Minimally invasive implantable needle for brain computer interface and method of making and related products
By employing a composite process of overall electrochemical polishing and ultrafast laser micro-cutting, the problems of low yield and poor consistency in traditional implant needle preparation have been solved, enabling high-quality, low-cost mass production of minimally invasive implant needles and supporting efficient and reliable implantation of brain-computer interfaces.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEZE QIYUAN (BEIJING) TECH CO LTD
- Filing Date
- 2025-12-22
- Publication Date
- 2026-07-14
Smart Images
Figure CN121589535B_ABST
Abstract
Description
Technical Field
[0001] This disclosure belongs to the field of high-end neuromedical device manufacturing and brain-computer interface (BCI) technology, specifically relating to a minimally invasive implantation needle for brain-computer interface, its preparation method and related products. Background Technology
[0002] In invasive brain-computer interface (BCI) technology, to achieve high-quality and stable neural signal recording, it is often necessary to implant flexible microelectrode arrays into the cerebral cortex or deep nuclei. This process typically requires a rigid, ultra-sharp implantation needle (or "guide needle") as a temporary carrier. The implantation needle is a key tool for precisely and minimally invasively implanting flexible microelectrode arrays into brain tissue. It can pierce the meninges and carry the flexible electrodes to the target site before withdrawing, thereby minimizing tissue damage along the implantation path.
[0003] Currently, most implantation needles of this type are made by electrochemical etching of a single metal wire. However, this traditional method suffers from the following bottlenecks that seriously affect the success rate and reliability of the surgery:
[0004] ① Low yield and high cost: The randomness of single-piece preparation is high, and key parameters such as tip curvature radius, cone angle, and surface roughness vary significantly within and between batches. According to statistics, the yield of tips that meet stringent brain implantation standards is usually less than 30%. A large number of defective products lead to a surge in surgical preparation costs, and inadequate polishing may cause unnecessary tissue tearing or vascular damage during surgery due to tip defects.
[0005] ② Risk of hidden damage: Microscopic cracks or burrs are easily generated at the electrochemical etching fracture site or mechanical cutting site. These defects may peel off and remain in the brain tissue during implantation, causing inflammatory reactions or affecting electrode performance, and are potential sources of risk for long-term implantation.
[0006] ③ Inability to meet batch production and consistency requirements: Clinical research and future applications of brain-computer interfaces require a large number of standardized, high-performance implantation needles. Traditional serial fabrication methods cannot meet this requirement in terms of both efficiency and quality consistency.
[0007] ④ Although attempts have been made to use lasers to directly cut and shape tungsten sheets, the surface melting, oxidation, and microcracks caused by the laser heat-affected zone (HAZ) severely degrade the mechanical strength and biocompatibility of the needle tip. Furthermore, the mechanical stress generated by direct cutting and separation can lead to needle tip deformation or micro-chipping, and the yield rate cannot be guaranteed.
[0008] Therefore, there is an urgent need in this field for a method for preparing implantation needles that can simultaneously achieve high quality, high yield, high consistency, and mass production capability. Summary of the Invention
[0009] The purpose of this disclosure is to provide a minimally invasive implantable needle for brain-computer interfaces, its preparation method, and related products. This disclosure can overcome the shortcomings of the prior art and provide a universal minimally invasive implantable needle that can be used with various biocompatible metals.
[0010] In a first aspect, this disclosure provides a method for preparing a minimally invasive implantable needle for a brain-computer interface, comprising the following steps: providing a metal substrate made of a biocompatible metal; performing a first overall electrochemical polishing on the metal substrate to provide a clean and flat initial surface; using an ultrafast laser to scan and cut an implantable needle array pattern on the polished metal substrate, with a cutting depth of 85% to 95% of the thickness of the metal substrate, wherein the scanned and cut metal substrate includes multiple implantable needle prototypes connected to the substrate body by micromechanical connection points; performing a second overall electrochemical polishing on the scanned and cut metal substrate until the micromechanical connection points are dissolved and the implantable needle prototypes naturally separate from the substrate body, thereby obtaining an implantable needle with a final geometric shape and surface finish.
