Figure 7.

Continuous ternary separation of plain noncoated 5 μm (gray), plain noncoated 10 μm (dark), and fluorescent carboxyl-coated 10 μm (bright) polystyrene beads in a spiral microchannel using curvature-induced DEP: snapshot image (a1) (enhanced), superimposed image (a2) and numerical prediction (a3) in the inlet region; superimposed image (b1) (enhanced) and numerical prediction (b2) in the center region; snapshot image (c1) (enhanced), superimposed image (c1) and numerical prediction (c3) in the trifurcation region; top-view images (d1, d2 and d3) of the particles sorted into the three outlet reservoirs, labeled as OR 1–3 in (a1). The block arrows indicate the flow directions (enhanced online). [URL: http//dx.doi.org/10.1063/1.3599883.1] [URL: http//dx.doi.org/10.1063/1.3599883.1] [URL: http//dx.doi.org/10.1063/1.3599883.1]