Method for preparing implantable sensor

Abstract

The present invention relates to a method for preparing an implantable sensor, the method comprising: using a first conductive ink to print or form a pattern of a first electrode on a substrate; using a liquid polymer to print or form a pattern of a substrate on the pattern of the first electrode, and reserving a first through-hole that penetrates the substrate, and then curing; using a second conductive ink to print or form a pattern of a second electrode on the substrate, and then curing; peeling off the substrate to obtain a two-electrode implantable sensor, wherein the first electrode and the second electrode of the implantable sensor can be connected to a connector on the same surface using the first through-hole. The present invention constructs an implantable sensor by a layer-by-layer preparation method, and when preparing the substrate, a first through-hole that penetrates the substrate is reserved, thereby eliminating the need to cut and open holes in the substrate. This not only effectively improves consistency and yield, but also effectively simplifies the process, reduces costs, and facilitates large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, in particular to a method for preparing an implantable sensor. Background Art

[0002] Implantable sensors typically use a flexible polymer substrate as a two-electrode system consisting of a working electrode and a counter electrode, or a three-electrode system consisting of a working electrode, a counter electrode, and a reference electrode, arranged on a single surface of the substrate using a planar staggered arrangement. However, because implantable sensors need to be implanted in the body, their overall size is limited. This results in a limited working electrode area when arranged on a single surface, resulting in reduced sensitivity and affecting measurement accuracy.

[0003] While printing the electrode system on both sides of the substrate can increase the working electrode area while maintaining the same size, thereby improving the sensitivity of the implantable sensor and making its measurement results more accurate, printing the electrode system on both sides of the substrate not only complicates the printing process but also requires cutting and opening holes in the substrate so that connectors can connect the electrodes on both sides simultaneously on the same side of the substrate. This results in poor stability of the implantable sensor, poor consistency, and low yield of the implantable sensor. Summary of the Invention

[0004] Based on this, it is necessary to provide a method for preparing an implantable sensor to address the above problems. The preparation method does not require cutting and opening holes, which can not only effectively improve consistency and yield, but also effectively simplify the process, reduce costs, and facilitate large-scale production.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: a method for preparing an implantable sensor, the preparation method comprising the following steps:

[0006] Printing or forming a pattern of a first electrode on a substrate using a first conductive ink;

[0007] Printing or printing a pattern of the substrate on the pattern of the first electrode using a liquid polymer, reserving a first through hole penetrating the substrate, and then curing;

[0008] Printing or printing a second electrode pattern on the substrate using a second conductive ink, and then curing the ink;

[0009] The substrate is peeled off to obtain a two-electrode implantable sensor, wherein the first electrode and the second electrode of the implantable sensor can be connected to the connector on the same surface by using the first through hole.

[0010] In one embodiment, the first conductive ink and the second conductive ink are independently selected from at least one of carbon paste, silver paste, platinum paste, gold paste, silver / silver chloride paste, and platinum-carbon mixed paste.

[0011] In one embodiment, the liquid polymer is selected from at least one of liquid polyethylene terephthalate, liquid polymethyl methacrylate, liquid polycarbonate, liquid polytetrafluoroethylene, liquid polyethylene, liquid polyvinyl chloride, or liquid polyimide.

[0012] In one embodiment, the thickness of the substrate is 20 μm-500 μm.

[0013] In one embodiment, the diameter of the through hole is 20 μm-1500 μm.

[0014] In one embodiment, before peeling off the substrate, the method further comprises:

[0015] Printing or printing an insulating layer pattern on the second electrode using an insulating paste, reserving a second through hole penetrating the insulating layer, and then curing;

[0016] A third conductive ink is used to print or form a pattern of a third electrode on the insulating layer, which is then cured. After the substrate is peeled off, a three-electrode implantable sensor is obtained. The first electrode, the second electrode, and the third electrode of the implantable sensor can be connected to the connector on the same surface using the first through hole and the second through hole.

[0017] In one embodiment, the insulating paste is selected from a thermally curable insulating paste or an ultraviolet curable insulating paste.

[0018] In one embodiment, the third conductive ink is silver / silver chloride paste.

[0019] In one embodiment, before the step of printing or printing the first conductive ink on the substrate, a sacrificial layer is formed on the substrate.

[0020] In one embodiment, the material of the sacrificial layer is selected from photoresist, hydrogel or water-soluble polymer.

