Eksigent Technologies, LLC

Sandia Corporation

Dh Technologies Development Pte. Ltd.

Sandia National Laboratories

Ab Sciex LLC

David W Neyer

Phillip Harris Paul

David J Rakestraw

Don Wesley Arnold

Deon Stafford Anex

Jason E Rehm

Joseph S Schoeniger

Christopher G Bailey

Kenneth R Hencken

Edwin J Hlavka

Anup Kumar Singh

Michael G Garguilo

A flow controller which uses a combination of hydrostatic pressure and electroosmotic flow to control the flow of a fluid. A driving fluid () whose flow rate is dependent on both hydrostatic pressures and electroosmotic flow can be used (a) directly as a working fluid in an operable device, for example a chromatograph, or (b) to displace a working fluid () from a storage container () into an operable device (), or both (a) and (b). The driving fluid () can be composed of one or more fluids. Part or all the driving fluid () is passed through an electroosmotic device () so as to increase or decrease the flow rate induced by hydrostatic pressure.

Flow control systems

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 10Farads/cm. 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.

Electrokinetic pump having capacitive electrodes

A liquid sample is prepared at a preparation site and then processed, e.g. in an HPLC column. The sample is prepared and conveyed to the device at a flow rate which is substantially less than the flow rate through the device. The different flow rates are preferably provided by variable rate working fluid supplies which drive the sample from the preparation site and through the device.

Flow rate control

A method of pumping fluid including the steps of providing an electrokinetic pump comprising a pair of double-layer capacitive electrodes having a capacitance of at least 10Farads/cmand being connectable to a power source, a porous dielectric material disposed between the electrodes and a reservoir containing pump fluid; connecting the electrodes to a power source; and moving pump fluid out of the reservoir substantially without the occurrence of Faradaic processes in the pump. The invention also includes an electrokinetic pump system having a pair of double-layer capacitive electrodes having a capacitance of at least 10Farads/cm; a porous dielectric material disposed between the electrodes; a reservoir containing pump fluid; and a power source connected to the electrodes; the electrodes, dielectric material and power source being adapted to move the pump fluid out of the reservoir substantially without the occurrence of Faradaic processes in the pump.

Electrokinetic delivery systems, devices and methods

Variable potential electrokinetic devices and electrokinetic multipliers used for pumping and flow control are disclosed that offer improvements in safety and design flexibility. The devices of the present invention take advantage of combinations of pumping conduits and conducting conduits to permit the use of lower operating voltages in pumps, pressure multipliers, and flow controllers. Devices having N pumping stages and 2N+1 electrodes permit the use of arbitrary voltages at the fluid connection points between the devices and other system components, further improving device safety and flexibility.

Variable potential electrokinetic devices

A laminated flow device comprises a porous material encapsulated within bonding material. The porous material forms a flow path and the bonding material forms an enclosure surrounding the flow path. Micro-components, such as capillaries, electrodes, reservoirs, bridges, electrokinetic elements, and detectors, can be encapsulated within the device.

Laminated flow device

An electrokinetic device is capable of operating for extended periods of time, e.g. days to a week, without producing significant gaseous byproducts and without significant evolution of the pump fluid. Features of the electrokinetic device include: the electrodes in the electrokinetic device are capacitive with a capacitance of at least 10Farads/cm; at least part of the inner surfaces of the electrodes have an area greater than the effective area of the porous dielectric material; at least part of the inner surfaces of the electrodes have a current flux less than 20 microamperes/cm; and at least part of the inner surfaces of the electrodes have a current flux that varies by less than a factor of two. The electrokinetic device can have one or several of these features in any combination.

Electrokinetic device having capacitive electrodes

In accordance with the present invention, stable electroosmotic flow systems and methods for designing the same are disclosed. The invention provides electroosmotic flow systems comprising electroosmotic flow elements, including bridge elements, that have matching flux ratios, i.e., when two or more elements of an electroosmotic flow system are in fluidic and electrical communication at a junction, the flux ratio for each of the elements is selected so that the difference in flux ratios of any two elements is less than a target value. The invention also provides methods for designing such systems. Also disclosed is a novel design for the terminal portions of electroosmotic flow (EOF) and bridge elements and for junctions in electroosmotic flow systems, whereby the elements are designed so that the terminal current flux is much smaller than the element current flux.

Bridges, elements and junctions for electroosmotic flow systems

A variable flow rate injector provides accurate, precise, and reproducible injection volumes that have low dispersion. The invention is particularly well-suited for HPLC injection volumes &#x3c;500 nL but can be used to inject larger volumes and in different applications as well. Injections are performed at a first flow rate and separations are performed at a second flow rate. For improved HPLC system performance, the first flow rate is less than the second flow rate. The injector uses a variable flow rate fluid supply that allows rapid switching between flow rates desired for injection and flow rates desired for separations.

Variable flow rate injector

Apparatus for eliminating siphoning, &ldquo;dead&rdquo; regions, and fluid concentration gradients in microscale analytical devices. In its most basic embodiment, the present invention affords passive injection control for both electric field-driven and pressure-driven systems by providing additional fluid flow channels or auxiliary channels disposed on either side of a sample separation column. The auxiliary channels are sized such that volumetric fluid flow rate through these channels, while sufficient to move the sample away from the sample injection region in a timely fashion, is less than that through the sample separation channel or chromatograph.

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Castro Valley, CA, United States of America

David W Neyer