Dynamical trapping of colloids at the stagnation points of electro-osmotic vortices of the second kind

摘要: By applying a stepwise overlimiting voltage to nanoslot system in equilibrium, it is possible follow the time evolution of electroconvective instability vortex array via depletion dynamics or, alternatively, by following dielectrophoretically trapped particles at stagnation points each hydrodynamic pairs. Particles are advected point hydrodynamics, where they short-range dielectrophoretic force. It experimentally confirmed that wavelength selection process occurs diffusive scale and mechanism, started Rubinstein Zaltzman eventually determined lateral geometry dictated Dukhin's electro-osmosis second kind. The steady-state case was numerically studied solving fully coupled problem, confirming indeed converging type. particle's planar (two-dimensional) equations motion solved after adding force accounts for quasi-three-dimensional effects. shown this can account trapping interface.