Deep brain stimulating electrode based on carbon nanotube fibers and preparation method thereof

Abstract

The invention relates to a deep brain stimulating electrode based on carbon nanotube fibers and a preparation method thereof.The deep brain stimulating electrode based on the carbon nanotube fibers comprises a core layer, an inner skin layer and an outer skin layer which are coaxially distributed, the core layer is the carbon nanotube fibers, one end of each carbon nanotube fiber extends out of the inner skin layer to form a signal output end, and the other end of each carbon nanotube fiber extends out of the outer skin layer to form a signal output end; the inner skin layer is a graphene fiber conducting ring, and the outer skin layer is a flexible insulating ring. According to the invention, the carbon nanotube fiber is used as an inner core electrode material, so that the carbon nanotube fiber electrode has excellent conductivity, can effectively store charges, and gives large-capacity charge stimulation to the brain of an organism in a short time; meanwhile, magnetic field interference can be reduced, MRI artifacts are effectively reduced in MRI detection, MRI compatibility is improved, and the success rate and stability of an operation are improved; the flexible insulating ring provides mechanical support for the electrode, the electrode is protected from being eroded by surrounding tissue fluid in the brain, physical damage or deformation of the electrode is reduced, and the long-term stability of the electrode used in the brain is improved.

Description

Technical Field

[0001] This invention belongs to the field of deep brain stimulation electrode technology, specifically relating to a deep brain stimulation electrode based on carbon nanotube fibers and its preparation method. Background Technology

[0002] Deep brain stimulation (DBS) is a minimally invasive neurosurgical procedure that uses stereotactic techniques to implant stimulating electrodes at specific target points in the brain to deliver high-frequency electrical stimulation, thereby modulating the excitability of corresponding nuclei to achieve therapeutic goals. It is used to treat movement disorders such as Parkinson's disease and essential tremor, and is gradually being explored for its application in improving conditions such as epilepsy, treatment-resistant obsessive-compulsive disorder, and depression.

[0003] Most existing deep brain stimulation (DBS) electrodes are made of materials such as platinum-iridium alloys, tungsten, and gold, which possess good stability and electrochemical properties. However, metal electrodes can affect MRI detection. Therefore, to improve MRI compatibility, this invention utilizes carbon nanotube fibers to fabricate DBS electrodes. Carbon nanotube fibers exhibit excellent conductivity, mechanical strength, and biocompatibility, and can improve MRI compatibility to a certain extent, making them a new choice for DBS electrode materials. Summary of the Invention

[0004] Based on the aforementioned shortcomings and deficiencies in the existing technology, the purpose of this invention is to provide a deep brain stimulation electrode based on carbon nanotube fibers and its preparation method.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A deep brain stimulation electrode based on carbon nanotube fibers includes a core layer, an endothelial layer, and an outer skin layer coaxially distributed. The core layer is made of carbon nanotube fibers, with one end of the carbon nanotube fibers extending beyond the endothelial layer to form a signal output terminal. The endothelial layer is a graphene fiber conductive ring, and the outer skin layer is a flexible insulating ring.

[0007] As a preferred embodiment, the graphene fiber is a graphene fiber doped with metal particles, wherein the metal particles are Au or Pt.

[0008] As a preferred embodiment, the doping amount of the metal particles is 5-10 wt%.

[0009] As a preferred embodiment, the doping is performed using chemical vapor deposition.

[0010] As a preferred embodiment, the core layer has a diameter of 5–20 μm, the inner skin layer has a thickness of 3–5 μm, and the outer skin layer has a thickness of 3–5 μm.

[0011] As a preferred embodiment, the outer diameter of the deep brain stimulation electrode is 15–25 μm.

[0012] As a preferred embodiment, the length of one end of the carbon nanotube fiber extending beyond the endothelial layer is 10–20 μm.

[0013] As a preferred embodiment, the flexible insulating ring is made of polyimide, polydimethylsiloxane, or parylene.

[0014] As a preferred embodiment, the signal output terminal of the deep brain stimulation electrode is connected to a metal connector as an electrode connector, and the metal connector is made of Au or Pt.

[0015] The present invention also provides a method for preparing a deep brain stimulation electrode as described in any of the preceding embodiments, comprising the following steps:

[0016] (1) Preparation of carbon nanotube fibers;

[0017] (2) Graphene was deposited on the surface of carbon nanotube fibers to obtain graphene fiber conductive rings.

[0018] (3) Coating or injection molding a flexible insulating ring onto the surface of the graphene fiber conductive ring.

[0019] As a preferred embodiment, in step (2), metal particles are doped into graphene fibers using chemical vapor deposition.

