Super-flexible electronic device capable of being integrated on intravascular stent and application of super-flexible electronic device

Abstract

The invention relates to the technical field of intelligent stents, in particular to a super-flexible electronic device capable of being integrated on an intravascular stent and application of the super-flexible electronic device. The invention provides a super-flexible electronic device. The super-flexible electronic device comprises a self-expansion intravascular stent, a flexible substrate and an electrode, wherein the flexible substrate and the electrode are sequentially stacked on the surface of the self-expansion intravascular stent; the self-expansion intravascular stent is of a grid structure; the flexible substrate is of a grid structure, and the flexible substrate covers the surface of a part of grid lines of the grid structure; the electrode is located on the surface of the flexible substrate. The super-flexible electronic device has a deformation characteristic and does not affect the mechanical property of the support in the deformation process, and meanwhile the super-flexible electronic device has a signal monitoring function.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent stents, and in particular to an ultra-flexible electronic device that can be integrated into a vascular stent and applications thereof. Background Art

[0002] Cardiovascular disease (CVD) has become the most important factor endangering people's health. Among cardiovascular diseases, coronary heart disease is the main direct cause of death. For patients with coronary heart disease, one of the most common and effective treatments is to implant a heart stent to restore myocardial blood supply that is first damaged by arterial stenosis. During the operation, the doctor will deliver the stent to the narrowed part of the coronary artery through a catheter, and use balloon dilatation technology to expand the stent radially and adhere to the blood vessel wall. The traditional stent design adopts a physically expandable grid structure, and its main function is to support and maintain the inner cavity of the diseased blood vessel to restore it to a near normal size to prevent blockage again.

[0003] At present, there is a new type of intelligent stent, which adopts advanced micro-nano processing technology, and its surface inherits pressure sensor elements. In this way, the implanted intelligent stent can not only provide mechanical support, but also monitor the pressure changes inside the blood vessels in real time, so as to provide doctors with more accurate disease assessment and subsequent treatment decision-making basis. The stent is wrapped with a layer of polyparaxylene, and has passed the vitality experiment of human umbilical vein endothelial cells to verify the biocompatibility. The preparation process is to first make a 2D planar pressure sensor and stent, and then make the stent self-curl into a cylindrical shape after heat treatment. Since the stent is made as a whole at one time, the original function of the stent to expand through the physical structure is lost. At the same time, the flexible electronic devices on the surface of the stent are in the form of a film, which also limits the function of the stent to expand through the physical structure. The new stent lacks the function of deformation, and the stent needs to enter the human body in an expanded form, which is contrary to the minimally invasive nature of existing stents, and the bare stent is prone to restenosis and other problems after being implanted in the blood vessel. Summary of the invention

[0004] The purpose of the present invention is to provide an ultra-flexible electronic device that can be integrated into a vascular stent and its application, wherein the ultra-flexible electronic device has deformation characteristics and does not affect the mechanical properties of the stent during the deformation process, and the ultra-flexible electronic device has a signal monitoring function.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides an ultra-flexible electronic device, comprising a self-expanding vascular stent, a flexible substrate and electrodes sequentially stacked on the surface of the self-expanding vascular stent;

[0007] The self-expanding vascular stent is a grid structure;

[0008] The flexible substrate is a grid structure, and the flexible substrate covers a portion of the grid wire surface of the grid structure;

[0009] The electrodes are located on the surface of the flexible substrate.

[0010] Preferably, the grid shape of the self-expanding vascular stent is a diamond structure.

[0011] Preferably, the material of the flexible substrate is polyimide;

[0012] The grid shape of the flexible substrate is the same as the grid structure of the self-expanding vascular stent, and a plurality of grids of the self-expanding vascular stent constitute one grid of the flexible substrate.

[0013] Preferably, the grid line width in the flexible substrate is 0.06 mm to 1 mm, and the thickness of the flexible substrate is 10 to 200 μm.

[0014] Preferably, the electrode is also connected to a lead wire.

[0015] Preferably, the electrode comprises a first metal layer and a second metal layer stacked in sequence;

[0016] The first metal layer and the second metal layer are made of different materials.

