ELECTROACTIVE POLYMER TRANSDUCERS FOR TACTILE FEEDBACK DEVICES

• US 20120126959A1
• Filed: 11/04/2009
• Published: 05/24/2012
• Est. Priority Date: 11/04/2008
• Status: Abandoned Application

• Current Assignee: Bayer Materialscience AG (Covestro AG)
• Original Assignee: Bayer Materialscience AG (Covestro AG)
• Inventors: Weaber, Chris A., Polyakov, Ilya, Zarrabi, Alireza, Hitchcock, Roger
• Application Number:
  US13/127,140
• Publication Number:
  US 20120126959A1
• Time in Patent Office: Days
• US Class Current: 340/407.1
• CPC Class Codes: B06B 1/0688 with foil-type piezoelectric elements, e.g. PVDF
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: H10N 30/063 Forming interconnections, e.g. connection electrodes of multilayered piezoelectric or electrostrictive parts
• CPC Class Codes: H10N 30/206 using only longitudinal or thickness displacement, e.g. d33 or d31 type devices
• CPC Class Codes: H10N 30/50 having a stacked or multilayer structure
• CPC Class Codes: H10N 30/857 Macromolecular compositions
• CPC Class Codes: H10N 30/874 embedded within piezoelectric or electrostrictive material, e.g. via connections

Abstract

Electroactive transducers as well as methods of producing a haptic effect in a user interface device simultaneously with a sound generated by a separately generated audio signal and electroactive polymer transducers for sensory feedback applications in user interface devices are disclosed.

Claims

1. A method of producing a haptic effect in a user interface device simultaneously with a sound generated by a separately generated audio signal, the method comprising:

routing the audio signal to a filtering circuit;

altering the audio signal to produce a haptic drive signal by filtering a range of frequencies below a predetermined frequency; and

providing the haptic drive signal to a power supply coupled to an electroactive polymer transducer such that the power supply actuates the electroactive polymer transducer to drive the haptic effect simultaneously to the sound generated by the audio signal.

2. The method of claim 1, further comprising driving the electroactive polymer transducer to generate a sound effect using the filtered signal.

3. The method of claim 1, where the predetermined frequency comprises an optimal frequency of the electroactive polymer actuator.

4. The method of claim 1, where the pre-determined frequency comprises 200 hertz.

5. The method of claim 1, wherein altering the audio signal comprises filtering the positive portion of an audio waveform of the audio signal to produce the haptic signal.

6. The method of claim 1, wherein the electroactive polymer comprises a two phase electroactive polymer actuator and where altering the audio signal comprises filtering a positive portion of an audio waveform of the audio signal to drive a first phase of the electroactive polymer transducer, and inverting a negative portion of the audio waveform of the audio signal to drive a second phase of the electro active polymer transducer to improve performance of the electro active polymer transducer.

7. The method of claim 1, the audio signal comprises a sine waveform, and where altering the audio signal comprises converting the sine wave form to produce the haptic drive signal having a square waveform.

8. A method of producing a haptic effect in a user interface device simultaneously with a sound generated by a separately generated audio signal, the method comprising:

routing the audio signal to a triggering circuit;

generating a haptic drive signal based on a characteristic of the audio signal; and

providing the haptic drive signal to a power supply coupled to an electroactive polymer transducer such that the power supply actuates the electroactive polymer transducer to drive the haptic effect by controlling a haptic output frequency of the electroactive polymer transducer.

9. The method of claim 8, further comprising driving the electroactive polymer transducer to generate a sound effect using the filtered signal.

10. The method of claim 8, where the characteristic of the audio signal comprises a threshold voltage of the audio signal.

11. A transducer comprising:

an electroactive polymer film comprising a dielectric elastomer layer, wherein a portion of the dielectric elastomer layer is stretched between first and second electrodes wherein at least one overlapping portion of the electrodes defines an active film region with at least one remaining portion of film defining an inactive film region;

a first conductive layer disposed on at least a portion of the inactive film region and electrically coupled to the first electrode, and a second conductive layer disposed on at least a portion of the inactive film region and electrically coupled to the second electrode; and

at least one passive incompressible polymer layer, the incompressible polymer layer extending over at least a portion of one side of the electroactive polymer film, wherein activation of the active region changes a thickness dimension of the incompressible passive polymer layer.

