U.S. patent application number 16/918306 was filed with the patent office on 2020-10-22 for implantable electrodes comprising mechanically constrained biocompatible hydrogels with conductive passthrough.
This patent application is currently assigned to Verily Life Sciences LLC. The applicant listed for this patent is Verily Life Sciences LLC. Invention is credited to Kimberly Kam, Daniel Otts, Huanfen Yao.
Application Number | 20200330747 16/918306 |
Document ID | / |
Family ID | 1000004931088 |
Filed Date | 2020-10-22 |
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United States Patent
Application |
20200330747 |
Kind Code |
A1 |
Yao; Huanfen ; et
al. |
October 22, 2020 |
IMPLANTABLE ELECTRODES COMPRISING MECHANICALLY CONSTRAINED
BIOCOMPATIBLE HYDROGELS WITH CONDUCTIVE PASSTHROUGH
Abstract
Biomaterials, such as hydrogels, can be mechanically secured to
an electrode of an implantable device using a non-swellable shell.
Hydrogel can be applied to an electrode surface and then
mechanically constrained in place by a non-swellable shell. The
non-swellable material can be secured to a substrate supporting an
electrode or can otherwise surround an electrode and the hydrogel.
The non-swellable shell can include openings or passthroughs that
allow for electrical conduction across the non-swellable shell. The
hydrogel can extend out of the openings to contact adjacent
biological tissue. In some cases, an outer layer of hydrogel can
surround the non-swellable shell and connected to the inner layer
of hydrogel through the openings of the non-swellable shell.
Inventors: |
Yao; Huanfen; (Brisbane,
CA) ; Kam; Kimberly; (Orinda, CA) ; Otts;
Daniel; (Pleasanton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Verily Life Sciences LLC |
South San Francisco |
CA |
US |
|
|
Assignee: |
Verily Life Sciences LLC
South San Francisco
CA
|
Family ID: |
1000004931088 |
Appl. No.: |
16/918306 |
Filed: |
July 1, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15811774 |
Nov 14, 2017 |
10729901 |
|
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16918306 |
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62421702 |
Nov 14, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2562/0217 20170801;
A61B 5/686 20130101; A61B 5/6867 20130101; A61B 2562/046 20130101;
A61B 5/04 20130101; A61N 1/05 20130101; A61B 2562/125 20130101;
A61B 2562/0209 20130101; A61B 2562/14 20130101 |
International
Class: |
A61N 1/05 20060101
A61N001/05; A61B 5/04 20060101 A61B005/04; A61B 5/00 20060101
A61B005/00 |
Claims
1. An electrode array, comprising: at least one electrode
comprising a conductible metal layer; a substrate supporting the at
least one electrode; hydrogel material disposed over the at least
one electrode; and a non-swellable coating surrounding the at least
one electrode and disposed over the hydrogel material, wherein the
non-swellable coating: conforms to a shape of the hydrogel
material; and mechanically secures the hydrogel material against
the at least one electrode.
2. The electrode array of claim 1, wherein the non-swellable
coating forms a cavity surrounding the hydrogel material, wherein a
position of the non-swellable coating is secured based on an
outward pressure exerted by the hydrogel material within the
cavity.
3. The electrode array of claim 1, further comprising one or more
anchoring features formed on the at least one electrode, wherein
the one or more anchoring features include a textured surface that
secures the hydrogel material.
4. The electrode array of claim 1, wherein the hydrogel material is
electrically conductive.
5. The electrode array of claim 1, wherein the non-swellable
coating includes one or more openings, wherein at least a portion
of the hydrogel material swells through the one or more openings to
conduct an electric signal between the at least one electrode and a
biological tissue when the electrode array is positioned adjacent
to the biological tissue.
6. The electrode array of claim 5, further comprising additional
hydrogel material disposed over the non-swellable coating, wherein
the hydrogel material is coupled to the additional hydrogel
material through the one or more openings.
7. The electrode array of claim 5, wherein the one or more openings
are formed at a part of the non-swellable coating nearest to the at
least one electrode.
8. An implantable device, comprising: an electrode array
comprising: at least one electrode comprising a conductible metal
layer; a substrate supporting the at least one electrode; hydrogel
material disposed over the at least one electrode; and a
non-swellable coating surrounding the at least one electrode and
disposed over the hydrogel material, wherein the non-swellable
coating: conforms to a shape of the hydrogel material; and
mechanically secures the hydrogel material against the at least one
electrode; and a controller electrically coupled to the electrode
array.
9. The implantable device of claim 8, wherein the non-swellable
coating forms a cavity surrounding the hydrogel material, wherein a
position of the non-swellable coating is secured based on an
outward pressure exerted by the hydrogel material within the
cavity.
10. The implantable device of claim 8, further comprising one or
more anchoring features formed on the at least one electrode,
wherein the one or more anchoring features include a textured
surface that secures the hydrogel material.
11. The implantable device of claim 8, wherein the hydrogel
material is electrically conductive.
12. The implantable device of claim 8, wherein the non-swellable
coating includes one or more openings, wherein at least a portion
of the hydrogel material swells through the one or more openings to
conduct an electric signal between the at least one electrode and a
biological tissue when the electrode array is positioned adjacent
to the biological tissue.
13. The implantable device of claim 12, further comprising
additional hydrogel material disposed over the non-swellable
coating, wherein the hydrogel material is coupled to the additional
hydrogel material through the one or more openings.
14. The electrode array of claim 12, wherein the one or more
openings are formed at a part of the non-swellable coating nearest
to the at least one electrode.
15. A method of preparing an electrode array, comprising: providing
an electrode on a substrate, the electrode comprising a conductible
metal layer; applying hydrogel material over the electrode; and
coating the hydrogel material with a non-swellable coating, wherein
the non-swellable coating: conforms to a shape of the hydrogel
material; and mechanically secures the hydrogel material to the
electrode.
16. The method of claim 15, wherein the non-swellable coating forms
a cavity surrounding the hydrogel material, wherein a position of
the non-swellable coating is secured based on an outward pressure
exerted by the hydrogel material within the cavity.
17. The method of claim 15, further comprising forming one or more
anchoring features on the electrode, wherein the one or more
anchoring features include a textured surface that secures the
hydrogel material.
18. The method of claim 15, further comprising creating one or more
openings in the non-swellable coating, wherein at least a portion
of the hydrogel material swells through the one or more openings to
conduct an electric signal between the electrode and a biological
tissue when the electrode array is positioned adjacent to the
biological tissue.
19. The method of claim 18, further comprising applying an
additional hydrogel material over the non-swellable coating,
wherein the hydrogel material is coupled to the additional hydrogel
material through the one or more openings.
20. The method of claim 18, wherein the one or more openings are
created at a part of the non-swellable coating nearest to the
electrode.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
Nonprovisional application Ser. No. 15/811,774, filed Nov. 14,
2017, which claims the benefit of U.S. Provisional Application No.
62/421,702 filed Nov. 14, 2016, each of which is hereby
incorporated by reference in their entirety for all purposes.
TECHNICAL FIELD
[0002] The present disclosure relates to medical devices generally
and more specifically to coatings for implantable electrodes.
BACKGROUND
[0003] Implantable electrodes can suffer from in vivo fouling, such
as due to protein adsorption to the surface of the implantable
electrodes. This initial protein adsorption can trigger the
beginning of an inflammatory response, which may eventually
culminate as fibrotic tissue deposition at the implant site. The
fibrotic tissue deposition can act as a capacitive tissue layer and
can consequently lead to a gradual increase in impedance over time
as the tissue continues to build. As surrounding impedance
increases, the implant becomes less efficient and may require more
power to operate as desired. As a result, the efficacy and/or
battery lifetime of the implant may be decreased and an implant
user may require follow-up surgery to replace the fouled
implant.
