A connection line structure

Abstract

The application discloses a connecting wire structure, which comprises at least two conductive lines. The connecting wire structure has higher reliability, and at least one conductive line can conduct electricity after one of the conductive lines between two intersection points is broken. In actual use, as long as all the conductive lines between the two intersection points are not completely broken, the connecting wire structure can still normally conduct electricity.

Description

Technical Field

[0001] The present application belongs to the field of neural interfaces, and more specifically, the present application relates to a connecting wire structure. Background Art

[0002] Neuroengineering has gradually become an emerging science and field. Combining biomedical engineering techniques and methods, neuroengineering focuses on research and development of methods for neuronal cell regeneration, tissue property assessment, and interfacing between neural and electronic devices. Neural interfaces are a primary method for implementing neuroengineering. Neural interfaces refer to direct connections between the human or animal brain and external devices, enabling information exchange between the two. Neural interfaces, sometimes also referred to as "brain ports" or "brain-computer fusion perception," are direct pathways between the human or animal brain (or brain cell cultures) and external devices. In unidirectional neural interfaces, a computer either receives commands from the brain or sends signals to the brain (for example, video reconstruction), but not simultaneously. Bidirectional neural interfaces, on the other hand, allow for two-way information exchange between the brain and external devices. Research on neural interfaces has been ongoing for over 40 years, and sensory functions that have been restored or are currently being attempted include hearing, vision, and vestibular perception.

[0003] In neural interfaces, improved signal recording is mainly attributed to microneedle electrodes, which are invisible to the naked eye and penetrate the outermost layer of the skin to collect neural signals. Their main function is to collect human neural action and sensory potential signals. They are usually connected to a readout circuit chip used to read out neural signals through a wired wire to achieve data transmission. Existing neural interface microneedle arrays are mostly flexible patch-type and rigid microneedle arrays. Among them, the flexible patch-type microneedle base flexibly adheres to the pia mater to ensure that the needle body contacts the surface of the pia mater. However, due to the limited depth of penetration of the flexible patch into the pia mater, the collected information is limited and can only collect signals from the surface of the pia mater, but cannot collect EEG signals deep into the brain tissue. Rigid microneedles have certain advantages in the process of implantation into brain tissue due to their greater rigidity. However, their material has a large Young's modulus, which causes greater damage to the brain tissue after implantation, making it unfavorable for long-term implantation and signal extraction. Therefore, more research is currently underway on flexible microneedle electrodes. However, due to the flexibility of the electrodes, the connecting wires will also deform under the action of external forces, and the connecting wires often break.

[0004] Therefore, there is an urgent need to develop a new type of microneedle that combines the advantages of rigid microneedles and flexible microneedles, works stably, and can ensure long-term implantation. Summary of the Invention

[0005] The main purpose of this application is to propose a connecting wire structure, which aims to solve the technical problem that the signal cannot be conducted after the connecting wire is broken under the action of external force.

[0006] In order to solve the above technical problems, according to one aspect of the present application, the present application provides the following technical solution: providing a connecting wire structure, including at least two strands of conductive wires.

[0007] In one embodiment, different conductive lines intersect at at least two locations.

[0008] In one embodiment, the conductors between adjacent intersections do not overlap.

[0009] In one embodiment, the shape of the conductive wire is wavy, square or sawtooth.

[0010] In one embodiment, the conductive line is formed by a semiconductor process.

[0011] In one embodiment, the conductive line includes a metal layer and a protective layer, and the protective layer is disposed on the metal layer.

[0012] In one embodiment, the connecting wire structure is applied to a microneedle, and the microneedle includes: at least one microneedle body, at least one body electrode point is provided on the microneedle body, at least one welding point is provided at the tail of the microneedle body, and the body electrode point and the welding point are connected through the connecting wire structure.

[0013] In one embodiment, the microneedle body is provided with at least one slit.

[0014] In one embodiment, the denser the slits are, the greater the number of intersection points is.

[0015] In one embodiment, the microneedle body is coated with a biodegradable film, and the biodegradable film is used to balance the stress in different areas of the microneedle body.

[0016] Compared with the prior art, this application has the following beneficial effects:

[0017] The present application provides a connecting wire structure having at least two conductors. This connecting wire structure has a higher reliability. If one conductor between two intersections breaks, at least one conductor still remains conductive. In actual use, as long as all conductors between the two intersections are not completely broken, the connecting wire structure can still conduct normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of this application and should not be regarded as limiting the scope of protection of this application. In each of the drawings, similar components are numbered similarly.

