Three-dimensional inclined metal microneedle array and processing method thereof

Abstract

The invention provides a three-dimensional inclined metal micro-needle array and a processing method thereof, and belongs to the technical field of medical instruments and the field of machining, the three-dimensional inclined metal micro-needle array comprises a micro-needle array substrate, vertical micro-needle bodies vertically distributed in the middle according to columns and inclined micro-needle bodies symmetrically distributed on the two sides according to columns, the inclined micro-needle bodies incline towards the center position, the inclination angle is 45-90 degrees, and the inclined micro-needle bodies are arranged on the micro-needle array substrate. The shapes and sizes of the microneedles in the same column are completely the same, the contours of the microneedle arrays in different columns can be different, and the design can meet different task or function requirements for personalized design; a low-speed wire cutting technology is adopted for sequentially cutting according to columns and rows to achieve three-dimensional microneedle array machining, and non-machining areas are reserved on the two sides during machining according to the columns so as to improve the cutting precision; low-melting-point metal is used for pouring after column-by-column machining is completed, the integrity of the workpiece is enhanced, the cutting precision is further improved, and protection can be provided for follow-up machining of the microneedle; the low-melting-point metal has the advantages of being easy to cast and remove, capable of being repeatedly used and low in cost, and the convenience of the method can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices and mechanical processing, and relates to a three-dimensional inclined metal microneedle array and a processing method thereof. Background Art

[0002] Microneedle (MN) is a micro needle with a diameter of tens of micrometers to millimeters and a tip curvature radius of several micrometers to tens of micrometers, often in the form of an array. Due to its tiny size, the microneedle array can be used to pierce only the stratum corneum of the skin without touching the deeper tissues of the skin, thus ensuring painlessness and minimally invasiveness. At the same time, it can form micron-level channels (arrays) on the surface of the skin to achieve efficient transdermal drug delivery or biological sampling. Therefore, it shows great application potential in transdermal drug delivery, vaccination, tissue fluid extraction, and biomarker detection.

[0003] Microneedle arrays have different functions and a wide variety of types. Commonly, they can be divided into coplanar microneedle arrays and heteroplanar microneedle arrays according to the relative position of the needle body and the substrate. The length direction of the needle body of the coplanar microneedle array is in the same plane as the substrate, while the overall length direction of the heteroplanar microneedle array is generally perpendicular to the substrate plane. However, in some special applications, an inclined microneedle array with a certain inclination angle between the needle body length direction and the substrate plane will bring many benefits. First, in biological sampling, the inclined microneedle can increase the contact depth between the needle body and the skin tissue while keeping the vertical depth of penetration unchanged by changing the inclination angle, thereby achieving efficient sample collection and greatly reducing the patient's discomfort; in terms of tissue wound treatment, a symmetrically arranged inclined microneedle array can be designed for tissue traction at the wound, so that the skin tissues on both sides of the wound are close to each other, achieving a suture effect, thereby promoting wound healing. However, because the inclined microneedle array needle body will inevitably be affected by lateral forces, and the microneedles used for wound traction are generally required to be long and slender, they are prone to breakage or buckling under the combined effects of lateral forces and penetration reaction forces, so the design and material selection of the inclined microneedle array must fully consider the impact of the above effects. In addition, compared with the vertical microneedle array, the processing difficulty of the inclined microneedle will undoubtedly increase, especially when the inclination angles of the individual needles in the microneedle array are different, the difficulty will be further increased, and a special preparation process is required to achieve the goal.

[0004] As mentioned above, the tilted microneedle material must have high enough strength and rigidity to resist the lateral force and penetration reaction force during use, so brittle materials such as silicon, ceramics, or softer polymer materials are not suitable for the preparation of tilted microneedle arrays. In comparison, metal materials have better strength and rigidity and are suitable for the preparation of tilted microneedle arrays, but the processing methods of metal material microneedle arrays are relatively limited. The main processing methods are laser cutting, mold stamping, electroplating, and ultra-precision machining. Among them, laser cutting involves local high temperature, which may lead to poor processing accuracy of the microneedle tip and is not suitable for processing inhomogeneous planar microneedle arrays; mold stamping generally uses laser cutting to make inhomogeneous planar microneedles and then uses a mold to bend the needle body to form an inhomogeneous planar microneedle array. In addition to the aforementioned shortcomings of laser cutting, it also has disadvantages such as expensive molds and poor control of stamping deformation accuracy. It is also not suitable for the processing of inclined microneedle arrays; electroplating can prepare metal microneedle arrays with high precision, good consistency and high arrangement density, but the preparation process is complicated, the control requirements are high, and the cost is also high. There is no precedent for using this method to prepare inclined microneedle arrays; ultra-precision machining can process metal materials at the micron or even nanometer scale, and can prepare microneedles with complex shapes and extremely high precision, but the processing process is complicated, time-consuming and expensive, and is not suitable for large-scale production. There is no relevant report on its use in processing inclined microneedle arrays.