[0004] Efforts to decrease the in vivo impedance and increase the
overall lifetime of the implant can include coating the electrode
in a biomaterial that resists protein adsorption, however such
biomaterials can be very difficult to reliable secure to or around
an electrode. Attachment can be attempted using covalent bonding
between the hydrogel and an oxide layer of the electrode. However,
for certain electrodes, such as noble metals, robust covalent
bonding can be very challenging to achieve. These materials may not
easily form an oxide layer, without which the biomaterial has no
functional handle on which to reliably, chemically attach.
Unreliable attachment of biomaterials can result in further
problems and can result in a lower effective lifespan of the
implant than desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The specification makes reference to the following appended
figures, in which use of like reference numerals in different
figures is intended to illustrate like or analogous components.
[0006] FIG. 1 is a top view of an electrode array prior to hydrogel
application according to certain aspects of the present
disclosure.
[0007] FIG. 2 is a partial cutaway view of the electrode array of
FIG. 1 taken along line A:A according to certain aspects of the
present disclosure.
[0008] FIG. 3 is top view of an electrode array having anchoring
features according to certain aspects of the present
disclosure.
[0009] FIG. 4 is a partial cutaway view of the electrode array of
FIG. 3 taken along line B:B according to certain aspects of the
present disclosure.
[0010] FIG. 5 is a partial cutaway view depicting an electrode
array having anchoring features that are apertures according to
certain aspects of the present disclosure.
[0011] FIG. 6 is a partial cutaway view depicting an electrode
array having anchoring features that are apertures with applied
hydrogel according to certain aspects of the present
disclosure.
[0012] FIG. 7 is a partial cutaway view depicting an electrode
array having anchoring features that are voids according to certain
aspects of the present disclosure.
[0013] FIG. 8 is a partial cutaway view depicting an electrode
array having anchoring features that are voids with applied
hydrogel according to certain aspects of the present
disclosure.
[0014] FIG. 9 is a partial cutaway view depicting an electrode
array having anchoring features that are surface textures according
to certain aspects of the present disclosure.
[0015] FIG. 10 is a partial cutaway view depicting an electrode
array having anchoring features that are surface textures with
applied hydrogel according to certain aspects of the present
disclosure.
[0016] FIG. 11 is a flowchart depicting a process for mechanically
securing hydrogel to an electrode using anchoring features
according to certain aspects of the present disclosure.
[0017] FIG. 12 is top view of an electrode array prior to hydrogel
application according to certain aspects of the present
disclosure.
[0018] FIG. 13 is a cutaway view of the electrode array of FIG. 12
taken along line C:C according to certain aspects of the present
disclosure.
[0019] FIG. 14 is a cutaway view depicting an electrode array prior
to hydrogel application according to certain aspects of the present
disclosure.
[0020] FIG. 15 is a cutaway view depicting an electrode array with
an applied hydrogel layer according to certain aspects of the
present disclosure.
[0021] FIG. 16 is a cutaway view depicting an electrode array with
a non-swellable shell over an applied hydrogel layer according to
certain aspects of the present disclosure.
[0022] FIG. 17 is a cutaway view depicting an electrode array with
a non-swellable shell having openings according to certain aspects
of the present disclosure.
[0023] FIG. 18 is a cutaway view depicting an electrode array with
hydrogel exposed through openings in a non-swellable shell
according to certain aspects of the present disclosure.
[0024] FIG. 19 is a cutaway view depicting an electrode array with
an outer hydrogel layer connected to an inner hydrogel layer
through openings in a non-swellable shell according to certain
aspects of the present disclosure.
[0025] FIG. 20 is a cutaway view depicting an electrode array with
hydrogel anchored using a non-swellable shell and void anchoring
features of the electrodes according to certain aspects of the
present disclosure.
[0026] FIG. 21 is a cutaway view depicting an electrode array with
hydrogel anchored using a non-swellable shell and aperture
anchoring features of the electrodes according to certain aspects
of the present disclosure.
[0027] FIG. 22 is a cutaway view depicting an electrode array with
hydrogel contained within a non-swellable shell according to
certain aspects of the present disclosure.
[0028] FIG. 23 is a cutaway view depicting an electrode array with
hydrogel contained within a non-swellable shell with an outer
hydrogel layer according to certain aspects of the present
disclosure.
[0029] FIG. 24 is a flowchart depicting a process for mechanically
securing hydrogel to an electrode using a non-swellable layer
according to certain aspects of the present disclosure.
[0030] FIG. 25 is a scanning electron micrograph depicting a first
example electrode having hydrogel mechanically coupled to a
textured anchoring feature according to certain aspects of the
present disclosure.
[0031] FIG. 26 is a scanning electron micrograph depicting a second
example electrode having hydrogel mechanically coupled to a
textured anchoring feature according to certain aspects of the
present disclosure.
[0032] FIG. 27 is a schematic diagram depicting an implantable
medical device electrically coupled to biological tissue according
to certain aspects of the present disclosure.
DETAILED DESCRIPTION
[0033] Certain aspects and features of the present disclosure
relate to mechanically securing biomaterials, such as hydrogels, to
an electrode of an implantable device. The hydrogel can be
mechanically secured to an electrode via anchoring features of the
electrode. Anchoring features can include apertures, voids,
textures, or other patterns created in or on the electrode. The
hydrogel can incorporate into the anchoring features to
mechanically hold the hydrogel against the electrode. The anchoring
features, by being located in or on the electrode, can further
increase the surface area of the electrode that is exposed to the
hydrogel, which can facilitate the conduction of electrical signals
between the electrode and surrounding biological tissue. The
substrate supporting the electrode can include additional anchoring
features that further assist in mechanically securing the
hydrogel.
[0034] The hydrogel can be mechanically secured to an electrode via
anchoring features of the electrode. Anchoring features can include
apertures, voids, textures, or other patterns created in or on the
electrode. The hydrogel can incorporate into the anchoring features
to mechanically hold the hydrogel against the electrode. The
anchoring features, by being located in or on the electrode, can
further increase the surface area of the electrode that is exposed
to the hydrogel, which can facilitate the conduction of electrical
signals between the electrode and surrounding biological tissue.
The substrate supporting the electrode can include additional
anchoring features that further assist in mechanically securing the
hydrogel.
[0035] In some cases, a flexible electrode array can include
multiple electrodes. Anchoring features can be created by
perforating the electrodes to create apertures. Any suitable method
can be used to perforate the electrodes, such as mechanical
drilling, laser drilling, laser cutting, laser ablation, or other
suitable techniques. In some cases, anchoring features, such as
apertures, can be formed during formation of the electrodes, such
as through masking techniques. Anchoring features, such as
apertures, can also be created in the substrate as well as the
electrodes. A hydrogel coating precursor can be applied to the
outward facing surfaces of the electrodes, and optionally
substrates, as well as on the inner surfaces of the anchoring
features (e.g., apertures). While apertures are described above,
other anchoring features can be used, such as voids, blind holes
(e.g., not through holes), hot embossing, cold embossing, bead
blasting, or any other technique for creating anchoring features or
increasing the surface roughness of the electrode. In some cases,
an anchoring feature can be an opening that extends any depth into
the electrode, such as an aperture extending through the electrode
thickness or a void that extends partially through the electrode
thickness. In some instances, the hydrogel coating may only be
selectively applied to certain portions of the electrode array
assembly (e.g. directly over one or more of the electrodes).