[0021] In the preparation method of the present invention, an implantable sensor is constructed through a layer-by-layer preparation method. When preparing the substrate, a first through-hole is reserved that penetrates the substrate. As a result, the first electrode and the second electrode of the implantable sensor can be connected to the connector on the same surface using the first through-hole, eliminating the need to cut the substrate. This not only effectively improves consistency and yield, but also effectively simplifies the process, reduces costs, and facilitates large-scale production. In addition, compared to the method of printing electrodes on both sides of the substrate, the preparation method of the present invention does not require manual or equipment flipping of the substrate, which reduces equipment requirements, and the electrode patterning is flexible and the alignment is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic plan view of the surface where the first electrode of the implantable sensor is located according to one embodiment of the present invention;

[0024] Figure 2 For the present invention Figure 1 A schematic plan view of the surface where the second electrode of the implantable sensor is located;

[0025] Figure 3 FIG. 1 is a schematic structural diagram of a working end of an implantable sensor shown in another embodiment of the present invention.

[0026] In the figure: 20, first electrode; 30, substrate; 301, first through hole; 40, second electrode; 50, insulating layer; 60, third electrode. DETAILED DESCRIPTION

[0027] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments or embodiments and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, including any two related listed items, any more related listed items, or the combination of all related listed items.

[0029] Combine Figures 1 to 2 As shown, a method for preparing an implantable sensor according to an embodiment of the present invention includes the following steps:

[0030] S1, printing or forming a pattern of a first electrode 20 on a substrate using a first conductive ink;

[0031] S2, using a liquid polymer to print or print the pattern of the substrate 30 on the pattern of the first electrode 20, and to reserve a first through hole 301 penetrating the substrate 30, and then to cure;

[0032] S3, printing or forming a pattern of the second electrode 40 on the substrate 30 using the second conductive ink, and then curing the ink;

[0033] S4 , peeling off the substrate to obtain a two-electrode implantable sensor. The first electrode 20 and the second electrode 40 of the implantable sensor can be connected to the connector on the same surface using the first through hole 301 .

[0034] In step S1, the substrate is generally selected from a glass substrate, a plastic substrate or a metal substrate, preferably a non-sticky substrate such as a glass substrate or a polytetrafluoroethylene substrate, which is conducive to the peeling effect between the substrate and the implantable sensor.

[0035] The substrate and the implantable sensor can be directly peeled off, or a sacrificial layer can be prepared first and then removed by wet etching to achieve the purpose of peeling. When using a sacrificial layer, a sacrificial layer can be first formed on the substrate, wherein the material of the sacrificial layer is selected from photoresist, hydrogel or water-soluble polymer.

[0036] It is understood that the substrate may be cleaned and dried before use.

[0037] In step S1, the first conductive ink is selected from at least one of carbon paste, silver paste, platinum paste, gold paste, silver / silver chloride paste, and platinum-carbon mixed paste. When the first conductive ink is used to print or form the pattern of the first electrode 20 on the substrate, the pattern of the first electrode 20 includes the pattern of the contact area 20A and the pattern of the working area 20B. After printing or forming, the pattern is dried for a period of time to prevent the first conductive ink from flowing. Drying can be performed by air drying, for example. Then, step S2 is performed, in which the pattern of the substrate 30 is printed or formed using a liquid polymer, and both are cured simultaneously. This ensures better adhesion between the first electrode 20 and the substrate 30, preventing them from falling off.

[0038] Optionally, the liquid polymer is selected from at least one of liquid polyethylene terephthalate, liquid polymethyl methacrylate, liquid polycarbonate, liquid polytetrafluoroethylene, liquid polyethylene, liquid polyvinyl chloride or liquid polyimide.

[0039] In step S3, the second conductive ink is selected from at least one of carbon paste, silver paste, platinum paste, gold paste, silver / silver chloride paste, and platinum-carbon mixed paste. When the second conductive ink is used to print or form the pattern of the second electrode 40, the pattern of the second electrode 40 includes a pattern of the contact area 40A and a pattern of the working area 40B.

[0040] Specifically, in the two-electrode implantable sensor, the first electrode 20 can be a working electrode and the second electrode 40 can be a counter electrode, or the first electrode 20 can be a counter electrode and the second electrode 40 can be a working electrode. Therefore, in steps S1 and S3, the conductive ink is selected according to the properties of the specific electrodes.

[0041] In step S2 and step S3, the curing method can be thermal curing, light curing, radiation curing, etc. Specifically, when thermal curing is used, the temperature is preferably 80°C-200°C, and the time is preferably 10 minutes-200 minutes. When light curing is used, ultraviolet light curing is preferably used.

