MULTI-SITE ELECTRODE ARRAYS AND METHODS OF MAKING THE SAME

• US 20170007813A1
• Filed: 09/20/2016
• Published: 01/12/2017
• Est. Priority Date: 03/21/2014
• Status: Active Grant

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah Research Foundation (State of Utah)
• Inventors: Negi, Sandeep, Bhandari, Rajmohan
• Granted Patent: US 10,799,132 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/685 Microneedles
• CPC Class Codes: A61B 5/6868 Brain
• CPC Class Codes: A61M 2037/0053 Methods for producing microneedles
• CPC Class Codes: A61M 2037/0061 Methods for using microneedles
• CPC Class Codes: A61M 2205/3303 Using a biosensor
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2210/0693 Brain, cerebrum
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes

Abstract

A multi-site electrode array (100) can include a microneedle array and a set of electrically active sites (115). The microneedle array includes a plurality of microneedles (105) supported on a base substrate (110). The set of electrically active sites (115) can be arranged at and/or near the tip of each microneedle (105), and in many cases along a shaft of the microneedles. Further, at least a portion of the active sites (115) can be independently electrically addressable such that a remaining portion of the active sites (115) are optionally electrically shunted together. In some cases all of the active sites (115) are independently electrically addressable

Claims

1. A multi-site electrode array comprising:

a) a microneedle array including a plurality of microneedles supported on a base substrate; and

b) a set of electrically active sites arranged on each microneedle, each active site in the set being independently electrically addressable.

2. The array of claim 1, wherein the array is a two dimensional array such that the plurality of microneedles are distributed in two dimensions across the base substrate.

3. The array of claim 1, wherein the plurality of microneedles are substantially parallel to one another.

4. The array of claim 1, wherein the microneedles and the base substrate are formed of a contiguous and common material.

5. The array of claim 1, wherein a spatial configuration across the plurality of microneedles for the sets of electrically active sites forms a three-dimensional volume of electrically active sites.

6. The array of claim 1, wherein at least a portion of the electrically interactive sites are electrically connected to a base contact via independent lead lines formed of an electrically conductive material deposited along a shaft portion of the microneedles, wherein at least a portion of the base contacts are electrically independent of one another.

7. The array of claim 1, further comprising transistor gates and pads oriented on an underside of the base substrate and adapted to independently connect each electrically active site to a controller and a current source.

8. The array of claim 1, wherein the set of electrically active sites includes a tip site and a plurality of side shaft sites.

9. The array of claim 8, wherein the side shaft sites are selected from the group consisting of ring sites, spot sites, interdigitated electrodes, and combinations thereof

10. The array of claim 8, wherein the side shaft sites are interdigitated electrodes such that the array is a sensor.

11. The array of claim 8, wherein at least a portion of the plurality of side shaft sites are oriented at varying distances from the tip.

12. The array of claim 1, further comprising an electrically insulating coating over the microneedle array such that at least one active site from the set of electrically active sites is exposed.

14. The method of claim 12, wherein the depositing further includes forming a tetrode of electrically interactive sites on each microneedle, the tetrode including a tip site and three additional side shaft sites.

16. The method of claim 12, wherein the set of electrically active sites includes a tip site and a plurality of ring sites, said ring sites circumscribing the microneedle shaft near the tip site, and wherein the ring sites are oriented at progressively greater distances from the tip site.

17. The method of claim 12, wherein the portion of the set of active sites form multiple clusters along the shaft of the microneedle.

18. The method of claim 12, wherein the depositing is accomplished via focused ion beam (FIB) deposition.

19. The method of claim 12, wherein the insulator includes parylene-C, and exposure of active sites is accomplished by ablating parylene-C via focused ion beam deposition (FIB).

20. The method of claim 12, wherein the depositing electrically conductive traces is performed by electrochemical deposition after the insulating, wherein portions of the insulator has been selectively removed via focused ion beam deposition (FIB) ablation in a pattern to expose areas defining the electrically interactive sites and traces.

21. The method of claim 12, wherein the depositing electrically conductive traces is performed by sputtering or evaporation using a shadow mask.

22. The method of claim 12, further comprising surface treating at least portions of the array to form pseudoporous surfaces.

13. A method of making a multi-site electrode array, comprising:

a) forming the multi-site electrode array including a plurality of microneedles supported on a base substrate;

b) depositing electrically conductive traces along shafts of the microneedles to form at least a portion of a set of electrically active sites arranged on each microneedle, at least a portion of active sites in the set being independently electrically addressable from one another; and

c) insulating the microneedles with an insulator such that at least one active site of each set of the active sites are exposed.

15. The method of claim 13, wherein the side shaft sites are deposited at shaft surface locations equidistant from the tip site such that the tetrode of four electrically active sites form a tetrahedron.

23. A multi-site channel array comprising:

a) a microneedle array including a plurality of microneedles supported on a base substrate; and

b) a set of channels arranged on each microneedle, each channel in the set being independent of one another and having an active site at a distal end of the channel.

24. The array of claim 23, wherein at least a portion of the set of channels is a conduit adapted for communication of light to the active site.

25. The array of claim 23, wherein at least a portion of the set of channels is a conduit adapted for communication of a fluid to the active site from a fluid reservoir.

26. The array of claim 25, wherein the fluid includes a pharmaceutically active agent.