vertical focusing device utilizing dielectrophoretic force and its application on microflow cytometer," J. Microelectromech. Syst. 13, 923-932 (2004).
[CrossRef]

2003

S. L. Anna, N. Bontoux, and H. A. Stone, "Formation of dispersions using "flow focusing" in microchannels," Appl. Phys. Lett. 82, 364-366 (2003).
[CrossRef]

C. Coirault, J. C. Pourny, F. Lambert, Y. Lecarpentier, "Optical tweezers in biology and medicine," Med.Sci. 19, 364-367 (2003).

2002

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

2001

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

1999

D. P. Schrum, C. T. Culbertson, S. C. Jacobson, and J. M. Ramsey, "Microchip flow cytometry using electrokinetic focusing," Anal. Chem. 71, 4173-4177 (1999).
[CrossRef] [PubMed]

1998

J. B. Knight, A. Vishwanath, J. P. Brody, and R. H. Austin, "Hydrodynamic focusing on a silicon chip: Mixing nanoliters in microseconds," Phys. Rev. Lett. 80, 3863-3866 (1998).
[CrossRef]

T. Tlusty, A. Meller, R. Bar-Ziv, "Optical gradient forces of strongly localized fields," Phys. Rev. Lett. 81, 1738-1741 (1998).
[CrossRef]

1996

Y. Harada and T. Asakura, "Radiation forces on a dielectric sphere in the Rayleigh scattering regime," Opt. Commun. 124, 529-541 (1996).
[CrossRef]

R. M. Simmons, J. T. Finer, S. Chu, and J. A. Spudich, "Quantitative measurements of force and displacement using an optical trap," Biophys. J. 70, 1813-1822 (1996).
[CrossRef] [PubMed]

1994

U. S. Agarwal, A. Dutta, and R. A. Mashelkar, "Migration of macromolecules under flow: the physical origin and engineering implications," Chem. Eng. Sci. 49, 1693-1717 (1994).
[CrossRef]

1986

1978

D. L. Ermak and J. A. McCammon, "Brownian dynamics with hydrodynamic interactions," J. Chem. Phys. 69, 1352-1360 (1978).
[CrossRef]

A. Ashkin, "Trapping of atoms by resonance radiation pressure," Phys. Rev. Lett. 40, 729-732 (1978).
[CrossRef]

1976

P. Vasseur and R. G. Cox, "The lateral migration of a spherical particle in two-dimensional shear flows," J. Fluid Mechanics 78, 385-413 (1976).
[CrossRef]

1972

N. M. Natarajan and S. M. Lakshmanan, "Laminar Flow in rectangular ducts: prediction of velocity profiles and friction factor," Indian J. Technol. 10, 435-438 (1972).

Agarwal, U. S.

U. S. Agarwal, A. Dutta, and R. A. Mashelkar, "Migration of macromolecules under flow: the physical origin and engineering implications," Chem. Eng. Sci. 49, 1693-1717 (1994).
[CrossRef]

Anna, S. L.

S. L. Anna, N. Bontoux, and H. A. Stone, "Formation of dispersions using "flow focusing" in microchannels," Appl. Phys. Lett. 82, 364-366 (2003).
[CrossRef]

Applegate, R.

Asakura, T.

Y. Harada and T. Asakura, "Radiation forces on a dielectric sphere in the Rayleigh scattering regime," Opt. Commun. 124, 529-541 (1996).
[CrossRef]

Ashkin, A.

Austin, R. H.

J. B. Knight, A. Vishwanath, J. P. Brody, and R. H. Austin, "Hydrodynamic focusing on a silicon chip: Mixing nanoliters in microseconds," Phys. Rev. Lett. 80, 3863-3866 (1998).
[CrossRef]

Baek, J.Y.

H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
[CrossRef]

Bar-Ziv, R.

T. Tlusty, A. Meller, R. Bar-Ziv, "Optical gradient forces of strongly localized fields," Phys. Rev. Lett. 81, 1738-1741 (1998).
[CrossRef]

Beebe, D. J.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Bjorkholm, J. E.

Bontoux, N.

S. L. Anna, N. Bontoux, and H. A. Stone, "Formation of dispersions using "flow focusing" in microchannels," Appl. Phys. Lett. 82, 364-366 (2003).
[CrossRef]

Brody, J. P.

