Investigation of trapping process in “Centrifuge-on-a-chip”

“Centrifuge-on-a-chip” is a versatile and

multifunctional microfluidic chip which can conduct

operations of selective trapping, enrichment, labeling and

solution exchange. In this work, the mechanism of selective

trapping ability was studied by both the experiments and

numerical simulation. We proved the existence of shear

gradient lift force in the expansion-contraction cavity and

derived an explicit expression of it. Also, a numerical

modeling was developed to study the trapping process of

micro-particles in a “Centrifuge-on-a-chip”. The effects of

flow condition and particle size on the trapping process were

investigated. It demonstrates that the derived expression and

developed model are suitable for the prediction of particles’

trapping process, which can assist the design of

“Centrifuge-on-a-chip”.