Microelectrode arrays

• US 5,254,235 A
• Filed: 02/26/1992
• Issued: 10/19/1993
• Est. Priority Date: 02/26/1992
• Status: Expired due to Term

• Current Assignee: YSI Incorporated (Xylem, Inc.)
• Original Assignee: The Yellow Springs Instrument Company Incorporated
• Inventors: Wu, Huan P.
• Primary Examiner(s): Valentine, Donald R.
• Application Number:
  US07/841,843
• Time in Patent Office: 601 Days
• Field of Search: 204/416, 204/418, 204/419, 204/400, 204/283, 204/284, 204/286, 204/280, 204/434
• US Class Current: 204/284
• CPC Class Codes: G01N 27/403 Cells and electrode assemblies

Abstract

A microelectrode array for use in electroanalytical chemistry in measuring the electrical characteristics of a solution. A microdisk electrode array is formed by sealing a piece of minigrid into an electroinactive embedding material. One end of the embedding material is polished off to expose an array of microdisks which is defined by ends of the minigrid filaments.

Claims

1. A microelectrode array for use in electrochemical analysis, comprising:

a conductive minigrid having a plurality of vertical filaments and a plurality of horizontal filaments woven together, said minigrid having a measuring end;

means for mounting said minigrid defining a measuring surface; and

wherein said horizontal filaments of said minigrid are disposed essentially parallel to said measuring surface and said vertical filaments of said minigrid are disposed essentially perpendicular to said measuring surface, and said measuring end of said minigrid is located adjacent said measuring surface such that said measuring end of said minigrid forms an array of discrete conductive surfaces defined by end portions of said vertical filaments of said minigrid.

2. The microelectrode according to claim 1 wherein said array is linear.

3. The microelectrode according to claim 1 wherein said array is rectangular.

4. The microelectrode according to claim 1 wherein said array is circular or multicircular.

5. The microelectrode according to claim 1 wherein said minigrid has a filament density of approximately 10 to 1000 filaments per inch.

6. The microelectrode according to claim 1 wherein the ratio of the spacing of said vertical filaments to the width of said vertical filaments in said minigrid is greater than 7.

7. The microelectrode according to claim 1 wherein said vertical and horizontal filaments of said minigrid are metal wires.

8. The microelectrode according to claim 1 wherein said vertical filaments have a maximum width dimension greater than 1 μ

m but less than 20 μ

m.

9. The microelectrode according to claim 1 wherein the spacing between said horizontal filaments is greater than the spacing between said vertical filaments.

10. A microelectrode for use in electrochemical analysis, comprising:

a minigrid having a plurality of vertical filaments and a plurality of horizontal filaments woven together, each said vertical filament defining a measuring end;

mounting means for supporting said minigrid, said mounting means defining a measuring surface,

encasing means for encasing said minigrid and said mounting means; and

wherein said horizontal filaments are disposed parallel to said measuring surface and said vertical elements are disposed perpendicular to said measuring surface and said minigrid is located between said mounting means and said encasing means.

11. The microelectrode according to claim 10 wherein each measuring end is located adjacent to said measuring surface to define a plurality of discrete conductive surfaces.

12. The microelectrode according to claim 10 wherein said encasing means defines a surface which is coplanar with said measuring surface.

13. The microelectrode according to claim 12 wherein said measuring ends of said vertical filaments are coplanar with said measuring surface and define an array of microdisk electrodes.

14. The microelectrode according to claim 13 wherein said array of microdisk electrodes is linear.

15. The microelectrode according to claim 13 wherein said array of microdisk electrodes is rectangular.

16. The microelectrode according to claim 13 wherein said array of microdisk electrodes is circular or multicircular.

17. The microelectrode according to claim 10 wherein said minigrid has approximately 90 filaments per inch.

18. The microelectrode according to claim 10 wherein the ratio of the spacing of said filaments to the width of said filaments in said minigrid is approximately 14.

19. The microelectrode according to claim 10 wherein said vertical and horizontal filaments of said minigrid are metal wires.

20. The microelectrode according to claim 10 wherein said vertical and horizontal filaments have a maximum width dimension greater than 1 μ

m but less than 20 μ

m.

21. A microdisk electrode array for use in electrochemical analysis of solutions, comprising:

a cylinder formed of a precast electro-inactive material, said cylinder having a substantially planar end defining a measuring surface,

a minigrid having a plurality of vertical filaments and a plurality of horizontal filaments woven together, said minigrid extending around said precast cylinder and having a measuring end located adjacent to said measuring surface and a coupling end distal from said measuring surface, said measuring end defining a circular array of discrete contact surfaces;

a conductive wire for receiving the electrical signals from said minigrid;

means for coupling said conductive wire to said coupling end of said minigrid; and

an encasing layer of electro-inactive material encasing said minigrid and said cylinder, said encasing layer extending from said measuring surface toward said coupling end of said minigrid.

22. The electrode according to claim 21 wherein said electro-inactive material of said cylinder and said encasing layer are both formed of an epoxy material.

23. The electrode according to claim 21 wherein said minigrid has approximately 90 filaments per inch.