J. B. Knight, A. Vishwanath, J. P. Brody, and R. H. Austin, "Hydrodynamic focusing on a silicon chip: Mixing nanoliters in microseconds," Phys. Rev. Lett. 80, 3863-3866 (1998).
[CrossRef]

Chang, C. M.

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

Chiu, D. T.

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
[CrossRef] [PubMed]

Choo, J.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Chu, S.

R. M. Simmons, J. T. Finer, S. Chu, and J. A. Spudich, "Quantitative measurements of force and displacement using an optical trap," Biophys. J. 70, 1813-1822 (1996).
[CrossRef] [PubMed]

A. Ashkin, J. M. Dziedzic, J. E. Bjorkholm, and S. Chu, "Observation of a single-beam gradient force optical trap for dielectric particles," Opt. Lett. 11, 288-290 (1986).
[CrossRef] [PubMed]

Coirault, C.

C. Coirault, J. C. Pourny, F. Lambert, Y. Lecarpentier, "Optical tweezers in biology and medicine," Med.Sci. 19, 364-367 (2003).

Cox, R. G.

P. Vasseur and R. G. Cox, "The lateral migration of a spherical particle in two-dimensional shear flows," J. Fluid Mechanics 78, 385-413 (1976).
[CrossRef]

Culbertson, C. T.

D. P. Schrum, C. T. Culbertson, S. C. Jacobson, and J. M. Ramsey, "Microchip flow cytometry using electrokinetic focusing," Anal. Chem. 71, 4173-4177 (1999).
[CrossRef] [PubMed]

DiLuzio, W.

P. Garstecki, I. Gitlin, W. DiLuzio and G. M. Whitesides, "Formation of monodisperse bubbles in a microfluidic flow-focusing device," Appl. Phys. Lett. 85, 2649-2651 (2004).
[CrossRef]

Dutta, A.

U. S. Agarwal, A. Dutta, and R. A. Mashelkar, "Migration of macromolecules under flow: the physical origin and engineering implications," Chem. Eng. Sci. 49, 1693-1717 (1994).
[CrossRef]

Dziedzic, J. M.

Edgar, J. S.

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

Ermak, D. L.

D. L. Ermak and J. A. McCammon, "Brownian dynamics with hydrodynamic interactions," J. Chem. Phys. 69, 1352-1360 (1978).
[CrossRef]

Finer, J. T.

R. M. Simmons, J. T. Finer, S. Chu, and J. A. Spudich, "Quantitative measurements of force and displacement using an optical trap," Biophys. J. 70, 1813-1822 (1996).
[CrossRef] [PubMed]

Fong, C.

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

Fu, L. M.

C. H. Lin, G. B. Lee, L. M. Fu, and B. H. Hwey, "Vertical focusing device utilizing dielectrophoretic force and its application on microflow cytometer," J. Microelectromech. Syst. 13, 923-932 (2004).
[CrossRef]

Fujimoto, B. S.

C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
[CrossRef] [PubMed]

Garstecki, P.

S. Takeuchi, P. Garstecki, D. B. Weibel and G. M. Whitesides, "An axisymmetric flow-focusing microfluidic device," Adv. Mater. 17, 1067-1072 (2005).
[CrossRef]

P. Garstecki, I. Gitlin, W. DiLuzio and G. M. Whitesides, "Formation of monodisperse bubbles in a microfluidic flow-focusing device," Appl. Phys. Lett. 85, 2649-2651 (2004).
[CrossRef]

Gascoyne, P. R. C.

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

Gitlin, I.

P. Garstecki, I. Gitlin, W. DiLuzio and G. M. Whitesides, "Formation of monodisperse bubbles in a microfluidic flow-focusing device," Appl. Phys. Lett. 85, 2649-2651 (2004).
[CrossRef]

Goddard, G.

G. Goddard, J. C. Martin, S. W. Graves, and G. Kaduchak, "Ultrasonic particle-concentration for sheathless focusing of particles for analysis in a flow cytometer," Cytometry Part A,  69A, 66-74 (2006).
[CrossRef]

Graham, R.

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

Graves, S. W.

