Electroactive polymer devices for moving fluid

• US 7,362,032 B2
• Filed: 03/14/2006
• Issued: 04/22/2008
• Est. Priority Date: 07/20/1999
• Status: Expired due to Term

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Pelrine, Ronald E., Kornbluh, Roy David, Stanford, Scott E., Pei, Qibing, Heydt, Richard, Eckerle, Joseph S., Heim, Jonathan R.
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US11/375,930
• Publication Number:
  US 20060158065A1
• Time in Patent Office: 770 Days
• Field of Search: 310/800, 310/309
• US Class Current: 310/309
• CPC Class Codes: A61M 2205/0283 Electro-active polymers [EAP]
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/14212 Pumping with an aspiration and an expulsion action
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/14236 Screw, impeller or centrifugal type pumps
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/268 the displacement member being flexible, e.g. membranes, diaphragms or bladders
• CPC Class Codes: A61M 60/454 generated by electro-active actuators, e.g. using electro-active polymers or piezoelectric elements
• CPC Class Codes: A61M 60/894 Passive valves, i.e. valves actuated by the blood
• CPC Class Codes: A63H 3/365 allowing a choice of facial features, e.g. to change the facial expression change of expression through animation A63H3/48, self-moving A63H13/005; movable eyes A63H3/40
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2401/11 Electrostrictive transducers
• CPC Class Codes: B60G 2401/23 Memory materials
• CPC Class Codes: B60G 2500/20 Spring action or springs
• CPC Class Codes: F01L 2301/00 Using particular materials
• CPC Class Codes: F02G 1/043 the engine being operated by expansion and contraction of a mass of working gas which is heated and cooled in one of a plurality of constantly communicating expansible chambers, e.g. Stirling cycle type engines
• CPC Class Codes: F02G 2243/52 : acoustic
• CPC Class Codes: F04B 17/00 : Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 35/00 : Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
• CPC Class Codes: F04B 35/04 : the means being electric
• CPC Class Codes: F04B 35/045 : using solenoids
• CPC Class Codes: F04B 43/043 : Micropumps
• CPC Class Codes: F04B 43/08 : having tubular flexible members F04B43/12 takes precedence
• CPC Class Codes: F04B 43/084 : the tubular member being deformed by stretching or distortion
• CPC Class Codes: F04B 43/09 : Pumps having electric drive
• CPC Class Codes: F04B 43/095 : Piezoelectric drive
• CPC Class Codes: F04B 43/14 : having plate-like flexible members
• CPC Class Codes: F04D 33/00 : Non-positive-displacement pumps with other than pure rotation, e.g. of oscillating type F04D35/00 takes precedence; hand-held fans A45B
• CPC Class Codes: F05C 2225/08 : Thermoplastics
• CPC Class Codes: F15C 5/00 : Manufacture of fluid circuit elements; Manufacture of assemblages of such elements integrated circuits
• CPC Class Codes: F16F 15/005 : using electro- or magnetostrictive actuation means generating of mechanical vibrations operating with electrostriction B06B1/06, with magnetostriction B06B1/08; vehicle suspension arrangements characterised by use of piezoelectric elements B60G17/01941; piezoelectric, electrostrictive and magnetostrictive devices per se H10N30/00
• CPC Class Codes: F25B 9/14 : characterised by the cycle used, e.g. Stirling cycle
• CPC Class Codes: H02N 11/006 : Motors
• CPC Class Codes: H04R 19/02 : Loudspeakers H04R19/01 takes precedence
• CPC Class Codes: H04R 23/00 : Transducers other than those covered by groups H04R9/00 - H04R21/00 diaphragms for transducers of the distributed-mode type H04R7/045
• CPC Class Codes: Y10S 310/80 : Piezoelectric polymers, e.g. PVDF

Abstract

The invention describes devices for performing thermodynamic work on a fluid, such as pumps, compressors and fans. The thermodynamic work may be used to provide a driving force for moving the fluid. Work performed on the fluid may be transmitted to other devices, such as a piston in a hydraulic actuation device. 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 perform thermodynamic work on the fluid. The devices may be designed to efficiently operate at a plurality of operating conditions, such as operating conditions that produce an acoustic signal above or below the human hearing range. The devices may be used in thermal control systems, such as refrigeration system, cooling systems and heating systems.

