Microfluidics and Nanofluidics

, Volume 10, Issue 6, pp 1247–1256

Application of reconfigurable pinhole mask with excimer laser to fabricate microfluidic components

  • Kevin Conlisk
  • Sébastian Favre
  • Theo Lasser
  • Gerard M. O’Connor
Article

Abstract

An excimer laser incorporating a reconfigurable intelligent pinhole mask (IPM) is demonstrated for the fabrication of microfluidic geometries on a poly(methyl methacrylate) substrate. Beam reconfiguration techniques are used to overcome some of the drawbacks associated with traditional scanning laser ablation through a static mask. The production of zero lead-in (ZLI) features are described, where the ramp lead-in angle—inherent to scanning laser ablation—is reduced to be in line with the cross-sectional side-wall angle of the microchannel itself. The technique is applied to eliminate under-cutting and ramping at channel junctions—features resulting from scanning ablation through a fixed mask—and produce flat crossing sections, junctions and inlets. The development of a prediction model for microchannel visualisation and refinement prior to the fabrication step is also described. The model includes variables from the IPM, laser, scanning stage and material etch rate allowing quantitative measurement of generated microchannel geometry. One application of the model is the development of microchannel mixing geometry which is analysed using computational fluid dynamic (CFD) techniques. For this purpose, the effect of varying the overall channel geometry on mixing within a microchannel was investigated for flows with low Reynolds numbers. The resulting geometry is found to reduce the distance required for mixing by 50% in comparison to a straight planar channel, thereby enabling smaller device geometries.