[0019] Figure 1 This is a schematic structural diagram of a microneedle electrode in one embodiment of the present application;

[0020] Figure 2 Schematic diagram of the structure of a microneedle body in one embodiment of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0022] The components of the embodiments of the present application generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but rather merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0023] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0024] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0025] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meaning as in the context of the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments of the present application.

[0026] Example 1

[0027] This embodiment provides a connecting wire structure comprising at least two conductors, wherein different conductors intersect at at least two locations, and the conductors between adjacent intersections do not overlap. For example, at least two conductors are arranged in a "twisted" pattern. This connecting wire structure offers enhanced reliability. If one conductor between two intersections breaks, at least one conductor remains conductive. In actual use, as long as all conductors between the two intersections are not broken, the connecting wire structure will remain conductive.

[0028] In an optional embodiment, the shape of the conductive wire is wavy, square or sawtooth.

[0029] In this embodiment, the conductive wire is formed using a semiconductor process, such as MEMS technology. Specifically, the conductive wire includes a metal layer and a protective layer, and the protective layer is disposed on the metal layer. In an actual manufacturing process, a passivation layer can be first formed on the substrate, then a metal layer is formed on the passivation layer, and finally, a protective layer is formed on the metal layer.

[0030] Given that the microneedles currently on the market all use traditional rigid microneedles, such microneedles cannot adapt to the deformation of blood vessels when implanted into human or animal tissues, causing implant damage. In order to overcome the above problems, microneedles made of flexible materials or microneedle electrodes with flexible structures are currently more commonly used, so that they can adaptively deform according to the expansion and contraction state of blood vessels, reducing implant damage. However, since the electrodes are flexible, they often deform with the activity of brain tissue or blood vessels, and the connecting wires therein will also deform under the action of external forces, and the connecting wires often break, requiring surgery to replace the implanted microneedle electrodes, which is costly and causes greater damage.

[0031] To address the aforementioned issues, the aforementioned connecting wire structure can be applied to a microneedle. The microneedle comprises: at least one microneedle body, at least one body electrode disposed on the microneedle body, and at least one solder joint disposed at the tail of the microneedle body. The body electrode and the solder joint are connected via the connecting wire structure. This connecting wire structure offers enhanced reliability: if one conductor breaks, the other conductor remains conductive, thereby improving the reliability of the microneedle during long-term implantation in human tissue.

[0032] In this embodiment, at least one slit is provided on the microneedle body. When at least two slits are provided on the microneedle body, the slits are spaced apart along the length direction of the microneedle body, and the two adjacent slits are staggered, and the slits are perpendicular or inclined to the length direction of the microneedle body so that the microneedle body can be deformed.

[0033] Specifically, the microneedle body can be constructed using a rigid material as a substrate. The body electrode specifically includes a substrate and a plurality of slits distributed on the substrate. The slits are spaced apart along the length direction of the body electrode (hereinafter referred to as the first direction for ease of description), with adjacent slits staggered, and the slits are perpendicular or oblique to the first direction. The slits can be perpendicular to the length direction of the body electrode (i.e., the first direction) or oblique to the length direction of the body electrode. Providing slits on the substrate can reduce the rigidity of the entire body electrode to a certain extent. However, the size of the slits must be controlled within a certain range and cannot be too small, otherwise it will result in a lack of flexibility.

[0034] Here, the shape of the slit is not particularly limited, and can be a strip shape, a wave shape, a sawtooth shape, etc.

[0035] In this embodiment, where the slits are densely packed, the greater the deformation of the microneedle body, the greater the possibility that a certain wire will break under the action of external force. To improve reliability, the denser the slits, the greater the number of intersections.

[0036] In actual application scenarios, due to the differences in the size of the slits, the stress levels in different areas of the microneedle body are not exactly the same. In actual use, under the same applied force, the areas with greater stress may not deform, the flexibility of the microneedle body is poor, and the areas with less stress may deform excessively and break. To avoid the above situation, in a preferred embodiment, the microneedle body is coated with a biodegradable film. The biodegradable film is used to balance the stresses in different areas of the microneedle body so that the stress levels in different areas of the microneedle body are substantially the same. The biodegradable film can be coated on the entire surface of the microneedle body (including the slits), or it can be coated only on the area outside the slits.

[0037] In this embodiment, the stress magnitude can be determined based on the area size of a single region between the slits, and the biodegradable film can be coated differently according to the stress magnitude of each region. Specifically, the larger the area of ​​a single region, the greater the corresponding stress, and the thinner the coated biodegradable film; the smaller the area of ​​a single region, the smaller the corresponding stress, and the thinner or thicker the coated biodegradable film.

[0038] Among them, the biodegradable film can be coated by a hot melt coating process.

