Robert L Crocker

US Patent:

7012342, Mar 14, 2006

Filed:

Jun 3, 2003

Appl. No.:

10/454179

Inventors:

James Frederick Stamps - Livermore CA, US
Robert Ward Crocker - Fremont CA, US
Daniel Dadwa Yee - Dublin CA, US
David Wright Dils - Fort Worth TX, US

Assignee:

Sandia National Laboratories - Livermore CA

International Classification:

H02J 1/00

US Classification:

307 29, 361170, 361173, 710305, 702286, 307 39, 204602

Abstract:

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

US Patent:

7094326, Aug 22, 2006

Filed:

Dec 24, 2002

Appl. No.:

10/330607

Inventors:

Robert W. Crocker - Fremont CA, US
Cindy K. Harnett - Livermore CA, US
Judith L. Rognlien - Livermore CA, US

Assignee:

Sandia National Laboratories - Livermore CA

International Classification:

G01N 27/453
B28B 1/44

US Classification:

204600, 204280, 264 42

Abstract:

An electrode device for high pressure applications. These electrodes, designed to withstand pressure of greater than 10,000 psi, are adapted for use in microfluidic devices that employ electrokinetic or electrophoretic flow. The electrode is composed, generally, of an outer electrically insulating tubular body having a porous ceramic frit material disposed in one end of the outer body. The pores of the porous ceramic material are filled with an ion conductive polymer resin. A conductive material situated on the upper surface of the porous ceramic frit material and, thus isolated from direct contact with the electrolyte, forms a gas diffusion electrode. A metal current collector, in contact with the gas diffusion electrode, provides connection to a voltage source.

US Patent:

7204264, Apr 17, 2007

Filed:

Sep 15, 2004

Appl. No.:

10/941216

Inventors:

Robert W. Crocker - Fremont CA, US
Pamela F. Caton - Berkely CA, US
Geoff C. Gerhardt - Milbury MA, US

Assignee:

Waters Investments Ltd. - New Castle DE

International Classification:

F15C 1/04

US Classification:

137 15, 137 74, 1372511, 137828

Abstract:

A freeze-thaw valve and a method of micro-machining the freeze-thaw valve is provided and includes a valve housing, wherein the valve housing defines a housing cavity and includes a housing inlet, a housing vent, a capillary tubing inlet and a capillary tubing outlet. A valve body is provided, at least a portion of which is lithographically constructed, wherein the valve body includes a refrigerant inlet, a refrigerant outlet and an expansion chamber. The expansion chamber is disposed to communicate the refrigerant inlet with the refrigerant outlet and includes a restriction region having a flow restriction. Additionally, the valve body is disposed within the housing cavity to form an insulating channel between the valve housing and the valve body.

US Patent:

7225683, Jun 5, 2007

Filed:

Sep 11, 2003

Appl. No.:

10/661401

Inventors:

Cindy K. Harnett - Livermore CA, US
Robert W. Crocker - Fremont CA, US
Bruce P. Mosier - San Francisco CA, US
Pamela F. Caton - Berkeley CA, US
James F. Stamps - Livermore CA, US

Assignee:

Sandia National Laboratories - Livermore CA

International Classification:

G01F 1/58

US Classification:

7386112

Abstract:

A device for measuring fluid flow rates over a wide range of flow rates (10 μL/min) and at pressures at least as great as 2,000 psi. The invention is particularly adapted for use in microfluidic systems. The device operates by producing compositional variations in the fluid, or pulses, that are subsequently detected downstream from the point of creation to derive a flow rate. Each pulse, comprising a small fluid volume, whose composition is different from the mean composition of the fluid, can be created by electrochemical means, such as by electrolysis of a solvent, electrolysis of a dissolved species, or electrodialysis of a dissolved ionic species. Measurements of the conductivity of the fluid can be used to detect the arrival time of the pulses, from which the fluid flow rate can be determined. A pair of spaced apart electrodes can be used to produce the electrochemical pulse. In those instances where it is desired to measure a wide range of fluid flow rates a three electrode configuration in which the electrodes are spaced at unequal distances has been found to be desirable.

