Inertial modulation of hydrophoretic cell sorting and focusing

This paper demonstrates a method of modulating hydrophoretic focusing and sorting by inertial forces in a microfluidic device. At low Reynolds number (Re), hydrophoresis enables size-based sorting by generating specific equilibrium positions for differently sized particles. As increasing Re, hydrophoresis becomes coupled with inertial effects that bias the equilibrium positions to create a narrow focusing stream. Using this method, we achieved both size-based sorting and sheathless focusing in a device. (C) 2014 AIP Publishing LLC.