Keywords

Excimer laser Intelligent pinhole mask Microfluidic mixer Prediction model PMMA 

References

  1. Abdelgawad M, Watson M, Young E, Mudrik J, Ungrin M, Wheeler A (2008) Soft lithography: masters on demand. Lab Chip 8:1379–1385CrossRefGoogle Scholar
  2. Becker H, Gartner C (2008) Polymer microfabrication technologies for microfluidic systems. Anal Bioanal Chem 390:89–111CrossRefGoogle Scholar
  3. Bhagat A, Peterson E, Papautsky I (2007) A passive planar micromixer with obstructions for mixing at low reynolds numbers. JMM 17:1017–1024Google Scholar
  4. Chong A, Jin-Woo C (2004) Springer handbook of nanotechnology. Springer, New YorkGoogle Scholar
  5. Chung C, Shih T (2008) Effect of geometry on fluid mixing of the rhombic micromixers. Microfluid Nanofluid 4:419–425CrossRefGoogle Scholar
  6. Gower MC (1999) Excimer laser micromachining: a 15-year perspective. In: Proceedings of laser applications in microelectronic and optoelectronic manufacturing IV, vol 3618, San Jose, CA, USA, pp 251–261. SPIEGoogle Scholar
  7. Heng Q, Tao C, Tie-chuan Z (2006) Surface roughness analysis and improvement of micro-fluidic channel with excimer laser. Microfluid Nanofluid 2:357–360CrossRefGoogle Scholar
  8. Hong TF, Ju WJ, Wu MC, Tai CH, Tsai CH, Fu LM (2010) Rapid prototyping of pmma microfluidic chips utilizing a CO2 laser. Microfluid Nanofluid 9(6):1125–1133Google Scholar
  9. Khan Malek C (2006a) Laser processing for bio-microfluidics applications (part I). Anal Bioanal Chem 385:1351–1361CrossRefGoogle Scholar
  10. Khan Malek C (2006b) Laser processing for bio-microfluidics applications (part II). Anal Bioanal Chem 385:1362–1369CrossRefGoogle Scholar
  11. Klank H, Kutter J, Geschke O (2002) CO2-laser micromachining and back-end processing for rapid production of pmma-based microfluidic systems. Lab Chip 2:242–246CrossRefGoogle Scholar
  12. Li C, Yang J, Tzang C, Zhao J, Yang M (2006) Using thermally printed transparency as photomasks to generate microfluidic structures in pdms material. Sens Actuators A 126:463–468CrossRefGoogle Scholar
  13. Lim D, Kamotani Y, Cho B, Mazumder J, Takayama S (2003) Fabrication of microfluidic mixers and artificial vasculatures using a high-brightness diode-pumped Nd:YAG laser direct write method. Lab Chip 3:318–323CrossRefGoogle Scholar
  14. Liu A, He F, Wang K, Zhou T, Lu Y, Xia X (2005) Rapid method for design and fabrication of passive micromixers in microfluidic devices using a direct-printing process. Lab Chip 5:974–978CrossRefGoogle Scholar
  15. Lucio do Lago C, Torres da Silva H, Neves C, Alves Brito-Neto J, Fracassi da Silva J (2003) A dry process for production of microfluidic devices based on the lamination of laser-printed polyester films. Anal Chem 75:3853–3858CrossRefGoogle Scholar
  16. Nguyen NT, Wu Z (2005) Micromixers—a review. J Micromech Microeng 15(2):R1CrossRefGoogle Scholar
  17. Pfleging W, Kohler R, Schierjott P, Hoffmann W (2009) Laser patterning and packaging of CCD-CE-chips made of pmma. Sens Actuators B 138:336–343CrossRefGoogle Scholar
  18. Rizvi NH (1999) Production of novel 3d microstructures using excimer laser mask projection techniques. In: Proceedings of design, test, and microfabrication of MEMS and MOEMS, vol 3680, Paris, France, pp 546–552. SPIEGoogle Scholar
  19. Roberts M, Rossier J, Bercier P, Girault H (1997) Uv laser machined polymer substrates for the development of microdiagnostic systems. Anal Chem 69:2035–2042CrossRefGoogle Scholar
  20. Shih T, Chung C (2007) A high-efficiency planar micromixer with convection and diffusion mixing over a wide reynolds number range. Microfluid Nanofluid 5(2):175–183Google Scholar
  21. Shim J, Nikcevic I, Rust M, Bhagat A, Heineman W, Seliskar C, Ahn C, Papautsky I (2007) Simple passive micromixer using recombinant multiple flow streams. In: Proceedings of microfluidics, BioMEMS, and medical microsystems, V, vol 6465, p 64650Y. SPIEGoogle Scholar
  22. Sidler T, Favre S, Lopez A, Gianotti R, Lasser T, Wolleschensky R (2004) Intelligent pinhole with sub-micrometer resolution. In: Proceedings of the 13th international conference on microoptics (MOC’04), Jena, GermanyGoogle Scholar
  23. Stroock A, Dertinger S, Ajdari A, Mezic I, Stone H, Whitesides G (2002) Chaotic mixer for microchannels. Science 295:647–651CrossRefGoogle Scholar
  24. Tan A, Rodgers K, Murrihy J, OMathuna C, Glennon J (2001) Rapid fabrication of microfluidic devices in poly(dimethylsiloxane) by photocopying. Lab Chip 1:7–9CrossRefGoogle Scholar
  25. Waddell E, Locascio L, Kramer G (2002) Uv laser micromachining of polymers for microfluidic applications. ALA 7:78–82Google Scholar
  26. Yoshida Y (2007) Fabrication of bio-chips by laser ablation. In: Proceedings of photon processing in microelectronics and photonics VI, vol 6458, p 64580A–8 San Jose, CA, USA. SPIEGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Kevin Conlisk
    • 1
  • Sébastian Favre
    • 2
  • Theo Lasser
    • 3
  • Gerard M. O’Connor
    • 1
  1. 1.National Centre for Laser Applications, School of PhysicsNational University of Ireland GalwayGalwayIreland
  2. 2.Swiss Manufacturing OperationMedtronicSwitzerland
  3. 3.BM 5143 (Btiment BM)LausanneSwitzerland

Personalised recommendations