G. Goddard, J. C. Martin, S. W. Graves, and G. Kaduchak, "Ultrasonic particle-concentration for sheathless focusing of particles for analysis in a flow cytometer," Cytometry Part A,  69A, 66-74 (2006).
[CrossRef]

Groisman, A.

C. Simonnet and A. Groisman, "Two-dimensional hydrodynamic focusing in a simple microfluidic device," Appl. Phys. Lett. 87, 114104 (2005).
[CrossRef]

Growtherg, J. B.

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Han, C. S.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Harada, Y.

Y. Harada and T. Asakura, "Radiation forces on a dielectric sphere in the Rayleigh scattering regime," Opt. Commun. 124, 529-541 (1996).
[CrossRef]

Hsiung, S. K.

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

Huang, G. R.

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

Huh, D.

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Hung, C. I.

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

Hung, Y. C.

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

Hwei, B. H.

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

Hwey, B. H.

C. H. Lin, G. B. Lee, L. M. Fu, and B. H. Hwey, "Vertical focusing device utilizing dielectrophoretic force and its application on microflow cytometer," J. Microelectromech. Syst. 13, 923-932 (2004).
[CrossRef]

Jacobson, S. C.

D. P. Schrum, C. T. Culbertson, S. C. Jacobson, and J. M. Ramsey, "Microchip flow cytometry using electrokinetic focusing," Anal. Chem. 71, 4173-4177 (1999).
[CrossRef] [PubMed]

Jeffries, G. D. M.

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

Jeong, W. J.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Kaduchak, G.

G. Goddard, J. C. Martin, S. W. Graves, and G. Kaduchak, "Ultrasonic particle-concentration for sheathless focusing of particles for analysis in a flow cytometer," Cytometry Part A,  69A, 66-74 (2006).
[CrossRef]

Ke, B. J.

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

Kim, J. Y.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Kim, S.H.

H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
[CrossRef]

Knight, J. B.

J. B. Knight, A. Vishwanath, J. P. Brody, and R. H. Austin, "Hydrodynamic focusing on a silicon chip: Mixing nanoliters in microseconds," Phys. Rev. Lett. 80, 3863-3866 (1998).
[CrossRef]

Kumacheva, E.

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
[CrossRef] [PubMed]

Kurabayashi, K.

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Kuyper, C. L.

C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
[CrossRef] [PubMed]

Lai, H. F.

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

Lakshmanan, S. M.

N. M. Natarajan and S. M. Lakshmanan, "Laminar Flow in rectangular ducts: prediction of velocity profiles and friction factor," Indian J. Technol. 10, 435-438 (1972).

Lambert, F.

C. Coirault, J. C. Pourny, F. Lambert, Y. Lecarpentier, "Optical tweezers in biology and medicine," Med.Sci. 19, 364-367 (2003).

Lecarpentier, Y.

C. Coirault, J. C. Pourny, F. Lambert, Y. Lecarpentier, "Optical tweezers in biology and medicine," Med.Sci. 19, 364-367 (2003).

Lee, E. K.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Lee, G. B.

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

C. H. Lin, G. B. Lee, L. M. Fu, and B. H. Hwey, "Vertical focusing device utilizing dielectrophoretic force and its application on microflow cytometer," J. Microelectromech. Syst. 13, 923-932 (2004).
[CrossRef]

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

Lee, S. H.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Lee, S.H.

H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
[CrossRef]

Lewis, P. C.

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
[CrossRef] [PubMed]

Liao, T. L.

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

Lin, C. H.

C. H. Lin, G. B. Lee, L. M. Fu, and B. H. Hwey, "Vertical focusing device utilizing dielectrophoretic force and its application on microflow cytometer," J. Microelectromech. Syst. 13, 923-932 (2004).
[CrossRef]

Liphardt, J.

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

Marr, D.

Martin, J. C.

G. Goddard, J. C. Martin, S. W. Graves, and G. Kaduchak, "Ultrasonic particle-concentration for sheathless focusing of particles for analysis in a flow cytometer," Cytometry Part A,  69A, 66-74 (2006).
[CrossRef]

Mashelkar, R. A.