[0036] In some cases, the metal electrodes can be fabricated to
include anchoring features. Such electrodes can take the form of
mesh-like metal structures. In this manner, the starting seed metal
may be patterned, for example with photolithography, and then the
seed pattern mesh may be plated up to the specified thickness. In a
subtractive process, a full-thickness metal may be clad onto the
substrate, a high-aspect ratio electrode pattern may be defined
photolithographically to the metal, the metal etched to form the
mesh, and the photoresist layer removed. In any case, a variety of
approaches can be used to physically anchor and/or entrap an
applied hydrogel precursor so that it the hydrogel is substantially
affixed to the electrode using mechanical anchoring without the
need to rely primarily on covalently bonding the hydrogel to the
metal. Once a hydrogel precursor is applied, it may be cross-linked
in place using a flood ultraviolet (UV) system, if UV-curable, or
any other suitable technique (e.g., heating to initiate a thermal
polymerization of the precursor).
[0037] Certain aspects and features of the present disclosure
relate to mechanically securing biomaterials, such as hydrogels, to
an electrode of an implantable device using a non-swellable shell.
Hydrogel can be applied to an electrode surface and then
mechanically constrained in place by a non-swellable shell. The
non-swellable material can be secured to a substrate supporting an
electrode or can otherwise surround an electrode and the hydrogel.
The non-swellable shell can include openings or passthroughs that
allow for electrical conduction across the non-swellable shell. The
hydrogel can extend out of the openings to contact adjacent
biological tissue. In some cases, an outer layer of hydrogel can
surround the non-swellable shell and connected to the inner layer
of hydrogel through the openings of the non-swellable shell.
[0038] In some cases, biocompatible hydrogels may be mechanically
affixed to the electrode array using a non-swellable shell. In this
approach, after a first hydrogel layer is applied to the electrode
array, a non-swellable and patternable secondary coating can be
applied. This second, non-swellable coating can further restrict
movement and/or delamination of the hydrogel from the electrode
array. Any suitable non-swellable material, conformal, or
biocompatible coating may be used, such as parylene C or any of the
other parylene vapor deposition polymers. In cases where the
hydrogel may be selectively applied to the electrode array (e.g.
just over the electrode metal), existing techniques to adhere the
non-swellable material (e.g., parylene) to the substrate of the
electrode array can be employed, such as any suitable primer or
pre-treatment to assist in chemically anchoring the non-swellable
material to the substrate. While the non-swellable material may be
chemically anchored to the substrate, the hydrogel layer may not
necessarily be chemically anchored to the electrodes and rather may
be mechanically held in place due to physical interaction with the
non-swellable material. Once the non-swellable material is in
place, various openings or apertures may be created in the
non-swellable material through any suitable technique, such as
laser ablation, mechanical drilling, milling, inductively coupled
plasma (ICP) etching, or any other convenient fabrication
technique. The openings may allow the hydrogel to at least
partially swell up through the openings. In some cases, an
additional layer of hydrogel precursor can be applied over the
non-swellable material. This additional layer may entangle or
otherwise form an interpenetrating network with the first layer of
hydrogel through the openings in the non-swellable material,
thereby locking it in place. Such a secondary hydrogel coating may
improve overall fouling resistance of the electrode array and may
lead to better overall performance and biocompatibility.
[0039] Certain aspects and features of the present disclosure may
be especially suitable for securing biomaterials (e.g., hydrogels)
to electrodes made of noble metals (e.g., platinum, gold, and
palladium). In some cases, the electrodes may specifically be made
of platinum or gold. Platinum or gold can be especially useful as
an implantable electrode due to their high biocompatibility and
ability to be surface roughened. Metal electrodes and/or electrode
arrays may be fabricated in any suitable geometries. Electrodes may
be fabricated on thin, flexible substrates, such as polyimide, or a
liquid crystal polymer (LCP).
[0040] As used herein, references are made to securing hydrogels to
electrodes, however various aspects and features the present
disclosure may involve securing other biomaterials to electrodes,
such as brush layers, semi-interpenetrating networks, or other
natural and/or synthetic polymeric compositions. The biomaterials
can be electrically conductive, such as being naturally conductive
or including conductive materials incorporated therein. For
example, biomaterials can include a sufficient concentration of
dissolved ions suitable for providing desired electrical
conductivity. Any suitable hydrogel can be used, such as a
cross-linked polyethylene glycol (PEG) diacrylate. As used herein,
the term hydrogel may refer to a hydrogel precursor or a hydrogel,
as appropriate.
[0041] In some cases, a non-swelling or low-swelling hydrogel can
be uses. In some cases, a polymerizable hydrogel precursor may
contain a non-reactive diluent (e.g., glycol ethers or alcohols),
which can displace a volume equal to or approximately equal to the
volume of physiological fluid that would ultimately swell the
biocompatible hydrogel in vivo. In this manner, the swelling forces
of the biocompatible hydrogel may be controlled to limit
delamination of the hydrogel coating from the electrode array.
[0042] Certain aspects and features the present disclosure allow
hydrogels to be mechanically secured to electrodes without the need
to rely on covalent bonding between the hydrogel and the electrode.
Such mechanical bonding can provide for a more robust and reliable
attachment of the hydrogel to the electrode, especially for
electrodes made of noble metals. Using the techniques disclosed
herein, an implant can include desirable electrode materials (e.g.,
noble metals) and still retain the benefit of hydrogel coatings
(e.g., improved biocompatibility) that would otherwise normally be
very difficult to achieve with desirable electrode materials.
[0043] The improved ability to secure the hydrogel to an electrode
using the techniques disclosed herein can allow the electrode to
remain implanted for longer with no or fewer negative side effects.
By reducing the amount of fibrotic response around an implant using
the techniques described herein, the implant may be able to
continue functioning without needing to compensate for otherwise
expected increases in surrounding impedance that would have
otherwise occurred due to fibrotic response. Thus, the implant may
be able to function for longer on the same power supply or function
similarly using a smaller power supply. An implant using certain
aspects and features of the present disclosure may operate for a
longer lifetime than previously possible, such as 10 or 20 years,
thus decreasing the need for subsequent follow-up surgeries for a
user.
[0044] These illustrative examples are given to introduce the
reader to the general subject matter discussed here and are not
intended to limit the scope of the disclosed concepts. The
following sections describe various additional features and
examples with reference to the drawings in which like numerals
indicate like elements, and directional descriptions are used to
describe the illustrative embodiments but, like the illustrative
embodiments, should not be used to limit the present disclosure.
The elements included in the illustrations herein may not be drawn
to scale. Specifically, various elements of the figures may be
shown in exaggerated dimensions for explanatory purposes.
[0045] FIG. 1 is top view of an electrode array 100 prior to
hydrogel application according to certain aspects of the present
disclosure. The electrode array 100 can include a plurality of
electrodes 102, although in some cases an array may include only a
single electrode. Each electrode 102 can include a base layer 104
and an upper layer 106, although in some cases an electrode 102 can
include only a single layer of metal or more than two layers of
metal. In some cases, the base layer 104 and upper layer 106 can be
different metals, such as a base layer 104 of gold and an upper
layer 106 of platinum (e.g., platinum iridium). As used herein,
reference to metals used to form an electrode 102 includes suitable
alloys of those metals (e.g., platinum can refer to a platinum
iridium alloy). Each electrode 102 can have an upper surface 108.
While the base layer 104 is depicted as larger in diameter than the
upper layer 106, that need not be the case and each layer can be
any suitable size. The electrodes 102 of electrode array 100 are
depicted as circular in shape, however any suitable shaped
electrodes may be used, such as square, hexagonal, or others. The
spacing of electrodes can be densely and regularly spaced with or
without gaps in-between.
[0046] The electrodes 102 of the electrode array 100 can be
supported on a substrate 110. The electrodes 102 can be coupled to
the substrate in any suitable manner, such as formed on the
substrate 110, attached to the substrate 110, or embedded within
the substrate 110. The substrate 110 can have an upper surface 120
to which the electrodes 102 are coupled, although electrodes 102
can be coupled to more than one surface of the substrate 110 in
some cases. Electrical conductors (e.g., wires) can be embedded
within the substrate 110 and connect the electrodes 102 to other
equipment, such as a controller of an implant.
