Joule Heating in Electroosmotically Driven Circular Constriction Microchannel

U. Sanjay [1], P. Sarith[2], R. Ajith Kumar[1]
[1]Amrita Vishwa Vidhyapeetham, Kollam, Kerala, India.
[2]National institute of Technology, Calicut, Kerala, India.
Published in 2013

Liquid transport in lab-on-a-chip (LOC) devices occurs through a microchannel that uses an electroosmotic flow actuation mechanism. This method has a plug-like velocity profile, which is ideal in species transport and in wall-bounded reactions. Under substantial joule heating, it is not possible to maintain a plug-like velocity distribution. My work investigates the effects of joule heating where a layer of polydimethyl siloxane (PDMS) is also included along the liquid domain; the temperature rise in the moving liquid increases the temperature of the PDMS wall by conduction. Simulations are done using COMSOL Multiphysics®. Electric potential (DC) is applied across the channel for electroosmotic flow. Results are obtained by varying the electric potential, zeta potential and by providing a taper to the constriction channel.