[0039] The biodegradable film comprises biodegradable polyester and / or copolyester and / or starch or starch-based materials, and the thickness of the biodegradable film is less than 20 μm.

[0040] Example 2

[0041] A preferred embodiment of the present application provides a microneedle for neural interface, which is implanted into human tissue or animal tissue, such as Figure 1-2 As shown, the microneedle comprises at least one microneedle body 1, which has at least one body electrode 2. The body electrode 2 can simultaneously read EEG signals and write stimulation signals. In the embodiments of the present application, there is no particular limitation on the number of body electrodes 2 on each microneedle body 1, and there can be one or more. When there are multiple body electrodes 2, each body electrode 2 is independent of the others and can be controlled by an integrated circuit chip 5 to operate independently.

[0042] The microneedle body 1 is also provided with at least one indium column for connecting the body electrode point 2. The body electrode point 2 and the indium column are electrically connected through a wire 3. As for the number of wires 3, in a preferred embodiment of the present application, at least two strands are included, and each wire 3 can independently realize the reading of EEG signals and the writing of stimulation signals.

[0043] In a preferred embodiment of the present application, each strand of the wire 3 is wavy, and two or more strands of the wire 3 are combined together to form a "twisted" structure, that is, when the microneedle body 1 is implanted in human tissue for a long time, when one strand of the wire 3 breaks, the other strand of the wire 3 can still conduct electrical signals, thereby ensuring the reliability of the microneedle and avoiding the need to replace the microneedle as a whole due to a failure caused by the breakage of the wire 3, repeating the operation, and causing tissue damage.

[0044] In a preferred embodiment of the present application, a groove of a certain depth is machined along the length of the base of the microneedle body 1. The groove thins the base material of the microneedle body 1, which can reduce the rigidity of the microneedle body 1, making the microneedle body 1 flexible, reducing implant damage, and facilitating long-term implantation in human tissue. The groove is used to accommodate the wire 3 connecting the indium column and the body electrode point 2, so that the wire 3 is embedded in the base material of the microneedle body 1. The groove can be filled with a biocompatible flexible material or not. This ensures that when the microneedle reaches the maximum degree of bending deformation, the wire 3 is still not in a taut state, avoiding the wire 3 from breaking due to stretching.

[0045] In a preferred embodiment of the present application, the microneedle body 1 is rigid in a first direction along its length, and is flexible in a second direction, wherein the second direction is inclined to the first direction, or the second direction is perpendicular to the first direction.

[0046] The above-mentioned microneedle body 1 is set to be rigid along the first direction of its length, so that the microneedle body 1 has a certain rigidity, which makes it easier for the operator to implant the microneedle body 1 into the soft tissue of a human or animal. In order to overcome the damage caused to the soft tissue of the human body or animal during implantation of the conventional rigid microneedle that is rigid in all directions, the above-mentioned embodiment sets the second direction of the microneedle body 1 to be flexible. The second direction is inclined to the first direction, or the second direction is perpendicular to the first direction. In other words, the second direction is not parallel to the first direction. At this time, the flexible deformation in the second direction is reflected in both the length direction and the width direction of the microneedle body, so that the microneedle body can be appropriately deformed according to the expansion and contraction state of the blood vessels.

[0047] like Figure 2 As shown, a preferred embodiment of the present application provides a specific structure of a microneedle 1, which achieves that the microneedle 1 is rigid in a first direction along its length and flexible in a second direction. The base of the microneedle 1 is provided with a plurality of slits 4, each provided on either side of the base of the microneedle 1, with a wire 3 connecting the electrode 2 and the indium pillar in the middle. The slits 4 provided on both sides of the base are spaced apart along the first direction, and the slits 4 are perpendicular or oblique to the first direction. Adjacent slits 4 can be staggered or not, and the lengths of adjacent slits 4 can be equal or unequal. The slits 4 can be perpendicular to the length direction of the microneedle (i.e., the first direction) or oblique to the length direction of the microneedle. The provision of slits 4 on the base can reduce the rigidity of the entire microneedle 1 to a certain extent. However, the size of the slits 4 needs to be controlled within a certain range. They should not be too large, otherwise the rigidity of the microneedle will be greatly reduced, making implantation difficult, nor too small, otherwise the flexibility will be lacking. Here, the shape of the slit 4 is not particularly limited, and can be a strip shape, a wave shape, a sawtooth shape, etc.

[0048] The slit 4 may be through or not through along the thickness direction of the substrate. Whether it is through or not can be determined according to actual conditions and is not specifically limited here. Generally, in the case of through, the overall flexibility is stronger, and in the case of not through, the flexibility will be weakened to a certain extent and the rigidity will be enhanced.

