Microfluidics and Nanofluidics

, Volume 10, Issue 5, pp 1097–1107 | Cite as

Reliable magnetic reversible assembly of complex microfluidic devices: fabrication, characterization, and biological validation

  • Marco Rasponi
  • Francesco Piraino
  • Nasser Sadr
  • Matteo Laganà
  • Alberto Redaelli
  • Matteo Moretti
Original Paper


Current standard procedures for fabrication of microfluidic devices combine polydimethylsiloxane (PDMS) replica molding with subsequent plasma treatment to obtain an irreversible sealing onto a glass/silicon substrate. However, irreversible sealing introduces several limitations to applications and internal accessibility of such devices as well as to the choice of materials for fabrication. In the present work, we describe and characterize a reliable, flexible and cost effective approach to fabricate devices that reversibly adhere to a substrate by taking advantage of magnetic forces. This is shown by implementing a PDMS/iron micropowder layer aligned onto a microfluidic layer and coupled with a histology glass slide, in union with either temporary or continuous use of a permanent magnet. To better represent the complexity of microfluidic devices, a Y-shaped configuration including lower scale parallel channels on each branch has been employed as reference geometry. To correctly evaluate our system, current sealing methods have been reproduced on the reference geometry. Sealing experiments (pressure control, flow control and hydraulic characterization) have been carried out, showing consistent increases in terms of maximum achievable flow rates and pressures, as compared to devices obtained with other available reversible techniques. Moreover, no differences were detected between cells cultured on our magnetic devices as compared to cells cultured on permanently sealed devices. Disassembly of our devices for analyses allowed to stain cells by hematoxylin and eosin and for F-actin, following traditional histological processes and protocols. In conclusion, we present a method allowing reversible sealing of microfluidic devices characterized by compatibility with: (i) complex fluidic layer configurations, (ii) micrometer sized channels, and (iii) optical transparency in the channel regions for flow visualization and inspection.


Microfluidics Reversible bonding Magnetism Micropowder Chondrocyte 



The authors appreciate helpful conversations with Dr Giancarlo Franceschetti, who made important contributions to the formative stages of this research. The authors also thank Mara Licini, Clara Nozza, Alice Sormani and Lia Volpatti for their valuable help during hydraulic measurements. This work was partially supported by Cariplo Foundation grant # 2008-2531 and Progetto Roberto Rocca.