[0047] Electrodes 102 of electrode array 110 are depicted in a
repeating pattern, however any number of electrodes 102 may be
positioned in any suitable fashion on the electrode array 110,
including randomly.
[0048] FIG. 2 is a partial cutaway view of the electrode array 100
of FIG. 1 taken along line A:A according to certain aspects of the
present disclosure. The substrate 110 can support the electrodes
102 on its top surface 120. Each electrode 102 can include a base
layer 104 supporting an upper layer 106 having an upper surface
108.
[0049] FIG. 3 is top view of an electrode array 300 having
anchoring features 322 according to certain aspects of the present
disclosure. The electrode array 300 can be the electrode array 100
of FIG. 1 after anchoring features 322 have been formed thereon
(e.g., through mechanical drilling or laser ablation). The
anchoring features 322 can include a plurality of apertures 324
created through the electrodes 302. In some cases, apertures 324
can also be created through the substrate 310.
[0050] FIG. 4 is a partial cutaway view of the electrode array 300
of FIG. 3 taken along line B:B according to certain aspects of the
present disclosure. The electrode array 300 can include multiple
anchoring features 322. The electrode array 300 can include a one
or more apertures 324 passing through each electrode 302. In some
cases, the apertures 324 can also pass through the substrate 310.
In some cases, one or more additional anchoring features 326 can
occur on the substrate 310 and not on the electrodes 302. The
additional anchoring feature 326 can be an aperture that passes
through the substrate 310, but not the electrodes 302.
[0051] FIG. 5 is a partial cutaway view depicting an electrode
array 500 having anchoring features 522 that are apertures 524
according to certain aspects of the present disclosure. The
electrode array 500 can be electrode array 300 of FIG. 3. The
electrode array 500 can include one or more electrodes 502
supported by a substrate 510. The electrodes 502 can include a base
layer 504 and an upper layer 506. The electrodes 502 can have a
thickness 512. Any suitable thickness 512 can be used, such as
thickness between about 3 microns to about 6 microns, although
other thicknesses can be used, including less than 3 microns and
greater than 6 microns. In some cases, the base layer 504 can have
a thickness 516 that is about three to about five microns in
thickness, although other values can be used. In some cases, the
upper layer 506 can have a thickness 514 that is about 0.5 to about
1 micron in thickness, although other values can be used. In some
cases, the base layer 504 of made of gold or a gold alloy and the
upper layer 506 is made of platinum or a platinum alloy. The
electrodes 502 can have any suitable dimensions, such as about 500
microns to about 2 mm in diameter, although other sizes can be
used.
[0052] Apertures 524 can be formed in the electrodes 502, such as
using any suitable technique. The apertures 524 can be any suitable
size, such as approximately 5 microns to approximately 50 microns,
although other ranges may be used. An aperture 524 can be an
opening that extends entirely through a material. As used herein,
aperture 524 extends through the electrode 502. Apertures 524 also
happen to extend through the substrate 510, although that need not
always be the case. In some cases, additional anchoring features
526 can include apertures passing through the substrate 510 at
locations not occupied by an electrode 502. The substrate 510 can
have a thickness 518 of any suitable size. In some cases, substrate
510 is thin and flexible to facilitate maneuverability and
implantation of the electrode array 500.
[0053] FIG. 6 is a partial cutaway view depicting an electrode
array 600 having anchoring features 622 that are apertures 626 with
applied hydrogel 632 according to certain aspects of the present
disclosure. The electrode array 600 can be the electrode array 500
of FIG. 5 after hydrogel 632 has been applied thereto. The hydrogel
632 can be placed over the electrodes 602 and optionally over the
substrate 610. The hydrogel 632 can be introduced into the
anchoring features 622 of the electrodes 602 (e.g., apertures 624),
optionally including any additional anchoring features 626 of the
substrate 610. The hydrogel 632 can have a total thickness 630 and
an over-electrode thickness 628. The over-electrode thickness 628
can represent a minimum, maximum, or average thickness of the
hydrogel 632 as measured from the top surface 608 of an electrode
602. The over-electrode thickness 628 of the hydrogel 632 can be
any suitable thickness, such as about 10 microns to about 100
microns, although other ranges can be used. In some cases, the
over-electrode thickness 628 of the hydrogel 632 is in the tens of
microns.
[0054] FIG. 7 is a partial cutaway view depicting an electrode
array 700 having anchoring features 722 that are voids 734
according to certain aspects of the present disclosure. The
electrode array 700 can be electrode array 100 of FIG. 1 after
anchoring features 722 have been applied thereto. The electrode
array 700 can include one or more electrodes 702 supported by a
substrate 710. The electrodes 702 can include a base layer 704 and
an upper layer 706. The electrodes 702 can have a thickness 712.
Any suitable thickness 712 can be used, such as thickness between
about 3 microns to about 6 microns, although other thicknesses can
be used, including less than 3 microns and greater than 6 microns.
In some cases, the base layer 704 can have a thickness 716 that is
about three to about five microns in thickness, although other
values can be used. In some cases, the upper layer 706 can have a
thickness 714 that is about 0.5 to about 1 micron in thickness,
although other values can be used. In some cases, the base layer
704 of made of gold or a gold alloy and the upper layer 706 is made
of platinum or a platinum alloy. The electrodes 702 can have any
suitable dimensions, such as about 700 microns to about 2 mm in
diameter, although other sizes can be used.
[0055] Voids 734 can be formed in the electrodes 702, such as using
any suitable technique. The voids 734 can be any suitable size,
such as approximately 5 microns to approximately 50 microns,
although other ranges may be used. A void 734 can extend partially
into a material (e.g., into an electrode 702) without extending
fully through the material. As used herein, void 734 extends into
at least a portion of electrode 702. Void 734 can extend partially
or fully through the thickness 714 of the upper layer 706 and may
optionally extend partially through the thickness 716 of the base
layer 704. Any suitable technique can be used to create the voids
734, such as laser ablation. In some cases, voids can also be
formed in the substrate 710 to act as additional anchoring
features. The substrate 710 can have a thickness 718 of any
suitable size. In some cases, substrate 710 is thin and flexible to
facilitate maneuverability and implantation of the electrode array
700.
[0056] FIG. 8 is a partial cutaway view depicting an electrode
array 800 having anchoring features 822 that are voids 834 with
applied hydrogel 832 according to certain aspects of the present
disclosure. The electrode array 800 can be the electrode array 700
of FIG. 7 after hydrogel 832 has been applied thereto. The hydrogel
832 can be placed over the electrodes 802 and optionally over the
substrate 810. The hydrogel 832 can be introduced into the
anchoring features 822 of the electrodes 802 (e.g., voids 834),
optionally including any additional anchoring features of the
substrate 810. The hydrogel 832 can have a total thickness 830 and
an over-electrode thickness 828. The over-electrode thickness 828
can represent a minimum, maximum, or average thickness of the
hydrogel 832 as measured from the top surface 808 of an electrode
802. The over-electrode thickness 828 of the hydrogel 832 can be
any suitable thickness, such as about 10 microns to about 100
microns, although other ranges can be used. In some cases, the
over-electrode thickness 828 of the hydrogel 832 is in the tens of
microns.
[0057] FIG. 9 is a partial cutaway view depicting an electrode
array having anchoring features 922 that are surface textures 936
according to certain aspects of the present disclosure. The
electrode array 900 can be electrode array 100 of FIG. 1 after
anchoring features 922 have been applied thereto. The electrode
array 900 can include one or more electrodes 902 supported by a
substrate 910. The electrodes 902 can include a base layer 904 and
an upper layer 906. The electrodes 902 can have a thickness 912.
Any suitable thickness 912 can be used, such as thickness between
about 3 microns to about 6 microns, although other thicknesses can
be used, including less than 3 microns and greater than 6 microns.
