Electrokinetic pump with fixed stroke volume
AssigneeEksigent Technologies, LLC
InventorsMansour A. Saleki, Antonio Reis
Life of this patent
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Abstract
An electrokinetic pump and fluid delivery system is provided that may include any of a number of features. One feature of the fluid delivery system is that it can deliver a fixed volume of fluid with each stroke of the electrokinetic pump. Another feature of the fluid delivery system is that it can accurately deliver fluid at a target flow rate over time. Methods associated with use of the electrokinetic pump and fluid delivery system are also covered.
Claims35
A method of pumping a fixed stroke volume of fluid with an electrokinetic pump, the method comprising:
- applying a forward voltage across a pair of electrodes for only a portion of a forward stroke period to move a pump fluid from a first chamber to a second chamber such that a first movable member in fluid communication with the first chamber moves from a starting limit to an ending limit prior to lapse of the forward stroke period;
- and
- continuing to apply a forward voltage across the pair of electrodes without moving the pump fluid for a forward occlusion period until lapse of the remaining portion of the forward stroke period without degrading the pump fluid.
A fluid delivery system, comprising:
- an electrokinetic pump filled with a pump fluid and comprising a first chamber separated from a second chamber by a porous dielectric material disposed between a pair of capacitive electrodes, wherein the first chamber contains a first movable member in fluid communication with the pump fluid and the second chamber contains a second movable member in fluid communication with the pump fluid;
- and
- a fluid delivery cartridge filled with a delivery fluid and comprising a compression chamber, the fluid delivery cartridge coupled to the electrokinetic pump, wherein the second movable member is disposed between the second chamber and the compression chamber, the compression chamber having a fluid inlet and a fluid outlet;
- and
- a controller programmed to apply a forward voltage across the pair of capacitive electrodes for a stroke period, the stroke period comprising the time to displace a fixed stroke volume of the delivery fluid from the fluid delivery cartridge through the fluid outlet and a nonzero time when the net pump fluid flow across the porous dielectric material is zero.
A method of managing an accumulated charge on a pair of capacitive electrodes in a one-directional electrokinetic pump, the method comprising:
- applying a forward voltage to the pair of capacitive electrodes to move a pump fluid from a first chamber to a second chamber by electro-osmosis through a porous membrane;
- measuring the accumulated charge on the pair of capacitive electrodes;
- and
- applying a reverse voltage to the pair of capacitive electrodes when the accumulated charge exceeds a threshold value to discharge the pair of capacitive electrodes and generate a differential pressure across the porous membrane without net pump fluid movement through the porous membrane.
Dependencies are inferred from the claim text.