Electrokinetic motion of particles in xanthan gum solutions*

The interest in the ability to control and predict the motion of particles in microfluidic devices has been increasing. It is a known fact that particles move parallel to the applied electric field in straight uniform microchannels. Numerous studies have been conducted to investigate electrokinetic motion of particles in Newtonian fluids. However, the behavior in non-Newtonian fluids needs further study since many biological and chemical fluids exhibit non-Newtonian characteristics. In this work, we present an experimental study of electrokinetic motion of particles in xanthan gum solutions through straight rectangular microchannels. The effects of multiple parameters including electric field magnitude, particle size, microchannel depth and xanthan gum concentration are investigated. This study will provide useful experimental data for validating theoretical and numerical models on electrokinetic particle motion in shear-thinning fluids.