In some cases, the base layer 904 can have a thickness 916 that is
about three to about five microns in thickness, although other
values can be used. In some cases, the upper layer 906 can have a
thickness 914 that is about 0.5 to about 1 micron in thickness,
although other values can be used. In some cases, the base layer
904 of made of gold or a gold alloy and the upper layer 906 is made
of platinum or a platinum alloy. The electrodes 902 can have any
suitable dimensions, such as about 900 microns to about 2 mm in
diameter, although other sizes can be used.
[0058] Surface textures 936 can be formed in the electrodes 902,
such as using any suitable technique. The surface textures 936 can
increase the average roughness of the upper surface 908 of the
electrodes 902. The surface textures 936 can have any suitable
precision, such as precision from approximately 5 microns to
approximately 50 microns, although other ranges may be used. A
surface texture 936 can include elements that extend partially into
the upper layer 906 of the electrode 902. Any suitable technique
can be used to create the surface textures 936, such as laser
ablation or electrical discharge texturing. In some cases, surface
textures can also be formed in the substrate 910 to act as
additional anchoring features. The substrate 910 can have a
thickness 918 of any suitable size. In some cases, substrate 910 is
thin and flexible to facilitate maneuverability and implantation of
the electrode array 900.
[0059] FIG. 10 is a partial cutaway view depicting an electrode
array 1000 having anchoring features 1022 that are surface textures
1034, the electrode array 1000 including applied hydrogel 1032
according to certain aspects of the present disclosure. The
electrode array 1000 can be the electrode array 900 of FIG. 9 after
hydrogel 1032 has been applied thereto. The hydrogel 1032 can be
placed over the electrodes 1002 and optionally over the substrate
1010. The hydrogel 1032 can be introduced into the anchoring
features 1022 of the electrodes 1002 (e.g., surface textures 1036),
optionally including any additional anchoring features of the
substrate 1010. The hydrogel 1032 can have a total thickness 1030
and an over-electrode thickness 1028. The over-electrode thickness
1028 can represent a minimum, maximum, or average thickness of the
hydrogel 1032 as measured from the top surface 1008 of an electrode
1002. The over-electrode thickness 1028 of the hydrogel 1032 can be
any suitable thickness, such as about 10 microns to about 100
microns, although other ranges can be used. In some cases, the
over-electrode thickness 1028 of the hydrogel 1032 is in the tens
of microns.
[0060] FIG. 11 is a flowchart depicting a process 1100 for
mechanically securing hydrogel to an electrode using anchoring
features according to certain aspects of the present disclosure. At
block 1102, an electrode can be provided. In some cases, the
electrode can be pre-manufactured. In some cases, the electrode can
be fabricated on a substrate. At block 1106, an anchoring feature
can be created on the electrode. Any suitable anchoring feature can
be created. Creating an anchoring feature can include creating an
aperture through the electrode at block 1108, creating a void on
the electrode surface at block 1110, or texturizing the electrode
surface at block 1112. In some cases, creating an anchor feature at
block 1106 can include any combination of block 1108, block 1110,
and block 1112. In some cases, other anchoring features can be
created at block 1106. At block 1114, hydrogel is introduced to the
anchoring feature. At block 1114, hydrogel can also be introduced
to the electrode and optionally the substrate. In some cases,
introducing hydrogel at block 1114 includes introducing a hydrogel
precursor. In some cases, introducing hydrogel at block 1114 can
include pre-swelling the hydrogel, such as with a material selected
to be offset by physiological fluids when the implant is
implanted.
[0061] FIG. 12 is top view of an electrode array 1200 prior to
hydrogel application according to certain aspects of the present
disclosure. The electrode array 1200 can include a plurality of
electrodes 1202, although in some cases an array may include only a
single electrode. Each electrode 1202 can include a base layer 1204
and an upper layer 1206, although in some cases an electrode 1202
can include only a single layer of metal or more than two layers of
metal. In some cases, the base layer 1204 and upper layer 1206 can
be different metals, such as a base layer 1204 of gold and an upper
layer 1206 of platinum (e.g., platinum iridium). As used herein,
reference to metals used to form an electrode 1202 includes
suitable alloys of those metals (e.g., platinum can refer to a
platinum iridium alloy). Each electrode 1202 can have an upper
surface 1208. While the base layer 1204 is depicted as larger in
diameter than the upper layer 1206, that need not be the case and
each layer can be any suitable size. The electrodes 1202 of
electrode array 1200 are depicted as circular in shape, however any
suitable shaped electrodes may be used, such as square.
[0062] The electrodes 1202 of the electrode array 1200 can be
supported on a substrate 1210. The electrodes 1202 can be coupled
to the substrate in any suitable manner, such as formed on the
substrate 1210, attached to the substrate 1210, or embedded within
the substrate 1210. The substrate 1210 can have an upper surface
1220 to which the electrodes 1202 are coupled, although electrodes
1202 can be coupled to more than one surface of the substrate 1210
in some cases. Electrical conductors (e.g., wires) can be embedded
within the substrate 1210 and connect the electrodes 1202 to other
equipment, such as a controller of an implant.
[0063] Electrodes 1202 of electrode array 1210 are depicted in a
repeating pattern, however any number of electrodes 1202 may be
positioned in any suitable fashion on the electrode array 1210,
including randomly.
[0064] FIG. 13 is a cutaway view of the electrode array 1200 of
FIG. 12 taken along line C:C according to certain aspects of the
present disclosure. The substrate 1210 can support the electrodes
1202 on its top surface 1220. Each electrode 1202 can include a
base layer 1204 supporting an upper layer 1206 having an upper
surface 1208.
[0065] FIG. 14 is a cutaway view depicting an electrode array 1400
prior to hydrogel application according to certain aspects of the
present disclosure. The electrode array 1400 can be electrode array
1200 of FIG. 12. The electrode array 1400 can include one or more
electrodes 1402 supported by a substrate 1410. The electrodes 1402
can include a base layer 1404 and an upper layer 1406. The
electrodes 1402 can have a thickness 1412. Any suitable thickness
1412 can be used, such as thickness between about 3 microns to
about 6 microns, although other thicknesses can be used, including
less than 3 microns and greater than 6 microns. In some cases, the
base layer 1404 can have a thickness 1416 that is about three to
about five microns in thickness, although other values can be used.
In some cases, the upper layer 1406 can have a thickness 1414 that
is about 0.5 to about 1 micron in thickness, although other values
can be used. In some cases, the base layer 1404 of made of gold or
a gold alloy and the upper layer 1406 is made of platinum or a
platinum alloy. The electrodes 1402 can have any suitable
dimensions, such as about 500 microns to about 2 mm in diameter,
although other sizes can be used.
[0066] The substrate 1410 can have a thickness 1418 of any suitable
size. In some cases, substrate 1410 is thin and flexible to
facilitate maneuverability and implantation of the electrode array
1400.
[0067] FIG. 15 is a cutaway view depicting an electrode array 1500
with an applied hydrogel layer 1532 according to certain aspects of
the present disclosure. The electrode array 1500 can be electrode
array 1400 of FIG. 14 after hydrogel 1532 has been applied thereto.
The hydrogel 1532 can be applied over the electrodes 1502 and
optionally over the substrate 1510.
[0068] FIG. 16 is a cutaway view depicting an electrode array 1600
with a non-swellable shell 1638 over an applied hydrogel layer 1632
according to certain aspects of the present disclosure. The
electrode array 1600 can be electrode array 1500 of FIG. 15 after a
non-swellable shell 1638 has been applied thereto. The
non-swellable shell 1638 can be applied over the hydrogel layer
1632 and can couple to the substrate 1610. The non-swellable shell
1638 can couple to the substrate 1610 at locations devoid of
hydrogel (e.g., due to masking during hydrogel application). In
some cases, a pre-treatment can be applied to the substrate 1610 to
facilitate coupling of the non-swellable shell 1638 thereto. The
non-swellable shell 1638 can define a cavity 1642 between the
non-swellable shell 1638 and the electrodes 1602, which is filled
with the hydrogel 1632.
