Robert M Crocker

US Patent:

6675660, Jan 13, 2004

Filed:

Jul 31, 2002

Appl. No.:

10/210647

Inventors:

Bruce P. Mosier - San Francisco CA
Robert W. Crocker - Fremont CA
Cindy K. Harnett - Livermore CA

Assignee:

Sandia National Laboratories - Livermore GA

International Classification:

G01P 518

US Classification:

7386107

Abstract:

A device for measuring fluid flow rates over a wide range of flow rates (1 nL/min to 10 L/min) and at pressures at least as great as 10,000 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.

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:

7213473, May 8, 2007

Filed:

Dec 15, 2004

Appl. No.:

11/016310

Inventors:

Bruce P. Mosier - San Francisco CA, US
Robert W. Crocker - Fremont CA, US
Kamlesh D. Patel - Dublin CA, US
Cindy K. Harnett - Livermore CA, US

Assignee:

Sandia National Laboratories - Livermore CA

International Classification:

G01F 1/37

US Classification:

7386152

Abstract:

An apparatus that couples automated injection with flow feedback to provide nanoliter accuracy in controlling microliter volumes. The apparatus comprises generally a source of hydraulic fluid pressure, a fluid isolator joined to the outlet of the hydraulic pressure source and a flow sensor to provide pressure-driven analyte metering. For operation generally and particularly in microfluidic systems the hydraulic pressure source is typically an electrokinetic (EK) pump that incorporates gasless electrodes. The apparatus is capable of metering sub-microliter volumes at flowrates of 1–100 μL/min into microsystem load pressures of up to 1000–50 psi, respectively. Flowrates can be specified within 0. 5 μL/min and volumes as small as 80 nL can be metered.

US Patent:

7384526, Jun 10, 2008

Filed:

May 17, 2004

Appl. No.:

10/848201

Inventors:

Bruce P. Mosier - San Francisco CA, US
Robert W. Crocker - Fremont CA, US
Kamlesh D. Patel - Dublin CA, US

Assignee:

Sandia Corporation - Livermore CA

International Classification:

G01N 27/453
B01L 3/02

US Classification:

204600, 422100

Abstract:

Electrokinetic (“EK”) pumps convert electric to mechanical work when an electric field exerts a body force on ions in the Debye layer of a fluid in a packed bed, which then viscously drags the fluid. Porous silica and polymer monoliths (2. 5-mm O. D. , and 6-mm to 10-mm length) having a narrow pore size distribution have been developed that are capable of large pressure gradients (250-500 psi/mm) when large electric fields (1000-1500 V/cm) are applied. Flowrates up to 200 μL/min and delivery pressures up to 1200 psi have been demonstrated. Forces up to 5 lb-force at 0. 5 mm/s (12 mW) have been demonstrated with a battery-powered DC-DC converter. Hydraulic power of 17 mW (900 psi@ 180 uL/min) has been demonstrated with wall-powered high voltage supplies. The force and stroke delivered by an actuator utilizing an EK pump are shown to exceed the output of solenoids, stepper motors, and DC motors of similar size, despite the low thermodynamic efficiency.

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:

20040221507, Nov 11, 2004

Filed:

May 7, 2003

Appl. No.:

10/431153

Inventors:

Benjamin Wu - San Ramon CA, US
Karl Wally - Lafayette CA, US
Steven Rice - Oakland CA, US
Robert Crocker - Fremont CA, US

International Classification:

C01B003/02

US Classification:

048/198300, 048/198200, 048/198700, 048/215000, 048/127900, 048/21400A, 048/21400R

Abstract:

Experiments were conducted to investigate the reforming of organic compounds (primarily methanol) in supercritical water at 550 C.-700 C. and 27.6 MPa in a tubular Inconel 625 reactor. The results show that methanol can be completely converted to a product stream that is low in methane and near the equilibrium composition of hydrogen, carbon monoxide, and carbon dioxide. The effect of reactor temperature, feed concentration of methanol, and residence time on both conversion and product gas composition are presented.