U. S. Agarwal, A. Dutta, and R. A. Mashelkar, "Migration of macromolecules under flow: the physical origin and engineering implications," Chem. Eng. Sci. 49, 1693-1717 (1994).
[CrossRef]

McCammon, J. A.

D. L. Ermak and J. A. McCammon, "Brownian dynamics with hydrodynamic interactions," J. Chem. Phys. 69, 1352-1360 (1978).
[CrossRef]

Meller, A.

T. Tlusty, A. Meller, R. Bar-Ziv, "Optical gradient forces of strongly localized fields," Phys. Rev. Lett. 81, 1738-1741 (1998).
[CrossRef]

Mok, M.

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

Natarajan, N. M.

N. M. Natarajan and S. M. Lakshmanan, "Laminar Flow in rectangular ducts: prediction of velocity profiles and friction factor," Indian J. Technol. 10, 435-438 (1972).

Nie, Z.

M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

Oakey, J.

Oh, H.J.

H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
[CrossRef]

Pauzauskie, P. J.

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

Pourny, J. C.

C. Coirault, J. C. Pourny, F. Lambert, Y. Lecarpentier, "Optical tweezers in biology and medicine," Med.Sci. 19, 364-367 (2003).

Radenovic, A.

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

Ramsey, J. M.

D. P. Schrum, C. T. Culbertson, S. C. Jacobson, and J. M. Ramsey, "Microchip flow cytometry using electrokinetic focusing," Anal. Chem. 71, 4173-4177 (1999).
[CrossRef] [PubMed]

Rohrbach, A.

A. Rohrbach, "Stiffness of optical traps: quantitative agreement between experiment and electromagnetic theory," Phys. Rev. Lett. 95, 168102 (2005).
[CrossRef] [PubMed]

Schiro, P. G.

C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
[CrossRef] [PubMed]

Schrum, D. P.

D. P. Schrum, C. T. Culbertson, S. C. Jacobson, and J. M. Ramsey, "Microchip flow cytometry using electrokinetic focusing," Anal. Chem. 71, 4173-4177 (1999).
[CrossRef] [PubMed]

Schwartz, J. A.

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

Seo, M.

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
[CrossRef] [PubMed]

Seong, G. H.

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

Seong, G.H.

H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
[CrossRef]

Shelby, J. P.

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

Shi, L.

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

Shroff, H.

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

Simmons, R. M.

R. M. Simmons, J. T. Finer, S. Chu, and J. A. Spudich, "Quantitative measurements of force and displacement using an optical trap," Biophys. J. 70, 1813-1822 (1996).
[CrossRef] [PubMed]

Simonnet, C.

C. Simonnet and A. Groisman, "Two-dimensional hydrodynamic focusing in a simple microfluidic device," Appl. Phys. Lett. 87, 114104 (2005).
[CrossRef]

Skerlos, S. J.

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Spudich, J. A.

R. M. Simmons, J. T. Finer, S. Chu, and J. A. Spudich, "Quantitative measurements of force and displacement using an optical trap," Biophys. J. 70, 1813-1822 (1996).
[CrossRef] [PubMed]

Squier, J.

Stone, H. A.

S. L. Anna, N. Bontoux, and H. A. Stone, "Formation of dispersions using "flow focusing" in microchannels," Appl. Phys. Lett. 82, 364-366 (2003).
[CrossRef]

Takayama, S.

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Takeuchi, S.

S. Takeuchi, P. Garstecki, D. B. Weibel and G. M. Whitesides, "An axisymmetric flow-focusing microfluidic device," Adv. Mater. 17, 1067-1072 (2005).
[CrossRef]

Tlusty, T.

T. Tlusty, A. Meller, R. Bar-Ziv, "Optical gradient forces of strongly localized fields," Phys. Rev. Lett. 81, 1738-1741 (1998).
[CrossRef]

Trepagnier, E.

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

Tung, Y.-C.

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Vasseur, P.

P. Vasseur and R. G. Cox, "The lateral migration of a spherical particle in two-dimensional shear flows," J. Fluid Mechanics 78, 385-413 (1976).
[CrossRef]

Vestad, T.

Vishwanath, A.

J. B. Knight, A. Vishwanath, J. P. Brody, and R. H. Austin, "Hydrodynamic focusing on a silicon chip: Mixing nanoliters in microseconds," Phys. Rev. Lett. 80, 3863-3866 (1998).
[CrossRef]

Vykoukal, D. M.