[0005] In addition to the above methods, this research team and other individual teams have also proposed a method of cutting microneedle arrays using slow wire cutting, which has high processing accuracy, high efficiency and low cost. However, during the cutting process, the metal wire will generate a certain lateral force on the object being cut. When the object being cut is a slender microneedle body, it may be deformed under the action of the lateral force, which will eventually lead to poor processing accuracy. Comprehensive considerations from both design and processing aspects are required to accurately process the required three-dimensional inclined microneedle array. At present, there are no public reports on the use of slow wire cutting for three-dimensional inclined microneedle arrays.

[0006] In summary, there is an urgent need for a tilted metal microneedle array design and a processing method thereof. Summary of the invention

[0007] The purpose of the present invention is to provide a three-dimensional inclined metal microneedle array and a processing method thereof, so as to adapt to the combined effect of the lateral force and the penetration reaction force suffered by the inclined microneedle array during use, avoid the breakage or buckling of the microneedle body, and take into account the advantages of low penetration force, painlessness and minimally invasiveness. In addition, the present invention also provides a solution to the problem of precision control in the processing of the three-dimensional inclined metal microneedle array.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A three-dimensional inclined metal microneedle array, comprising a microneedle array substrate 1, vertical microneedle bodies 2 vertically distributed in columns in the middle, and inclined microneedle bodies symmetrically distributed in columns on both sides, wherein the microneedle bodies in the same column have the same shape and size, and the microneedle bodies in the same row may have different shapes, and the design can take into account the special functional requirements and processing convenience requirements of the microneedle array. Among them, the inclined microneedle bodies symmetrically distributed in columns on both sides include a left inclined microneedle body 3 and a right inclined microneedle body 4.

[0010] The thickness of the microneedle array substrate 1 is between 0.05 mm and 2 mm, and can be flexibly adjusted according to functional requirements to control the flexibility of the substrate.

[0011] The vertical microneedle body 2 is located at the center of the substrate 1 and arranged in rows, and the microneedles in the same row have exactly the same shape and size; when the wound is uneven, the vertical microneedle body 2 can pin the tissues on both sides of the wound; when the wound is relatively flat, the vertical microneedle body 2 can be omitted.

[0012] Furthermore, each vertical microneedle body 2 includes a left side 2-1, a right side 2-2, a front side 2-3, and a rear side 2-4, a total of four sides. Specifically:

[0013] From the column direction, the left side 2-1 and the right side 2-2 of the vertical microneedle body 2 are both curved surfaces, and the two curved surfaces intersect at the tip of the vertical microneedle body 2 to form a sharp needle tip. The distance between the two curved surfaces gradually increases from the tip to the root to resist the bending stress caused by the lateral load that may come from both sides of the wound. From the row direction, the front side 2-3 and the rear side 2-4 of the vertical microneedle body 2 are both planes, and the distance between the two planes from the root to the tip of the vertical microneedle body 2 gradually decreases, but still maintains a certain distance at the top, so that the tip of the vertical microneedle body 2 forms a sharp edge with a certain width. This design can reduce the insertion force while avoiding the tip of the needle body from being too thin to cause fracture or buckling failure.

[0014] The left-side inclined microneedle body 3 and the right-side inclined microneedle body 4 are symmetrically distributed in rows along both sides of the vertical microneedle body 2, inclined toward the center position, with an inclination angle of 45° to 90°. When the inclination angle is 90°, it is a completely vertically distributed microneedle array, and the shapes and sizes of the microneedles in the same row are exactly the same, which is convenient for subsequent processing.