  1. Abgrall P, Lattes C, Conédéra V, Dollat X, Colin S, Gué AM (2006) A novel fabrication method of flexible and monolithic 3d microfluidic structures using lamination of. J Micromech Microeng 16(1):113–121CrossRefGoogle Scholar
  2. Arroyo MT, Fernàndez LJ, Agirregabiria M, Ibañez N, Aurrekoetxea J, Blanco FJ (2007) Novel all-polymer microfluidic devices monolithically integrated within metallic electrodes for sds-cge of proteins. J Micromech Microeng 17(7):1289–1298CrossRefGoogle Scholar
  3. Becker H, Gartner C (2000) Polymer microfabrication methods for microfluidic analytical applications. Electrophoresis 21(1):12–26. doi: 10.1002/(SICI)1522-2683(20000101)21:1<12:AID-ELPS12>3.0.CO;2-7 CrossRefGoogle Scholar
  4. Brown L, Koerner T, Horton JH, Oleschuk RD (2006) Fabrication and characterization of poly(methylmethacrylate) microfluidic devices bonded using surface modifications and solvents. Lab Chip 6(1):66–73. doi: 10.1039/b512179e CrossRefGoogle Scholar
  5. Brydson J (1999) Plastics materials, 7th edn. Elsevier, AmsterdamGoogle Scholar
  6. Buch JS, Kimball C, Rosenberger F, Highsmith WE Jr, DeVoe DL, Lee CS (2004) DNA mutation detection in a polymer microfluidic network using temperature gradient gel electrophoresis. Anal Chem 76(4):874–881. doi: 10.1021/ac034913y CrossRefGoogle Scholar
  7. Dang F, Shinohara S, Tabata O, Yamaoka Y, Kurokawa M, Shinohara Y, Ishikawa M, Baba Y (2005) Replica multichannel polymer chips with a network of sacrificial channels sealed by adhesive printing method. Lab Chip 5(4):472–478. doi: 10.1039/b417398h CrossRefGoogle Scholar
  8. Démarteau O, Wendt D, Braccini A, Jakob M, Schafer D, Heberer M, Martin I (2003) Dynamic compression of cartilage constructs engineered from expanded human articular chondrocytes. Biochem Biophys Res Commun 310(2):580–588. doi: S0006291X03018655 CrossRefGoogle Scholar
  9. Fischer AH, Jacobson KA, Rose J, Zeller R (2008) Media for mounting fixed cells on microscope slides. Cold Spring Harb Protoc 4. doi: 10.1101/pdb.ip52
  10. Griebel A, Rund S, Schonfeld F, Dorner W, Konrad R, Hardt S (2004) Integrated polymer chip for two-dimensional capillary gel electrophoresis. Lab Chip 4(1):18–23. doi: 10.1039/b311032j CrossRefGoogle Scholar
  11. Herold KE, Rasooly A (2009) Lab-on-a-chip technology, vol 1: fabrication and microfluidics. Caister Academic Press, NorfolkGoogle Scholar
  12. Hromada LP, Nablo BJ, Kasianowicz JJ, Gaitan MA, DeVoe DL (2008) Single molecule measurements within individual membrane-bound ion channels using a polymer-based bilayer lipid membrane chip. Lab Chip 8(4):602–608. doi: 10.1039/b716388f CrossRefGoogle Scholar
  13. Huang FC, Chen YF, Lee GB (2007) Ce chips fabricated by injection molding and polyethylene/thermoplastic elastomer film packaging methods. Electrophoresis 28(7):1130–1137. doi: 10.1002/elps.200600351 CrossRefGoogle Scholar
  14. Jakob M, Demarteau O, Schafer D, Hintermann B, Dick W, Heberer M, Martin I (2001) Specific growth factors during the expansion and redifferentiation of adult human articular chondrocytes enhance chondrogenesis and cartilaginous tissue formation in vitro. J Cell Biochem 81(2):368–377. doi: 10.1002/1097-4644(20010501)81:2<368:AID-JCB1051>3.0.CO;2-J CrossRefGoogle Scholar
  15. Jang K, Sato K, Igawa K, Chung U-i, Kitamori T (2008) Development of an osteoblast-based 3d continuous-perfusion microfluidic system for drug screening. Anal Bioanal Chem 390(3):825–832. doi: 10.1007/s00216-007-1752-7 CrossRefGoogle Scholar
  16. Johansson BL, Larsson A, Ocklind A, Öhrlund Å (2002) Characterization of air plasma-treated polymer surfaces by ESCA and contact angle measurements for optimization of surface stability and cell growth. J Appl Polym Sci 86(10):2618–2625. doi: 10.1002/app.11209 CrossRefGoogle Scholar
