Figure 2.

Equilibrium-based DEP sorting. Different particle types, symbolized here by squares, circles, and triangles, respectively, experience different forces for a given set of electric fields acting from the electrode arrays lining the sorting channel. The force ratio describes the relative efficiency of the electric fields acting from either side of the sorting element to push them toward the opposite side. In the example shown, the force ratio for the square particles is 5 [Fig. 2a], for the circle particles it is 1 [Fig. 2b], and for the triangle particles, it is 0.2 [Fig. 2c]. Accordingly, the square particles are focused toward a position close to the left channel wall, the circle particles toward the channel midline, whereas the minimum of the potential well for the triangle particles is located toward the right channel wall. If a mixture of the three particle types is flowed down the sorting channel, each particle type is centered toward its own equilibrium positions, and hence, the mixture gets sorted [Fig. 2d].