Microfluidics and Nanofluidics

, Volume 5, Issue 4, pp 479–491 | Cite as

Temperature modeling and measurement of an electrokinetic separation chip

  • Tiina SikanenEmail author
  • Thomas Zwinger
  • Santeri Tuomikoski
  • Sami Franssila
  • Reijo Lehtiniemi
  • Carl-Magnus Fager
  • Tapio Kotiaho
  • Antti Pursula
Research Paper


This work presents experimental [infrared (IR) thermography] and computational (finite element model) results of temperature distributions of an electrokinetic separation chip. Thermal characteristics of both the electrolyte solution and the polymer chip (SU-8) are taken into account in modeling temperature distributions during electrokinetic flow. Multiphysics and multiscale simulation couples electrostatics, heat transfer, and fluid dynamics. The accompanying IR thermography is a non-contact method, which can measure fractional temperature differences with sub-second time resolution. Any structures or temperature marker molecules interfering with the experiment are not needed. Nominal spot size in the IR measurements is 30 μm with a field of view of several millimeters enabling both local and chip-scale temperature monitoring simultaneously. As a result, we present a computer model for electrokinetic chips, which enables simulation of fractional temperature changes during electrophoresis under real operating conditions. The accuracy of the model is within ±1°C when the deviation in electrochemical processes is taken into account. The simulation results also suggest that the temperature on the chip surface qualitatively reflects the temperature inside the microchannel with an average offset of 1–2°C.


Electroosmotic flow Numerical simulation IR thermography 



This work has been financially supported by the National Technology Agency of Finland (TEKES), the Academy of Finland (project no. 211019), the University of Helsinki Research Funds and the Finnish Cultural Foundation.