[0042] When preparing the substrate 30, the present invention reserves a first through-hole 301 that penetrates the substrate 30. Therefore, the first electrode 20 and the second electrode 40 of the implantable sensor can be connected to the connector on the same surface using the first through-hole 301, eliminating the need to cut the substrate 30. This not only effectively improves consistency and yield, but also effectively simplifies the process, reduces costs, and facilitates large-scale production. In addition, compared to the method of printing electrodes on both sides of the substrate, the preparation method of the present invention does not require manual or equipment to flip the substrate, reducing equipment requirements, and the electrode patterning is flexible and the alignment is more accurate.

[0043] Optionally, when printing or printing the pattern of the substrate 30, the position of the first through hole 301 can be reserved at the contact area 20A of the first electrode 20, and then the second electrode 40 is prepared on the substrate 30. In this way, the first electrode 20 and the second electrode 40 can be connected to the connector on the surface where the second electrode 40 is located.

[0044] At this time, the first through hole 301 may be further filled with conductive ink, which can improve the connection stability between the first electrode 20 and the connector.

[0045] Optionally, when printing or printing the pattern of the substrate 30, the pattern of the substrate 30 completely covers the pattern of the first electrode 20, and a first through hole 301 is reserved at any position. The position where the first through hole 301 is located serves as the contact area 40A of the second electrode 40. Then, when printing or printing the second conductive ink, the second conductive ink is filled into the first through hole 301. After the second conductive ink in the first through hole 301 is cured, it becomes the contact area 40A of the second electrode 40. In this way, the first electrode 20 and the second electrode 40 can be connected to the connector on the surface where the first electrode 20 is located.

[0046] To ensure the flexibility of the implantable sensor of the present invention, the thickness of the substrate 30 is preferably 20 μm to 500 μm, more preferably 50 μm to 300 μm, and even more preferably 150 μm to 250 μm. Furthermore, to ensure effective connection between the first electrode 20 or the second electrode 40 and the connector via the first through-hole 301, the diameter of the first through-hole 301 is 20 μm to 1500 μm.

[0047] like Figure 3 As shown, another embodiment of the implantable sensor provided by the present invention is a three-electrode implantable sensor. Unlike the two-electrode implantable sensor, it further includes an insulating layer 50 and a third electrode 60 sequentially covering the second electrode 40.

[0048] Therefore, during preparation, before peeling off the substrate, the following steps are also included:

[0049] Printing or printing a pattern of the insulating layer 50 on the second electrode 40 using an insulating paste, and reserving a second through hole penetrating the insulating layer 50, and then curing;

[0050] A pattern of the third electrode 60 is printed or printed on the insulating layer 50 using a third conductive ink, and then cured. After peeling off the substrate, a three-electrode implantable sensor is obtained. The first electrode 20, the second electrode 40 and the third electrode 60 of the implantable sensor can be connected to the connector on the same surface using the first through hole 301 and the second through hole.

[0051] The insulating paste is selected from thermally curable insulating paste or ultraviolet curable insulating paste, the third electrode 60 is generally a reference electrode, and the third conductive ink is preferably silver / silver chloride paste.

[0052] Optionally, the insulating paste and the third conductive ink can also be cured by thermal curing, photocuring, radiation curing, etc. Specifically, when thermal curing is used, the temperature is preferably 80°C-200°C, and the time is preferably 10 minutes-200 minutes. When photocuring is used, ultraviolet light curing is preferably used.

[0053] It can be understood that the first electrode 20, the second electrode 40 and the third electrode 60 of the three-electrode implantable sensor can be connected to the connector at the surface where the first electrode 20 is located, and can also be connected to the connector at the surface where the third electrode 60 is located.

[0054] Optionally, when printing or printing the pattern of the substrate 30, the position of the first through hole 301 can be reserved at the contact area 20A of the first electrode 20, and then the second electrode 40 is prepared on the substrate 30, and then when printing or printing the pattern of the insulating layer 50, two second through holes penetrating the insulating layer 50 are reserved, one overlapping with the position of the first through hole 301, and one reserved at the contact area 40A of the second electrode 40. In this way, the first electrode 20, the second electrode 40 and the third electrode 60 can be connected to the connector on the surface where the third electrode 60 is located.

[0055] At this time, the first through hole 301 and the second through hole can be further filled with conductive ink, which can improve the connection stability between the first electrode 20, the second electrode 40 and the connector.

