The net flow of electrolyte induced by an ac electric potential applied to an array of asymmetric pairs of microelectrodes has recently been reported. The interaction between the oscillating electric field and the oscillating induced charge at the diffuse double layer on the electrodes results in a steady electro-osmotic velocity distribution on top of the electrodes. This slip velocity distrib...

We study the response of a spherical colloid under alternating electric fields (AC fields) by mesoscopic simulation method, accounting in full for hydrodynamic and electrostatic interactions. We focus on a special case of uncharged colloids. The main polarization mechanism is the "volume polarization", where ionic currents are deflected by the core of the uncharged colloid. Specifically, we com...

The electric field fire extinguishing technology is an efficient, clean, and new that can be operated at a long distance. In order to study the synergistic mechanism of “electric-flow-heat” in process transverse AC extinguishing, ionic wind formed by influence on each charged particle during burning ethanol–air diffusion flame simulated non-premixed combustion model, experimental phenomenon que...

Under suitable conditions, a DNA molecule in solution will develop a strong electric dipole moment. This induced dipole allows the molecule to be manipulated with field gradients, in a phenomenon known as dielectrophoresis (DEP). Pure dielectrophoretic motion of DNA requires alternate current (AC) electric fields to suppress the electrophoretic effect of the molecules net charge. In this paper,...

Frequency-dependent fluid flow in electrolytes on microelectrodes subjected to ac voltages has recently been reported. The fluid flow is predominant at frequencies of the order of the relaxation frequency of the electrode-electrolyte system. The mechanism responsible for this motion has been termed ac electro-osmosis: a continuous flow driven by the interaction of the oscillating electric field...

The novel effects resulting from the entrainment of low mobility ions during alternating current (ac) electrospray ionization are examined through mass spectrometry and voltage/current measurements. Curious phenomena such as pH modulation at high frequencies (>150 kHz) of an applied ac electric field are revealed and explained using simple mechanistic arguments. Current measurements are utilize...

The scanning dielectrophoresis system consists of a pair of microneedles connected to a waveform generator of arbitrary ac electric fields. Consequently, our scanning method is able to place and move the strong electric field spot between the electrode tips anywhere, just as optical tweezers have done the focus of light beam. In this paper, we demonstrate non-contact manipulations unique to our...

Positive AC dielectrophoresis (DEP) is used to align ensembles of CdSe nanowires (NWs) near patterned micro-electrodes. Such wires, with the same crystal structure as CdSe quantum dots (QDs) and nanorods (NRs) but with significantly larger aspect ratios and sizable induced and intrinsic dipole moments, have a DEP mobility 10~100 times higher than other materials of the same dimension. As a cons...

[1] We report results of a field campaign conducted in the Nevada desert with a suite of electric field instruments consisting of a field mill (FM) and a short dipole antenna (SDA). Furthermore, we show that a combination of the measurements of these two instruments allows the estimation of the electric resistivity of air, an important quantity that is extremely difficult to measure near the Ea...