Active manipulation of cells, such as trapping, focusing, and isolation, is essential for various bioanalytical applications. Herein, we report a hybrid electrokinetic technique for manipulating mammalian cells in physiological fluids. This technique applies a combination of negative dielectrophoretic force and hydrodynamic drag force induced by electrohydrodynamics, which is effective in condu...

The ability to manipulate biological cells and micrometer-scale particles plays an important role in many biological and colloidal science applications. However, conventional manipulation techniques, such as optical tweezers, electrokinetic forces (electrophoresis, dielectrophoresis (DEP), and traveling-wave dielectrophoresis), magnetic tweezers, acoustic traps, and hydrodynamic flows, cannot a...

We develop a multiphysics model to study the contribution of electrokinetics on the biomolecular detection process and provide a physical explanation of the two to three orders of magnitude difference in detection time between experimental results and theoretical predications at ultralow concentration. The electrokinetic effects, including electrophoretic force and electroosmotic flow, have bee...

In a recent paper in this journal, Jefimenko (Jefimenko O D 2001 J. Phys. A: Math. Gen. 34 6143–56) used time-dependent generalizations of the Coulomb and Biot–Savart laws to infer the existence of ‘electrokinetic’ and ‘magnetokinetic’ fields due to radial acceleration of charges in circular motion. It is shown here that for the stationary charge and current distributions discussed in Jefimenko...

The classical theory of electrokinetic phenomena is based on the mean-field approximation that the electric field acting on an individual ion is self-consistently determined by the local mean charge density. This paper considers situations, such as concentrated electrolytes, multivalent electrolytes, or solvent-free ionic liquids, where the mean-field approximation breaks down. A fourth-order m...

Electrokinetic manipulation refers to the control of particle and cell motions using an electric field. It is an efficient technique for microfluidic applications with the ease of operation and integration. It, however, suffers from an intrinsic drawback of low throughput due to the linear dependence of the typically very low fluid permittivity. We demonstrate in this work a significantly enhan...

We theoretically evaluate the prospect of using electrokinetic phenomena to convert hydrostatic energy to electrical power. An expression is derived for the energy conversion efficiency of a two-terminal fluidic device in terms of its linear electrokinetic response properties. For a slitlike nanochannel of constant surface charge density, we predict that the maximum energy conversion efficiency...

The time dependence of a charge accumulation in a 10-15 M albumin solution, flowing through a measuring cell of an analytical flow system injector, had a nonlinear character under certain conditions, within a human physiological temperature range. Sharp charge increases depended on albumin concentration. This effect must be taken into consideration when generating models that describe electroki...