[0011] In some alternative embodiments, the metal substrate is selected from tungsten foil, titanium foil, and stainless steel foil.
[0012] In some alternative implementations, the process parameters for the first and second overall electrochemical polishing are optimized independently based on the type of material of the selected metal substrate.
[0013] In some optional embodiments, when the metal substrate is tungsten foil, the first electrochemical polishing and the second overall electrochemical polishing are carried out in an alkali metal hydroxide electrolyte with a concentration of 0.1-1 mol / L and a polishing voltage of 20-30 V.
[0014] In some alternative implementations, the ultrafast laser is a femtosecond laser or a picosecond laser.
[0015] In some alternative embodiments, the micromechanical connection point is micrometer-sized and dissolves at a higher rate than the implantation needle prototype during the second overall electrochemical polishing process.
[0016] In some alternative embodiments, during the second overall electrochemical polishing process, the implantation needle prototype with initial defects may have its micromechanical connection points break prematurely due to abnormal stress.
[0017] In some alternative embodiments, during the second overall electrochemical polishing process, the thermal damage layer on the surface of the implantation needle prototype caused by laser cutting is dissolved.
[0018] In a second aspect, this disclosure provides a minimally invasive implantation needle for brain-computer interfaces prepared by the method described in the first aspect.
[0019] Thirdly, this disclosure provides an array structure of minimally invasive implantable needles for brain-computer interfaces, integrally formed from a metal substrate by ultrafast laser scanning and cutting, comprising: a substrate body; a plurality of implantable needle prototypes arranged in an array; and a micromechanical connection pad connecting the substrate body and the implantable needle prototypes; wherein the cross-sectional area of the micromechanical connection point is smaller than the cross-sectional area of the implantable needle prototypes.
[0020] As described above, this disclosure presents a minimally invasive implantation needle for brain-computer interfaces, its preparation method, and related products. By employing a composite process combining whole-plate electrochemical polishing and laser micro-dissection, this disclosure achieves a near 100% product yield, ensuring that almost every implantation needle has a perfect geometry and a non-destructive surface. Furthermore, it enables wafer-level mass production, thereby meeting the growing demand for high-performance implantation tools in advanced medical technologies such as brain-computer interfaces, and ensuring the safety, reliability, and repeatability of brain implantation surgery.
[0021] Compared with the prior art, the beneficial effects of the present invention include:
[0022] (1) Revolutionary high yield and reliability: The pass rate is increased from less than 30% in traditional methods to nearly 100%. It ensures that almost every needle tip has a perfect geometry and a non-damaging surface, greatly reducing the surgical risk and failure rate caused by tool defects.
[0023] (2) Significant clinical advantages: The ultra-sharp and consistent needle tip can ensure that the meninges are pierced with minimal force, greatly reducing the displacement and damage to the nerve tissue and blood vessels along the route; the biological-grade smooth surface is free of burrs and microcracks, reducing tissue friction resistance during implantation and the risk of long-term inflammation.
[0024] (3) Strong mass production capacity and cost advantage: It has achieved a leap from "handicraft" to "modern industry", with a large number of qualified needles produced per piece and a significant reduction in the cost per needle, which can meet the needs of large-scale shipment and application.
[0025] (4) Laying the foundation for automated implantation surgery: Highly consistent needle tip performance is a prerequisite for the precise planning and reliable execution of robot-assisted or fully automated brain-computer interface implantation surgery.