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

Vykoukal, J.

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

Wei, H.-H.

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Weibel, D. B.

S. Takeuchi, P. Garstecki, D. B. Weibel and G. M. Whitesides, "An axisymmetric flow-focusing microfluidic device," Adv. Mater. 17, 1067-1072 (2005).
[CrossRef]

Whitesides, G. M.

S. Takeuchi, P. Garstecki, D. B. Weibel and G. M. Whitesides, "An axisymmetric flow-focusing microfluidic device," Adv. Mater. 17, 1067-1072 (2005).
[CrossRef]

P. Garstecki, I. Gitlin, W. DiLuzio and G. M. Whitesides, "Formation of monodisperse bubbles in a microfluidic flow-focusing device," Appl. Phys. Lett. 85, 2649-2651 (2004).
[CrossRef]

Xu, S.

M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

Yang, P. D.

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

Yang, S. Y.

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

Yu, C. H.

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

Zhao, Y.

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
[CrossRef] [PubMed]

Adv. Mater.

S. Takeuchi, P. Garstecki, D. B. Weibel and G. M. Whitesides, "An axisymmetric flow-focusing microfluidic device," Adv. Mater. 17, 1067-1072 (2005).
[CrossRef]

Anal. Chem.

D. P. Schrum, C. T. Culbertson, S. C. Jacobson, and J. M. Ramsey, "Microchip flow cytometry using electrokinetic focusing," Anal. Chem. 71, 4173-4177 (1999).
[CrossRef] [PubMed]

Appl. Phys. Lett.

S. L. Anna, N. Bontoux, and H. A. Stone, "Formation of dispersions using "flow focusing" in microchannels," Appl. Phys. Lett. 82, 364-366 (2003).
[CrossRef]

P. Garstecki, I. Gitlin, W. DiLuzio and G. M. Whitesides, "Formation of monodisperse bubbles in a microfluidic flow-focusing device," Appl. Phys. Lett. 85, 2649-2651 (2004).
[CrossRef]

C. Simonnet and A. Groisman, "Two-dimensional hydrodynamic focusing in a simple microfluidic device," Appl. Phys. Lett. 87, 114104 (2005).
[CrossRef]

ASME J. Fluids Eng.

G. B. Lee, C. I. Hung, B. J. Ke, G. R. Huang, B. H. Hwei, and H. F. Lai, "Hydrodynamic focusing for a micromachined flow cytometer," ASME J. Fluids Eng. 123, 672-679 (2001).
[CrossRef]

Biomed. Microdevices

D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Growtherg, S. J. Skerlos, K. Kurabayashi, and S. Takayama, "Use of air-liquid two-phase flow in hydrophobic microfluidic channels for disposable flow cytometers," Biomed. Microdevices 4, 141-149 (2002).
[CrossRef]

Biophys. J.

R. M. Simmons, J. T. Finer, S. Chu, and J. A. Spudich, "Quantitative measurements of force and displacement using an optical trap," Biophys. J. 70, 1813-1822 (1996).
[CrossRef] [PubMed]

Chem. Eng. Sci.

U. S. Agarwal, A. Dutta, and R. A. Mashelkar, "Migration of macromolecules under flow: the physical origin and engineering implications," Chem. Eng. Sci. 49, 1693-1717 (1994).
[CrossRef]

Cytometry Part A

G. Goddard, J. C. Martin, S. W. Graves, and G. Kaduchak, "Ultrasonic particle-concentration for sheathless focusing of particles for analysis in a flow cytometer," Cytometry Part A,  69A, 66-74 (2006).
[CrossRef]

Indian J. Technol.

N. M. Natarajan and S. M. Lakshmanan, "Laminar Flow in rectangular ducts: prediction of velocity profiles and friction factor," Indian J. Technol. 10, 435-438 (1972).

