A diffusion-based cyclic particle extractor

  • 244 Accesses

  • 5 Citations


A cyclic particle extractor based on particle diffusion is presented. The extraction realized by the device features simplicity, programmability, and low cost. Although conventional particle separation based on diffusion can be spontaneously realized without any active inputs, the extraction efficiency decreases as the size difference between particles decreases or if the diffusion length is insufficient. In this article, a primary extraction procedure including four operational steps is proposed to facilitate the process. By simply repeating the procedure, the separation scheme is additive, and increased efficiency is observed with each additional cycle. A mixture of 0.5- and 3-μm polystyrene particles was separated in up to 10 extraction cycles. Using a 2.5-Hz phase frequency, the average flow velocity was 2.5 mm/s. An unequal volume ratio of the sample stream to extraction stream (45:55) created a barrier region to help minimize unwanted (large) particles from entering the extraction stream. The initial concentration of the extracted small particles was 7.5% after 2 cycles, but jumped up to 38% after 10 cycles.

This is a preview of subscription content, log in to check access.

Access options

Buy single article

Instant unlimited access to the full article PDF.

US$ 39.95

Price includes VAT for USA

Subscribe to journal

Immediate online access to all issues from 2019. Subscription will auto renew annually.

US$ 99

This is the net price. Taxes to be calculated in checkout.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15


  1. Atebcia J, Beebe DJ (2006) Steady flow generation in microcirculatory systems. Lab Chip 6:567–574

  2. Bhagat ASS, Kuntaegowdanahalli SS, Papautsky I (2008) Continuous particle separation in spiral microchannels using dean flows and differential migration. Lab Chip 8:1906–1914

  3. Bowden SA, Monaghan PB, Wilson R, Parnell J, Cooper JM (2006) The liquid-liquid diffusive extraction of hydrocarbons from a North Sea oil using a microfluidic format. Lab Chip 6:740–743

  4. Brody JP, Yager P (1997) Diffusion-based extraction in a microfabricated device. Sens Actuators A 58:13–18

  5. Brody JP, Osborne TD, Forster FK, Yager P (1996) A planar microfabricated fluid filter. Sens Actuators A 54:704–708

  6. Carbajal-Tinoco MD, Lopez-Fernandez R, Arauz-Lara L (2007) Assymetry in colloidal diffusion near a rigid wall. Phys Rev Lett 99:138303

  7. Cho BS, Schuster TG, Zhu X, Chang D, Smith GD, Takayama S (2003) Passively driven integrated microfluidic system for separation of motile sperm. Anal Chem 75(7):1671–1675

  8. Christensen AM, Chang-Yen DA, Gale BK (2005) Characterization of interconnects used in PDMS microfluidic systems. J Micromech Microeng 15:928–934

  9. Chuang HS, Wereley ST (2009a) Design, fabrication and characterization of a conducting PDMS for microheaters and temperature sensors. J Micromech Microeng 19:045010

  10. Chuang HS, Wereley ST (2009b) Rapid patterning of slurry-like elastomer composites using a laser-cut tape. J Micromech Microeng 19:097001

  11. Chuang HS, Amin AM, Wereley ST, Thottethodi M, Vijaykumar TN, Jacobson SC (2008) Polydimethylsiloxane (PDMS) peristaltic pump characterization for programmable lab-on-a-chip applications. In: Proceedings of the 12th international conference on miniaturized systems for chemistry and life Sciences (μTAS 2008), San Diego, CA

  12. Frej NA, Prieve DC (1993) Hindered diffusion of a single sphere very near a wall in a nonuniform force field. J Chem Phys 98:7552–7564

  13. Grafton MM, Geheb B, Jang JH, Chuang HS, Rajdev P, Reece LM, Irazoqui PP, Wereley ST, Jung B, Leary JF (2009) Microfabrication of a two-stage BioMEMS microfluidic cell sorter. Proc SPIE 7207:72070A

