ELECTROACTIVE POLYMER-BASED FLOW SENSOR AND METHODS RELATED THERETO

• US 20130199281A1
• Filed: 04/28/2011
• Published: 08/08/2013
• Est. Priority Date: 04/30/2010
• Status: Active Grant

• Current Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Original Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Inventors: Zhu, Guoming G., Tan, Xiaobo, Hung, David Ling-Shun
• Granted Patent: US 9,903,788 B2
• Time in Patent Office: Days
• US Class Current: 73/114.42
• CPC Class Codes: G01F 1/28 by drag-force, e.g. vane type or impact flowmeter
• CPC Class Codes: G01F 1/72 Devices for measuring pulsing fluid flows
• CPC Class Codes: G01M 15/02 Details or accessories of testing apparatus

Abstract

An apparatus includes an electroactive polymer member and a first electric terminal and a second electric terminal. The electroactive polymer member has a free portion configured to change position relative to a fixed portion in response to an external stimulus corresponding to at least one of a flow parameter or a fluid parameter. The first electric terminal and the second electric terminal are coupled to the electroactive polymer member. The first electric terminal and the second electric terminal provide an electrical signal in response to the change.

Claims

1. An apparatus comprising:

an electroactive polymer member having a free portion configured to change position relative to a fixed portion in response to an external stimulus corresponding to at least one of a flow parameter or a fluid parameter; and

a first electric terminal and a second electric terminal coupled to the electroactive polymer member wherein the first electric terminal and the second electric terminal provide an electrical signal in response to the change.

2. The apparatus of claim 1 wherein the electroactive polymer (EAP) member includes at least one of a conjugated polymer member and an ionic polymer-metal composite (IPMC) member.

3. The apparatus of claim 1 further including a flow channel and wherein the free portion is disposed in the flow channel.

4. The apparatus of claim 1 wherein the flow channel is configured to carry a fluid medium.

5. The apparatus of claim 1 wherein the electroactive polymer member includes at least one beam.

6. The apparatus of claim 1 wherein the free portion is cantilevered relative to the fixed portion.

7. The apparatus of claim 1 wherein the free portion has a length and a width such that a ratio of the length to width is greater than 2.

8. The apparatus of claim 1 further including a flow channel having a flow axis and wherein the free portion has a length aligned substantially perpendicular to the flow axis.

9. The apparatus of claim 1 wherein the first electric terminal is coupled to a first surface of the electroactive polymer member and the second electric terminal is coupled to a second surface of the electroactive polymer member, the first surface opposite the second surface.

10. A system comprising:

a sensor having an electrical terminal coupled to an electroactive polymer member, the terminal configured to provide a signal based on deformation of the member, the member deformable in response to at least one of a flow characteristic of a fluid medium or a fluid parameter of the fluid medium; and

a processor configured to receive the signal and configured to generate an output corresponding to the sensor.

11. The system of claim 10 further comprising a flow channel and wherein the member is disposed within the channel.

12. The system of claim 10 wherein the processor is configured to provide the output based on at least one of a stationary displacement of the member or a dynamic response of the member.

13. The system of claim 10 wherein the output is based on at least one of a peak amplitude, a decay response, or a frequency of damped oscillations.

14. The system of claim 10 wherein the output is correlated with a temperature of the fluid medium.

15. The system of claim 10 wherein the output is correlated with at least one of a flow rate, a pressure, a flow duration, a viscosity, a duty cycle, or a density.

16. The system of claim 10 wherein the fluid medium comprises a fuel.

17. A method comprising:

providing a flowing fluid medium;

positioning an electroactive polymer member in the flow channel, the member deformable based on flow of a fluid in the flow channel;

electrically coupling the electroactive polymer member to a processor; and

configuring the processor to provide an output based on an electrical signal from the member.

18. The method of claim 17 wherein providing the flowing fluid medium includes providing a flow channel.

19. The method of claim 17 wherein positioning the electroactive polymer member includes positioning an ionic polymer-metal composite (IPMC).

20. The method of claim 17 wherein positioning the member includes aligning a longitudinal axis of the member substantially perpendicular to a flow axis of the flow channel.

21. The method of claim 17 wherein electrically coupling the electroactive polymer member includes providing a first electrical contact on a first surface of the member and providing a second electrical contact on a second surface of the member, the first surface opposite the second surface.

22. The method of claim 17 wherein configuring the processor includes providing executable instructions.

23. The method of claim 22 wherein providing executable instructions includes storing data to discern a first fluid in the flow channel from a second fluid in the flow channel.

24. The method of claim 22 wherein providing executable instructions includes providing instructions to generate the output at a time substantially simultaneous with the deformation of the member.

25. The method of claim 17 further comprising discretizing the electroactive polymer member into a finite number of rigid-body elements and utilizing multi-link dynamic modeling to approximate a measured time response for the electroactive polymer member in the flowing fluid medium.

26. The method of claim 25 further comprising determining a drag force (F_di) produced by the flowing fluid medium by modeling the flowing fluid medium as a concentrated load applied at a gravity center of each of the rigid-body elements, with a drag force direction determined by a flow direction of the flowing fluid medium.

27. The method of claim 26 wherein the beam sensor is capable of identifying a viscosity of the flowing fluid medium from its electronic signal.