Apparatus and method for fluid injection

• US 6,893,547 B2
• Filed: 06/14/2001
• Issued: 05/17/2005
• Est. Priority Date: 06/14/2000
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Vykoukal, Jody V., Becker, Frederick F., Gascoyne, Peter, Schwartz, Jon
• Primary Examiner(s): Mayekar, Kishor
• Application Number:
  US09/883,109
• Publication Number:
  US 20020063060A1
• Time in Patent Office: 1,433 Days
• Field of Search: 204/547, 204/643, 204/450, 204/600, 347/55
• US Class Current: 204/547
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0877 Flow chambers
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0424 Dielectrophoretic forces
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502784 specially adapted for droplet or plug flow, e.g. digital microfluidics automatic analysis using a stream of discrete samples in a tube system G01N35/08
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: B03C 5/005 Dielectrophoresis, i.e. dielectric particles migrating towards the region of highest field strength B03C5/02 takes precedence; electrophoresis B01D57/02

Abstract

Methods and apparatuses for metered injection of a fluid packet. A vessel containing a fluid is pressurized to a pressure less than or equal to a hold-off pressure. The fluid is subjected to an extraction force to form the fluid packet and extract the fluid packet from the vessel onto a surface.

Claims

1. A method for metered injection of a fluid packet, comprising:

pressurizing a vessel containing a fluid to a pressure less than or equal to a hold-off pressure;

subjecting the fluid to an extraction force comprising dielectrophoresis to form the fluid packet and extract the fluid packet from the vessel onto a surface; and

removing the fluid packet from the surface through an exit port.

2. The method of claim 1, wherein the extraction force is produced by an electrode.

3. The method of claim 2, wherein the electrode is coupled to the surface.

4. The method of claim 1, wherein the extraction force is produced by an electrode array.

5. The method of claim 1, wherein the vessel comprises a flow-through injector.

6. The method of claim 1, wherein the pressure is between 65% and 85% of the holdoff pressure.

7. The method of claim 6, wherein the pressure is between 75% and 85% of the holdoff pressure.

8. The method of claim 6, wherein the size of the fluid packet is electronically controlled.

9. The method of claim 1, wherein there are two or more exit ports.

10. The method of claim 1, wherein the exit port is coupled to a conventional fluidics device.

11. The method of claim 1, further comprising the metered injection of two or more fluid packets from two or more pressurized vessels.

12. The method of claim 11, further comprising using a switching pump, wherein the switching pump switches the extraction force between a first fluid packet in a first pressurized vessel and a second fluid packet in a second pressurized vessel.

13. A method for metered injection of a fluid packet, comprising:

pressurizing a vessel containing a first fluid to a pressure less than or equal to a hold off pressure, the first fluid comprising a first dielectric material;

energizing one or more electrodes coupled to a surface adjacent the vessel, the surface including a second fluid comprising a second dielectric material;

subjecting the first fluid to an extraction force comprising dielectrophoresis from the one or more electrodes to form the fluid packet and extract the fluid packet from the vessel onto a surface; and

removing the fluid packet from the surface through an exit port.

14. An apparatus for moving a fluid packet, the apparatus comprising:

a vessel configured to contain a fluid;

a pressure manifold coupled to the vessel;

a pressure reservoir coupled to the manifold and configured to pressurize the vessel to a pressure less than or equal to a hold off pressure;

a device capable of generating a programmable extraction force, the extraction force comprising dielectrophoresis and being configured to form the fluid packet and extract the fluid packet from the vessel onto a surface;

an exit port coupled to the surface and configured to receive the fluid packet.

15. The apparatus of claim 14, wherein the exit port is hydrophilic.

16. The apparatus of claim 14, comprising a plurality of exit ports.

17. The apparatus of claim 14, further comprising a conventional fluidics device coupled to the exit port.

18. The apparatus of claim 14, wherein the vessel comprises a flow-through injector.

19. The apparatus of claim 14, wherein there are two or more pressurized vessels.

20. The apparatus of claim 19, further comprising using switching pump, wherein the switching pump is configured to switch the extraction force between a first fluid packet in a first pressurized vessel and a second fluid packet in a second pressurized vessel.