[0026] (5) Industrial applicability and commercial value: This disclosure can be directly integrated with automated production lines, from metal substrate feeding, laser processing, electrochemical polishing to final cleaning, coating and packaging, for continuous production, and has great potential for industrial transformation. Attached Figure Description
[0027] Other features, objects, and advantages of this disclosure will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. The drawings are for illustrative purposes only and are not intended to limit the invention. In the drawings:
[0028] Figure 1 This is a schematic flowchart of a method for preparing a minimally invasive implantable needle for a brain-computer interface according to an embodiment of this disclosure;
[0029] Figure 2 This is a schematic diagram of the structure of a metal substrate according to an embodiment of the present disclosure;
[0030] Figure 3 This is a schematic diagram of an array structure of a minimally invasive implantation needle for a brain-computer interface according to an embodiment of the present disclosure;
[0031] Figure 4 This is a schematic diagram of the structure of a minimally invasive implantation needle for a brain-computer interface according to an embodiment of this disclosure.
[0032] Figure label:
[0033] 100: Metal substrate;
[0034] 110: Substrate body; 120: Implantation needle prototype; 130: Micromechanical connection point;
[0035] 200: Minimally invasive implantation needle. Detailed Implementation
[0036] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.
[0037] It should be readily understood that the meanings of “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest sense, such that “on” means not only “directly on something,” but also “on something” including intermediate components or layers existing between the two.
[0038] Furthermore, for ease of description, spatial relative terms such as “below,” “under,” “lower,” “above,” and “upper” may be used herein to describe the relationship of one component or part to another component or part shown in the accompanying drawings. In addition to the orientations described in the figures, spatial relative terms are also intended to cover different orientations of the device during use or operation. The device may be oriented in other ways (rotated 90° or otherwise), and the spatial relative descriptive terms used herein may be interpreted accordingly.
[0039] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art in understanding and reading the content described herein, and are not intended to limit the implementation conditions of this disclosure. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this disclosure, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "above," "first," "second," and "a" used in this specification are merely for clarity of description and are not intended to limit the scope of this disclosure. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this disclosure's implementation.
[0040] It should be noted that, unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other. This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.
[0041] refer to Figure 1 , Figure 1 This is a schematic flowchart illustrating a method for preparing a minimally invasive implantable needle for a brain-computer interface according to an embodiment of this disclosure. The method of this disclosure employs a composite process of "overall polishing - laser micro-connection - overall fine polishing and natural separation." Figure 1 As shown, the method of this disclosure includes the following steps:
[0042] Step S1, Initial polishing of the entire metal substrate: as follows Figure 2 As shown, a metal substrate 100 made of biocompatible metal is provided, and the metal substrate 100 is subjected to a first overall electrochemical polishing to provide a clean and flat initial surface.
[0043] The metal substrate 100 can be selected from one of the following biocompatible metal foils: tungsten foil, titanium foil, stainless steel foil, etc. The method disclosed herein first performs large-area, uniform, overall electrochemical polishing on the selected metal substrate 100. This step aims to remove rolling marks, oxide layers, and contaminants from the surface of the raw material, providing an atomically clean and smooth initial surface, laying the foundation for subsequent precision laser processing. The electrochemical polishing parameters (electrolyte composition, voltage, time, etc.) can be optimized according to the specific metal material.
[0044] Step S2, Laser Micro-connection Forming: such as Figure 2 As shown, an implantation needle array pattern is scanned and cut on a polished metal substrate 100 using an ultrafast laser. The cutting depth is 85% to 95% of the thickness of the metal substrate. The scanned and cut metal substrate 100 includes multiple implantation needle prototypes 120 connected to the substrate body 110 by micromechanical connection points 130.