[0015] Further, the left-side inclined microneedle body 3 is a three-dimensional curved structure, and each inclined microneedle body 3 includes a left side 3-1, a right side 3-2, a front side 3-3, and a rear side 3-4, a total of four sides, specifically:

[0016] From the column direction, the side away from the center is the left side 3-1, and the side close to the center, that is, the inward side is the right side 3-2, wherein the left side 3-1 is a curved surface and the right side 3-2 is a plane. The inward side is designed as a plane, which can better prevent the tissue from slipping off the microneedle in actual use, and the distance between the curved surface 3-1 and the plane 3-2 gradually decreases from the root to the tip of the microneedle body, and finally converges at the tip. On the one hand, this design can form a sharp needle tip to reduce the penetration force required to penetrate the tissue, and on the other hand, it can better resist the bending stress gradually increasing from the tip to the root caused by the lateral force exerted by the tissue on the left-side inclined microneedle body 3, thereby preventing the left-side inclined microneedle body 3 from breaking.

[0017] Seen from the running direction, the front side surface 3-3 and the rear side surface 3-4 are both planes, and the two planes gradually approach each other from the root to the tip of the microneedle body, so that the left-side inclined microneedle body 3 gradually becomes thinner in the direction formed by the two planes, but still maintains a certain distance at the top of the microneedle body, so that the tip of the inclined microneedle body 3 forms a sharp edge with a certain width; this design can reduce the penetration force while avoiding the tip of the needle body from being too thin and causing breakage or buckling failure.

[0018] The right-side inclined microneedle body 4 and the left-side inclined microneedle body 3 are completely identical in structure, size and quantity, but have opposite inclination directions, i.e., the right-side inclined microneedle body 4 and the left-side inclined microneedle body 3 are symmetrically arranged along both sides of the vertical microneedle body 2 .

[0019] The roots of the vertical microneedle body 2 , the left-side inclined microneedle body 3 and the right-side inclined microneedle body 4 are connected to the microneedle array substrate 1 by arc transition, so as to avoid stress concentration and facilitate processing.

[0020] Furthermore, the materials of the microneedle array substrate 1, the middle vertical microneedle 2, the left inclined microneedle body 3 and the right inclined microneedle body 4 are all metal materials, including 304 stainless steel, 316 stainless steel, titanium alloy and the like.

[0021] A method for processing the above three-dimensional inclined metal microneedle array comprises the following steps:

[0022] The first step: selecting metal materials with good mechanical properties, electrical conductivity and biocompatibility as raw materials for microneedle processing, wherein the metal materials include 304 stainless steel, 316 stainless steel, titanium alloy and the like.

[0023] Step 2: Firstly, the raw material is processed into a right hexahedron as the processing blank 5.

[0024] Step 3: Use the slow wire cutting technology to machine a through cavity 6 on the workpiece 5, and the cross section of the through cavity 6 is formed by the path P1 and the path P2.

[0025] The slow-wire cutting technology is used to cut the lower side of the blank 5 in rows along the path P1; the path P1 is consistent with the outer contour of the designed three-dimensional inclined metal microneedle array when viewed in the row direction, and after the processing is completed, a continuous prismatic needle body along the row direction is obtained.

[0026] The slow-wire cutting technology is used to cut in rows along the path P2 on the upper side of the processing blank 5. The starting position of the path P2 is the ending position of the path P1, and the ending position of the path P2 is the starting position of the path P1, that is, the path P2 and the path P1 form a closed path, so that the material in the path is completely separated from the blank 5. After removing this part of the material, a through cavity 6 is formed on the processing blank 5.

[0027] Step 5: Melt the low-melting-point metal and pour it into the through cavity 6. After cooling, the low-melting-point metal fits tightly with the outer contour of the microneedle cut along the path P1, so that the metal wire cuts the entire processing blank 5 during subsequent row cutting, thereby improving the workpiece's resistance to the lateral force exerted by the metal wire during processing, ensuring that the microneedle body does not deform during cutting, thereby improving the cutting accuracy. In addition, the low-melting-point metal and the microneedle body are consolidated into a whole, which can also provide additional protection for the microneedle array body during subsequent processing to prevent damage to the needle body caused by touch.

[0028] Step 6: Use slow wire cutting technology to cut the right side of the processed blank 5 after the fifth step along the path P3 in rows. The path P3 is consistent with the outer contour of the designed three-dimensional inclined metal microneedle array in rows, and can contain multiple contour cycles to improve processing efficiency.

