Figure 3.

Comparison of the numerically predicted contour of electric field squared (top row), ${\mathit{E}}^2$ (the darker color the larger magnitude), and arrows (length proportional to the velocity magnitude) of negative dielectrophoretic particle velocity, ${\mathit{U}}_{DEP}$, in terms of $-\nabla {\mathit{E}}^2$ in between a symmetric (a) and an asymmetric (b) ratchet microchannel.