US Patent:

7348688, Mar 25, 2008

Filed:

Jan 10, 2006

Appl. No.:

11/330269

Inventors:

James Frederick Stamps - Livermore CA, US
Robert Ward Crocker - Fremont CA, US
Daniel Dadwa Yee - Dublin CA, US
David Wright Dils - Fort Worth TX, US

Assignee:

Sandia Corporation - Livermore CA

International Classification:

H02J 1/00

US Classification:

307 29, 307 39

Abstract:

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

US Patent:

8563325, Oct 22, 2013

Filed:

Sep 29, 2010

Appl. No.:

12/893915

Inventors:

Michael Bartsch - Menlo Park CA, US
Michael P. Kanouff - Livermore CA, US
Scott M. Ferko - Livermore CA, US
Robert W. Crocker - Fremont CA, US
Karl Wally - Lafayette CA, US

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

B01L 3/00

US Classification:

436180, 436174, 422503, 422502

Abstract:

A coaxial fluid flow microreactor system disposed on a microfluidic chip utilizing laminar flow for synthesizing particles from solution. Flow geometries produced by the mixing system make use of hydrodynamic focusing to confine a core flow to a small axially-symmetric, centrally positioned and spatially well-defined portion of a flow channel cross-section to provide highly uniform diffusional mixing between a reactant core and sheath flow streams. The microreactor is fabricated in such a way that a substantially planar two-dimensional arrangement of microfluidic channels will produce a three-dimensional core/sheath flow geometry. The microreactor system can comprise one or more coaxial mixing stages that can be arranged singly, in series, in parallel or nested concentrically in parallel.

US Patent:

20040107996, Jun 10, 2004

Filed:

Dec 9, 2002

Appl. No.:

10/314707

Inventors:

Robert Crocker - Fremont CA, US
Kamlesh Patel - Livermore CA, US
Gabriela Chirica - Livermore CA, US

International Classification:

G05D007/06

US Classification:

137/487500

Abstract:

A flow control apparatus for controlling and regulating liquid flow rates. The apparatus is designed for the regulation and control of the flow of very small quantities of liquid over a continuous range from a few microliters/min to below one nanoliter/min from a high pressure source. The apparatus comprises a low permeability liquid flow channel, electrodes positioned within the liquid flow channel; and a power supply connected to the electrodes. Connected to the outlet of a high pressure liquid source, such as an electrokinetic pump, the variable flow apparatus controls flow from the pump by generating an opposing or augmenting electroosmotic within the low permeability flow channel. By adding an accumulator in combination with the variable flow apparatus to modulate the pressure-driven flow from the accumulator, the dynamic flow range is enhanced.

US Patent:

58826211, Mar 16, 1999

Filed:

May 9, 1997

Appl. No.:

8/853971

Inventors:

Narayan Doddapaneni - Alburquerque NM
James C. F. Wang - Livermore CA
Robert W. Crocker - Fremont CA
David Ingersoll - Alburquerque NM
David W. Firsich - Dayton OH

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

H01M 404

US Classification:

423445R

Abstract:

A method of producing carbon materials for use as electrodes in rechargeable batteries. Electrodes prepared from these carbon materials exhibit intercalation efficiencies of. apprxeq. 80% for lithium, low irreversible loss of lithium, long cycle life, are capable of sustaining a high rates of discharge and are cheap and easy to manufacture. The method comprises a novel two-step stabilization process in which polymeric precursor materials are stabilized by first heating in an inert atmosphere and subsequently heating in air. During the stabilization process, the polymeric precursor material can be agitated to reduce particle fusion and promote mass transfer of oxygen and water vapor. The stabilized, polymeric precursor materials can then be converted to a synthetic carbon, suitable for fabricating electrodes for use in rechargeable batteries, by heating to a high temperature in a flowing inert atmosphere.