[0029] Step 7: Using the slow wire cutting technology, cut along the path P4 on the right side of the processed blank 5 after the sixth step. The distance between the path P4 and the path P3 is consistent with the required thickness of the microneedle array substrate 1.

[0030] In the eighth step, since the subsequent processing has a lower precision requirement, in order to improve efficiency and reduce costs, the subsequent steps are all processed using fast wire cutting technology. The processed blank 5 after the seventh step is cut into pieces as needed to remove excess material, and finally a three-dimensional inclined metal microneedle array coated with a low-melting-point metal is obtained.

[0031] In the ninth step, the low melting point metal coated on the three-dimensional inclined microneedle array is heated and melted to be removed, thereby finally obtaining a three-dimensional inclined metal microneedle array.

[0032] Furthermore, in the fifth step, the melting point of the low-melting-point metal is selected in the range of about 100°C to 250°C. If the melting point is too low, local friction heat generation and melting may occur during the cutting process. If the melting point is too high, it may cause unnecessary troubles in pouring and melting.

[0033] Furthermore, in the third step, the starting position and the ending position of the path P1 are kept at a certain distance from the outer edge of the blank 5, and the uncut material at the edge can provide lateral support for subsequent row cutting to ensure subsequent processing accuracy. In the sixth step, both sides of the path P3 are kept at a certain distance from the outer edge of the blank 5 to ensure the integrity of the cutting process and improve the cutting accuracy.

[0034] Furthermore, in the eighth step, the fast wire cutting technology is used for processing, and cutting is first performed along the path P5 and the path P6 to remove the excess material at the front and rear ends of the processed blank 5. Then the cutting is performed according to the path P7, the path P8, the path P9 and the path P10, and the blank is divided according to the microneedle array period, and finally a microneedle array block coated with a low melting point metal is obtained. The path P5 runs through the entire blank 5 along the row direction, and the excess material at the front end of the blank 5 is removed. The path P6 runs through the entire blank 5 along the row direction, and the excess material at the rear end of the blank 5 is removed. The paths P7 and P8 both run through the entire blank 5 along the row direction, and the processed blank is cut according to the number of microneedle array periods originally designed to obtain a single microneedle array. The path P9 runs through the entire blank 5 along the column direction, and the excess material on the left side of the blank 5 is removed. The path P10 runs through the entire blank 5 along the column direction, and the excess material on the right side of the blank 5 is removed.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The three-dimensional inclined metal microneedle array designed in the present invention is arranged symmetrically on both sides of the column and inclined toward the center, which can provide a better pulling effect on the wound tissue.

[0037] (2) The three-dimensional inclined metal microneedle array designed by the present invention is designed by columns and rows, that is, the three-dimensional contour dimensions of the microneedle bodies in the same column are completely consistent, and the contours of the microneedle arrays in different columns can be different; the microneedle bodies in the same row have the same cross-sectional contour when viewed along the row direction, but the microneedle bodies in different columns of the same row can have different cross-sectional contours when viewed along the column direction. This design can not only meet the needs of different tasks or functions for personalized design, so as to improve the treatment effect and patient satisfaction, but also greatly improve the convenience and efficiency of the slow-moving wire cutting process by columns and rows, thereby reducing costs.

[0038] (3) The shape and size design of each needle body in the three-dimensional inclined metal microneedle array designed by the present invention takes into account the comprehensive requirements of low microneedle penetration resistance, high resistance to bending and fracture, high resistance to compression and buckling, and high ability to prevent tissue detachment, thereby achieving the unity of functionality and safety.

[0039] (4) The present invention uses slow-wire cutting technology to cut in columns and rows, thus effectively realizing the processing of three-dimensional microneedle arrays.

[0040] (5) The present invention reserves unprocessed areas on both sides during row processing, thereby improving the overall rigidity of the prismatic microneedle array and its lateral resistance to the cutting wire during subsequent cutting, thereby ensuring cutting accuracy.

[0041] (6) After the array processing is completed, the present invention uses low-melting-point metal casting to further enhance the overall rigidity of the prismatic microneedle array during subsequent cutting, improve the cutting accuracy, and provide additional protection for the microneedle array during subsequent processing, which is the key innovation of the present invention.