  17. Khademhosseini A, Yeh J, Eng G, Karp J, Kaji H, Borenstein J, Farokhzad OC, Langer R (2005) Cell docking inside microwells within reversibly sealed microfluidic channels for fabricating multiphenotype cell arrays. Lab Chip 5(12):1380–1386. doi: 10.1039/b508096g CrossRefGoogle Scholar
  18. Le Berre M, Crozatier C, Velve Casquillas G, Chen Y (2006) Reversible assembling of microfluidic devices by aspiration. Microelectron Eng 83(4–9):1284–1287. doi: 10.1016/j.mee.2006.01.257 CrossRefGoogle Scholar
  19. Li L, Ismagilov RF (2010) Protein crystallization using microfluidic technologies based on valves, droplets, and slipchip. Annu Rev Biophys 39(1):139–158. doi: 10.1146/annurev.biophys.050708.133630 CrossRefGoogle Scholar
  20. McDonald JC, Duffy DC, Anderson JR, Chiu DT, Wu H, Schueller OJ, Whitesides GM (2000) Fabrication of microfluidic systems in poly(dimethylsiloxane). Electrophoresis 21(1):27–40. doi: 10.1002/(SICI)1522-2683(20000101)21:1<27:AID-ELPS27>3.0.CO;2-C CrossRefGoogle Scholar
  21. Ong SM, Zhang C, Toh YC, Kim SH, Foo HL, Tan CH, van Noort D, Park S, Yu H (2008) A gel-free 3d microfluidic cell culture system. Biomaterials 29(22):3237–3244. doi: 10.1016/j.biomaterials.2008.04.022 CrossRefGoogle Scholar
  22. Pocius A (2002) Adhesion and adhesives technology: an introduction, 2nd edn. Hanser/Gardner Publications, CincinnatiGoogle Scholar
  23. Rafat M, Raad DR, Rowat AC, Auguste DT (2009) Fabrication of reversibly adhesive fluidic devices using magnetism. Lab Chip 9(20):3016–3019. doi: 10.1039/b907957b CrossRefGoogle Scholar
  24. Rodriguez-Villarreal AI, Arundell M, Carmona M, Samitier J (2010) High flow rate microfluidic device for blood plasma separation using a range of temperatures. Lab Chip 10(2):211–219. doi: 10.1039/b904531g CrossRefGoogle Scholar
  25. Rötting O, Röpke W, Becker H, Gärtner C (2002) Polymer microfabrication technologies. Microsyst Technol 8(1):32–36. doi: 10.1007/s00542-002-0106-9 CrossRefGoogle Scholar
  26. Shenton MJ et al (2001) Adhesion enhancement of polymer surfaces by atmospheric plasma treatment. J Phys D 34(18):2754–2760CrossRefGoogle Scholar
  27. Sui G, Lee CC, Kamei K, Li HJ, Wang JY, Wang J, Herschman HR, Tseng HR (2007) A microfluidic platform for sequential ligand labeling and cell binding analysis. Biomed Microdev 9(3):301–305CrossRefGoogle Scholar
  28. Sun Y, Kwok YC, Nguyen N-T (2006) Low-pressure, high-temperature thermal bonding of polymeric microfluidic devices and their applications for electrophoretic separation. J Micromech Microeng 16(8):1681–1688CrossRefGoogle Scholar
  29. Taberham A, Kraft M, Mowlem M, Morgan H (2008) The fabrication of lab-on-chip devices from fluoropolymers. J Micromech Microeng 18(6):064011CrossRefGoogle Scholar
  30. Unger MA, Chou HP, Thorsen T, Scherer A, Quake SR (2000) Monolithic microfabricated valves and pumps by multilayer soft lithography. Science 288(5463):113–116. doi: 10.1126/science.288.5463.113 CrossRefGoogle Scholar
  31. Wallow TI, Morales AM, Simmons BA, Hunter MC, Krafcik KL, Domeier LA, Sickafoose SM, Patel KD, Gardea A (2007) Low-distortion, high-strength bonding of thermoplastic microfluidic devices employing case-ii diffusion-mediated permeant activation. Lab Chip 7(12):1825–1831. doi: 10.1039/b710175a CrossRefGoogle Scholar
  32. Xia Y, Whitesides GM (1998) Soft lithography. Annu Rev Mat Sci 28:153–184. doi: 10.1146/annurev.matsci.28.1.153 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Marco Rasponi
    • 1
  • Francesco Piraino
    • 1
  • Nasser Sadr
    • 2
  • Matteo Laganà
    • 3
  • Alberto Redaelli
    • 1
  • Matteo Moretti
    • 2
    • 3
  1. 1.Bioengineering DepartmentPolitecnico Di MilanoMilanItaly
  2. 2.IRCCS Istituto Ortopedico GaleazziMilanItaly
  3. 3.Gruppo Ospedaliero San Donato FoundationMilanItaly

Personalised recommendations