[0017] The present invention also provides a method for preparing the ultra-flexible electronic device described in the above technical solution, comprising the following steps:

[0018] After spin coating a sacrificial layer and a flexible base photoresist on the surface of the silicon wafer, patterned first exposure, first development and rinsing are sequentially performed to obtain a base layer;

[0019] After spin coating negative photoresist on the surface of the substrate layer, patterned second exposure and second development are sequentially performed, an electrode layer is evaporated, and after removing the sacrificial layer on the surface of the silicon wafer, the obtained flexible functional layer is attached to the surface of the self-expanding vascular stent, and the flexible substrate covers the surface of part of the grid wires of the grid structure of the self-expanding vascular stent, thereby obtaining the ultra-flexible electronic device.

[0020] Preferably, the flexible substrate photoresist is a polyimide photoresist;

[0021] The spin coating of the flexible substrate photoresist comprises a first spin coating, a second spin coating and a third spin coating performed sequentially,

[0022] The developer used in the first development is cyclopentanone, and the rinse liquid used in the rinse is PGMEA rinse liquid;

[0023] The first exposure also includes soft baking;

[0024] The first exposure also includes post-baking;

[0025] The rinsing step also includes hard drying.

[0026] Preferably, the negative photoresist is RN246 photoresist;

[0027] The second exposure also includes soft baking;

[0028] The second exposure also includes post-baking.

[0029] The present invention also provides the application of the ultra-flexible electronic device described in the above technical solution or the ultra-flexible electronic device prepared by the preparation method described in the above technical solution in the field of intelligent brackets.

[0030] The present invention provides an ultra-flexible electronic device, comprising a self-expanding vascular stent, a flexible substrate and an electrode sequentially stacked on the surface of the self-expanding vascular stent; the self-expanding vascular stent is a grid structure; the flexible substrate is a grid structure, and the flexible substrate covers a portion of the grid line surface of the grid structure; the electrode is located on the surface of the flexible substrate. Compared with traditional thin-film flexible electronic devices, the ultra-flexible electronic device of the present invention can be stretched and deformed together with the self-expanding vascular stent, while retaining the deformation characteristics and giving the stent electrical properties. At the same time, the electrode is made on the substrate, which can maintain its effectiveness during stretching and bending, that is, when stretched, the overall resistance value does not change significantly (the reason is that the substrate layer replaces the tension and compression at the bend with twisting and rotation during stretching, the metal part is not stretched and compressed, and its cross-street area and length do not change, so the resistance value does not change). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the plane deployment of the self-expanding stent described in Example 1;

[0032] Figure 2 The diagram is a schematic diagram of the pattern of the flexible substrate layer described in Example 1 (a) and a diagram of the combination of the flexible substrate and the self-expanding stent (b);

[0033] Figure 3 This is a schematic diagram of the shape of the electrode layer described in Example 1;

[0034] Figure 4 The actual unfolded image (a) and the actual image after stretching (b) of the ultra-flexible electronic device described in Example 1;

[0035] Figure 5 The actual image (a) and thickness measurement result image (b) of the flexible substrate described in Example 1;

[0036] Figure 6The physical pictures of the flexible substrate functional layer before and after stretching described in Example 1 (a is the physical picture before stretching, b is the physical picture after 120% stretching);

[0037] Figure 7 A physical diagram of the two electrolytic structures designed on each patterned flexible substrate layer in the flexible substrate functional layer described in Example 1. DETAILED DESCRIPTION

[0038] The present invention provides an ultra-flexible electronic device, comprising a self-expanding vascular stent, a flexible substrate and electrodes sequentially stacked on the surface of the self-expanding vascular stent;

[0039] The self-expanding vascular stent is a grid structure;

[0040] The flexible substrate is a grid structure, and the flexible substrate covers a portion of the grid wire surface of the grid structure;

[0041] The electrodes are located on the surface of the flexible substrate.

[0042] In the present invention, the grid shape of the self-expanding vascular stent is preferably a diamond structure. In the present invention, the nominal diameter of the self-expanding vascular stent is preferably 6 mm, the effective length is preferably 20 mm, and the diameter of the metal part is preferably 0.06 mm. In an embodiment of the present invention, the model of the self-expanding vascular stent is HC*TDE-6020, purchased from Shanghai Xinwei Medical (planar unfolding schematic diagram of the self-expanding stent).

