Figure 7

Hybrid electrokinetics for mixing, separation, and concentration. (A) Fluorescence images of electrokinetic-induced mixing (top) and diffusion-based mixing (bottom) at the beginning (left) and after 10 sec (right) [146]. (B) Schematic for particle concentration with hybrid electrokinetics. Long range fluid motion drives particles to regions near the electrode where other local electrokinetic forces trap the particles [146]. (C) Concentration nanoparticles on top of the electrode with hybrid electrokinetics [146]. (D) Schematic on the left demonstrates the separation of 200 nm particles (green) from 2 μm particles (red) [146]. Dielectrophoretic force dominates for large particles and traps them at the electrode edge while 200 nm particles are pushed toward the centre of the electrode. Schematic on the right illustrates the separation of 200 nm particles (green) from 20 nm particles (red). At an appropriate frequency, dielectrophoretic force is adequate for trapping 200 nm particles but not for trapping 20 nm particles. (E) Top row shows the separation of 200 nm particles (green) from 2 μm particles (red) [146]. Bottom row shows the separation of 200 nm particles (green) from 20 nm particles (red).