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Microfluidic sorting in an optical lattice

Abstract

The response of a microscopic dielectric object to an applied light field can profoundly affect its kinetic motion1. A classic example of this is an optical trap, which can hold a particle in a tightly focused light beam2. Optical fields can also be used to arrange, guide or deflect particles in appropriate light-field geometries3,4. Here we demonstrate an optical sorter for microscopic particles that exploits the interaction of particles—biological or otherwise—with an extended, interlinked, dynamically reconfigurable, three-dimensional optical lattice. The strength of this interaction with the lattice sites depends on the optical polarizability of the particles, giving tunable selection criteria. We demonstrate both sorting by size (of protein microcapsule drug delivery agents) and sorting by refractive index (of other colloidal particle streams). The sorting efficiency of this method approaches 100%, with values of 96% or more observed even for concentrated solutions with throughputs exceeding those reported for fluorescence-activated cell sorting5. This powerful, non-invasive technique is suited to sorting and fractionation within integrated (‘lab-on-a-chip’) microfluidic systems, and can be applied in colloidal, molecular and biological research.

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Figure 1: The concept of optical fractionation.
Figure 2: Separation by index of refraction.
Figure 3: Typical efficiencies.
Figure 4: Optical fractionation by size.

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References

  1. Tatarkova, S. A., Sibbett, W. & Dholakia, K. Brownian particle in an optical potential of the washboard type. Phys. Rev. Lett. 91, 038101 (2003)

    Article  ADS  Google Scholar 

  2. Ashkin, A., Dziedzic, J. M., Bjorkholm, J. E. & Chu, S. Observation of a single-beam gradient force optical trap for dielectric particles. Opt. Lett. 11, 288–290 (1986)

    Article  ADS  CAS  Google Scholar 

  3. Burns, M. M., Fournier, J. M. & Golovchenko, J. A. Optical matter—crystallization and binding in intense optical-fields. Science 249, 749–754 (1990)

    Article  ADS  CAS  Google Scholar 

  4. Korda, P. T., Taylor, M. B. & Grier, D. G. Kinetically locked-in colloidal transport in an array of optical tweezers. Phys. Rev. Lett. 89, 128301 (2002)

    Article  ADS  Google Scholar 

  5. Fu, A. Y., Spence, C., Scherer, A., Arnold, F. H. & Quake, S. R. A microfabricated fluorescence-activated cell sorter. Nature Biotechnol. 17, 1109–1111 (1999)

    Article  CAS  Google Scholar 

  6. Han, J. & Craighead, H. G. Separation of long DNA molecules in a microfabricated entropic trap array. Science 288, 1026–1029 (2000)

    Article  ADS  CAS  Google Scholar 

  7. Nykypanchuk, D., Strey, H. H. & Hoagland, D. A. Brownian motion of DNA confined within a two-dimensional array. Science 297, 987–990 (2002)

    Article  ADS  CAS  Google Scholar 

  8. Ertas, D. Lateral separation of macromolecules and polyelectrolytes in microlithographic arrays. Phys. Rev. Lett. 80, 1548–1551 (1998)

    Article  ADS  CAS  Google Scholar 

  9. Duke, T. A. J. & Austin, R. H. Microfabricated sieve for the continuous sorting of macromolecules. Phys. Rev. Lett. 80, 1552–1555 (1998)

    Article  ADS  CAS  Google Scholar 

  10. Chou, C. F. et al. Electrodeless dielectrophoresis of single- and double-stranded DNA. Biophys. J. 83, 2170–2179 (2002)

    Article  ADS  CAS  Google Scholar 

  11. Galbraith, D. W., Anderson, M. T. & Herzenberg, L. A. in Methods in Cell Biology Vol. 58 (eds Sullivan, K. F. & Kay, S. A.) 315–341 (Academic, London, 1999)

    Google Scholar 

  12. Athanasopoulou, A., Koliadima, A. & Karaiskakis, G. New methodologies of field-flow fractionation for the separation and characterization of dilute colloidal samples. Instrum. Sci. Technol. 24, 79–94 (1996)

    Article  CAS  Google Scholar 

  13. Dholakia, K., Spalding, G. C. & MacDonald, M. Optical tweezers: The next generation. Phys. World 15, 31–35 (2002)

    Article  CAS  Google Scholar 

  14. MacDonald, M. P. et al. Creation and manipulation of three-dimensional optically trapped structures. Science 296, 1101–1103 (2002)

    Article  ADS  CAS  Google Scholar 

  15. Greiner, M., Mandel, O., Esslinger, T., Hansch, T. W. & Bloch, I. Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms. Nature 415, 39–44 (2002)

    Article  ADS  CAS  Google Scholar 

  16. Korda, P. T., Spalding, G. C. & Grier, D. G. Evolution of a colloidal critical state in an optical pinning potential landscape. Phys. Rev. B 66, 024504 (2002)

    Article  ADS  Google Scholar 

  17. Crocker, J. C. & Grier, D. G. Methods of digital video microscopy for colloidal studies. J. Colloid Interface Sci. 179, 298–310 (1996)

    Article  ADS  CAS  Google Scholar 

  18. MacDonald, M. P., Spalding, G. C. & Dholakia, K. Transport and fractionation of brownian particles in an optical lattice. Phys. Rev. Lett. (submitted)

  19. Imasaka, T., Kawabata, Y., Kaneta, T. & Ishidzu, Y. Optical chromatography. Anal. Chem. 67, 1763–1765 (1995)

    Article  CAS  Google Scholar 

  20. Marmottant, P. & Hilgenfeldt, S. Controlled vesicle deformation and lysis by single oscillating bubbles. Nature 423, 153–156 (2003)

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

We thank P. Campbell for supplying protein microcapsules, and A. Riches for blood samples. This work was supported by the UK Engineering and Physical Sciences Research Council, the Research Corporation, and the National Science Foundation.

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Correspondence to M. P. MacDonald.

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MacDonald, M., Spalding, G. & Dholakia, K. Microfluidic sorting in an optical lattice. Nature 426, 421–424 (2003). https://doi.org/10.1038/nature02144

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