[0020] Compared with the prior art, the beneficial effects of this invention are:

[0021] I. This invention uses carbon nanotube fibers as the core electrode material, which has excellent conductivity and can effectively store charge, providing a large amount of charge stimulation to the brain of the organism in a short time. At the same time, it can reduce magnetic field interference, effectively reduce MRI artifacts in MRI detection, improve MRI compatibility, and enhance the success rate and stability of surgery.

[0022] II. This invention uses graphene fibers or metal (Au or Pt) doped graphene fibers to form rings that encapsulate and cover carbon nanotube fibers. By doping the metal with the graphene fibers, the conductivity and biocompatibility of the electrode can be improved, allowing for a high degree of matching with the brain and further enhancing the stability of the electrode.

[0023] Third, this invention uses a flexible insulating ring made of polyimide / polydimethylsiloxane / poly(p-xylene) as the outer ring to cover the entire electrode. This provides mechanical support for the electrode, protects it from erosion by the surrounding tissue fluid in the brain, reduces physical damage or deformation, and improves the long-term stability of the electrode during use in the brain.

[0024] Fourth, the signal output terminal of the deep brain stimulation electrode of the present invention uses Au / Pt as the electrode connector, which has good conductivity and can stably transmit signals, thereby improving the utilization efficiency of the electrode. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the deep brain stimulation electrode of Embodiment 1 of the present invention. Detailed Implementation

[0026] To more clearly illustrate the embodiments of the present invention, specific implementation methods will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0027] Example 1:

[0028] like Figure 1 As shown, the deep brain stimulation electrode based on carbon nanotube fibers in this embodiment includes a core layer, an endothelial layer, and an outer skin layer distributed coaxially. Carbon nanotube fiber 1 serves as the core layer, graphene fiber conductive ring 2 serves as the endothelial layer, and flexible insulating ring 3 serves as the outer skin layer. One end of carbon nanotube fiber 1 extends beyond the endothelial layer to form a signal output terminal, which is connected to a metal connector 4.

[0029] The outer diameter of the deep brain stimulation electrode in this embodiment is 20 μm;

[0030] The carbon nanotube fiber 1 has a diameter of 10 μm, an inner skin layer thickness of 5 μm, and an outer skin layer thickness of 5 μm; the exposed length of the extended end of the carbon nanotube fiber 1 is 10 μm.

[0031] The graphene fiber conductive ring 2 in this embodiment is composed of Au and graphene fiber. The conductive ring plays an important role in the electrode, storing charge and further improving the conductivity and mechanical properties of the electrode, while also improving the biocompatibility of the electrode and making it highly compatible with the brain.

[0032] In this embodiment, the flexible insulating ring 3 is one or more of polyimide, polydimethylsiloxane, and parylene. The flexible insulating ring 3 can provide mechanical support for the electrode, prevent short circuits, and protect the electrode from physical damage or deformation.

[0033] In this embodiment, the metal connector 4 is made of Au to ensure stable signal transmission. The connection between the carbon nanotube fiber 1 and the metal connector 4 is achieved through electrochemical deposition.

[0034] The above-mentioned method for preparing deep brain stimulation electrodes based on carbon nanotube fibers includes the following steps:

[0035] S1. Preparation of carbon nanotube fibers;

[0036] Ethanol, ferrocene, and thiophene solution were used as liquid carbon sources and injected into a high-temperature reactor at a certain injection rate under the action of a carrier gas. This allowed the liquid carbon sources to vaporize in the high-temperature reactor, resulting in a stocking-shaped carbon nanotube fiber precursor structure. This carbon nanotube fiber precursor was then passed through a liquid such as water, and the capillary densification effect of the liquid was used to rapidly shrink and fiberize the fibers, resulting in continuous carbon nanotube fibers. The carbon nanotube fibers were then collected using a winding device.

[0037] The diameter of the carbon nanotube fibers is controlled at 10 μm.

[0038] S2. Preparation of graphene fiber conductive rings:

[0039] Au was doped into graphene fibers using chemical vapor deposition, with the doping amount controlled at 10 wt%. The fibers were then deposited into rings using a heat treatment method to form hybrid graphene fiber conductive rings.

[0040] Among them, the graphene fiber conductive ring is tightly connected to the carbon nanotube fiber; in addition, after the graphene fiber conductive ring is tightly connected to the carbon nanotube fiber, a section of exposed length is left to connect with the metal connector.

[0041] The exposed length of the carbon nanotube fiber is 10 μm.