  1. Allison SW, Gilles GT (1997) Remote thermometry with thermographic phosphors: instrumentation and applications. Rev Sci Instrum 68:2615–2650CrossRefGoogle Scholar
  2. Benninger RKP, Koc Y, Hofmann O, Requejo-Isidro J, Neil MAA, French PMW, deMello AJ (2006) Quantitative 3D mapping of fluidic temperatures within microchannel networks using fluorescence lifetime imaging. Anal Chem 78:2272–2278CrossRefGoogle Scholar
  3. Chaudhari AM, Woudenberg TM, Albin M, Goodson KE (1998) Transient liquid crystal thermometry of microfabricated PCR vesselarrays. J Microelectromech Syst 7:345–355CrossRefGoogle Scholar
  4. Erickson D (2005) Towards numerical prototyping of labs-on-chip: modeling for integrated microfluidic devices. Microfluid Nanofluid 1:301–318CrossRefGoogle Scholar
  5. Erickson D, Sinton D, Li D (2003) Joule heating and heat transfer in poly(dimethylsiloxane) microfluidic systems. Lab Chip 3:141–149CrossRefGoogle Scholar
  6. Franssila S, Marttila K, Kolari P, Östman T, Kotiaho T, Kostiainen R, Lehtiniemi R, Fager C-M, Manninen J (2006) A microfabricated nebulizer for liquid vaporization in chemical analysis. J Microelectromech Syst 15:1251–1259CrossRefGoogle Scholar
  7. Golonka LJ, Rugyszczak H, Zawada T, Radojewski J, Grabowska I, Chudy M, Dybko A, Brzozka Z, Stadnik D (2005) LTCC based microfluidic system with optical detection. Sens Actuators B 111–112:396–402CrossRefGoogle Scholar
  8. Guerin L, Bossel M, Demierre M, Calmes S, Renaud P (1997) Simple and low cost fabrication of embedded microchannels by using a new thick-film photoplastic. In: Proceedings of the Transducers ‘97 conference, ChicagoGoogle Scholar
  9. Hardt S, Schilder B, Tiemann D, Kolb G, Hessel V, Stephan P (2007) Analysis of flow patterns emerging during evaporation in parallel microchannels. Int J Heat Mass Transf 50:226–239CrossRefGoogle Scholar
  10. Horiuchi K, Dutta P (2004) Joule heating effects in electroosmotically driven microchannel flows. Int J Heat Mass Transf 47:3085–3095zbMATHCrossRefGoogle Scholar
  11. Incroprera FP, De Witt DP (1985) Fundamentals of heat and mass transfer. Wiley, New YorkGoogle Scholar
  12. Karniadakis GE, Beskok A (2002) Microflows: fundamentals and simulation. Springer, New YorkGoogle Scholar
  13. Kim SH, Noh J, Jeon MK, Kim KW, Lee LP, Woo SI (2006) Micro-Raman thermometry for measuring the temperature distribution inside the microchannel of a polymerase chain reaction chip. J Micromech Microeng 16:526–530CrossRefGoogle Scholar
  14. Kutter JP, Mogensen KB, Klank H, Geschke O (2004) Microfluidics—components. In: Geschke O, Klank H, Tellemann P (eds) Microsystem engineering of lab-on-a-chip devices. Wiley-VCH, WeinheimGoogle Scholar
  15. Lide DR (ed) (2006) CRC handbook of chemistry and physics, 87th edn. CRC Press, Boca RatonGoogle Scholar
  16. Patil VA, Narayanan V (2006) Spatially resolved temperature measurement in microchannels. Microfluid Nanofluid 2:291–300CrossRefGoogle Scholar
  17. Petersen NJ, Nikolajsen RPH, Mogensen KB, Kutter JP (2004) Effect of Joule heating on efficiency and performance for microchip-based and capillary-based electrophoretic separation systems: A closer look. Electrophoresis 25:253–269CrossRefGoogle Scholar
  18. Reitz JR, Milford FJ, Christy RW (1979) Foundations of electromagnetic theory. Addison-Wesley, BostonGoogle Scholar
  19. Ross D, Gaitan M, Locascio LE (2001) Temperature measurement in microfluidic systems using a temperature-dependent fluorescent dye. Anal Chem 73:4117–4123CrossRefGoogle Scholar
  20. Saeki S, Funakoshi J, Saito T, Nakamura K, Nishida T (2006) Quantitative temperature measurement of micro-electrophoretic flow using two-color laser-induced fluorescence. In: Proceedings of the 10th international conference on miniaturized systems for chemistry and life sciences (MicroTAS), TokyoGoogle Scholar
  21. Sato Y, Irisawa G, Ishizuka M, Hishida K, Maeda M (2003) Visualization of convective mixing in microchannel by fluorescence imaging. Meas Sci Technol 12:114–121CrossRefGoogle Scholar
  22. Shin WC, Besser RS (2006) A micromachined thin-film gas flow sensor for microchemical reactors. J Micromech Microeng 16:731–741CrossRefGoogle Scholar
  23. Sikanen T, Tuomikoski S, Ketola RA, Kostiainen R, Franssila S, Kotiaho T (2005) Characterization of SU-8 for electrokinetic microfluidic applications. Lab Chip 5:888–896CrossRefGoogle Scholar
  24. Swinney K, Bornhop DJ (2002) Quantification and evaluation of Joule heating in on-chip capillary electrophoresis. Electrophoresis 23:613–620CrossRefGoogle Scholar
  25. Tang GY, Yang C, Chai JC, Gong HQ (2004a) Numerical analysis of the thermal effect on electroosmotic flow and electrokinetic mass transport in microchannels. Anal Chim Acta 507:27–37CrossRefGoogle Scholar
  26. Tang GY, Yang C, Chai JC, Gong HQ (2004b) Joule heating effect on electroosmotic flow and mass species transport in a microcapillary. Int J Heat Mass Transf 47:215–277zbMATHCrossRefGoogle Scholar
  27. Tuomikoski S, Franssila S (2005) Free-standing SU-8 microfluidic chips by adhesive bonding and release etching. Sens Actuators A 120:408–415CrossRefGoogle Scholar
  28. Venditti R, Xuan X, Li D (2006) Experimental characterization of the temperature dependence of zeta potential and its effect on electroosmotic flow velocity in microchannels. Microfluid Nanofluid 2:493–499CrossRefGoogle Scholar
  29. White FM (1991) Viscous fluid flow. McGraw-Hill, New York (Appendix A)Google Scholar
  30. Xu Y, Chiu C-W, Jiang F, Lin Q, Tai Y-C (2005) A MEMS multi-sensor chip for gas flow sensing. Sens Actuators A 121:253–261CrossRefGoogle Scholar
  31. Xue Z, Qiu H (2005) Integrating micromachined fast response temperature sensor array in a glass microchannel. Sens Actuators A 122:189–195CrossRefGoogle Scholar
  32. Zhang Y, Tadigadapa S (2005) Thermal characterization of liquids and polymer thin films using a microcalorimeter. Appl Phys Lett 86:034101 (3 pages)CrossRefGoogle Scholar
  33. Zhang Y, Bao N, Yu X-D, Xu J-J, Chen H-Y (2004) Improvement of heat dissipation for polydimethylsiloxane microchip electrophoresis. J Chromatogr A 1057:247–251CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Tiina Sikanen
    • 1
    • 2
    Email author
  • Thomas Zwinger
    • 3
  • Santeri Tuomikoski
    • 4
  • Sami Franssila
    • 4
  • Reijo Lehtiniemi
    • 5
  • Carl-Magnus Fager
    • 5
  • Tapio Kotiaho
    • 1
    • 2
  • Antti Pursula
    • 3
  1. 1.Laboratory of Analytical Chemistry, Department of ChemistryUniversity of HelsinkiHelsinkiFinland
  2. 2.Division of Pharmaceutical Chemistry, Faculty of PharmacyUniversity of HelsinkiHelsinkiFinland
  3. 3.CSC-Scientific Computing LtdEspooFinland
  4. 4.Micro- and Nanoscience LaboratoryHelsinki University of TechnologyHUTFinland
  5. 5.Nokia Research CenterNokia GroupFinland

Personalised recommendations