Temperature modeling and measurement of an electrokinetic separation chip
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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.
KeywordsElectroosmotic 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.
- 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
- Incroprera FP, De Witt DP (1985) Fundamentals of heat and mass transfer. Wiley, New YorkGoogle Scholar
- Karniadakis GE, Beskok A (2002) Microflows: fundamentals and simulation. Springer, New YorkGoogle Scholar
- 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
- Lide DR (ed) (2006) CRC handbook of chemistry and physics, 87th edn. CRC Press, Boca RatonGoogle Scholar
- Reitz JR, Milford FJ, Christy RW (1979) Foundations of electromagnetic theory. Addison-Wesley, BostonGoogle Scholar
- 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
- White FM (1991) Viscous fluid flow. McGraw-Hill, New York (Appendix A)Google Scholar