[0043] In the present invention, the material of the flexible substrate is preferably polyimide. In the present invention, the polyimide itself has the advantages of good photosensitivity and metal adhesion, and the polyimide is a relatively commonly used flexible material with good mechanical properties and micro-processing stability. Compared with PMDS, its elastic modulus is larger, the metal layer is not easy to break after being attached to the surface of the substrate, and the processing technology of the polyimide is also simpler, the obtained substrate structure strength is better, and it is not easy to break when stretched. Compared with SU-8 photoresist, the processing process of the polyimide is simpler, the substrate surface is smoother, and the structural strength is better and it is not easy to break.

[0044] In the present invention, the thickness of the flexible substrate is preferably 10-200 μm, more preferably 5-30 μm, and more preferably 15 μm. In the present invention, the flexible substrate of the above thickness ensures good structural strength of the substrate layer while also avoiding the problem of affecting the natural unfolding shape of the stent due to the substrate layer being too thick.

[0045] In the present invention, the grid line width in the flexible substrate is preferably 0.06 mm to 1 mm. In the present invention, the grid line width at the rhombus bend is 0.06 mm, and the grid line width at the rest is 1 mm. In the present invention, the grid shape of the flexible substrate is preferably the same as the grid structure of the self-expanding vascular stent, and several grids of the self-expanding vascular stent constitute one grid of the flexible substrate. In an embodiment of the present invention, every 9 grids of the self-expanding vascular stent constitute one grid of the flexible substrate.

[0046] In the present invention, the flexible substrate can be stretched to 125% of the original length, more preferably 120% of the original length, and after multiple stretching, the structure itself is not damaged. The deformation mode of the substrate layer is consistent with the deformation mode of the self-expanding vascular stent, which is a diamond deformation. Therefore, after being attached to the surface of the self-expanding vascular stent, it can be deformed together with the self-expanding vascular stent.

[0047] In the present invention, the electrode is preferably connected to a lead; the electrode preferably includes a first metal layer and a second metal layer stacked in sequence, and the materials of the first metal layer and the second metal layer are preferably different. In the present invention, the first metal layer is preferably a chromium layer, and the second metal layer is preferably a gold layer. In the present invention, the thickness of the chromium layer is preferably 10 to 50 nm, more preferably 20 nm; the thickness of the gold layer is preferably 100 to 300 nm, more preferably 200 nm.

[0048] In the present invention, two electrodes (such as Figure 3 As shown, two electrodes are located on the grid surface of the flexible substrate and the two electrodes do not contact each other).

[0049] In the present invention, the lead wire is used to connect the electrode to an external electronic device. The electrode is stacked with chromium and gold in sequence. Chromium helps gold adhere to the surface of the substrate layer, and gold is relatively stable and suitable for use as a surface electrode.

[0050] The present invention makes electrodes on the surface of a flexible substrate, and can maintain effectiveness when stretched and bent. Two electrodes are designed and made on each patterned substrate layer, and the resistance value is measured from both ends, which is 36.1kΩ. When the substrate layer is stretched, the overall resistance value does not change significantly. The reason is that when the flexible substrate is stretched, the tension and compression at the bend are replaced by twisting and rotation. The metal part is not stretched or compressed, and its cross-sectional area and length do not change, so the resistance value does not change.

[0051] In the present invention, compared with thin-film flexible electronic devices, after the flexible substrate in the ultra-flexible electronic device of the present invention is attached to the surface of the self-expanding vascular stent, it will not affect the natural deformation mode of the self-expanding vascular stent. It has both curling deformation and stretching deformation, and can enter and exit the catheter together with the self-expanding vascular stent.

[0052] The present invention also provides a method for preparing the ultra-flexible electronic device described in the above technical solution, comprising the following steps:

[0053] After spin coating a sacrificial layer and a flexible base photoresist on the surface of the silicon wafer, patterned first exposure, first development and rinsing are sequentially performed to obtain a base layer;

[0054] After spin coating negative photoresist on the surface of the substrate layer, patterned second exposure and second development are sequentially performed, an electrode layer is evaporated, and after removing the sacrificial layer on the surface of the silicon wafer, the obtained flexible functional layer is attached to the surface of the self-expanding vascular stent, and the flexible substrate covers the surface of part of the grid wires of the grid structure of the self-expanding vascular stent, thereby obtaining the ultra-flexible electronic device.