12. The transducer of claim 11, further comprising a first conductive via extending through the transducer at a location which includes the first electrode and a second conductive via extending through the transducer at a location which includes the second electrode.

13. The transducer of claim 11, further comprising a first and a second passive incompressible polymer layers, where the first and second passive incompressible polymer layers are located on each side of the electroactive polymer film.

14. A transducer assembly comprising;

at least two stacked layers of electroactive polymer film, each electroactive polymer film comprising a thin dielectric elastomer layer, wherein a portion of the dielectric elastomer layer is sandwiched between first and second electrodes wherein the overlapping portions of the electrodes define an active film region with the remaining portion of film defining an inactive film region, wherein the active film regions of the respective layers of electroactive polymer film are in stacked alignment and the inactive active film regions of the respective layers of electroactive polymer film are in stacked alignment;

a first conductive layer disposed on at least a portion of the inactive film region of each electroactive polymer film and electrically coupled to the first electrode thereof, and a second conductive layer disposed on at least a portion of the inactive film region of each electroactive polymer film and electrically coupled to the second electrode thereof; and

a passive incompressible polymer layer over each exposed side of the electroactive polymer films, wherein activation of the active regions changes a thickness dimension of the passive incompressible polymer layer.

15. The transducer assembly of claim 14, further comprising a first conductive via extending through the stacked electroactive polymer films at a location which includes the first electrode of each film and a second conductive via extending through the stacked electroactive polymer films at a location which includes the second electrodes.

16. An inertial electroactive polymer transducer, comprising:

an electroactive polymer film stretched between a top and bottom frame components, where a central portion of frame is open to expose a central surface of the electroactive polymer film;

a first output member on the central surface of the electroactive polymer film; and

at least one inertial mass affixed to the output disk wherein upon application of voltage difference across a first and second electrodes on the electroactive polymer film causes displacement of the polymer film causing the inertial mass to move.

17. The inertial electroactive polymer transducer of claim 16, further comprising a second electroactive polymer film sandwiched between a top and bottom second frame components, where a central portion of second frame is open to expose a second central surface of the electroactive polymer film;

and

a second output member on the central surface of the electroactive polymer film, where the inertial mass is located between the affixed between the first and second output members.

18. The inertial electroactive polymer transducer of claim 16, wherein the electroactive polymer is configured to displace in a plane of the electroactive polymer film.

19. The inertial electroactive polymer transducer of claim 16, wherein the electroactive polymer is configured to displace in a direction perpendicular to a plane of the electroactive polymer film.

20. The inertial electroactive polymer transducer of claim 16, wherein the electroactive polymer is spring biased.

21. The inertial electroactive polymer transducer of claim 16, wherein the inertial electroactive polymer transducer further comprises at least one housing assembly.

22. The inertial electroactive polymer transducer of claim 21, wherein the electroactive polymer film and inertial mass are encased within the housing assembly.

23. The inertial electroactive polymer transducer of claim 22, where the housing assembly is configured to electrically insulate the inertial electroactive polymer transducer.

24. The inertial electroactive polymer transducer of claim 21, wherein the housing assembly further comprises at least one mechanical stop to limit movement of the inertial mass to prevent damage to the actuator cartridge resulting from excessive movement.

25. The inertial electroactive polymer transducer of claim 24, where the at least one mechanical stop comprises at least one fastener located within the housing assembly.

26. The inertial electroactive polymer transducer of claim 16, where the inertial mass comprises a shaped surface to engage a stop within the housing to limit movement of the inertial mass to a distance between the shaped surface and the stop to prevent damage to the actuator cartridge resulting from excessive movement.

27. The inertial electroactive polymer transducer of claim 16, where a weight of the inertial mass is selected dependent upon a resonant frequency of the electroactive polymer film.

28. The inertial electroactive polymer transducer of claim 16, where the housing assembly comprises a portion of a housing of a user interface device.