[0069] FIG. 17 is a cutaway view depicting an electrode array 1700
with a non-swellable shell 1738 having openings 1740 according to
certain aspects of the present disclosure. The electrode array 1700
can be electrode array 1600 of FIG. 16 after openings 1740 have
been formed in the non-swellable shell 1738. The cavity 1742
defined by the non-swellable shell 1638 and the electrodes 1602 can
therefore include openings 1740 through which hydrogel 1632 may
pass. Any suitable number and size of openings 1740 can be used.
The number and size of openings 1740 can be selected to provide
sufficient mechanical retention properties while also providing
sufficient electrical conductivity through the non-swellable shell
1738 (e.g., via hydrogel 1732 passing through the openings
1740.
[0070] FIG. 18 is a cutaway view depicting an electrode array 1800
with hydrogel 1832 exposed through openings 1840 in a non-swellable
shell 1838 according to certain aspects of the present disclosure.
The electrode array 1800 can be electrode array 1700 of FIG. 17
after sufficient time has passed to allow the hydrogel 1832 to
swell through the openings 1840 of the non-swellable shell 1838.
The openings 1840 can therefore facilitate electrical conductivity
from the outside of the non-swellable shell 1838 to the electrodes
1802 via hydrogel 1832 (e.g., conductive hydrogel) in the cavity
1842 of the non-swellable shell 1838 and swelling out of the
openings 1840 of the non-swellable shell 1838.
[0071] FIG. 19 is a cutaway view depicting an electrode array 1900
with an outer hydrogel layer 1946 connected to an inner hydrogel
layer 1944 through openings 1940 in a non-swellable shell 1938
according to certain aspects of the present disclosure. The
electrode array 1900 can be electrode array 1700 of FIG. 17 after
an outer hydrogel layer 1946 has been applied to the outer surface
of the non-swellable shell 1938. The outer hydrogel layer 1946 can
couple to the inner hydrogel layer 1944 to form a uniform hydrogel
mass 1932 that is mechanically held in place by the non-swellable
shell 1938 embedded therein. The non-swellable shell 1938 can
become embedded within the hydrogel 1932 by coupling of the outer
hydrogel layer 1946 to the inner hydrogel layer 1644 through
openings 1940. Thus, the openings 1940 can facilitate electrical
conductivity from the outside of the non-swellable shell 1938
(e.g., the outer surface of the outer hydrogel layer 1946) to the
electrodes 1902 via the hydrogel mass 1932.
[0072] FIG. 20 is a cutaway view depicting an electrode array 2000
with hydrogel 2032 anchored using a non-swellable shell 2038 and
anchoring features 2022 of the electrodes 2002 that are voids 2034
according to certain aspects of the present disclosure. The
electrode array 2000 can be similar to electrode array 1900 of FIG.
19, but with electrodes 2002 having anchoring features 2022 that
are voids 2034, similar to electrodes 702 of FIG. 7. Thus, the
hydrogel mass 2032 including an outer hydrogel layer 2046 coupled
to an inner hydrogel layer 2044 can be secured to the electrodes
2002 via the non-swellable shell 2038 coupled to the substrate 2010
as well as the anchoring features 2022 of the electrodes 2002.
[0073] FIG. 21 is a cutaway view depicting an electrode array 2100
with hydrogel 2132 anchored using a non-swellable shell 2138 and
anchoring features 2122 of the electrodes 2102 that are apertures
2124 according to certain aspects of the present disclosure. The
electrode array 2100 can be similar to electrode array 1900 of FIG.
19, but with electrodes 2102 having anchoring features 2122 that
are apertures 2124, similar to electrodes 502 of FIG. 5. Thus, the
hydrogel mass 2132 including an outer hydrogel layer 2146 coupled
to an inner hydrogel layer 2144 can be secured to the electrodes
2102 via the non-swellable shell 2138 coupled to the substrate 2110
as well as the anchoring features 2122 of the electrodes 2102. In
some cases, other anchoring features (e.g., surface textures 936 of
FIG. 9) can be used in addition to or instead of anchoring features
2122.
[0074] FIG. 22 is a cutaway view depicting an electrode array 2200
with hydrogel 2232 contained within a non-swellable shell 2238
according to certain aspects of the present disclosure. The
non-swellable shell 2238 can surround a cross section of the
electrode array 2200, thereby forming a cavity 2242 surrounding the
electrodes 2202 and substrate 2210 at that particular cross
section. Thus, hydrogel 2232 within the cavity 2242 can be located
adjacent the electrodes 2202 as well as opposite the substrate 2210
from the electrodes 2202. The non-swellable shell 2238 can include
openings 2240 through which hydrogel 2232 can swell out. The
electrode array 2200 can be similar to electrode array 1800 of FIG.
18, however with its non-swellable shell 2238 held in place
relative to the substrate 2210 via outward pressure from the
hydrogel 2232 within the cavity 2242, rather than being directly
coupled to the substrate 2210.
[0075] FIG. 23 is a cutaway view depicting an electrode array 2300
with an inner hydrogel layer 2344 contained within a non-swellable
shell 2338 that is connected to an outer hydrogel layer 2346
through openings 2340 in the non-swellable shell 2338 according to
certain aspects of the present disclosure. The non-swellable shell
2338 can surround a cross section of the electrode array 2300,
similar to the non-swellable shell 2238 of FIG. 22, thereby forming
a cavity 2342 surrounding the electrodes 2302 and substrate 2310 at
that particular cross section. Thus, an inner hydrogel layer 2344
within the cavity 2342 can be located adjacent the electrodes 2302
as well as opposite the substrate 2310 from the electrodes 2302.
The non-swellable shell 2338 can include openings 2340 through
which an outer hydrogel layer 2346 can couple to the inner hydrogel
layer 2344 to form a single hydrogel mass 2332. The electrode array
2300 can be similar to electrode array 1900 of FIG. 19, however
with its non-swellable shell 2338 held in place relative to the
substrate 2310 via outward pressure from the inner hydrogel layer
2344 within the cavity 2342, rather than being directly coupled to
the substrate 2310.
[0076] As seen in FIG. 23, openings 2340 are depicted in the
non-swellable layer 2338 on both the upper side (e.g., nearest the
electrodes 2302) and the lower side (e.g., the side opposite the
substrate 2310 from the electrodes 2302. In some cases, openings
2340 are only provided in the non-swellable layer 2338 on the side
nearest the electrodes 2302. In some cases, openings 2340 are only
provided in the non-swellable layer 2338 at locations adjacent the
electrodes 2302.
[0077] FIG. 24 is a flowchart depicting a process 2400 for
mechanically securing hydrogel to an electrode using a
non-swellable layer according to certain aspects of the present
disclosure. At block 2402, an electrode can be provided. In some
cases, the electrode can be pre-manufactured. In some cases, the
electrode can be fabricated on a substrate. At optional block 2404,
an anchoring feature can be created on the electrode. Any suitable
anchoring feature can be created. Creating an anchoring feature can
include creating an aperture through the electrode at block 2406,
creating a void on the electrode surface at block 2408, or
texturizing the electrode surface at block 2410. In some cases,
creating an anchor feature at block 2404 can include any
combination of block 2406, block 2408, and block 2410. In some
cases, other anchoring features can be created at block 2404.