[0042] (7) The present invention uses a low-melting-point metal with a low melting point and good electrical conductivity as a protective material for the tiny needle body during processing, which has the advantages of easy pouring and removal, reusability, and low cost, thereby improving the convenience of the processing method and reducing the processing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 3D schematic diagram of a typical 3D inclined metal microneedle array;

[0044] Figure 2 The schematic diagram of the three-dimensional inclined metal microneedle array is a view along the column direction (front view);

[0045] Figure 3 The schematic diagram of the three-dimensional inclined metal microneedle array is a view along the row direction (side view);

[0046] Figure 4 A three-dimensional view of a vertical microneedle body 2;

[0047] Figure 5 A view perpendicular to the microneedle body 2 along the column direction (front view);

[0048] Figure 6 A view perpendicular to the microneedle body 2 along the row direction (side view);

[0049] Figure 7 A three-dimensional view of a tilted microneedle body 3;

[0050] Figure 8 A view of the tilted microneedle body 3 along the column direction (front view);

[0051] Fig. 9A view of the tilted microneedle body 3 along the row direction (side view);

[0052] Fig.10 Schematic diagram of the path for cutting the microneedle array contour along the column direction of the three-dimensional inclined metal microneedle array processing blank;

[0053] Fig.11 Schematic diagram of the cutting path for processing the blank along the row direction to form a low melting point metal pouring cavity;

[0054] Fig.12 Schematic diagram of the process after the low melting point metal pouring cavity in the blank is completed;

[0055] Fig.13 Schematic diagram of the processed blank after pouring low melting point metal into the cavity;

[0056] Fig.14 Schematic diagram of the path of cutting the microneedle array contour along the row direction of the processing blank;

[0057] Fig.15 Schematic diagram of the cutting path for processing the blank to form a three-dimensional microneedle array substrate;

[0058] Fig.16 Schematic diagram of the path for partition cutting of the blank after the main contour of the three-dimensional microneedle array is processed;

[0059] Fig.17 Schematic diagram of a three-dimensional tilted metal microneedle array after all cutting steps are completed but covered with a low-melting-point metal.

[0060] In the figure: 1 microneedle array substrate; 2 vertical microneedle bodies arranged vertically in columns in the middle; 3 left-side inclined microneedle bodies arranged in columns; 4 right-side inclined microneedle bodies arranged in columns; 5 processed blanks; 6 through cavities;

[0061] 2-1 left side of the microneedle body 2; 2-2 right side of the microneedle body 2; 2-3 front side of the microneedle body 2; 2-4 rear side of the microneedle body 2;

[0062] 3-1 The left side surface of the left-side inclined microneedle array needle body 3; 3-2 The right side surface of the left-side inclined microneedle array needle body 3; 3-3 The front side surface of the left-side inclined microneedle array needle body 3; 3-4 The rear side surface of the left-side inclined microneedle array needle body 3. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings. The embodiments of the present invention are intended to fully illustrate and explain the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

[0064] A three-dimensional inclined metal microneedle array and a processing method thereof are as follows:

[0065] S1: Design the arrangement rule, geometry and size of the microneedle body, and number parameters of the three-dimensional inclined metal microneedle array according to functional requirements. Figure 1 As shown, there are 5 rows and 7 columns, with a total of 35 microneedles. The front view along the column direction is as follows Figure 2 As shown, the side view along the row direction is as follows Figure 3 As shown, the column spacing is 2.13mm and the row spacing is 2.13mm.

[0066] S2: The microneedle body 2 in the fourth column from left to right is perpendicular to the microneedle array substrate 1. The three-dimensional shape of the vertical microneedle body 2 is as follows Figure 4 The corresponding front view and side view are as follows: Figure 5 and Figure 6 As shown. The right side 2-1 and the left side 2-2 of the vertical microneedle body 2 are both arc surfaces with an arc radius of 2mm. The two arc surfaces are 0.5mm apart at the root and intersect at the tip to form a sharp needle tip. The front side 2-3 and the rear side 2-4 of the vertical microneedle body 2 are both planes. The two planes are 0.5mm apart at the root and 0.1mm apart at the tip. The above design can reduce the penetration force while improving the microneedle body's ability to resist lateral forces. The four sides of the vertical microneedle body 2 and the microneedle array substrate 1 are all transitioned by an arc with a radius of 0.3mm. See details. Figures 4 to 6 This design can reduce stress concentration and reduce processing difficulty.

