Electroactive polymer electrodes

• US 7,468,575 B2
• Filed: 07/09/2007
• Issued: 12/23/2008
• Est. Priority Date: 07/20/1999
• Status: Expired due to Term

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Kornbluh, Roy D., Pei, Qibing, Joseph, Jose P., Pelrine, Ronald E.
• Primary Examiner(s): Dougherty, Thomas M
• Application Number:
  US11/774,918
• Publication Number:
  US 20080191585A1
• Time in Patent Office: 533 Days
• Field of Search: 310/363, 310/365
• US Class Current: 310/363
• 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 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 35/045 using solenoids
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F05C 2225/08 Thermoplastics
• CPC Class Codes: F25B 9/14 characterised by the cycle used, e.g. Stirling cycle
• CPC Class Codes: H01G 5/16 using variation of distance between electrodes
• CPC Class Codes: H02N 2/023 Inchworm 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: H10N 30/098 Forming organic materials
• CPC Class Codes: H10N 30/2042 Cantilevers, i.e. having one fixed end
• CPC Class Codes: H10N 30/206 using only longitudinal or thickness displacement, e.g. d33 or d31 type devices
• CPC Class Codes: H10N 30/30 with mechanical input and electrical output, e.g. functioning as generators or sensors
• CPC Class Codes: H10N 30/308 Membrane type
• CPC Class Codes: H10N 30/857 Macromolecular compositions
• CPC Class Codes: H10N 30/87 Electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: H10N 30/878 the principal material being non-metallic, e.g. oxide or carbon based
• CPC Class Codes: Y10S 310/80 Piezoelectric polymers, e.g. PVDF
• CPC Class Codes: Y10T 29/49826 : Assembling or joining

Abstract

Described herein are transducers, their use and fabrication. The transducers convert between mechanical and electrical energy. The present invention further relates to compliant electrodes that conform to the shape of a polymer included in a transducer.

Claims

1. An electrode for use with an electroactive polymer, the electrode comprising:

a compliant portion in contact with a portion of the electroactive polymer, wherein the compliant portion comprises one or more regions of high conductivity and one or more regions of low conductivity, and wherein the one or more regions of low conductivity comprise a charge distribution layer that has a conductance greater than the electroactive polymer.

2. The electrode of claim 1 wherein the regions of high conductivity comprise a set of patterned traces.

3. The electrode of claim 2 wherein the set of patterned traces comprise a metal material.

4. The electrode of claim 2 wherein the set of patterned traces are configured to allow expansion and contraction of the electroactive polymer in multiple directions.

5. The electrode of claim 4 wherein the set of patterned traces include a zig-zag pattern.

6. The electrode of claim 1 wherein the patterned metal traces are offset from patterned metal traces included in a second electrode on an opposing side of the electroactive polymer.

7. The electrode of claim 1 wherein the charge distribution layer has a conductance less than a material used in the one or more regions of high conductivity.

8. The electrode of claim 1 wherein the one or more regions of low conductivity has a surface resistivity in the range of about 10⁶ ohms to about 10¹¹ ohms.

9. The electrode of claim 1 wherein the electrode is patterned to form an active area according to the geometry of the electrode.

10. The electrode of claim 9 wherein the set of patterned traces form the active area according to the geometry of the patterned traces.

11. The electrode of claim 1 wherein the electroactive polymer includes an additive.

12. The electrode of claim 11 wherein the additive improves at least one of polymer dielectric breakdown strength, maximum linear strain, dielectric constant, elastic modulus, response time, and actuation voltage.

13. The electrode of claim 1 wherein the charge distribution layer includes carbon black.

14. The electrode of claim 1 wherein the charge distribution layer includes colloidal silver.