Biomedical Microdevices

, Volume 10, Issue 1, pp 55–63 | Cite as

Microfluidic cell counter/sorter utilizing multiple particle tracing technique and optically switching approach



This paper proposes a novel microfluidic system based on a computer controlled digital image processing (DIP) technique and optical tweezers for automatic cell/microparticle recognition, counting and sorting in a continuous flow environment. In the proposed system, the cells/microparticles are focused electrokinetically into a narrow sample stream and are then driven through the region of interest (ROI), where they are recognized and traced in real time using a proprietary DIP system. Synchronized control signals generated by the DIP system are then used to actuate a focused IR laser beam to displace the target cells from the main sample stream into a neighboring sheath flow, which carries them to a downstream collection channel where they are automatically counted. Experimental trials show that the microchip is capable of continuously sorting and counting microparticles with diameters of 5 and 10 μm. In addition, a sample composed of yeast cells and polystyrene (PS) beads is successfully sorted and collected with a 100% of yield ratio and 91.9% of recovery ratio. The proposed system provides a simple, low-cost, high-performance solution for cell manipulation in microfluidic devices.


Microfluidics Microparticle Digital image processing Electrokinetic focus Optical tweezers 


\( \overline{V} \)

particle velocity within the electric-driven flow (pixel/s)

\( \overline{u} \)

particle velocity in the x-axis direction within the electric-driven flow (pixel/s)

\( \overline{v} \)

particle velocity in the y-axis direction within the electric-driven flow (pixel/s)


particle position (pixel)


time (s)


time interval between two consequent image frame (s)


viscosity of the buffer liquid (N·s/m2)


fluid velocity of the electric-driven flow (m/s)


radius of particle



buffered oxide etchant


charge coupled device


deionized water


digital image processing


fluorescence-activated cell sorters


hydrogen chloride


human–machine interface




laser induced fluorescence






numerical aperture


personal computer


region of interest





Financial supports from the National Science Council of Taiwan are acknowledged. (NSC 95-2314-B-110-002-MY3).


  1. A. Ashkin, J.M. Dziedzic, J.E. Bjorkholm, S. Chu, Opt. Lett., 11, 288 (1986)CrossRefGoogle Scholar
  2. B.S. Edwards, T. Oprea, E.R. Prossnitz, L.A. Sklar, Curr. Opin. Chem. Biol. 8, 392 (2004)CrossRefGoogle Scholar
  3. J. Enger, M. Goksör, K. Ramser, P. Hagberg, D. Hanstorp, Lab Chip, 4, 196 (2004)CrossRefGoogle Scholar
  4. E. Fallman, S. Schedin, J. Jass, M. Andersson, B.E. Uhlin, O. Axner, Biosens. Bioelectron. 19, 1429 (2004)CrossRefGoogle Scholar
  5. S. Fiedler, S.G. Shirley, T. Schnelle, G. Fuhr, Anal. Chem. 70, 1909 (1998)CrossRefGoogle Scholar
  6. A.Y. Fu, C. Spence, A. Scherer, F.H. Arnold, S.R. Quake, Nat. Biotechnol. 17, 1109 (1999)CrossRefGoogle Scholar
  7. D. Holmes, H. Morgan, N.G. Green, Biosens. Bioelectron. 21, 1621 (2006)CrossRefGoogle Scholar
  8. A. Ishijima, H. Kojima, T. Funatsu, M. Tokunaga, H. Higuchi, H. Tanaka, T. Yanagida, Cell 92, 161 (1998)CrossRefGoogle Scholar
  9. G.B. Lee, C.H. Lin, S.C. Chang, J. Micromechanics Microengineering 15, 447 (2005)CrossRefGoogle Scholar
  10. P.C.H. Li, D.J. Harrison, Anal. Chem. 69, 1564 (1997)CrossRefGoogle Scholar
  11. C.H. Lin, G.B. Lee, J. Micromechanics Microengineering 13, 447 (2003)CrossRefMathSciNetGoogle Scholar
  12. C.H. Lin, G.B. Lee, L.M. Fu, B.H. Hwey, Journal of Microelectromechanical Systems 13, 923 (2004)CrossRefGoogle Scholar
  13. C.H. Lin, G.B. Lee, Y.H. Lin, G.L. Chang, J. Micromechanics Microengineering 11, 726 (2001)CrossRefGoogle Scholar
  14. N.H. Maerz, Proc. 6th Annual Symposium ICAR, 195 (1998)Google Scholar
  15. C. Mio, T. Gong, A. Terray, D.W.M. Marr, Rev. Sci. Instrum. 71, 2196 (2000)CrossRefGoogle Scholar
  16. S. Shoji, Electron. Commun. Jpn. 2, 82, 21 (1999)CrossRefGoogle Scholar
  17. F. Vajda, Mathematical Modelling and Simulation of Industrial and Economic Processes, IEE Colloquium on 1/1 (1994).Google Scholar
  18. M.M. Wang, E. Tu, D.E. Raymond, J.M. Yang, H.C. Zhang, N. Hagen, B. Dees, E.M. Mercer, A.H. Forster, I. Kariv, P.J. Marchand, W.F. Butler, Nat. Biotechnol. 23, 83 (2005)CrossRefGoogle Scholar
  19. J. Wietzorrek, M. Stadler,V. Kachel, Oceans Engineering for Today’s Technology and Tomorrow’s Preservation 1, I/688 (1994).Google Scholar
  20. H.-S. Wu, J. Barba, J. Gil, IEEE Trans. Biomed. Eng. 45, 400 (1998)CrossRefGoogle Scholar
  21. C.Q. Yi, C.W. Li, S.L. Ji, M.S. Yang, Anal. Chim. Acta 560, 1 (2006)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  1. 1.Department of Mechanical and Electro-mechanical EngineeringNational Sun Yat-sen UniversityKaohsiungRepublic of China
  2. 2.Institute of Biomedical SciencesNational Sun Yat-sen UniversityKaohsiungRepublic of China
  3. 3.Advanced Crystal Opto-electronics Research CenterNational Sun Yat-sen UniversityKaohsiungRepublic of China

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