[0045] This step is crucial. Utilizing the ultra-high precision and extremely low thermal effect of ultrafast lasers such as femtosecond or picosecond lasers, a pre-defined array of implantable needles is scanned and cut onto the polished metal substrate 100. The key to this step lies in "incomplete cutting": the laser only cuts to the vast majority of the metal substrate 100's thickness (e.g., 85%-95%), intentionally preserving several precisely defined "micromechanical connection points" with micrometer-level dimensions. These connection points act as "anchor points," ensuring that thousands of implantable needle prototypes 120 remain firmly connected to the substrate body 110 after processing, forming a "stand-up" integrated structure. The final scanned and cut metal substrate 100 has the following structure: multiple implantable needle prototypes 120 are embedded in the substrate body 110, and the implantable needle prototypes 120 are connected to the substrate body 110 through micromechanical connection points 130. The implantable needle prototypes 120, the substrate body 110, and the micromechanical connection points 130 are all formed from the same metal substrate 100 through scanning and cutting. This design can completely solve the problems of loss, contamination, and collision damage of micron-sized parts in intermediate processes.
[0046] Step S3, Integrated Fine Polishing and Natural Separation: The metal substrate 100 after scanning and cutting is subjected to a second overall electrochemical polishing until the micromechanical connection point 130 is dissolved and the implant needle prototype 120 is naturally separated from the substrate body 110, thereby obtaining the implant needle 200 with the final geometric shape and surface finish.
[0047] This step involves electrochemically polishing the monolithic metal substrate 100, which contains the prototype array of implanted needles, again using it as the anode. This step is crucial for quality assurance and high-efficiency production, and is the core innovation of this disclosure. For example, the scanned and cut metal substrate 100 can be polished in an alkali metal hydroxide electrolyte with a concentration of 0.1-1 mol / L at a polishing voltage of 20-30 V. This second monolithic electrochemical polishing achieves the following objectives.
[0048] ① Intelligent Separation and Final Screening: Micromechanical connection points, due to their minimal cross-sectional area, dissolve fastest in the electrolyte. As polishing progresses, the connection points gradually become thinner. Only when the entire implant needle body (including the critical tip) is polished to a perfect state will the connection point naturally break due to size exhaustion. This ensures that almost every detached implant needle is a "passable" product. Almost any implant needle prototype with serious initial defects (such as abnormal laser cutting) may have its micromechanical connection points break prematurely due to abnormal stress, thus being eliminated in the early stages of fine polishing. This approach helps achieve "built-in quality screening" in the production process, ensuring a near 100% yield rate.
[0049] ② Surface polishing and repair: The second overall electrochemical polishing can uniformly dissolve and remove almost all the thermal damage layers caused by the laser, producing a perfect electrochemically polished surface that meets the requirements for bio-implantation grade.
[0050] ③ Surface regeneration: By uniformly dissolving and removing the unavoidable, extremely thin heat-affected layer at the laser-cut edge, the surface of the implanted needle can be restored to a perfect, biocompatible, electrochemically polished surface.
[0051] ④ Shape refinement: By controlling the polishing parameters, the needle tip can be further sharpened and the sides of the needle body can be smoothed to achieve the final shape required by the design.
[0052] The above describes the method of this disclosure. This method can simultaneously process hundreds to thousands of implantation needle tip prototypes on a single substrate and process them simultaneously under identical final polishing conditions, ensuring unparalleled batch consistency. It achieves both mass production and extreme consistency, providing a key tool for brain-computer interface surgery with predictable performance and reproducible results.
[0053] The method of this disclosure will be further explained below using medical pure tungsten sheets as an example, combined with specific scenario embodiments, but the scope of protection of this disclosure is not limited thereto. This scenario embodiment includes the following steps:
[0054] (1) Design and materials: CAD (Computer Aided Design) design can be used for miniature insertion needles for brain-computer interface electrode implantation;
[0055] (2) Select high-purity tungsten foil with a thickness of 0.15 mm.
[0056] (3) Initial polishing: Using tungsten foil as the anode, polish in a 0.1-1 mol / L sodium hydroxide (NaOH) or potassium hydroxide (KOH) aqueous solution (used as the tungsten electrolyte) for 30-40 minutes with a 20-30V DC power supply to obtain a uniform and bright surface. Polishing references, such as voltage, time, and solution concentration, can be adjusted according to the actual polishing effect.