Claims

1. A device for performing thermodynamic work on a fluid, the device comprising:

one or more transducers, each transducer comprising at least two electrodes and an electrostatic polymer in electrical communication with the at least two electrodes wherein a portion of the electrostatic polymer is arranged to deflect from a first position to a second position in response to a change in electric field, and wherein the electrostatic polymer has a maximum actuation pressure between about 0.05 MPa and about 10 MPa;

at least one surface in contact with a fluid and operatively coupled to the one or more transducers wherein the deflection of the portion of the electrostatic polymer causes the thermodynamic work to be imparted to the fluid and wherein the thermodynamic work is transmitted to the fluid via the one surface.

2. The device of claim 1, wherein the maximum actuation pressure is between about 0.3 MPa and about 3 MPa.

3. The device of claim 1, wherein the device is selected from the group consisting of a pump, a compressor, a hydraulic actuator, a fan and combinations thereof.

4. The device of claim 1, wherein the deflection of the portion of the electrostatic polymer changes the at least one surface from a first shape to a second shape.

5. The device of claim 1, wherein the fluid is one of compressible, incompressible or combinations thereof.

6. The device of claim 1, wherein the fluid is one of a Newtonian or a non-Newtonian fluid.

7. The device of claim 1, wherein the fluid is selected from the group consisting of a gas, a plasma, a liquid, a mixture of two or more immiscible liquids, a supercritical fluid, a slurry, a suspension, and combinations thereof.

8. The device of claim 1, wherein the deflection of the one portion of the electrostatic polymer generates one of rotational motion, linear motion, vibrational motion or combinations thereof for the one surface.

9. The device of claim 1, wherein the thermodynamic work provides a driving force to move the fluid from a first location to a second location.

10. The device of claim 1, further comprising one or more fluid conduits used to provide at least a portion of a flow path for allowing the fluid to travel through the device.

11. The device of claim 1, further comprising a fluid conduit wherein the deflection of the portion of the electrostatic polymer generates a peristaltic motion in the fluid conduit to move the fluid through the fluid conduit.

12. The device of claim 1, further comprising one or more valves for controlling one of a flow rate, a flow direction and combinations thereof of the fluid through the flow path.

13. The device of claim 1, further comprising a heat exchanger for adding or for removing heat energy from the fluid.

14. The device of claim 1, wherein the deflection of the portion of the electrostatic polymer induces a wave like motion in the one surface and wherein the wave like motion imparts the thermodynamic work to the fluid.

15. The device of claim 1, further comprising a fluid conduit wherein the deflection of the portion of electrostatic polymer generates a wave-like motion in the fluid conduit to move fluid in the fluid conduit through the conduit.

16. The device of claim 1, further comprising an output shaft designed to receive a hydraulic force generated from a pressure in the fluid.

17. The device of claim 16, wherein the deflection in the portion of the electrostatic polymer causes the pressure in the fluid to increase and provide the hydraulic force for moving the output shaft.

18. The device of claim 1, wherein the deflection of the portion of the electrostatic polymer further causes a change in a characteristic of the fluid that is transmitted to the fluid via the one surface.

19. The device of claim 18, wherein the characteristic of the fluid is selected from the group consisting of a flow rate, a flow direction, a flow vorticity, a flow momentum, mixing, flow turbulence, fluid energy, a fluid thermodynamic property, and a fluid rheological property.

20. The device of claim 1, wherein the electrostatic polymer comprises a material selected from the group consisting of a silicone elastomer, an acrylic elastomer, a polyurethane, a copolymer comprising PVDF, and combinations thereof.

21. The device of claim 1, further comprising an insulation barrier designed or configured to protect the one surface from constituents of the fluid in contact with the one surface.

22. The device of claim 1, wherein the electrostatic polymer is elastically pre-strained at the first position to improve a mechanical response of the electrostatic polymer between the first position and second position.

23. The device of claim 1, wherein the device is a pump comprising one of the group consisting of a bellows bump, a centrifugal pump, a diaphragm pump, a rotary pump, a gear pump and an air-lift pump.

24. The device of claim 1, wherein the electrostatic polymer comprises a dielectric elastomer.