[0067] S3: From left to right, the first to third columns are all left-side tilted microneedle bodies 3, and they are all tilted inwards toward the fourth column, with an inclination angle of 75° and a height of 1.5 mm. The three-dimensional shape of the left-side tilted microneedle body 3 is as follows: Figure 7 As shown, from the column direction, the outer side of the left inclined microneedle body 3 is the left side surface 3-1, which is a curved surface, and the inner side is the right side surface 3-2, which is a flat surface. The two intersect at the tip to form a sharp needle tip, as shown in FIG. Figure 8 Considering that the tissue contraction force is the largest near the middle of the wound in actual application, and the contraction force will gradually decrease away from the wound, the shapes of the microneedles in the first to third columns of this embodiment are slightly different, as shown in FIG. Figure 2 Specifically: the curved surface 3-1 and the flat surface 3-2 of the left-side inclined microneedle array needle body 3 in the first column are 0.3 mm apart at the root and intersect at the tip, and the curvature radius of the curved surface 3-1 is 3 mm, making the microneedles in the first column relatively slender and sharp, reducing the penetration force; the curved surface 3-1 and the flat surface 3-2 of the left-side inclined microneedle array needle body 3 in the second column are 0.4 mm apart at the root and intersect at the tip, and the curvature radius of the curved surface 3-1 is 3 mm, making the microneedles in the second column thicker than those in the first column; the curved surface 3-1 and the flat surface 3-2 of the left-side inclined microneedle array needle body 3 in the third column are 0.4 mm apart at the root and intersect at the tip, and the curvature radius of the curved surface 3-1 is 2 mm, making the microneedles in the third column thicker than those in the second column, thereby improving the ability to resist lateral forces. From the row direction, the front and rear side surfaces 3-3 and 3-4 of the left inclined microneedle array needle body 3 are both planes, and the two planes are 0.5 mm apart at the root and 0.1 mm apart at the tip. Fig. 9 The four sides of each microneedle body of the left-side inclined microneedle array needle body 3 in the first to third columns are all transitioned to the microneedle array substrate 1 by an arc with a radius of 0.3 mm. Figures 7 to 9 As shown, this design can reduce stress concentration and reduce processing difficulty.

[0068] S4: Columns 5 to 7 are located to the right of column 4, symmetrical to columns 3 to 1, respectively. Figure 1 and Figure 2 shown.

[0069] S5: Select 316L stainless steel with good biocompatibility, excellent strength and toughness as the microneedle material, and first process the raw material into Fig.10 The straight hexahedron processed blank 5 shown is 40 mm long, 30 mm wide and 15 mm high.

[0070] S6: Using slow wire cutting technology to cut the front side of the blank 5 Fig.10 The path P1 shown is cut into columns. Figure 2 The three-dimensional inclined metal microneedle array shown has a consistent outer contour when viewed in the column direction, and after processing is completed, a continuous prismatic needle body along the column direction is obtained; the starting position and the end position of the path P1 are each kept at a distance of 5 mm from the outer edge of the processed blank 5, providing lateral support for subsequent row cutting to ensure subsequent processing accuracy.

[0071] S7: Using slow wire cutting technology Fig.10 The end of the path P1 shown follows Fig.11The path P2 shown in the figure is cut, the starting position of the path P2 is the ending position of the path P1, and the ending position of the path P2 is the starting position of the path P1, that is, the path P2 and the path P1 form a closed path, so that the material in the path is completely separated from the blank 5; the height distance between the path P1 and the path P2 is determined to be 5mm, and the cut material is removed to form the following on the processed blank 5. Fig.12 A through cavity 6 is shown.

[0072] S8: Melt a low melting point metal with a melting point of 150°C and pour it into Fig.12 In the through cavity 6 shown, after cooling, the low-melting-point metal is closely fitted to the outer contour of the microneedle cut according to the path P1, so that the metal wire cuts the entire blank during subsequent row cutting, which improves the resistance to the lateral force applied by the metal wire and ensures that the microneedle body does not deform during cutting, thereby improving the cutting accuracy; in addition, the low-melting-point metal and the microneedle body are consolidated as a whole, which can also provide additional protection during subsequent processing to prevent damage to the needle body caused by touch. In this embodiment, the low-melting-point metal is a lead-tin-bismuth alloy.