[0055] In the present invention, unless otherwise specified, all preparation raw materials are commercially available products well known to those skilled in the art.

[0056] In the present invention, after spin coating a sacrificial layer and a flexible base photoresist on the surface of a silicon wafer, patterned first exposure, first development and rinsing are sequentially performed to obtain a base layer.

[0057] Before the spin coating, the present invention preferably pre-treats the silicon wafer, and the pre-treatment preferably includes cleaning, baking and cooling performed in sequence. In the present invention, the cleaning is preferably conventional cleaning with deionized water. In the present invention, the baking temperature is preferably 150°C and the time is preferably 10 minutes. In the present invention, the silicon wafer is preferably covered with a glass culture dish during baking to avoid contamination by splashing of other liquids. In the present invention, the purpose of baking is to remove water vapor from the surface of the silicon wafer. The present invention does not have any special limitation on the cooling process, and it can be carried out using a process well known to those skilled in the art.

[0058] The present invention does not have any special limitation on the process of spin coating the sacrificial layer, and the process well known to those skilled in the art can be used. In the present invention, the process of spin coating the flexible substrate photoresist is preferably to drip the flexible substrate photoresist on the surface of the silicon wafer and then spin coat. In the present invention, the flexible substrate photoresist on the surface of the silicon wafer after dripping preferably covers one-third of the surface area of ​​the silicon wafer. In the present invention, the flexible substrate photoresist is preferably a polyimide photoresist (BL-301 photoresist). In the present invention, the spin coating of the flexible substrate photoresist preferably includes a first spin coating, a second spin coating and a third spin coating performed in sequence, and the rotation speed of the first spin coating is preferably 10rpm, and the time is preferably 10s; the rotation speed of the second spin coating is preferably 1000rpm, and the time is preferably 30s; the rotation speed of the third spin coating is preferably 1500rpm, and the time is preferably 40s. In the present invention, the thickness of the base layer obtained after the spin coating is preferably 15μm.

[0059] After the spin coating is completed, the present invention also preferably includes placing the obtained silicon wafer coated with the flexible base photoresist on a smooth and flat surface for standing; the standing time is preferably 5 minutes. In the present invention, the standing time is preferably related to the thickness of the spin coating, and the thicker the thickness, the longer the standing time; the purpose of the standing is to make the flexible base photoresist evenly distributed on the silicon wafer.

[0060] After the standing is completed, the present invention further preferably includes soft baking, and the temperature of the soft baking is preferably 100° C. and the time is preferably 4 minutes. In the present invention, the soft baking is preferably performed on a hot plate.

[0061] In the present invention, the first exposure preferably includes pre-exposure preparation and exposure performed sequentially.

[0062] In the present invention, the pre-exposure preparation preferably includes: attaching a film to a transparent glass surface with the patterned side of the film facing downward to obtain a glass substrate; and installing the glass substrate as a mask plate on a photolithography machine.

[0063] The present invention attaches a film sheet to a transparent glass surface with the patterned side of the film sheet facing downward to obtain a glass substrate. In the present invention, the attachment is preferably performed by using an adhesive tape. In the present invention, the patterned side of the film sheet is turned downward in order to contact the patterned side with the sample to be exposed. In the present invention, the side of the glass substrate to which the film sheet is not attached is preferably smooth and complete, and there should be no protrusions to avoid the thickness of the glass substrate being successfully installed on the photolithography machine.

[0064] In the present invention, the glass substrate is installed as a mask plate on a photolithography machine. In the present invention, the size of the mask plate is preferably larger than the size of the silicon wafer. In the present invention, the mask plate is preferably vacuum-adsorbed on the mold surface of the photolithography machine by an air pump.

[0065] In the present invention, the first exposure preferably includes: placing the silicon wafer with the flexible base photoresist spin-coated on the stage of the photolithography machine, and the machine automatically loads the sample (silicon wafer with the flexible base photoresist spin-coated) to contact the mask plate to perform the first exposure. In the present invention, the exposure dose of the first exposure is preferably 200mJ / cm 2 , the spacing is preferably 10μm.

