KR101737385B1

KR101737385B1 - A nerve cuff electrode made of hybrid materials and a manufacturing method thereof

Info

Publication number: KR101737385B1
Application number: KR1020150150450A
Authority: KR
Inventors: 변동학; 김소희
Original assignee: 광주과학기술원
Priority date: 2015-10-28
Filing date: 2015-10-28
Publication date: 2017-05-18
Also published as: KR20170049268A

Abstract

In order to solve the problems of the polyimide-based cuff electrode and the perylene-based cuff electrode described above, the present invention provides a nerve cuff electrode that satisfies high biocompatibility and optical transmittance by different materials of the structure portion and the window portion The purpose. In order to accomplish the object of the present invention, a cuff-shaped electrode is disclosed according to one embodiment of the present invention. Wherein the cuff-shaped electrode comprises: a structure part for maintaining the cuff shape; An electrode part formed on the structure part; And a window portion formed between the structure portions, and the structure portion, the electrode portion, and the window portion may be formed of different materials.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a nerve electrode in the form of a cuff composed of dissimilar materials and a method of manufacturing the same.

The present invention relates to a cuff-shaped neural electrode made of dissimilar materials and a manufacturing method thereof. More specifically, the present invention relates to a cuff-shaped neural electrode capable of taking advantage of different materials by making materials of a structure and a window different, &Lt; / RTI >

A cuff-shaped electrode is a type of neural electrode used in neuroscience and neuroscience. This cuff electrode is designed so that its shape is suitable for peripheral nerves. Therefore, research has been conducted on the treatment of chronic pain, epilepsy, depression, and neural prostheses that replace sensory or motor neuronal transmission due to peripheral nerve cleavage. A typical commercially available cuff-shaped electrode has a cylindrical shape with one side of an elastomer material as shown in FIG. 1, and is used as a vagus nerve stimulation (VNS) electrode, (MicroProbes for Life science, MD, US). The other cuff electrode is based on polyimide (PI), and is mainly used for neural prosthesis research, and has the shape shown in FIG.

Polyimide is thermally deformable to a certain shape permanently (thermal deformation), has high electrical insulation, is transparent during the process but shows yellow translucent color after the process is completed. This is easy.

However, the polyimide-based cuff electrode has a large nerve wrapping force, resulting in a lower density of nerve cells, and a change in color and light transmittance of the hard bake, If the hard bake process is excessive or insufficient, the gas remains in the PI film. If the film comes into contact with the living body, it is harmful to the living body. If the electrode film is deteriorated in optical transmittance and color change, And it is disadvantageous that when the PI film is implanted into a living body for a long time, the film is broken or cracked due to a change in mechanical properties.

Because of these problems, PI-based cuff electrodes are mainly used, but recently, perylene (PPX) based cuff electrodes have also been reported.

Perylene can be used as a passivation and insulation layer against moisture and corrosion of the surface of PCBs and semiconductors, free of pinholes at thicknesses of 400 nm or more, It can be used for surface protection and electrical insulation of medical devices due to its high biocompatibility, and it has high optical transmittance at all wavelength ranges. (80% or more), and the water permeation / absorption rate is very low compared to other materials.

Fig. 3 shows a perylene-based cuff electrode that was developed and developed by Peking University. 2 (a) shows a similar shape when the PI-based electrode and the electrode of FIG. 3 (a) are flat. However, perylene-based cuff electrodes can not maintain a cylindrical shape through the material and have a separate strap structure to conform to the target peripheral nerve shape and position fix.

In order to solve the problems of the polyimide-based cuff electrode and the perylene-based cuff electrode described above, the present invention provides a nerve cuff electrode that satisfies high biocompatibility and optical transmittance by different materials of the structure portion and the window portion The purpose.

In order to accomplish the object of the present invention, a cuff-shaped electrode is disclosed according to one embodiment of the present invention.

Wherein the cuff-shaped electrode comprises: a window portion for satisfying the optical transmittance of the cuff shape; A structure part for maintaining the shape of the window part; And an electrode portion formed on the structure portion, wherein the structure portion, the electrode portion, and the window portion may be formed of different materials.

The window portion may be formed of a material that maintains flexibility after molding.

The window portion may be formed of at least one of perylene, polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

The structure part may be formed of a material to be fixed after molding.

The structure part may be formed of at least one of polyimide (PI), SU-8, and liquid crystal polymer (LCP).

The electrode unit may be formed of at least one of gold (Au), platinum (Pt), iridium (Ir), and iridium oxide (IrOx).

According to another embodiment of the present invention, a method for manufacturing a cuff-shaped electrode is disclosed.

The method includes applying a sacrificial layer to the carrier; Applying a window portion over the sacrificial layer; Applying and patterning a structure portion on the window portion; And applying an electrode portion on the patterned structure portion, wherein the window portion, the structure portion, and the electrode portion may be formed of different materials.