[0078] At optional block 2412, the substrate can be masked, such as
with a chemical or physical mask. At block 2414, hydrogel can be
introduced to the electrode surface. At block 2414, hydrogel may
also be introduced to the substrate. In cases where the substrate
is masked at block 2412, introducing hydrogel to the substrate at
block 2414 can include not introducing or removing hydrogel from
the portion of the substrate that was masked at block 2412. In some
cases, introducing the hydrogel at block 2414 can first include
cleaning the electrodes and/or the substrate.
[0079] At block 2416, a non-swellable layer is provided over the
hydrogel. In some cases, the non-swellable layer is provided
entirely over the hydrogel, such as seen with non-swellable layer
2338 of FIG. 23. In some cases, the non-swellable layer can be
coupled to the substrate at block 2416, such as seen in with
non-swellable layer 1938 of FIG. 19. In some cases where the
non-swellable layer is coupled to the substrate, providing the
non-swellable layer at block 2416 can further include first
applying a pre-treatment to the substrate and then applying the
non-swellable layer to the substrate. In some cases, providing the
non-swellable layer at block 2416 can include otherwise coupling
the non-swellable layer to the substrate.
[0080] In some cases, providing the non-swellable layer at block
2416 can include coupling the non-swellable layer to the substrate
at locations between adjacent electrodes, thus reducing electrical
conductivity through the inner hydrogel layer between the adjacent
electrodes.
[0081] In some cases, any sprayable hydrophobic polymer capable of
having openings created therein can be used for a non-swellable
layer. The term non-swellable layer can include a layer of material
exhibiting no or low swelling in vivo.
[0082] At block 2418, openings can be created in the non-swellable
layer. Openings can be created in any suitable manner, including
through photolithography, laser ablation, or other techniques. The
openings can pass entirely through the thickness of the
non-swellable layer. In some cases, at block 2418 the non-swellable
layer can be surface roughened.
[0083] At optional block 2420, an additional coating of hydrogel
can be applied around the non-swellable layer. This overcoating of
hydrogel can result in the hydrogel mass 2332 of FIG. 23.
[0084] FIG. 25 is a scanning electron micrograph 2500 depicting a
first example electrode 2502 having hydrogel 2532 mechanically
coupled to a textured anchoring feature according to certain
aspects of the present disclosure. The electrode 2502 can be
supported by a substrate 2510 and can include a base layer 2504
coupled to an upper layer 2506. The upper layer 2506 can include
anchoring features in the form of surface textures, such as surface
textures 936 of FIG. 9, into which the hydrogel 2532 can
interdigitate. Thus, the hydrogel 2532 can be mechanically affixed
to the electrode 2502 without the need to rely substantially on
covalent bonds between the hydrogel 2532 and the metal (e.g. noble
metal) of the upper layer 2506 of the electrode 2502.
[0085] FIG. 26 is a scanning electron micrograph 2600 depicting a
second example electrode 2602 having hydrogel 2632 mechanically
coupled to a textured anchoring feature according to certain
aspects of the present disclosure. The electrode 2602 can be
supported by a substrate 2610 and can include a base layer 2604
coupled to an upper layer 2606. The upper layer 2606 can include
anchoring features in the form of surface textures, such as surface
textures 936 of FIG. 9, into which the hydrogel 2632 can
interdigitate. Thus, the hydrogel 2632 can be mechanically affixed
to the electrode 2602 without the need to rely substantially on
covalent bonds between the hydrogel 2632 and the metal (e.g. noble
metal) of the upper layer 2606 of the electrode 2602.
[0086] FIG. 27 is a schematic diagram depicting an implantable
medical device 2700 electrically coupled to biological tissue 2752
according to certain aspects of the present disclosure. The
implantable medical device 2700 can include a controller 2748
coupled to an electrode array 2750. The implantable medical device
2700 can be located within a biological cavity 2754 (e.g., within a
body of a patient). The implantable medical device 2700 can be
separated from an external atmosphere 2756 by skin 2758 or other
tissue. The electrode array 2750 can be any electrode array
described herein, such as electrode array 2300 of FIG. 23. The
electrode array 2750 can be coupled to the biological tissue 2752
using any suitable technique, such as clamps, sutures, pins,
screws, adhesives, or other methods. Electrode array 2750 can
facilitate electrical communication between the controller 2748 and
the biological tissue 2752 by passing electrical signals through
the electrodes and hydrogel of the electrode array 2750. Thus,
electrode array 2750 can operate to send, receive, or send and
receive electrical signals to, from, or to and from biological
tissue 2752. Thus, electrode array 2750 can be suitable for use as
a stimulation device, a measurement device, or any combination
thereof.
[0087] The foregoing description of the embodiments, including
illustrated embodiments, has been presented only for the purpose of
illustration and description and is not intended to be exhaustive
or limiting to the precise forms disclosed. Numerous modifications,
adaptations, and uses thereof will be apparent to those skilled in
the art.
[0088] As used below, any reference to a series of examples is to
be understood as a reference to each of those examples
disjunctively (e.g., "Examples 1-4" is to be understood as
"Examples 1, 2, 3, or 4").
[0089] Example 1 is an implantable electrode array, comprising: at
least one electrode comprising a conductible metal layer having one
or more anchoring features; and a hydrogel layer mechanically
coupled to the conductible metal layer at the one or more anchoring
features.
[0090] Example 2 is the electrode array of example 1, wherein the
one or more anchoring features include an aperture passing through
a thickness of the at least one electrode.
[0091] Example 3 is the electrode array of examples 1 or 2, wherein
the one or more anchoring features include a void having a depth
that is less than a thickness of the at least one electrode.
[0092] Example 4 is the electrode array of examples 1-3, further
comprising a substrate having at least one additional anchoring
feature, wherein the at least one electrode is coupled to the
substrate, and wherein the hydrogel layer is further mechanically
coupled at the at least one additional anchoring feature.
[0093] Example 5 is the electrode array of examples 1-4, wherein
the hydrogel layer comprises electrically conductive hydrogel
material.
[0094] Example 6 is the electrode array of examples 1-5, wherein
the hydrogel layer comprises a non-swelling hydrogel material or a
low-swell hydrogel material.
[0095] Example 7 is the electrode array of examples 1-6, wherein
the conductible metal layer is a noble metal.
[0096] Example 8 is the electrode array of example 7, wherein the
conductible metal layer is selected from the group consisting of
platinum and gold.
[0097] Example 9 is an implantable device, comprising: an electrode
array positionable adjacent biological tissue, the electrode array
comprising: at least one electrode comprising a conductible metal
layer having one or more anchoring features; and a hydrogel layer
mechanically coupled to the conductible metal layer at the one or
more anchoring features, wherein the hydrogel layer is located
between the at least one electrode and the biological tissue for
conducting a signal between the at least one electrode and the
biological tissue when the electrode array is positioned adjacent
the biological tissue; and a controller electrically coupled to the
electrode array.
[0098] Example 10 is the implantable device of example 9, wherein
the one or more anchoring features include an aperture passing
through a thickness of the at least one electrode.
[0099] Example 11 is the electrode array of examples 9 or 10,
wherein the one or more anchoring features include a void having a
depth that is less than a thickness of the at least one
electrode.
[0100] Example 12 is the electrode array of examples 9-11, further
comprising a substrate having at least one additional anchoring
feature, wherein the at least one electrode is coupled to the
substrate, and wherein the hydrogel layer is further mechanically
coupled at the at least one additional anchoring feature.
[0101] Example 13 is the electrode array of examples 9-12, wherein
the hydrogel layer comprises electrically conductive hydrogel
material.
[0102] Example 14 is the electrode array of examples 9-13, wherein
the hydrogel layer comprises a non-swelling hydrogel material or a
low-swell hydrogel material.
[0103] Example 15 is the electrode array of examples 9-14, wherein
the conductible metal layer is a noble metal.
[0104] Example 16 is the electrode array of example 15, wherein the
conductible metal layer is selected from the group consisting of
platinum and gold.