[0066] After the first exposure, the present invention preferably further comprises post-baking, and the temperature of the post-baking is preferably 45° C., and the time is preferably 1 minute. After the post-baking is completed, the present invention preferably further comprises cooling, and the present invention has no special limitation on the cooling process, and natural cooling can be performed using a process well known to those skilled in the art.

[0067] In the present invention, the developer used in the first development is preferably cyclopentane. In an embodiment of the present invention, the developer used in the first development is specifically RS120 developer. In the present invention, the first development is preferably shaken in the developer; the present invention does not have any special limitation on the shaking process, and a process well known to those skilled in the art can be used to ensure that the purpose of accelerating the development speed is achieved. In the present invention, the rinsing liquid used in the rinsing is preferably PGMEA rinsing liquid. The present invention does not have any special limitation on the rinsing process, and a process well known to those skilled in the art can be used.

[0068] After the rinsing is completed, the present invention also preferably includes placing the obtained sample to allow the liquid on its surface to evaporate naturally.

[0069] After the rinsing is completed, hard baking is preferably further performed. In the present invention, the hard baking is preferably performed in a nitrogen atmosphere, the temperature of the hard baking is preferably 200-400° C., more preferably 200° C., and the time is preferably 2 hours.

[0070] After obtaining the base layer, the present invention spin-coats a negative photoresist on the surface of the base layer, sequentially performs a patterned second exposure and a second development, evaporates an electrode layer, removes a sacrificial layer on the surface of a silicon wafer, and then attaches the obtained flexible functional layer to the surface of a self-expanding vascular stent, and the flexible base covers a partial mesh wire surface of the mesh structure of the self-expanding vascular stent, thereby obtaining the ultra-flexible electronic device.

[0071] In the present invention, the negative photoresist is preferably RN246 photoresist.

[0072] In the present invention, the process of spin coating the negative photoresist is preferably: after placing the base layer on a coating machine, dropwise adding the negative photoresist and then spin coating.

[0073] In the present invention, the surface of the base layer is not flat due to the presence of the polyimide layer, so when the negative photoresist is dripped, the negative photoresist will be distributed according to the pattern shape of the surface. If the distribution is not broken, the photoresist will be unevenly distributed after spin coating. Therefore, all flexible substrates need to be covered when the negative photoresist is spin-coated.

[0074] In the present invention, the rotation speed of the spin coating negative photoresist is preferably 4000 rpm, and the time is preferably 60 s.

[0075] In the present invention, the thickness of the negative photoresist layer prepared by spin coating is preferably 3.5 μm.

[0076] After the spin coating is completed, the present invention further preferably includes sequential soft baking and cooling, wherein the temperature of the soft baking is preferably 90° C. and the time is preferably 120 seconds. The present invention has no special limitation on the cooling process, and a process well known to those skilled in the art can be used to cool to room temperature.

[0077] In the present invention, the exposure dose of the second exposure is preferably 120 mJ / cm 2 , the spacing is preferably 10 μm. In the present invention, in order to ensure the accuracy of the position of the electrode pattern during the second exposure, it is preferred that the cross mark on the mask plate overlaps the polyimide cross on the base layer.

[0078] After the second exposure is completed, the present invention further preferably includes post-baking and cooling in sequence, wherein the post-baking temperature is preferably 95° C. and the time is preferably 120 seconds. The present invention has no special limitation on the cooling process, and a process well known to those skilled in the art can be used.

[0079] In the present invention, the developer used in the second development is preferably diluted NMD-3, the mass concentration of the NMD-3 is preferably 2.38%, and the mass concentration of the diluted NMD-3 is preferably 1.785%; the time of the second development is preferably 30s.

[0080] After the second development is completed, the present invention also preferably includes rinsing and drying performed in sequence, and the rinsing liquid used in the rinsing is preferably deionized water. In the present invention, the rinsing liquid used in the rinsing cannot use isopropyl alcohol, otherwise it will cause the RN246 photoresist layer to fall off. The present invention does not have any special restrictions on the drying process, and a process well known to those skilled in the art is used to ensure that there is no moisture on the surface, and electron beam evaporation coating can be performed.