  14. Grover WH, Skelley AM, Liu CN, Lagally ET, Mathies RA (2003) Monolithic membrane valves and diaphragm pumps for practical large-scale integration into glass microfluidic devices. Sens Actuators B 89:315–323

  15. Haubert K, Drierb T, Beebe D (2006) PDMS bonding by means of a portable, low-cost corona system. Lab Chip 6:1548–1549

  16. Holl MR, Galambos P, Forster FK, Brody JP, Afromowitz M, Yager P (1996) Optimal design of a microfabricated diffusion-based extraction device. In: ASME on micro electromechanical systems, pp 183–189

  17. Huang P, Breuer KS (2007) Direct measurement of anisotropic near-wall hindered diffusion using total internal reflection velocimety. Phys Rev Lett E76:046307

  18. Kapishnikov S, Kantsler V, Steinberg V (2006) Continuous particle size separation and size sorting using ultrasound in a microchannel. J Stat Mech Theory Exp:P01012

  19. Kihm KD, Banerjee A, Choi CK, Takagi T (2004) Near-wall hindered Brownian diffusion of nanoparticles examined by three-dimensional ratiometric total internal reflection fluorescence microscopy (3-D R-TIRFM). Exp Fluids 37:811–824

  20. Kralj JG, Lis MTW, Schmidt MA, Jensen KF (2006) Continuous dielectrophoretic size-based particle sorting. Anal Chem 78:5019–5025

  21. Kumar A, Gorti VM, Shang H, Lee GU, Yip NK, Wereley ST (2008) Optical diffusometry techniques and applications in biological agent detection. J Fluids Eng 130(11):111401

  22. Lee GB, Lin CH, Chang SC (2005) Micromachine-based multi-channel flow cytometers for cell/particle counting and sorting. J Micromech Microeng 15:447–454

  23. Lillehoj P, Li N, Tsutsui H, Ho CH (2008) A compact microfluidic continuous flow separator for particle and cell sorting. In: MEMS 2008, IEEE, Tucson, AZ

  24. Lin CH, Lee CY, Tsai CH, Fu LM (2009) Novel continuous particle sorting in microfluidic chip utilizing cascaded squeeze effect. Microfluid Nanofluid 7(4):499–508

  25. Marc PJ, Sims CE, Allbritton NL (2007) Coaxial flow system for chemical cytometry. Anal Chem 79:9054–9059

  26. Niu X, Zhang M, Peng S, Wen W, Sheng P (2007) Real-time detection, control, and sorting of microfluidic droplets. Biomicrofluidics 1:044101

  27. Sadr R, Li H, Yoda M (2005) Impact of hindered Brownian diffusion on the accuracy of particle-image velocimetry using evanescent-wave illumination. Exp Fluids 38:90–98

  28. Williams SJ, Kumar A, Wereley ST (2008) Electrokinetic patterning of colloidal particles with optical landscapes. Lab Chip 8(11):1879–1882

  29. Yang SY, Hsiung SK, Hung YC, Chang CM, Liao TL, Lee GB (2006) A cell counting/sorting system incorporated with a microfabricated flow cytometer chip. Meas Sci Technol 17:2001–2009

Download references


The authors thank National Science Foundation grant NSF CCF-0726821 and NSF CCF-0726694 for support of this work. The authors also acknowledge the technical assistances from Purdue Birck Nanotechnology Center.

Author information

Correspondence to Steven T. Wereley.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (MPG 6842 kb)

Supplementary material 2 (MPG 3404 kb)

Supplementary material 1 (MPG 6842 kb)

Supplementary material 2 (MPG 3404 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Chuang, H., Jacobson, S.C. & Wereley, S.T. A diffusion-based cyclic particle extractor. Microfluid Nanofluid 9, 743–753 (2010) doi:10.1007/s10404-010-0589-0

Download citation


  • Diffusion
  • Particle sorting
  • Extraction
  • H filter
  • PDMS
  • Lab-on-a-chip