Numerical analysis of mixing by electrothermal induced flow in microfluidic systems

An electrothermal flow induced chaotic mixing in microfluidic systems is studied analytically and numerically. The flow is induced due to the Coulombic and dielectric forces arising from the variation of the dielectric properties with respect to the temperature in the presence of an electric field. The numerical model is validated using an analytical solution derived for basic flow patterns in a simplified geometry. The computational model has been used to illustrate the mixing in microcavity and T-sensor constructs. The simulations predict the chaotic nature of the mixing process, where the material interface evolution shows exponential growth. (C) 2007 American Institute of Physics.