The method may further include a step of applying an adhesive layer before the step of applying the electrode portion.

The method may further include coating the electrode portion with the same material as the window portion to protect the electrode portion.

The method may further comprise exposing the applied layer to protect the electrode portion.

The structure part may be formed of a material to be fixed after molding.

The structure portion may be formed of at least one of polyimide (PI), SU-8, and liquid crystal polymer.

According to the structure of the present invention as described above, the structure part of the cuff-shaped electrode has such a rigidity as to be able to maintain the shape of the electrode and the position with respect to the implantation part, the window part has a flexible structure, And thus it is possible to prevent necrosis of nerve cells which may occur due to long-term nerve cell wrapping with a minimum force in combination with the structure part.

Those skilled in the art will appreciate that the effects derived from the present invention are not limited to the above description and can be widely accepted.

Figure 1 shows a representative commercially available electrode in the form of a cuff.
Figure 2 shows a conventional cuff-shaped electrode formed on a polyimide base.
3 shows a cuff-shaped electrode conventionally formed on a perylene basis.
Fig. 4 shows a schematic view of a method of manufacturing a cuff-shaped electrode according to an embodiment of the present invention.
Figures 5 and 6 illustrate a cuff-shaped electrode according to one embodiment of the present invention.

Specific structural and functional descriptions of embodiments of the invention disclosed herein are merely illustrative for purposes of illustrating embodiments of the invention and that the embodiments according to the invention may be embodied in various forms, And should not be interpreted as being limited to the embodiments described in the application.

Since the embodiments according to the present invention can make various changes and have various forms, specific embodiments are illustrated in the drawings and described in detail herein. It should be understood, however, that the embodiments according to the concepts of the present invention are not intended to be limited to any particular mode of disclosure, but rather all variations, equivalents, and alternatives falling within the spirit and scope of the present invention.

The terms first and / or second, primary and / or secondary, etc. may be used to describe various components, but the components should not be limited by these terms. The terms are intended to distinguish one element from another, for example, without departing from the scope of the invention in accordance with the concepts of the present invention, the first element may be termed the second element, The second component may also be referred to as a first component.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise," "include," "have," and the like, specify that there is a specified feature, number, step, operation, component, section, element, Steps, operations, elements, parts, or combinations thereof, whether or not explicitly described or implied by the accompanying claims.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be construed as meaning consistent with meaning in the context of the relevant art and are not to be construed as ideal or overly formal in meaning unless expressly defined herein .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to a method and an apparatus for manufacturing a cuff-shaped electrode according to the present invention with reference to the accompanying drawings.

FIG. 4 illustrates a method of manufacturing a cuff-shaped electrode according to an embodiment of the present invention, and FIGS. 5 and 6 illustrate a cuff-shaped electrode according to an embodiment of the present invention.

According to an embodiment of the present invention, the structure portion may be formed of polyimide (PI), and the window portion may be formed of perylene (PPX).

PI is used as a structure to maintain shape and implant position, and PPX can be used as a window to improve optical compatibility and biocompatibility.

By applying different kinds of materials to the electrodes of the cuff type, the deficiencies can be complemented, and the production can be performed by the process as shown in FIG.

Referring to FIG. 4, (a) a sacrificial layer is applied to a carrier using an E-beam evaporator or a sputtering method. In this case, the carrier may be a silicon wafer or a glass substrate, and the sacrificial layer may be a metal such as Al (aluminum) or Ti (titanium).

(b) Apply the PPX layer on the sacrificial layer by CVD.

(c) Coating and patterning the PI layer. At this time, in the case of photosensitive PI, a pattern is formed through photolithography, and if not, a pattern is formed through an etching mask.

(d) Apply a metal to be used as an electrode by using an E-beam evaporator or a sputtering method. The metals that can be used at this time are Au (gold), Pt (platinum), Ir (iridium), IrOx (iridium oxide) and the like. Cr (chromium) or Ti (titanium) may be used as an adhesive layer before these metals are applied. Also, since PI is known to have better adhesion to metals than PPX, it is advantageous for electrode formation stability to deposit and pattern the PI.

(e) PPX is applied by CVD to protect and isolate electrodes and conductors. At this time, an adhesion promoter is used to improve the adhesion between PPX-PI and PPX-PPX.

(f) masking is performed using a photoresist (PR) except for a portion where the electrode is to be exposed.

(g) The PPX is etched through the oxidation plasma to expose the electrode portion, and the PR is removed.

(h) The sacrificial layer is removed using an etching solution, and the completed electrode is separated from the carrier.

