ELECTROKINETIC PUMP HAVING CAPACITIVE ELECTRODES
An electrokinetic pump achieves high and low flow rates without producing significant gaseous byproducts and without significant evolution of the pump fluid. A first feature of the pump is that the electrodes in the pump are capacitive with a capacitance of at least 10 −4 Farads/cm 2 . A second feature of the pump is that it is configured to maximize the potential across the porous dielectric material. The pump can have either or both features.
1 . An electrokinetic system, comprising:
an electrokinetic device including a pair of electrodes and a porous dielectric material between the electrodes, the pair of electrodes capable of having a voltage drop therebetween;
a liquid in the elecktrokinetic device between the pair of electrodes;
a power supply; and
a controller, the controller configured to:
(a) apply a positive current from the power supply to the electrodes to charge the capacitance of the electrodes and to move the liquid through the porous dielectric material in a first direction;
(b) reverse the current applied by the power supply to the electrodes prior to reaching a threshold voltage for a Faradaic process in the liquid; and
(c) apply a negative current from the power supply to the electrodes to move the liquid through the porous dielectric material in a second direction that is opposite to the first directions.