[0073] S9: Use slow wire cutting technology to cut the left edge of the blank 5 Fig.14 The path P3 shown is cut in rows, and the path P3 is Figure 3 The outer contour of the microneedle array shown in the figure is consistent in the row direction. In this embodiment, there are 3 contour cycles in total, that is, 3 completely identical three-dimensional inclined metal microneedle arrays will be obtained after the final processing is completed, so as to improve the processing efficiency; the two sides of the path P3 are kept at a distance of 5 mm from the outer edge of the blank 5 to ensure the integrity of the blank during the cutting process and improve the cutting accuracy;

[0074] S10: Use slow wire cutting technology to process the blank along 5 Fig.15 The path P4 is cut, and the distance between the path P4 and the path P3 is 0.2 mm in this embodiment, that is, the thickness of the microneedle array substrate 1 is 0.2 mm.

[0075] S11: Since the subsequent processing has a lower precision requirement, in order to improve efficiency and reduce costs, the subsequent steps in this embodiment are all processed using fast wire cutting technology. Fig.16 The paths P5, P6, P7, P8, P9 and P10 shown in the figure are cut in sequence to remove the excess material, and finally the following is obtained: Fig.17 The microneedle array coated with a low melting point metal is shown;

[0076] S12: The low melting point metal coated on the microneedle array is heated to 200°C to be melted and removed, and finally Figure 1 The three-dimensional inclined metal microneedle array is shown.

[0077] The above-described embodiments merely express the implementation methods of the present invention, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept and principle of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A three-dimensional inclined metal microneedle array, characterized in that: The three-dimensional inclined metal microneedle array comprises a microneedle array substrate (1), vertical microneedle bodies (2) vertically distributed in columns in the middle, and inclined microneedle bodies symmetrically distributed in columns on both sides, wherein the microneedle bodies in the same column have the same shape and size; wherein the inclined microneedle bodies symmetrically distributed in columns on both sides comprise left-side inclined microneedle bodies (3) and right-side inclined microneedle bodies (4).

2. A three-dimensional inclined metal microneedle array according to claim 1, characterized in that: The vertical microneedle body (2) is located at the center of the substrate 1 and arranged in rows, and the microneedles in the same row have exactly the same shape and size; The left-side inclined microneedle body (3) and the right-side inclined microneedle body (4) are symmetrically distributed in rows along both sides of the vertical microneedle body (2) and are inclined toward the center at an angle of 45° to 90°. When the inclination angle is 90°, it is a completely vertically distributed microneedle array, and the shapes and sizes of the microneedles in the same row are exactly the same.

3. The three-dimensional inclined metal microneedle array according to claim 1, characterized in that: The vertical microneedle body (2) comprises a left side surface (2-1), a right side surface (2-2), a front side surface (2-3), and a rear side surface (2-4), a total of four side surfaces; specifically: From the column direction, the left side (2-1) and the right side (2-2) of the vertical microneedle body (2) are both curved surfaces, and the two curved surfaces intersect at the tip of the microneedle body 2 to form a sharp needle tip, and the distance between the two curved surfaces gradually increases from the tip to the root; from the row direction, the front side (2-3) and the rear side (2-4) of the vertical microneedle body (2) are both planes, and the distance between the two planes gradually decreases from the root to the tip of the vertical microneedle body (2), but do not intersect at the top, and the tip of the vertical microneedle body (2) forms a cutting edge with width; The left-side inclined microneedle body (3) is a three-dimensional curved structure, including a left side (3-1), a right side (3-2), a front side (3-3), and a rear side (3-4), a total of four sides, specifically: From the column direction, the side away from the center is the left side (3-1), and the side close to the center is the right side (3-2), wherein the left side (3-1) is a curved surface and the right side (3-2) is a plane; the distance between the curved surface (3-1) and the plane (3-2) gradually decreases from the root of the microneedle body to the tip, and finally converges at the tip; from the row direction, the front side (3-3) and the rear side (3-4) are both planes, and the two planes and the plane gradually approach each other from the root of the microneedle body to the tip, so that the left inclined microneedle body (3) gradually becomes thinner in the direction formed by the two planes, but do not intersect at the top of the microneedle body, and the tip of the inclined microneedle body 3 forms a cutting edge with a width; The right-side inclined microneedle body (4) and the left-side inclined microneedle body (3) are completely identical in structure, size and number, but have opposite inclination directions.

