Electroactive polymer devices for controlling fluid flow

• US 7,537,197 B2
• Filed: 07/29/2007
• Issued: 05/26/2009
• Est. Priority Date: 07/20/1999
• Status: Expired due to Term

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Kornbluh, Roy David, Rosenthal, Marcus, Pelrine, Ronald E., Heim, Jonathan R., Heydt, Richard P., Eckerle, Joseph S.
• Primary Examiner(s): Fristoe, Jr., John K
• Application Number:
  US11/829,920
• Publication Number:
  US 20080245985A1
• Time in Patent Office: 667 Days
• Field of Search: 251/129.01, 251/129.08, 239/597, 239/601, 239/602
• US Class Current: 251/129.06
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 2099/0096 Fuel injection devices
• 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 99/0005 Lift valves
• CPC Class Codes: F16K 99/0011 Gate valves or sliding valves
• CPC Class Codes: F16K 99/0013 Rotary valves
• CPC Class Codes: F16K 99/0028 Valves having multiple inlets or outlets
• CPC Class Codes: F16K 99/0049 using an electroactive polymer [EAP]
• CPC Class Codes: Y10T 137/2191 By non-fluid energy field affecting input [e.g., transducer]
• CPC Class Codes: Y10T 137/2213 Electrically-actuated element [e.g., electro-mechanical transducer]

Abstract

The invention describes devices for controlling fluid flow, such as valves. The devices may include one or more electroactive polymer transducers with an electroactive polymer that deflects in response to an application of an electric field. The electroactive polymer may be in contact with a fluid where the deflection of the electroactive polymer may be used to change a characteristic of the fluid. Some of the characteristic of the fluid that may be changed include but are not limited to 1) a flow rate, 2) a flow direction, 3) a flow vorticity, 4) a flow momentum, 5) a flow mixing rate, 6) a flow turbulence rate, 7) a flow energy, 8) a flow thermodynamic property. The electroactive polymer may be a portion of a surface of a structure that is immersed in an external fluid flow, such as the surface of an airplane wing or the electroactive polymer may be a portion of a surface of a structure used in an internal flow, such as a bounding surface of a fluid conduit.

Claims

1. A fluid flow device comprising:

an electroactive polymer transducer comprising at least two compliant electrodes and an electroactive polymer in electrical communication with the at least two compliant electrodes, wherein a portion of the electroactive polymer is arranged to deflect from a first position to a second position in response to a change in electric field applied to the at least two compliant electrodes;

at least one surface of the device in contact with a fluid and operatively coupled to the electroactive polymer transducer, wherein the deflection of the portion of the electroactive polymer causes a change in a characteristic of the fluid that is transmitted to the fluid via the one surface,

wherein the electroactive polymer has an elastic modulus below about 100 MPa.

2. The fluid flow device of claim 1, wherein the characteristic of the fluid is selected from the group consisting of 1) a flow rate, 2) a flow direction, 3) a flow vorticity, 4) a flow momentum, 5) mixing, 6) flow turbulence, 7) fluid energy, 8) a fluid thermodynamic property, 9) a fluid rheological property.

3. The fluid flow device of claim 1, wherein the at least two compliant electrodes are located on opposing surfaces of the electroactive polymer.

4. The fluid flow device of claim 1, wherein the one surface is operatively coupled to the electroactive polymer transducer via a mechanical linkage.

5. The fluid flow device of claim 1, wherein the fluid flow device is a valve.

6. The fluid flow device of claim 1, wherein the electroactive polymer transducer comprises a rolled transducer.

7. The fluid flow device of claim 6, wherein the rolled transducer is adapted to deflect axially to perform as a linear actuator.

8. The fluid flow device of claim 6, wherein said axial deflection results in a mechanical force that is adapted to open or close an associated valve.

9. The fluid flow device of claim 6, wherein the rolled transducer includes a plurality of layers.

10. A valve, comprising:

an inlet and an exit adapted to allow fluid to enter and exit the valve;

a flow path between the inlet and exit adapted to allow fluid to pass through the valve;

at least one transducer comprising an electrode and an electroactive polymer in electrical communication therewith, wherein the electroactive polymer has an elastic modulus below about 100 MPa, and wherein at least a portion of the electroactive polymer is arranged to deflect from a first position to a second position in response to a change in electric field; and

a structure operatively coupled to said at least one transducer and said flow path, wherein the deflection of the portion of electroactive polymer causes an operating position of the structure to change such that the flow path is changed thereby.

11. The valve of claim 10, wherein the operation of said structure includes a first operating position and a second operating position.

12. The valve of claim 11, wherein said structure being in said first operating position results in said flow path being closed, and wherein said structure being in said second operating position results in said flow path being open.

13. The valve of claim 10, wherein said at least one transducer comprises a rolled transducer.

14. The valve of claim 13, wherein the rolled transducer is adapted to deflect axially to perform as a linear actuator.

15. The valve of claim 14, wherein said axial deflection results in a mechanical force that is adapted to open or close an associated valve.

16. The valve of claim 13, wherein the rolled transducer includes a plurality of layers.

17. The valve of claim 16, wherein each of said plurality of layers includes at least a portion of electrode and at least a portion of electroactive polymer.