Sensor with layered electrodes

Patent metadata

Field	Value
Publication number	US-9364177-B2
Application number	US-75779610-A
Country	US
Kind code	B2
Filing date	Apr 9, 2010
Priority date	Sep 23, 2005
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A thin film sensor, such as a glucose sensor, is provided for transcutaneous placement at a selected site within the body of a patient. The sensor includes several sensor layers that include conductive layers and includes a proximal segment defining conductive contacts adapted for electrical connection to a suitable monitor, and a distal segment with sensor electrodes for transcutaneous placement. The sensor electrode layers are disposed generally above each other, for example with the reference electrode above the working electrode and the working electrode above the counter electrode. The electrode layers are separated by dielectric layer.

First claim

What is claimed is:

1. A planar flexible analyte sensor comprising:
a base layer;
a first electrode layer disposed on the base layer and including a first electrode;
a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;
a second electrode layer disposed on the first insulative layer and including a second electrode; and
a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed,
wherein each of said base layer, first and second electrode layers, and first and second insulative layers is planar, wherein the first and second electrodes are in a staggered configuration, wherein said exposed portion of the first electrode and said exposed portion of the second electrode are configured to be in direct contact with a patient's bodily fluids for measuring said analyte within the patient's body, and wherein the maximum height of the flexible analyte sensor is about 25 microns.

2. The flexible analyte sensor of claim 1 , further comprising a third electrode layer disposed on the second insulative layer and including a third electrode.

3. The flexible analyte sensor of claim 2 , wherein the second electrode layer is directly above the first electrode layer, and wherein the third electrode layer is directly above the second electrode layer.

4. The flexible analyte sensor of claim 2 , wherein the first, second, and third electrodes are in a staggered configuration.

5. The flexible analyte sensor of claim 2 , wherein at least one of the first electrode, second electrode, and third electrode comprises chrome.

6. The flexible analyte sensor of claim 2 , wherein one of the electrodes is a counter electrode, one of the electrodes is a reference electrode, and one of the electrodes is a working electrode.

7. The flexible analyte sensor of claim 6 , wherein the reference electrode is plated with one or more compounds selected from the group consisting of silver and silver chloride.

8. The flexible analyte sensor of claim 6 , wherein at least one of the counter electrode and the working electrode is plated with platinum black.

9. The flexible analyte sensor of claim 2 , wherein the first electrode layer further includes a first conductive trace leading from the first electrode to a first conductive pad configured to electrically couple to sensor electronics, the second electrode layer further includes a second conductive trace leading from the second electrode to a second conductive pad configured to electrically couple to sensor electronics, and the third electrode layer further includes a third conductive trace leading from the third electrode to a third conductive pad configured to electrically couple to sensor electronics.

10. The flexible analyte sensor of claim 2 , wherein at least one of the base layer, the first insulative layer, the second insulative layer, and the third insulative layer includes polyimide.

11. The flexible analyte sensor of claim 2 , further comprising an enzyme layer including glucose oxidase disposed over the first, second, and third electrodes.

12. The flexible analyte sensor of claim 11 , wherein the enzyme layer further includes albumin.

13. The flexible analyte sensor of claim 11 , wherein the enzyme layer is disposed directly over the first, second, and third electrodes.

14. The flexible analyte sensor of claim 11 , further comprising a glucose limiting membrane disposed over the enzyme layer.

15. The flexible analyte sensor of claim 14 , wherein the glucose limiting membrane comprises at least one of a silane and polyamine.

16. The flexible analyte sensor of claim 15 , wherein the silane is polydimethylsiloxane.

17. The flexible analyte sensor of claim 14 , further comprising a hydrophilic membrane over the glucose limiting membrane.

18. The flexible analyte sensor of claim 2 , further comprising a third insulative layer disposed on the third electrode layer, wherein said third insulative layer leaves at least a portion of the third electrode exposed.

19. The flexible analyte sensor of claim 18 , wherein the first electrode layer is disposed directly on the base layer without any intervening layers, the first insulative layer is disposed directly on the first electrode layer without any intervening layers, the second electrode layer is disposed directly on the first insulative layer without any intervening layers, the second insulative layer is disposed directly on the second electrode layer without any intervening layers, the third electrode layer is disposed directly on the second insulative layer without any intervening layers, and the third insulative layer is disposed directly on the third electrode layer without any intervening layers.

20. The flexible analyte sensor of claim 19 , wherein the second electrode layer is directly above the first electrode layer, the third electrode layer is directly above the second electrode layer, and the first, second and third electrodes are in a staggered configuration.

21. The flexible analyte sensor of claim 1 , wherein the first electrode layer is disposed directly on the base layer without any intervening layers.

22. The flexible analyte sensor of claim 1 , wherein the first insulative layer is disposed directly on the first electrode layer without any intervening layers.

23. The flexible analyte sensor of claim 1 , wherein the second electrode layer is disposed directly on the first insulative layer without any intervening layers.

24. The flexible analyte sensor of claim 1 , wherein the second insulative layer is disposed directly on the second electrode layer without any intervening layers.

25. The flexible analyte sensor of claim 1 , wherein the height of each electrode layer is less than about 5000 angstroms and each insulative layer is about 5 microns.

26. The flexible analyte sensor of claim 1 , wherein at least one of the first electrode and the second electrode comprises one or more compounds selected from the group consisting of gold and chrome.

27. The flexible analyte sensor of claim 1 , wherein the flexible analyte sensor is configured to sense a current representative of the amount of glucose in the body of a patient.

28. An analyte monitoring system comprising:
(a) a planar flexible analyte sensor comprising:
a base layer;
a first electrode layer disposed on the base layer and including a first electrode;
a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;
a second electrode layer disposed on the first insulative layer and including a second electrode;
a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed; and
a third electrode layer disposed on the second insulative layer and including a third electrode,
wherein the first electrode layer further includes a first conductive trace leading from the first electrode to a first conductive pad configured to electrically couple to sensor electronics, the second electrode layer further includes a second conductive trace leading from the second electrode to a second conductive pad configured to electrically couple to sensor ele

Assignees

• Shah Rajiv
• Gottlieb Rebecca K
• Medtronic Minimed Inc

Inventors

• Shah Rajiv
• Gottlieb Rebecca K

Classifications

• A61B5/14532

  for measuring glucose, e.g. by tissue impedance measurement · CPC title

• C23C14/3414

  Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy · CPC title

• Y10T29/49005

  Acoustic transducer · CPC title

• C23C14/20

  on organic substrates · CPC title

• A61B5/6849

  in combination with a needle set · CPC title