4. The three-dimensional inclined metal microneedle array according to claim 1, characterized in that: The root of the vertical microneedle body (2) is connected to the microneedle array substrate (1) by an arc transition; the root of the left-side inclined microneedle body (3) is connected to the microneedle array substrate (1) by an arc transition; and the root of the right-side inclined microneedle body (4) is connected to the microneedle array substrate (1) by an arc transition.

5. The three-dimensional inclined metal microneedle array according to claim 1, characterized in that: The microneedle array substrate (1), the vertical microneedle body (2), the left-side inclined microneedle body (3) and the right-side inclined microneedle body (4) are all made of metal materials.

6. A three-dimensional inclined metal microneedle array according to claim 5, characterized in that: Including 304 stainless steel, 316 stainless steel or titanium alloy.

7. The three-dimensional inclined metal microneedle array according to claim 1, characterized in that: The thickness of the microneedle array substrate (1) is between 0.05 mm and 2 mm.

8. A method for processing a three-dimensional inclined metal microneedle array according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Select metal materials as raw materials for microneedle processing; Step 2: Processing the microneedle processing raw material into a right hexahedron as a processing blank (5); Step 3: a through cavity (6) is machined on the processed blank (5), wherein the cross section of the through cavity (6) is formed by the path P1 and the path P2; specifically: The process uses a slow-wire cutting technique to cut the lower side of the blank (5) in rows along a path P1; the path P1 is consistent with the outer contour of the designed three-dimensional inclined metal microneedle array viewed in the row direction, and after the processing is completed, a continuous prismatic needle body is obtained in the row direction; Using slow wire cutting technology to cut in rows along a path P2 on the upper side of the processing blank (5), the starting position of the path P2 is the ending position of the path P1, the ending position of the path P2 is the starting position of the path P1, the path P2 and the path P1 form a closed path, the material in the closed path is removed, and a through cavity (6) is formed on the processing blank (5); Step 5: Melting the low melting point metal and pouring it into the through cavity (6); after cooling, the low melting point metal closely fits the outer contour of the microneedle cut along the path P1; Step 6: Using a slow-wire cutting technique, the right side of the processed blank (5) after the fifth step is cut along a path P3 in rows, wherein the path P3 is consistent with the outer contour of the designed three-dimensional inclined metal microneedle array in rows; Step 7: Using a slow-wire cutting technique, cutting is performed along a path P4 on the right side of the processed blank (5) after the processing in the sixth step, wherein the distance between the path P4 and the path P3 is the same as the thickness of the microneedle array substrate (1); Step 8: Using fast wire cutting technology to cut and divide the processed blank (5) after the processing in step 7 into blocks as needed, removing excess materials, and obtaining a three-dimensional inclined metal microneedle array coated with a low melting point metal; In the ninth step, the low melting point metal coated on the three-dimensional inclined microneedle array is heated and melted to be removed to obtain a three-dimensional inclined metal microneedle array.

9. The method for processing a three-dimensional inclined metal microneedle array according to claim 8, characterized in that: In the fifth step, the melting point of the low melting point metal ranges from 100°C to 250°C; In the third step, a non-processing area is reserved between the starting position and the ending position of the path P1 and the outer edge of the processed blank (5). In the sixth step, unprocessed areas are reserved on both sides of the path P3 and the outer edge of the processed blank (5).

10. The method for processing a three-dimensional inclined metal microneedle array according to claim 8, characterized in that: In the eighth step, the processing is performed using a fast wire cutting technology, first cutting along the path P5 and the path P6 to remove the excess material at the front and rear ends of the processed blank (5); then cutting along the path P7, the path P8, the path P9 and the path P10 to divide the blank according to the microneedle array period, and finally obtaining a microneedle array block coated with a low melting point metal; The path P5 passes through the entire processing blank (5) along the row direction, and removes excess material at the front end of the processing blank (5); The path P6 passes through the entire processing blank (5) along the row direction, and removes the excess material at the rear end of the processing blank (5); The paths P7 and P8 both penetrate the entire processed blank (5) in the row direction, and the processed blank is cut according to the number of microneedle array cycles originally designed to obtain a single microneedle array; The path P9 passes through the entire processing blank (5) along the column direction, and removes the excess material on the left side of the processing blank (5); The path P10 passes through the entire processing blank (5) along the column direction, and removes excess material on the right side of the processing blank (5).

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