Mechanically-actuated microfluidic valve

• US 7,981,386 B2
• Filed: 06/20/2008
• Issued: 07/19/2011
• Est. Priority Date: 06/20/2008
• Status: Expired due to Fees

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, McAvoy, Gregory John
• Primary Examiner(s): Bullock; In Suk
• Assistant Examiner(s): Kingan; Timothy G
• Application Number:
  US12/142,781
• Publication Number:
  US 20090314971A1
• Time in Patent Office: 1,124 Days
• Field of Search: 422/103, 422500-505, 251/11, 251/129.01, 137/67, 137/833, 137/341, 137/799
• US Class Current: 422/538
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 2400/0633 with moving parts
• CPC Class Codes: B01L 2400/0655 pinch valves
• 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: C08L 2201/12 Shape memory
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F04B 43/14 having plate-like flexible members
• 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 99/0007 of cantilever type
• CPC Class Codes: F16K 99/0038 using shape memory alloys
• CPC Class Codes: Y10T 137/1624 Destructible or deformable element controlled
• CPC Class Codes: Y10T 137/2224 Structure of body of device
• CPC Class Codes: Y10T 137/6606 With electric heating element
• CPC Class Codes: Y10T 137/9138 Flexible

Abstract

A mechanically-actuated microfluidic valve. The valve comprises an inlet port; an outlet port; a thermal bend actuator; and a valve closure member cooperating with the actuator. Actuation of the thermal bend actuator causes movement of the closure member, thereby regulating a flow of fluid from the inlet port to the outlet port.

Claims

1. A mechanically-actuated microfluidic valve comprising:

an inlet port;

an outlet port;

a weir positioned between said inlet and outlet ports;

a pair of opposed thermal bend actuators, each of said actuators comprising;

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; and

a valve closure member cooperating with said actuators, such that actuation of said actuators causes movement of said closure member relative to a sealing face of said weir, thereby regulating a flow of fluid from said inlet port to said outlet port, wherein said closure member is comprised of an elastomer fused or bonded to the active beams of said actuators and bridges a space therebetween.

2. The microfluidic valve of claim 1, wherein said active beam is fused to said passive beam.

3. The microfluidic valve of claim 1, wherein said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling said actuator.

4. The microfluidic valve of claim 1, wherein said thermoelastic material is selected from the group consisting of:

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

5. The microfluidic valve of claim 1, wherein said passive beam is comprised of a material selected from the group consisting of:

silicon oxide, silicon nitride and silicon oxynitride.

6. The microfluidic valve of claim 1, wherein at least said actuator is defined in a MEMS layer of a silicon substrate.

7. The microfluidic valve of claim 6, wherein said substrate comprises control circuitry for controlling said actuator, said control circuitry being contained in at least one CMOS layer of said substrate.

8. The microfluidic valve of claim 1, wherein said inlet port and said outlet port are defined in a MEMS layer of a silicon substrate.

9. The microfluidic valve of claim 1, wherein said inlet port and said outlet port are defined in polymeric microfluidics platform.

10. The microfluidic valve of claim 1, wherein said closure member is comprised of polydimethylsiloxane (PDMS).

11. The microfluidic valve of claim 1, wherein said actuation causes open or closing of said valve.

12. The microfluidic valve of claim 1, wherein said actuation causes partial opening or partial closing of said valve.