[0057] (4) Laser micro-connection molding: A femtosecond laser is used. The laser cutting power and cutting time are programmed to cut the implantation needle array pattern according to the drawing. The laser cutting depth is 140μm (80-90% penetration). After molding, the tungsten implantation needle array stands upright on the substrate.
[0058] (5) Integrated fine polishing and natural separation: Place the entire metal substrate with needle array in a new 0.1-1 mol / L NaOH / KOH electrolyte and perform fine polishing with 20-30V DC (adjustable according to the actual polishing effect). Polishing is completed after the tungsten implant needles fall off by themselves.
[0059] (6) Collection and quality inspection: Collect the implanted needles from the bottom of the groove. Randomly sample 50 needles for microscopic inspection, with a pass rate of 100%. There are no visible defects on the surface.
[0060] refer to Figure 3 and combined Figure 2 An embodiment of this disclosure also provides an array structure of minimally invasive implantable needles for brain-computer interfaces, which is integrally formed by cutting a metal substrate 100 using an ultrafast laser scanning method, and includes: a substrate body 110; a plurality of implantable needle prototypes 120 arranged in an array; and a micromechanical connection point 130 connecting the substrate body 110 and the implantable needle prototypes 120; wherein the cross-sectional area of the micromechanical connection point 130 is smaller than the cross-sectional area of the implantable needle prototypes 120.
[0061] refer to Figure 4 An embodiment of this disclosure also provides a minimally invasive implantation needle 200 (hereinafter referred to as implantation needle) for brain-computer interface prepared by the method described above.
[0062] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.
Claims
1. A method for preparing a minimally invasive implantable needle for brain-computer interfaces, characterized in that, Includes the following steps: A metal substrate made of a biocompatible metal is provided, and the metal substrate is subjected to a first overall electrochemical polishing to provide a clean and flat initial surface; An implantation needle array pattern is scanned and cut on the polished metal substrate using an ultrafast laser. The cutting depth is 85% to 95% of the thickness of the metal substrate. The scanned and cut metal substrate includes multiple implantation needle prototypes connected to the substrate body by micromechanical connection points. The metal substrate after scanning and cutting is subjected to a second overall electrochemical polishing until the micromechanical connection points are dissolved, allowing the implant needle prototype to naturally separate from the substrate body, thereby obtaining an implant needle with the final geometry and surface finish.
2. The preparation method according to claim 1, characterized in that, The metal substrate is selected from tungsten foil, titanium foil, and stainless steel foil.
3. The preparation method according to claim 2, characterized in that, The process parameters for the first and second overall electrochemical polishing are optimized independently based on the type of metal substrate selected.
4. The preparation method according to claim 3, characterized in that, When the metal substrate is tungsten foil, the first overall electrochemical polishing and the second overall electrochemical polishing are carried out in an alkali metal hydroxide electrolyte with a concentration of 0.1-1 mol / L, and the polishing voltage is 20-30V.
5. The preparation method according to claim 1, characterized in that, The ultrafast laser is either a femtosecond laser or a picosecond laser.
6. The preparation method according to claim 1, characterized in that, The micromechanical connection point is micrometer-sized, and its dissolution rate is higher than that of the implantation needle prototype during the second overall electrochemical polishing process.
7. The preparation method according to claim 1, characterized in that, During the second overall electrochemical polishing process, the implantation needle prototype, which had initial defects, experienced premature breakage of its micromechanical connection points due to abnormal stress.
8. The preparation method according to claim 1, characterized in that, During the second overall electrochemical polishing process, the thermal damage layer on the surface of the implantation needle prototype caused by laser cutting is dissolved.
9. The preparation method according to claim 1, characterized in that, The cross-sectional area of the micromechanical connection point is smaller than the cross-sectional area of the implantation needle prototype.
10. A minimally invasive implantation needle for brain-computer interfaces, prepared by the method of any one of claims 1-9.