System and method for controlling fluid flow in a microfluidic circuit

• US 20070204926A1
• Filed: 03/02/2006
• Published: 09/06/2007
• Est. Priority Date: 03/02/2006
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Yin, Hongfeng, Killeen, Kevin, Brennen, Reid, Fazzio, Ronald, Beerling, Timothy
• Application Number:
  US11/366,197
• Publication Number:
  US 20070204926A1
• Time in Patent Office: Days
• US Class Current: 137/828
• CPC Class Codes: B01L 2200/143 Quality control, feedback systems
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2400/0677 phase change valves; Meltable, freezing, dissolvable plugs; Destructible barriers
• CPC Class Codes: B01L 2400/082 Active control of flow resistance, e.g. flow controllers
• 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 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: F16K 2099/0074 using photolithography, e.g. etching
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 2099/0084 Chemistry or biology, e.g. "lab-on-a-chip" technology
• CPC Class Codes: F16K 99/0001 Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0019 Valves using a microdroplet or microbubble as the valve member
• CPC Class Codes: F16K 99/0034 Operating means specially adapted for microvalves
• CPC Class Codes: F16K 99/0044 using thermo-electric means
• CPC Class Codes: G05D 7/0694 by action on throttling means or flow sources of very small size, e.g. microfluidics microvalves F16K99/0001; microstructural devices per se B81B
• CPC Class Codes: Y10T 137/2196 Acoustical or thermal energy

Abstract

A system for controlling fluid flow in a microfluidic circuit includes at least one microfluidic channel, and a heating element adjacent the at least one microfluidic channel, wherein when activated, the heating element boils liquid in the at least one microfluidic channel.

Claims

1. A system for controlling fluid flow in a microfluidic circuit, comprising:

at least one microfluidic channel;

a heating element adjacent the at least one microfluidic channel, wherein when activated, the heating element boils liquid in the at least one microfluidic channel; and

a bubble in the microfluidic channel, the bubble modulating fluid flow in the microfluidic channel.

2. The system of claim 1, in which the bubble at least partially fills the microfluidic channel.

3. The system of claim 1, further comprising a plurality of microfluidic channels arranged in parallel.

4. The system of claim 3, in which the plurality of microfluidic channels are of differing cross-sectional area.

5. The system of claim 4, in which each microfluidic channel comprises at least one heating element.

6. The system of claim 5, in which each microfluidic channel comprises a primary heating element and a secondary heating element.

7. The system of claim 5, further comprising feedback electronics, the feedback electronics configured to monitor fluid flow in the microfluidic channel and control the fluid flow by selectively activating the at least one heating element.

8. A method for controlling fluid flow in a microfluidic circuit, comprising:

providing a fluid cavity having fluid;

providing a heating element in the vicinity of the fluid cavity;

providing a power source to the heating element; and

heating the fluid such that the fluid boils, thus creating a bubble in the fluid cavity.

9. The method of claim 8, further comprising using the bubble to modulate fluid flow in a microfluidic channel associated with the fluid cavity.

10. The method of claim 8, in which a plurality of microfluidic channels arranged in parallel.

11. The method of claim 10, in which the plurality of microfluidic channels are of differing cross-sectional area.

12. The method of claim 11, in which each microfluidic channel comprises at least one heating element.

13. The method of claim 12, in which each microfluidic channel comprises a primary heating element and a secondary heating element.

14. The method of claim 12, further comprising monitoring fluid flow in the microfluidic channel and controlling the fluid flow by selectively activating the at least one heating element.

15. A system for controlling fluid flow in a microfluidic circuit, comprising:

at least one microfluidic channel;

a heating element adjacent the at least one microfluidic channel, wherein when activated, the heating element boils liquid in the at least one microfluidic channel forming a bubble in the at least one microfluidic channel, the bubble modulating fluid flow in the microfluidic channel.

16. The system of claim 15, further comprising a plurality of microfluidic channels arranged in parallel.

17. The system of claim 16, in which the plurality of microfluidic channels are of differing cross-sectional area.

18. The system of claim 17, in which each microfluidic channel comprises at least one heating element.

19. The system of claim 18, in which each microfluidic channel comprises a primary heating element and a secondary heating element.

20. The system of claim 18, further comprising feedback electronics, the feedback electronics configured to monitor fluid flow in the microfluidic channel and control the fluid flow by selectively activating the at least one heating element.