Thermal Bend Actuated Microfluidic Peristaltic Pump

• US 20090317273A1
• Filed: 06/20/2008
• Published: 12/24/2009
• Est. Priority Date: 06/20/2008
• Status: Active Grant

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, McAvoy, Gregory John
• Granted Patent: US 8,080,220 B2
• Time in Patent Office: Days
• US Class Current: 417/477.100
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F04B 43/12 having peristaltic action
• CPC Class Codes: F04B 43/14 having plate-like flexible members
• CPC Class Codes: Y10T 137/2202 By movable element
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

A peristaltic microfluidic pump. The pump comprises a pumping chamber positioned between an inlet and an outlet; a plurality of moveable fingers positioned in a wall of the pumping chamber, the fingers being arranged in a row along the wall; and a plurality of thermal bend actuators. Each actuator is associated with a respective finger such that actuation of the thermal bend actuator causes movement of the respective finger into the pumping chamber. The pump is configured to provide a peristaltic pumping action in the pumping chamber via movement of the fingers.

Claims

1. A peristaltic microfluidic pump comprising:

a pumping chamber positioned between an inlet and an outlet;

a plurality of moveable fingers positioned in a wall of said pumping chamber, said fingers being arranged in a row along said wall; and

a plurality of thermal bend actuators, each actuator being associated with a respective finger such that actuation of said thermal bend actuator causes movement of said respective finger into said pumping chamber,

wherein said pump is configured to provide a peristaltic pumping action in said pumping chamber via movement of said fingers.

2. The microfluidic pump of claim 1, wherein the pumping chamber is elongate, and said fingers are arranged in a row along a longitudinal wall of said pumping chamber.

3. The microfluidic pump of claim 2, wherein each finger extends transversely across said chamber.

4. The microfluidic pump of claim 3, wherein said fingers are arranged in opposed pairs of fingers, each finger in an opposed pair pointing towards a central longitudinal axis of said pumping chamber.

5. The microfluidic pump of claim 1, wherein each finger comprises said thermal bend actuator.

6. The microfluidic pump of claim 1, wherein said pumping chamber comprises a roof spaced apart from a substrate, and sidewalls extending between said roof and a floor defined by said substrate.

7. The microfluidic pump of claim 6, wherein said fingers are positioned in said roof.

8. The microfluidic pump of claim 1, wherein each thermal bend actuator comprises:

an active beam comprised of a thermoelastic material; and

a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.

9. The microfluidic pump of claim 8, wherein an extent of each finger is defined by said passive beam.

10. The microfluidic pump of claim 8, wherein said active beam is fused to said passive beam.

11. The microfluidic pump of claim 8, wherein said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling each actuator.

12. The microfluidic pump of claim 8, wherein said thermoelastic material is selected from the group comprising:

titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.

13. The microfluidic pump of claim 8, wherein said passive beam is comprised of a material selected from the group comprising:

silicon oxide, silicon nitride and silicon oxynitride.

14. The microfluidic pump of claim 6, wherein said substrate comprises control circuitry for controlling each actuator.

15. The microfluidic pump of claim 14, wherein said substrate is a silicon substrate having said control circuitry contained in at least one CMOS layer thereof.

16. The microfluidic pump of claim 1, wherein said wall is covered with a polymeric layer, said polymeric layer providing a mechanical seal between each finger and said wall.

17. The microfluidic pump of claim 16, wherein said polymeric layer is comprised of polydimethylsiloxane (PDMS).

18. The microfluidic pump of claim 6, wherein said inlet is defined in said substrate.

19. A microfluidic system comprising the microfluidic pump of claim 1.

20. The microfluidic system of claim 19, which is a LOC device or a Micro Total Analysis System.