J. Chem. Phys.

D. L. Ermak and J. A. McCammon, "Brownian dynamics with hydrodynamic interactions," J. Chem. Phys. 69, 1352-1360 (1978).
[CrossRef]

J. Fluid Mechanics

P. Vasseur and R. G. Cox, "The lateral migration of a spherical particle in two-dimensional shear flows," J. Fluid Mechanics 78, 385-413 (1976).
[CrossRef]

J. Microelectromech. Syst.

C. H. Lin, G. B. Lee, L. M. Fu, and B. H. Hwey, "Vertical focusing device utilizing dielectrophoretic force and its application on microflow cytometer," J. Microelectromech. Syst. 13, 923-932 (2004).
[CrossRef]

J. Microeletromech. Syst.

C. H. Yu, J. Vykoukal, D. M. Vykoukal, J. A. Schwartz, L. Shi, and P. R. C. Gascoyne, "Three-dimensional dielectrophoretic particle focusing channel for microcytometry applications," J. Microeletromech. Syst. 14, 480-487 (2005).
[CrossRef]

J. Micromech. Microeng.

H.J. Oh, S.H. Kim, J.Y. Baek, G.H. Seong and S.H. Lee, "Hydrodynamic micro-encapsulation of aqueous fluids and cells via ‘on the fly’ photopolymerization," J. Micromech. Microeng. 16, 285-291 (2006).
[CrossRef]

J. Phys. Chem. B

C. L. Kuyper, B. S. Fujimoto, Y. Zhao, P. G. Schiro, and D. T. Chiu, "Accurate sizing of nanoparticles using confocal correlation Spectroscopy," J. Phys. Chem. B 110, 24433-24441 (2006).
[CrossRef] [PubMed]

Langmuir

W. J. Jeong, J. Y. Kim, J. Choo, E. K. Lee, C. S. Han, D. J. Beebe, G. H. Seong, and S. H. Lee, "Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems," Langmuir 21, 3738-3741 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, P. C. Lewis, and E. Kumacheva, "Microfluidics: from dynamic lattices to periodic arrays of polymer disks," Langmuir 21, 4773-4775 (2005).
[CrossRef] [PubMed]

M. Seo, Z. Nie, S. Xu, M. Mok, P. C. Lewis, R. Graham and E. Kumacheva, "Continuous microfluidic reactors for polymer particles," Langmuir 21, 11614-11622 (2005).
[CrossRef] [PubMed]

Meas. Sci. Technol.

S. Y. Yang, S. K. Hsiung, Y. C. Hung, C. M. Chang, T. L. Liao, and G. B. Lee "A cell counting/sorting system incorporated with a microfabricated flow cytometer chip," Meas. Sci. Technol. 17, 2001-2009 (2006).
[CrossRef]

Nano Lett.

G. D. M. Jeffries, J. S. Edgar, Y. Zhao, J. P. Shelby, C. Fong, and D. T. Chiu, "Using polarization-shaped optical vortex traps for single-cell nanosurgery," Nano Lett. 7, 415-420 (2007).
[CrossRef] [PubMed]

Nat. Mater.

P. J. Pauzauskie, A. Radenovic, E. Trepagnier, H. Shroff, P. D. Yang, and J. Liphardt, "Optical trapping and integration of semiconductor nanowire assemblies in water," Nat. Mater. 5, 97-101 (2006).
[CrossRef] [PubMed]

Opt. Commun.

Y. Harada and T. Asakura, "Radiation forces on a dielectric sphere in the Rayleigh scattering regime," Opt. Commun. 124, 529-541 (1996).
[CrossRef]

Opt. Express

Opt. Lett.

Phys. Rev. Lett.

T. Tlusty, A. Meller, R. Bar-Ziv, "Optical gradient forces of strongly localized fields," Phys. Rev. Lett. 81, 1738-1741 (1998).
[CrossRef]

A. Rohrbach, "Stiffness of optical traps: quantitative agreement between experiment and electromagnetic theory," Phys. Rev. Lett. 95, 168102 (2005).
[CrossRef] [PubMed]

A. Ashkin, "Trapping of atoms by resonance radiation pressure," Phys. Rev. Lett. 40, 729-732 (1978).
[CrossRef]

J. B. Knight, A. Vishwanath, J. P. Brody, and R. H. Austin, "Hydrodynamic focusing on a silicon chip: Mixing nanoliters in microseconds," Phys. Rev. Lett. 80, 3863-3866 (1998).
[CrossRef]

Sci.