[0042] S3. Prepare a flexible insulating ring;

[0043] In this embodiment, the flexible insulating ring is made of polyimide, which is formed into a ring by coating or injection molding and heat treatment to obtain a deep brain stimulation electrode.

[0044] CNT fibers serve as the inner core electrode, Au / Pt and graphene fibers form conductive rings tightly covering the fiber surface, and polyimide / polydimethylsiloxane / poly(p-xylene) forms the outermost insulating flexible ring. The exposed tips of the carbon nanotube (CNT) fibers are connected to metal connectors such as Au / Pt to obtain a concentric deep brain stimulation electrode for deep brain stimulation (DBS).

[0045] Example 2:

[0046] The difference between the carbon nanotube fiber-based deep brain stimulation electrode in this embodiment and that in Embodiment 1 is:

[0047] Replacing the metal Au with Pt can meet the needs of different applications;

[0048] Other structures and preparation methods can be found in Example 1.

[0049] Example 3:

[0050] The difference between the carbon nanotube fiber-based deep brain stimulation electrode in this embodiment and that in Embodiment 1 is:

[0051] The graphene fiber conductive ring is an undoped graphene fiber conductive ring, which meets the needs of different applications.

[0052] Other structures and preparation methods can be found in Example 1.

[0053] Example 4:

[0054] The difference between the carbon nanotube fiber-based deep brain stimulation electrode in this embodiment and that in Embodiment 1 is:

[0055] The doping amount of metal particles in graphene fiber conductive rings can also be 5wt%, 6wt%, 7wt%, 8wt%, 9.5wt%, etc., which can be selected according to the actual application requirements;

[0056] Other structures and preparation methods can be found in Example 1.

[0057] Example 5:

[0058] The difference between the carbon nanotube fiber-based deep brain stimulation electrode in this embodiment and that in Embodiment 1 is:

[0059] The flexible insulating ring can also be made of polydimethylsiloxane, poly(p-xylene), or a combination of polyimide, polydimethylsiloxane, and poly(p-xylene), depending on the specific application requirements.

[0060] Other structures and preparation methods can be found in Example 1.

[0061] Given that there are numerous embodiments of the present invention, and the raw materials and quantities involved can be selected within a limited range according to actual needs, and that the experimental data for each embodiment are extensive and numerous, it is not suitable to list and describe them one by one here. However, the content to be verified and the final conclusions obtained in each embodiment are similar. Therefore, the verification content of each embodiment will not be described one by one here.

[0062] The above description is merely a detailed explanation of preferred embodiments and principles of the present invention. For those skilled in the art, there may be changes in specific implementation methods based on the ideas provided by the present invention, and these changes should also be considered within the scope of protection of the present invention.

Claims

1. A deep brain stimulation electrode based on carbon nanotube fibers, characterized in that, It includes a core layer, an inner skin layer, and an outer skin layer that are coaxially distributed. The core layer is made of carbon nanotube fibers, with one end of the carbon nanotube fibers extending beyond the inner skin layer to form a signal output terminal. The inner skin layer is a graphene fiber conductive ring, and the outer skin layer is a flexible insulating ring.

2. The deep brain stimulation electrode according to claim 1, characterized in that, The graphene fiber is a graphene fiber doped with metal particles, which are Au or Pt.

3. The deep brain stimulation electrode according to claim 2, characterized in that, The doping amount of the metal particles is 5-10 wt%.

4. The deep brain stimulation electrode according to claim 2, characterized in that, The doping was performed using chemical vapor deposition.

5. The deep brain stimulation electrode according to any one of claims 1-4, characterized in that, The core layer has a diameter of 5–20 μm, the inner skin layer has a thickness of 3–5 μm, and the outer skin layer has a thickness of 3–5 μm.

6. The deep brain stimulation electrode according to claim 5, characterized in that, The outer diameter of the deep brain stimulation electrode is 15–25 μm.

7. The deep brain stimulation electrode according to any one of claims 1-4, characterized in that, The length of one end of the carbon nanotube fiber extending beyond the endothelial layer is 10–20 μm.

8. The deep brain stimulation electrode according to claim 7, characterized in that, The flexible insulating ring is made of polyimide, polydimethylsiloxane, or parylene.

9. The method for preparing a deep brain stimulation electrode according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Preparation of carbon nanotube fibers; (2) Graphene was deposited on the surface of carbon nanotube fibers to obtain graphene fiber conductive rings. (3) Coating or injection molding a flexible insulating ring onto the surface of the graphene fiber conductive ring.

10. The preparation method according to claim 9, characterized in that, In step (2), metal particles are doped into graphene fibers using chemical vapor deposition.

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