[0081] In the present invention, the evaporation rate is preferably 1 angstrom per second.

[0082] After the evaporation is completed, the present invention further preferably comprises immersing the obtained product in acetone, and accelerating the falling of the metal layer (the metal layer portion outside the desired electrode pattern) by heating or ultrasonic treatment.

[0083] The present invention does not have any special limitation on the process of removing the silicon wafer and attaching the silicon wafer, and the process can be performed using a process well known to those skilled in the art.

[0084] The present invention also provides the application of the ultra-flexible electronic device described in the above technical solution or the ultra-flexible electronic device prepared by the preparation method described in the above technical solution in the field of intelligent stents. The present invention does not have any special limitation on the method of the application, and the method well known to those skilled in the art can be used.

[0085] The ultra-flexible electronic device and its preparation method and application provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be understood as limiting the protection scope of the present invention.

[0086] Example 1

[0087] After the silicon wafer is cleaned with deionized water, it is covered with a glass culture dish and baked on a hot plate at 150° C. for 10 minutes to remove surface moisture, and then cooled to obtain a pretreated silicon wafer; then a sacrificial layer is spin-coated, and after the spin coating is completed, it is baked to obtain a silicon wafer covered with a sacrificial layer.

[0088] After spin coating the sacrificial layer on the surface of the pretreated silicon wafer, baking is performed, BL-301 photoresist is dripped on the surface of the silicon wafer covered with the sacrificial layer, and after the dripped BL-301 photoresist covers about one-third of the surface of the silicon wafer, spin coating is performed (the spin coating includes spin coating at a rotation speed of 10 rpm for 10 seconds, spin coating at a rotation speed of 1000 rpm for 30 seconds, and then spin coating at a rotation speed of 1500 rpm for 40 seconds), the spin-coated silicon wafer is taken out and placed on a smooth and flat surface for 5 minutes to evenly distribute the photoresist on the silicon wafer, and then baked on a hot plate at 100° C. for 4 minutes to obtain a silicon wafer coated with photoresist;

[0089] The film was attached to the transparent glass surface with tape (the patterned side of the film was facing downward, and the side of the transparent glass without the film attached was smooth and complete), and then the glass substrate was installed on the photolithography machine as a mask (the size of the mask was larger than the size of the silicon wafer coated with photoresist), and an air pump was used to vacuum adsorb it on the mold surface for exposure (the exposure dose was 200mJ / cm 2, the spacing is 10μm), after the exposure is completed, the sample is removed, and baked on a hot plate at 45℃ for 1min. After natural cooling, it is developed in RS120 developer (shaking during the development process to speed up the development speed) until the pattern is basically revealed, and then rinsed in PGMEA rinse solution. After standing until the liquid on its surface evaporates naturally, it is baked at 200℃ in a nitrogen atmosphere oven for 2h to obtain a silicon wafer with a flexible substrate on the surface (the pattern of the flexible substrate layer is as shown in Figure 2 As shown in a, the actual picture is as follows Figure 5 As shown in a in the figure, the thickness measurement results are as follows Figure 5 As shown in b);