C. Coirault, J. C. Pourny, F. Lambert, Y. Lecarpentier, "Optical tweezers in biology and medicine," Med.Sci. 19, 364-367 (2003).

Other

J. G. Knudsen and D. L. Katz, Fluid dynamics and heat transfer (McGraw-Hill Book Co. Inc., New York 1958).

M. A. Van Dilla, Flow Cytometry: Instrumentation and Data Analysis (Academic, London, 1985).

M. R. Melamed, T. Lindmo, and M. L. Mendelsohn, Flow Cytometry and Sorting (New York, Wiley, 1991).

E. Altendorf, D. Zebert, M. Holl, and P. Yager, "Differential blood cell counts obtained using a microchannel based flow cytometer," in Proceedings of IEEE Conference on Solid-State Sensors and Actuators, Chicago, IL, 531-534 (1997).

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Figures (6)

Fig. 1.
Fig. 1.

(a). Schematic illustrating the scheme to achieve optical gradient flow focusing; note the coordinate system we used, where the x-axis is along the direction of fluid flow and the z-axis is along the direction of laser-beam propagation. (b)-(c). Distribution of the projected power density of the Gaussian beam on the x-y and the y-z plane.

Fig. 2.
Fig. 2.

(a). Simulated optical forces exerted on particles. Blue dash-dotted line: Fx at points along x axis; red dashed line: Fy at points along y axis; green solid line: Fz at points along z axis. (b). The corresponding potential energies due to optical trapping. Blue dash-dotted line: potential energy at points along x axis; red dashed line: potential energy at points along y axis; green solid line: potential energy at points along z axis.

Fig. 3.
Fig. 3.

The simulated flow trajectories of 100nm-diameter particles for electroosmotic flow (EOF) (a, b, c) and for pressure-driven flow (PDF) (d, e, f). The left (rectangular) side of each panel is a plot of 64 of the 1225 trajectories projected onto the x-y plane. The right (square) side of each panel is a plot showing where the 1225 trajectories cross the y-z plane at x =5μm. The different potential-well depths simulated are: (a, d) 10 kBT, (b, e) 20 kBT, and (c, f) 30 kBT.

Fig. 4.
Fig. 4.

The standard deviation (SD) of the trajectories of 100nm-diameter particles as they cross the plane at x =5μm [the right side of each panel in Figs. 3(a)–3(f)] for different depths of the potential well for both electroosmotic flow (EOF) and pressure-driven flow (PDF).

Fig. 5.
Fig. 5.

The simulated flow trajectories of nanoparticles for electroosmotic flow (EOF) (a, b, c) and pressure-driven flow (PDF) (d, e, f). On the left (rectangular) side of each panel is a plot of 64 of the 1225 trajectories projected onto the x-y plane. On the right side of each panel is a plot showing where the 1225 trajectories cross the y-z plane at x = 5μm. The highest power density of the focused laser beam is 8.5×1013 V 2/m 2 (which corresponds to a total power of the laser beam of ~ 3W). The diameters of the simulated nanoparticles are (a, d) 50nm, (b, e) 100nm, and (c, f) 200nm.

Fig. 6.
Fig. 6.

The standard deviation (SD) of the trajectories of nanoparticles as they cross the plane at x = 5μm (the right panel in Figs. 5(a)–5(f), as the diameter of the particles are increased from 50nm to 100nm and to 200nn. The highest power density at the laser focus is 8.5×1013 V 2/m 2 (which corresponds to a total power of ~ 3W at the laser focus). EOF: electroosmotic flow; PDF: pressure-driven flow

Equations (7)

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I x y z = A exp ( x ω x Nx y ω y Ny z ω z Nz ) 2 ,
F g ( r ) = π n f 2 ε 0 a 3 ( m 2 1 m 2 + 2 ) E ( r ) 2 ,
U ( r ) = r F ( s ) d s ,
r ( Δ t ) = r ( 0 ) + D F K B T Δ t + R ( Δ t ) ,
σ = 2 D Δ t .
F flow = 6 πηav ,
v x ( y , z ) v ¯ = ( m + 1 m ) ( n + 1 n ) [ 1 ( y y 0 ) m ] [ 1 ( z z 0 ) n ] ,

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