The planar electrode (FIG. 5) removed after the steps (a) to (h) is wrapped in a metal cylinder, and then placed in an oven at about 200 ° C. and fixed in a cuff shape (FIG. Thereafter, the process is completed by separating from the cylinder.

Referring to FIG. 6, a cuff-shaped electrode formed through the above process is shown.

The cuff-shaped electrode includes a structure portion 601 for retaining the cuff shape; An electrode part 602 formed on the structure part 601; And a window portion 603 formed between the structure portion 601 and the structure portion, the electrode portion, and the window portion may be formed of different materials.

In the present invention, since the window portion uses a material having flexibility and light transmittance and a low water / gas permeability such as PPX, it is possible to prevent cracks and breakage that occur during long-term implantation, The density reduction and necrosis of the PI can be prevented, the optical transmittance can be increased, and the problem of the living body due to the inadequacy of PI gas removal can be solved. Further, since the structure part is made of a material having a fixing property such as PI, it is possible to have an effect that it is possible to adhere to the entire surface of the nerve surface without requiring a separate device for maintaining the shape.

In the process according to the present invention, it is possible to consider that the PI has many different products in various companies, and that the thermal characteristics are different from each other. The temperature for the reshaping of the PI film was checked by literature, and the results were obtained from Richard Blaine International, Inc. Of VTEC-PI1388 was placed in an oven at 340C for 2 hours. And HD MicroSystems (or DuPont) PI2611 was exposed to heat for 1 hour in an oven at 230 degrees Celsius. For these two PIs, the process temperature is very high and the glass transition temperature is also 320 ° C and 360 ° C, respectively. For the Durimide 7500 series of Fujifilm, not these two PIs, the process temperature is lower than the previous two products, and the glass transition temperature is also very low at 285 degrees, which is expected to lower the process temperature for reshape of the electrode. As a result, it is considered that the present invention can be implemented more easily when a PI similar to this product or having a lower glass transition temperature is utilized.

The glass transition temperature and melting point of perylene (especially perylene-C) are known to be 90 degrees and 290 degrees Celsius, respectively, and the process temperature is known to be processable at temperatures below 200 degrees Celsius, so the process temperature is not a big problem.

According to another embodiment of the present invention, the structure part may be replaced with SU-8 or a liquid crystal polymer, and the window part may be replaced with PDMS (Polydimethylsiloxane), PET (polyethylene terephthalate) or PEN (Polyethylene Naphthalate).

When PDMS is used in the window portion, since PDMS is difficult to etch, it should be accessed by stamping or molding in step (g).

In addition, when PET or PEN is used in the window portion, since the raw material is a thin film, it is necessary to temporarily adhere to a silicon wafer or a glass substrate, or to cover the structure portion with a sandwich structure. have.

Claims

In a cuff-shaped electrode,
A window portion for satisfying the cuff-shaped optical transmittance;
A structure part for maintaining the shape of the window part;
An electrode part formed on the structure part; And
A protective layer applied over the electrode portion;
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Wherein the structure portion, the electrode portion, and the window portion are different materials, and the window portion and the protection layer are formed of the same material.

The method according to claim 1,
And the window portion is formed of a material that maintains flexibility after molding.

3. The method of claim 2,
Wherein the window portion is formed of at least one material selected from the group consisting of perylene, polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

The method according to claim 1,
Wherein the structure portion is formed of a material to be fixed after molding.

5. The method of claim 4,
Wherein the structure portion is formed of at least one of polyimide (PI), SU-8, and a liquid crystal polymer.

The method according to claim 1,
Wherein the electrode portion is formed of at least one of gold (Au), platinum (Pt), iridium (Ir), and iridium oxide (IrOx).

A method for manufacturing a cuff-shaped electrode,
Applying a sacrificial layer to the carrier;
Applying a window portion over the sacrificial layer;
Applying and patterning a structure portion on the window portion;
Applying an electrode portion over the patterned structure portion;
Applying the same material as the window portion to protect the electrode portion; And
Exposing the applied layer to protect the electrode portion;
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Wherein the window portion, the structure portion, and the electrode portion are formed of different materials.

8. The method of claim 7,
Further comprising the step of applying an adhesive layer prior to applying the electrode portion.

delete

8. The method of claim 7,
Wherein the window portion is formed of a material that maintains flexibility after molding.

12. The method of claim 11,
Wherein the window portion is formed of at least one material selected from the group consisting of perylene, polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

8. The method of claim 7,
Wherein the structure portion is formed of a material to be fixed after molding.

14. The method of claim 13,
Wherein the structure portion is formed of at least one of polyimide (PI), SU-8, and a liquid crystal polymer.

8. The method of claim 7,
Wherein the electrode portion is formed of at least one of gold (Au), platinum (Pt), iridium (Ir), and iridium oxide (IrOx).