[0049] In one embodiment, a slit is provided that penetrates the side of the substrate. The slit may penetrate or not penetrate, may penetrate simultaneously or not penetrate simultaneously, or may penetrate partially, without specific limitations herein. The microneedle body 1 that penetrates the side reduces the constraint of the rigid material on the side, making the rigid material more flexible in the second direction. In this case, the microneedle body 1 can more adaptively deform according to the expansion and contraction state of the blood vessel, reducing implant damage. However, in the case of penetrating the side of the substrate, the rigidity of the microneedle body 1 in the first direction is reduced, making insertion inconvenient, and the side is not smooth enough, making removal more difficult.

[0050] In one practical application scenario, the slit 4 can be filled with a biocompatible material that is degradable. During the implantation of the microneedle 1 into the target site, the biocompatible material filling the slit enhances the rigidity of the microneedle 1 in a first direction. After the microneedle 1 is implanted into the target site, after a period of time (approximately 30 minutes), the biocompatible material degrades under the action of cerebrospinal fluid, releasing the material in the slit and enhancing the flexibility of the microneedle in a second direction. The microneedle can adaptively deform according to the expansion and contraction state of the blood vessel, reducing implantation damage.

[0051] The microneedle also includes at least one integrated circuit chip 5, which is electrically connected to the microneedle body 1 and receives, analyzes, and processes the neural signals collected by the body electrode 2. Considering that conventionally, the integrated circuit chip 5 and the microneedle body 1 are connected by wires, the information collected by the microneedle body must be transmitted to the integrated circuit chip through the wires, which is slow and inefficient. Therefore, in some embodiments of the present application, the following improvements are made: the integrated circuit chip 5 is bonded to the tail of the microneedle body 1 to form an electrical connection between the two, reducing the information transmission path and improving the efficiency of information transmission.

[0052] On the other hand, a preferred embodiment of the present application provides a method for preparing the flexible microneedle, comprising the following steps:

[0053] Step S1: Preparation of microneedle body. A groove or slit mask pattern is formed on the substrate, exposed, and the groove or slit mask pattern is transferred to the photoresist, and then selective etching is performed to retain the area covered by the photoresist layer to obtain the microneedle body 1. The etching solution used for etching includes the water-soluble acid, which specifically includes a combined acid mode of a strong acid and a weak acid, or a weak acid, wherein the strong acid is nitric acid or sulfuric acid, and the weak acid is at least one of phosphoric acid, HF acid, formic acid, acetic acid, citric acid, isocitric acid, and glycolic acid. Among them, the use of a combination of strong acid and weak acid can slow down the reaction speed and avoid the etching speed being too fast to affect the silicon-based surface structure.

[0054] Step S2: Bonding the tail of the microneedle 1 to the integrated circuit chip 5 to form an electrical connection. The tail of the microneedle 1 is provided with an indium pillar, and a body electrode 2 is located near the tip of the microneedle. The body electrode 2 and the corresponding indium pillar are connected by a wire 3. The wire 3 has multiple strands, each of which is arranged in a wavy shape. The strands are twisted together to form a "twist" shape.

[0055] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A connecting line structure, characterized in that: For use in a neural interface, the neural interface comprises a microneedle, the microneedle comprises at least one microneedle body, at least one body electrode point is provided on the microneedle body, at least one soldering point is provided at the tail of the microneedle body, the body electrode point and the soldering point are connected via a connecting wire structure, the connecting wire structure comprises at least two strands of wire, different wires intersect at at least two locations, the wires between adjacent intersections do not overlap, and the at least two strands of wire are used to connect the same body electrode point and the same soldering point; At least one slit is provided on the microneedle body. When at least two slits are provided on the microneedle body, the slits are spaced apart along the length direction of the microneedle body, and two adjacent slits are staggered, and the slits are perpendicular or inclined to the length direction of the microneedle body so that the microneedle body can be deformed.

2. The connecting wire structure according to claim 1, wherein: The shape of the conductive wire is wavy, square or sawtooth.

3. The connecting wire structure according to claim 1, wherein: The conductive lines are formed by using a semiconductor process.

4. The connecting wire structure according to claim 1, wherein: The conductive line includes a metal layer and a protective layer, and the protective layer is arranged on the metal layer.

5. The connecting wire structure according to claim 1, wherein: The denser the slits are, the greater the number of intersections.

6. The connecting wire structure according to claim 1, characterized in that: The microneedle body is coated with a biodegradable film, and the biodegradable film is used to balance the stress of different areas of the microneedle body.

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