Structures and methods for increasing the speed of electroactive polymers

• US 8,383,226 B2
• Filed: 03/03/2005
• Issued: 02/26/2013
• Est. Priority Date: 03/12/2004
• Status: Active Grant

• Current Assignee: University of Maryland
• Original Assignee: University of Maryland
• Inventors: Smela, Elisabeth, Wang, Xuezheng
• Primary Examiner(s): Vo, Hai
• Application Number:
  US10/592,266
• Publication Number:
  US 20070205398A1
• Time in Patent Office: 2,917 Days
• Field of Search: 428/131, 428/315.5, 428/315.7
• US Class Current: 428/131
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: F03G 7/005 Electro-chemical actuators; Actuators having a material for absorbing or desorbing gas, e.g. a metal hydride; Actuators using the difference in osmotic pressure between fluids; Actuators with elements stretchable when contacted with liquid rich in ions, with UV light, with a salt solution
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 4/045 Electrochemical coating; Electrochemical impregnation
• CPC Class Codes: H01M 4/0497 Chemical precipitation
• CPC Class Codes: H01M 4/137 Electrodes based on electro-active polymers
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/602 Polymers
• CPC Class Codes: H01M 8/0289 Means for holding the electrolyte solid polymer electrolytes H01M8/1018
• CPC Class Codes: H01M 8/10 Fuel cells with solid electrolytes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/24273 including aperture
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/249979 Specified thickness of void-containing component [absolute or relative] or numerical cell dimension

Abstract

Structures are provided that include electroactive polymers. According to these structures, the electroactive materials have enhanced conductivity in a first direction. Also, the structures include either pores or inclusions. These pores or inclusions are non-parallel to the first direction. In addition, methods for forming structures that include electroactive polymers that have enhanced conductivity in a first direction are provided. These methods allow for pores and/or inclusions to be formed in the electroactive polymers.

Claims

1. A structure, comprising:

an ionic electroactive polymer having morphological features that confer anisotropic ion or mass conductivity within the polymer due to enhanced ion conductivity or enhanced mass conductivity in a first direction, wherein the first direction is substantially parallel to a surface of the polymer and the first direction is a fast transport direction, wherein the mass comprises an atom or molecule, and wherein the ion comprises a charged atom or a charged molecule; and

a plurality of pores located within the electroactive polymer, wherein the plurality of pores are substantially perpendicular to the first direction,

wherein the plurality of pores comprise at least one of trenches, stripes, or cross-hatches.

2. The structure of claim 1, wherein the electroactive polymer comprises a conjugated polymer.

3. The structure of claim 2, wherein the electroactive polymer comprises a polymer selected from at least one family of polymers selected from among polypyrroles, polyanalines, polythiophenes, paraphenylenevinylene and polyacetylene.

4. The structure of claim 1, wherein the electroactive polymer comprises crystalline regions,

wherein anisotropic conductivity is conferred upon the polymer.

5. The structure of claim 1, wherein, in the polymer,

chains are aligned substantially in a plane or substantially parallel to a line to confer anisotropic conductivity upon the polymer, or

monomer units of the chains are oriented, with no chain alignment, to confer anisotropic conductivity upon the polymer.

6. The structure of claim 1, wherein at least one pore in the plurality of pores extends from a surface of the polymer to an interior portion thereof.

7. The structure of claim 1, wherein the at least one pore in the plurality of pores is slanted relative to the first direction.

8. The structure of claim 1, wherein at least one pore in the plurality of pores has a diameter of between 1 nanometer and 1 micrometer.

9. The structure of claim 1, wherein at least one pore in the plurality of pores has a diameter of between 10 nanometers and 100 nanometers.

10. The structure of claim 1, wherein the electroactive polymer comprises a surfactant dopant.

11. The structure of claim 1, wherein the plurality of pores, which are located within the electroactive polymer, are configured to provide ions with access to the fast transport direction of the polymer.

12. A structure, comprising:

a matrix including an electroactive polymer having morphological features that confer anisotropic ion or mass conductivity in the polymer due to enhanced ion conductivity or enhanced mass conductivity in a first direction, wherein the first direction is substantially parallel to a surface of the polymer and the first direction is a fast transport direction, wherein the mass comprises an atom or molecule, and wherein the ion comprises a charged atom or a charged molecule; and

a plurality of inclusions included within the matrix, wherein at least one inclusion in the plurality of inclusions comprises a fast-ion transporting material, and wherein the plurality of inclusions are substantially perpendicular to the first direction.

13. The structure of claim 12, wherein the matrix comprises a conjugated polymer.

14. An apparatus, comprising:

an ionic electroactive polymer that comprises at least one fast ion transport direction and a plurality of pores,

wherein the fast ion transport direction is substantially parallel to a surface of the ionic electroactive polymer,

wherein the plurality of pores are substantially perpendicular to the fast ion transport direction,

wherein the plurality of pores are configured to provide ions with access to the fast ion transport direction of the ionic electroactive polymer, and

wherein the plurality of pores comprise at least one of trenches, stripes, or cross-hatches.

15. The apparatus according to claim 14, wherein in the ionic electroactive polymer,

polymer chains are aligned substantially in a plane or substantially parallel to a line to confer anisotropic conductivity upon the ionic electroactive polymer, or

monomer units of the polymer chains are oriented, with no chain alignment, to confer anisotropic conductivity upon the ionic electroactive polymer.

16. The apparatus according to claim 14, wherein the plurality of pores are further configured to allow the ions or mass to have access to the morphological features that confer the anisotropic conductivity.