[0056] Optionally, when printing or printing the pattern of the substrate 30, the pattern of the substrate 30 completely covers the pattern of the first electrode 20, and two first through holes 301 are reserved at any position, where the position of one of the first through holes 301 serves as the contact area 40A of the second electrode 40, and then when printing or printing the second conductive ink, the second conductive ink is filled into the first through hole 301, and after the second conductive ink in the first through hole 301 is cured, it becomes the contact area 40A of the second electrode 40, and then when printing or printing the pattern of the insulating layer 50, a second through hole is reserved at the position of the other first through hole 301, and then when printing or printing the third conductive ink, the third conductive ink is filled into the through first through hole 301 and the second through hole, and after the third conductive ink in the first through hole 301 and the second through hole is cured, it becomes the contact area of ​​the third electrode 60, so that the first electrode 20, the second electrode 40 and the third electrode 60 can be connected to the connector on the surface where the first electrode 20 is located.

[0057] Optionally, the first through hole 301 passing through the substrate 30 and the second through hole passing through the insulating layer 50 are in shapes of circles, rectangles, triangles, pentagons, hexagons, etc. Preferably, the first through hole 301 and the second through hole have the same shape and size.

[0058] Hereinafter, the preparation method of the implantable sensor will be further described through the following specific examples.

[0059] Example 1

[0060] A polytetrafluoroethylene substrate was cleaned with ethanol and then dried with nitrogen. A first platinum-carbon slurry was then pattern-printed on the polytetrafluoroethylene substrate using an automated screen printer, creating the working area and contact area of ​​the first platinum-carbon electrode. The slurry was then dried at room temperature for 10 minutes. Liquid polyimide was then printed on the substrate, with a first through-hole formed in the contact area of ​​the first platinum-carbon electrode. The substrate was then placed on a heating plate and cured at 200°C for 30 minutes, yielding a first platinum-carbon electrode and a polyimide substrate covering the first platinum-carbon electrode. The polyimide substrate had a first through-hole formed in the contact area of ​​the first platinum-carbon electrode.

[0061] A second platinum-carbon paste was then printed on the polyimide substrate and oven-cured at 130°C for 15 minutes to form a second platinum-carbon electrode. A UV-curable insulating paste was then printed on the second platinum-carbon electrode, and a second through-hole was reserved in the contact area of ​​the second platinum-carbon electrode and the first through-hole area of ​​the substrate. The paste was then cured under UV light for 15 minutes to form an insulating layer. A silver / silver chloride paste was then printed on the insulating layer and oven-cured at 130°C for 15 minutes to form a reference electrode. Finally, the polytetrafluoroethylene substrate was peeled off to obtain the implantable sensor.

[0062] Example 2

[0063] A polytetrafluoroethylene substrate was cleaned with ethanol and then dried with nitrogen. An automated inkjet printer was then used to pattern-print a first platinum-carbon slurry onto the polytetrafluoroethylene substrate, creating the working area and contact area of ​​the first platinum-carbon electrode. The slurry was then dried at room temperature for 10 minutes. Liquid polyimide was then printed onto the substrate, with a first through-hole formed in the contact area of ​​the first platinum-carbon electrode. The substrate was then placed on a heating plate and cured at 200°C for 30 minutes, yielding a first platinum-carbon electrode and a polyimide substrate covering the first platinum-carbon electrode. The polyimide substrate had a first through-hole formed in the contact area of ​​the first platinum-carbon electrode.

[0064] A second platinum-carbon paste was then printed on the polyimide substrate, filling the through-holes with the second platinum-carbon paste. The paste was then oven-cured at 130°C for 15 minutes to form a second platinum-carbon electrode. A UV-curable insulating paste was then printed on the working area of ​​the second platinum-carbon electrode. A second through-hole was reserved in the contact area of ​​the second platinum-carbon electrode and the first through-hole area of ​​the substrate. The paste was then cured under UV light for 15 minutes to form an insulating layer. A silver / silver chloride paste was then printed on the insulating layer and oven-cured at 130°C for 15 minutes to form a reference electrode. Finally, the polytetrafluoroethylene substrate was peeled off to obtain the implantable sensor.

[0065] Example 3

[0066] The silicon substrate was cleaned with acetone and then dried with nitrogen, followed by spin coating of photoresist and drying to serve as a sacrificial layer. Next, an automated screen printer was used to pattern print carbon paste on the photoresist layer, printing the working area and contact area of ​​the first carbon electrode, and drying at room temperature for 10 minutes. Liquid polyethylene terephthalate was then printed on it, and a first through-hole was reserved in the contact area of ​​the first carbon electrode. The substrate was then placed on a heating table and cured at 200°C for 30 minutes to obtain a first carbon electrode and a polyethylene terephthalate substrate covering the first carbon electrode, with the polyethylene terephthalate substrate having a first through-hole in the contact area of ​​the first carbon electrode.

