Microspheres in the vicinity of a bifurcation at moderate Reynolds numbers

In microfluidic filtration processes a mixture of particles in a suspension are separated by applying external forces on microparticles to displace particles of different characteristics. Microfluidic continuous flow filtration methods are passive filtration methods that separate particles by using a boundary that causes the particles to cross streamlines to be collected at different outputs. These methods can offer some advantages over other filtration methods as they require relatively small sample sizes and they prevent clogging, making the process efficient and cost effective. The devices used in this practice do not require a filter membrane which obstructs the particle path and often needs to be replaced. This means a range of particle sizes can be filtered using this method as long as they are small enough to pass through the channel of a device. One particular approach to microfluidic continuous flow filtration uses channels with bifurcating channels of different flow rates to move particles of different sizes along different streamlines. This paper describes the motion of particles at the flow boundaries of these bifurcations at low to moderate Reynolds numbers to see if the fate of the particles near this boundary are affected by Reynolds numbers. This will be studied by running a stream of different sized polymer beads near a bifurcation and making observations of the particle path at different flow rates.