[0090] A layer of RN246 photoresist was spin-coated on the surface of the flexible substrate layer of the silicon wafer with a flexible substrate on the surface (covering all the polyimide substrate layers, the spin coating speed was 4000 rpm, and the time was 60 s). After obtaining a photoresist layer with a thickness of 3.5 μm on the surface of the flexible substrate layer, it was soft-baked at 90° C. for 120 s, cooled to room temperature, and then exposed (the exposure dose of the exposure was 120 mJ / cm 2 , the spacing is 10μm), and after exposure, it is baked at 95℃ for 120s, and after cooling, it is developed in diluted NMD-3 (mass concentration is 1.785%) for 30s, and then rinsed in deionized water. After low-temperature drying, the electron beam evaporation coating process is used to evaporate 20nm of Cr and 200nm of Au at a rate of 1 angstrom per second (the shape of the electrode layer obtained by evaporation is as shown in the figure). Figure 3 After the evaporation is completed, the prepared sample is immersed in acetone, heated to 80°C or ultrasonically treated to accelerate the metal layer (the metal layer part outside the required electrode pattern) to fall off, and after removing the silicon wafer, the obtained flexible substrate functional layer (the actual picture of the flexible substrate functional layer before and after stretching is as shown in FIG. Figure 6 As shown, a is the physical picture before stretching, and b is the physical picture after 120% stretching. Figure 6 It can be seen that the flexible substrate functional layer can be stretched to 120% of its original length, and after multiple stretching, its own structure is not damaged; two electrodes are designed and manufactured on each patterned flexible substrate layer in the flexible substrate functional layer, as shown in the actual picture Figure 7 As shown, the resistance value measured from both ends is 36.1 kΩ) attached to the surface of a self-expanding vascular stent (model HC*TDE-6020, purchased from Shanghai Xinwei Medical) (the combination diagram of the flexible substrate and the self-expanding stent is as shown in Figure 2 b), and the flexible substrate covers the surface of part of the grid wire of the grid structure of the expandable vascular stent to obtain an ultra-flexible electronic device (the actual expansion diagram is shown in Figure 4 As shown in a in the figure, the actual image after stretching is as follows Figure 4 As shown in b, Figure 4 It can be seen that after the self-expanding vascular stent is deployed, the shape of the base layer can be matched with the stent, and the self-expanding vascular stent and the flexible base layer can be stretched together, and the two can be stretched together to simulate the situation of the stent entering the catheter).

[0091] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An ultra-flexible electronic device, characterized in that: It comprises a self-expanding vascular stent, a flexible substrate and electrodes sequentially stacked on the surface of the self-expanding vascular stent; The self-expanding vascular stent is a grid structure; The flexible substrate is a grid structure, and the flexible substrate covers a portion of the grid wire surface of the grid structure; The electrodes are located on the surface of the flexible substrate.

2. The ultra-flexible electronic device according to claim 1, characterized in that: The grid shape of the self-expanding vascular stent is a diamond structure.

3. The ultra-flexible electronic device according to claim 1, characterized in that: The material of the flexible substrate is polyimide; The grid shape of the flexible substrate is the same as the grid structure of the self-expanding vascular stent, and a plurality of grids of the self-expanding vascular stent constitute one grid of the flexible substrate.

4. The ultra-flexible electronic device according to claim 1 or 3, characterized in that: The grid line width in the flexible substrate is 0.06 mm to 1 mm, and the thickness of the flexible substrate is 10 to 200 μm.

5. The ultra-flexible electronic device according to claim 1, characterized in that: The electrodes are also connected to leads.

6. The ultra-flexible electronic device according to claim 1 or 5, characterized in that: The electrode comprises a first metal layer and a second metal layer stacked in sequence; The first metal layer and the second metal layer are made of different materials.

7. The method for preparing the ultra-flexible electronic device according to any one of claims 1 to 5, characterized in that: The following steps are involved: After spin coating a sacrificial layer and a flexible base photoresist on the surface of the silicon wafer, patterned first exposure, first development and rinsing are sequentially performed to obtain a base layer; After spin coating negative photoresist on the surface of the substrate layer, patterned second exposure and second development are sequentially performed, an electrode layer is evaporated, and after removing the sacrificial layer on the surface of the silicon wafer, the obtained flexible functional layer is attached to the surface of the self-expanding vascular stent, and the flexible substrate covers the surface of part of the grid wires of the grid structure of the self-expanding vascular stent, thereby obtaining the ultra-flexible electronic device.

8. The preparation method according to claim 7, characterized in that: The flexible substrate photoresist is a polyimide photoresist; The spin coating of the flexible substrate photoresist comprises a first spin coating, a second spin coating and a third spin coating performed sequentially, The developer used in the first development is cyclopentanone, and the rinse liquid used in the rinse is PGMEA rinse liquid; The first exposure also includes soft baking; The first exposure also includes post-baking; The rinsing step also includes hard drying.

9. The preparation method according to claim 7, characterized in that: The negative photoresist is RN246 photoresist; The second exposure also includes soft baking; The second exposure also includes post-baking.

10. Application of the ultra-flexible electronic device according to any one of claims 1 to 5 or the ultra-flexible electronic device prepared by the preparation method according to any one of claims 6 to 9 in the field of intelligent stents.

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