Heat Transfer and Electrokinetic Flow Analysis in Poly(Dimethylsiloxane) Microfluidic Systems

Abstract

Electrokinetic pumping is commonly used as a mechanism for species transport in microfluidic systems. Joule heating, caused by current flow through the buffer solution during electroosmotic flow, can lead to significant increases in the system temperature which can be detrimental to electrophoretic separations and temperature sensitive chemical reactions. In this paper, a combined experimental and numerical approach was used to examine Joule heating and heat transfer at a T intersection for PDMS/PDMS and PDMS/Glass hybrid microfluidic systems. In general it was found the PDMS/Glass chips maintained a more uniform and lower buffer temperature than the PDMS/PDMS systems, since the internally generated heat could be transferred more efficiently (due to the higher thermal conductivity of the glass component) from the channel network to the room temperature reservoir. This increase in temperature was shown to significantly increase the current load and the volume flow rate through the PDMS/PDMS system.