[0105] Example 17 is a method of preparing an electrode array,
comprising: providing an electrode comprising a conductible metal
layer; creating one or more anchoring features on the conductible
metal layer; and introducing a hydrogel layer, wherein introducing
the hydrogel layer includes mechanically securing the hydrogel
layer against the conductible metal layer using the one or more
anchoring features.
[0106] Example 18 is the method of example 17, wherein creating the
one or more anchoring features includes creating at least one
aperture through a thickness of the at least one electrode.
[0107] Example 19 is the method of examples 17 or 18, wherein
creating the one or more anchoring features includes creating a
void in the conductible metal layer extending from a surface of the
conductible metal layer to a depth that is less than a thickness of
the at least one electrode.
[0108] Example 20 is the method of examples 17-19, wherein
providing the electrode includes applying the conductible metal
layer to a substrate, the method further comprising creating at
least one additional anchoring feature in the substrate, wherein
introducing the hydrogel layer further includes mechanically
securing the hydrogel layer using the at least one additional
anchoring feature.
[0109] Example 21 is the method of examples 17-20, wherein the
hydrogel layer comprises electrically conductive hydrogel
material.
[0110] Example 22 is the method of examples 17-21, wherein the
hydrogel layer comprises a non-swelling hydrogel material or a
low-swell hydrogel material.
[0111] Example 23 is the method of examples 17-22, wherein the
conductible metal layer is a noble metal.
[0112] Example 24 is the method of example 23, wherein the
conductible metal layer is selected from the group consisting of
platinum and gold.
[0113] Example 25 is an electrode array, comprising: at least one
electrode comprising a conductible metal layer; a substrate
supporting the at least one electrode; a non-swellable material
defining an internal cavity surrounding the at least one electrode,
the non-swellable material having one or more openings; and
hydrogel material disposed within the internal cavity between the
non-swellable material and the at least one electrode, wherein the
non-swellable material mechanically secures the hydrogel material
against the at least one electrode.
[0114] Example 26 is the electrode array of example 25, further
comprising additional hydrogel material disposed opposite the
non-swellable material from the internal cavity, wherein the
additional hydrogel material contacts the hydrogel material.
[0115] Example 27 is the electrode array of examples 25 or 26,
wherein the non-swellable material is coupled to the top surface of
the substrate, and wherein the internal cavity is defined in part
by at least a portion of the top surface of the substrate.
[0116] Example 28 is the electrode array of examples 25-27, wherein
the internal cavity is sized to surround at least a portion of a
bottom surface of the substrate, and wherein the hydrogel material
is further disposed within the internal cavity between the
non-swellable material and the bottom surface of the substrate.
[0117] Example 29 is the electrode array of examples 25-28, wherein
the conductible metal layer of the at least one electrode includes
one or more anchoring features, and wherein the hydrogel material
is further mechanically coupled to the at least one electrode at
the one or more anchoring features.
[0118] Example 30 is the electrode array of examples 25-29, wherein
the substrate includes at least one additional anchoring feature,
and wherein the hydrogel layer is further mechanically coupled at
the at least one additional anchoring feature.
[0119] Example 31 is the electrode array of examples 25-30, wherein
the hydrogel layer comprises electrically conductive hydrogel
material.
[0120] Example 32 is the electrode array of examples 25-31, wherein
the hydrogel layer comprises a non-swelling hydrogel material or a
low-swell hydrogel material.
[0121] Example 33 is the electrode array of examples 25-32, wherein
the conductible metal layer is a noble metal.
[0122] Example 34 is the electrode array of example 33, wherein the
conductible metal layer is selected from the group consisting of
platinum and gold.
[0123] Example 35 is an implantable device, comprising: an
electrode array positionable adjacent biological tissue, the
electrode array comprising: at least one electrode comprising a
conductible metal layer; a substrate supporting the at least one
electrode; a non-swellable material defining an internal cavity
surrounding the at least one electrode, the non-swellable material
having one or more openings; and hydrogel material disposed within
the internal cavity between the non-swellable material and the at
least one electrode, wherein the non-swellable material
mechanically secures the hydrogel material against the at least one
electrode, and wherein at least a portion of the hydrogel extends
through the one or more openings for electrically coupling to the
biological tissue and conducting a signal between the at least one
electrode and the biological tissue when the electrode array is
positioned adjacent the biological tissue; and a controller
electrically coupled to the electrode array.
[0124] Example 36 is the implantable device of example 35, wherein
the electrode array further comprises additional hydrogel material
disposed opposite the non-swellable material from the internal
cavity, wherein the additional hydrogel material contacts the
hydrogel material for electrically coupling the hydrogel material
to the biological tissue through the additional hydrogel
material.
[0125] Example 37 is the implantable device of examples 35 or 36,
wherein the non-swellable material is coupled to the top surface of
the substrate, and wherein the internal cavity is defined in part
by at least a portion of the top surface of the substrate.
[0126] Example 38 is the implantable device of examples 35-37,
wherein the internal cavity is sized to surround at least a portion
of a bottom surface of the substrate, and wherein the hydrogel
material is further disposed within the internal cavity between the
non-swellable material and the bottom surface of the substrate.
[0127] Example 39 is the implantable device of examples 35-38,
wherein the conductible metal layer of the at least one electrode
includes one or more anchoring features, and wherein the hydrogel
material is further mechanically coupled to the at least one
electrode at the one or more anchoring features.
[0128] Example 40 is the implantable device of examples 35-39,
wherein the substrate includes at least one additional anchoring
feature, and wherein the hydrogel layer is further mechanically
coupled at the at least one additional anchoring feature.
[0129] Example 41 is the implantable device of examples 35-40,
wherein the hydrogel layer comprises electrically conductive
hydrogel material.
[0130] Example 42 is the implantable device of examples 35-41,
wherein the hydrogel layer comprises a non-swelling hydrogel
material or a low-swell hydrogel material.
[0131] Example 43 is the implantable device of examples 35-42,
wherein the conductible metal layer is a noble metal.
[0132] Example 44 is the implantable device of example 43, wherein
the conductible metal layer is selected from the group consisting
of platinum and gold.
[0133] Example 45 is a method of preparing an electrode array,
comprising: providing an electrode on a substrate, the electrode
comprising a conductible metal layer; applying hydrogel material to
the electrode; coating the hydrogel material with a non-swellable
material, wherein the non-swellable material mechanically secures
the hydrogel layer to the electrode; and creating one or more
openings in the non-swellable material to expose the hydrogel
material.
[0134] Example 46 is the method of example 45, wherein coating the
hydrogel material with the non-swellable material includes coupling
the non-swellable material to the substrate.
[0135] Example 47 is the method of examples 45 or 46, further
comprising masking a first portion of the substrate prior to
applying the hydrogel material to the electrode, wherein coating
the hydrogel material with the non-swellable material includes
coupling the non-swellable material to the first portion of the
substrate.
[0136] Example 48 is the method of examples 45-47, further
comprising overcoating the non-swellable material with additional
hydrogel material, wherein the additional hydrogel contacts the
hydrogel material through the openings in the non-swellable
material.
[0137] Example 49 is the method of examples 45-48, further
comprising creating one or more anchoring features on the
conductible metal layer, wherein applying hydrogel material to the
electrode includes mechanically securing the hydrogel layer against
the conductible metal layer using the one or more anchoring
features.
[0138] Example 50 is the method of examples 45-49, wherein the
hydrogel layer comprises electrically conductive hydrogel
material.
[0139] Example 51 is the method of examples 45-50, wherein the
hydrogel layer comprises a non-swelling hydrogel material or a
low-swell hydrogel material.
[0140] Example 52 is the method of examples 45-51, wherein the
conductible metal layer is a noble metal.
[0141] Example 53 is the method of example 52, wherein the
conductible metal layer is selected from the group consisting of
platinum and gold.
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