[0067] A platinum-carbon paste was then printed on a polyethylene terephthalate substrate, filling the through-holes with the paste. The paste was then oven-cured at 130°C for 15 minutes to form a platinum-carbon electrode. A UV-curable insulating paste was then printed on the working area of ​​the platinum-carbon electrode. A second through-hole was then reserved in the contact area of ​​the second platinum-carbon electrode and the first through-hole area of ​​the substrate. The paste was then cured under UV light for 15 minutes to form an insulating layer. A silver / silver chloride paste was then printed on the insulating layer and oven-cured at 130°C for 15 minutes to form a reference electrode. Finally, the photoresist layer was removed by wet etching to form the implantable sensor.

[0068] Example 4

[0069] The glass substrate was cleaned with acetone and then dried with nitrogen. A photoresist was then spin-coated and dried to serve as a sacrificial layer. An automated inkjet printer was then used to pattern-print a platinum-carbon slurry on the photoresist layer, creating the working area and contact area of ​​the first platinum-carbon electrode. The slurry was then dried at room temperature for 10 minutes. Liquid polycarbonate was then printed on the substrate, with a first through-hole reserved for the contact area of ​​the first platinum-carbon electrode. The substrate was then placed on a heating platform and cured at 200°C for 30 minutes, resulting in a first platinum-carbon electrode and a polycarbonate substrate covering the first platinum-carbon electrode. The polycarbonate substrate had a first through-hole extending through the contact area of ​​the first platinum-carbon electrode.

[0070] A carbon paste was then printed on the polycarbonate substrate, filling the through-holes with the paste. The paste was then oven-cured at 130°C for 15 minutes to form a carbon electrode. A UV-curable insulating paste was then printed on the working area of ​​the carbon electrode. A second through-hole was then reserved in the contact area of ​​the second platinum-carbon electrode and the first through-hole area of ​​the substrate. The paste was then cured under UV light for 15 minutes to form an insulating layer. A silver / silver chloride paste was then printed on the insulating layer and oven-cured at 130°C for 15 minutes to form a reference electrode. Finally, the photoresist layer was removed by wet etching to create the implantable sensor.

[0071] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations 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 patent for this invention shall be determined by the appended claims.

Claims

1. A method for preparing an implantable sensor, characterized in that: The preparation method comprises the following steps: Printing or forming a pattern of a first electrode on a substrate using a first conductive ink; Printing or printing a pattern of the substrate on the pattern of the first electrode using a liquid polymer, reserving a first through hole penetrating the substrate, and then curing; Printing or printing a second electrode pattern on the substrate using a second conductive ink, and then curing the ink; The substrate is peeled off to obtain a two-electrode implantable sensor, wherein the first electrode and the second electrode of the implantable sensor can be connected to the connector on the same surface by using the first through hole.

2. The method for preparing an implantable sensor according to claim 1, wherein: The first conductive ink and the second conductive ink are independently selected from at least one of carbon paste, silver paste, platinum paste, gold paste, silver / silver chloride paste, and platinum-carbon mixed paste.

3. The method for preparing an implantable sensor according to claim 1, wherein: The liquid polymer is selected from at least one of liquid polyethylene terephthalate, liquid polymethyl methacrylate, liquid polycarbonate, liquid polytetrafluoroethylene, liquid polyethylene, liquid polyvinyl chloride or liquid polyimide.

4. The method for preparing an implantable sensor according to claim 1, wherein: The thickness of the substrate is 20 μm-500 μm.

5. The method for preparing an implantable sensor according to claim 1, wherein: The diameter of the through hole is 20 μm-1500 μm.

6. The method for preparing an implantable sensor according to any one of claims 1 to 5, characterized in that: Before stripping the substrate, it also includes: Printing or printing an insulating layer pattern on the second electrode using an insulating paste, reserving a second through hole penetrating the insulating layer, and then curing; The third conductive ink is used to print or form a pattern of the third electrode on the insulating layer, which is then cured. After the substrate is peeled off, a three-electrode implantable sensor is obtained.

7. The method for preparing an implantable sensor according to claim 6, wherein: The insulating paste is selected from thermally curable insulating paste or ultraviolet curable insulating paste.

8. The method for preparing an implantable sensor according to claim 6, wherein: The third conductive ink is silver / silver chloride paste.

9. The method for preparing an implantable sensor according to any one of claims 1 to 5, characterized in that: Before the step of printing or printing the first conductive ink on the substrate, the method further includes forming a sacrificial layer on the substrate.

10. The method for preparing an implantable sensor according to claim 9, wherein: The material of the sacrificial layer is selected from photoresist, hydrogel or water-soluble polymer.

Images