A method for preparing a stent with electrodes

Abstract

This invention relates to the field of vascular stent fabrication technology, and discloses a method for fabricating a stent with electrodes, comprising the following steps: providing a planar stent precursor with thermally responsive deformation characteristics; forming a conductive layer on the surface of the planar precursor, and patterning the conductive layer to form at least one electrode unit and at least one conductive wire unit electrically connected to the electrode unit; forming a non-conductive material layer on at least a portion of the surface of the conductive layer; placing the planar precursor under constraint and heating it to a molding temperature below 300°C to soften the planar precursor, cause a shape memory phase transition or crystal structure transformation, and shape it into a stent structure using a mold; wherein, the non-conductive material layer maintains structural integrity and insulation properties at the molding temperature, the non-conductive material layer has windows for exposing the electrode unit, and the non-conductive material layer covers the conductive wire unit, thus avoiding thermal damage to the non-conductive material layer caused by high-temperature processes.

Description

Technical Field

[0001] This invention relates to the field of vascular stent fabrication technology, and more specifically to a method for fabricating a stent with electrodes. Background Technology

[0002] This invention relates to the field of medical device manufacturing technology, and more specifically to a method for preparing a vascular interventional stent electrode device. A vascular interventional stent electrode device is a functional medical device that integrates electrodes onto the surface of a stent and can be delivered to a target location within a blood vessel via a catheter. It is widely used in areas such as nerve signal monitoring, electrical stimulation therapy, and endovascular interventional diagnosis and treatment. Such devices typically require the stent to have good radial support and deformation recovery capabilities, while the electrodes and leads need to possess high-precision, high-density wiring capabilities and long-term electrical stability. This places high demands on the heterogeneous integration process of the stent substrate, conductive structure, and insulating layer.

[0003] In existing technologies, the fabrication of intravascular stent electrode devices primarily utilizes shape memory alloys such as nitinol as the stent substrate. High-temperature vacuum annealing (typically above 400°C) is used to crystallize and shape the stent to achieve superelasticity. For example, after shaping a nitinol stent at high temperature, SiO is deposited as an insulating layer via radio frequency sputtering. Existing technologies have also attempted to use polymeric insulating materials such as polyimide, but still follow the high-temperature shaping process. Furthermore, existing processes often involve direct electrode fabrication on the stent surface, but none have effectively unified planar micro-machining with curved surface structures.

[0004] However, existing technologies suffer from significant technical contradictions and reliability defects. On the one hand, the shaping temperature exceeding 400°C required for shape memory alloys such as nickel-titanium severely limits the range of insulating layer materials, making it difficult to apply flexible polymers such as polyimide and perylene due to their inability to withstand high temperatures, thus forcing the use of brittle inorganic materials such as SiO. On the other hand, SiO typically has an elongation at break of less than 2%, making it highly susceptible to microcracks during the cyclic deformation of the scaffold as it repeatedly contracts and expands with the heartbeat. This can lead to deterioration of insulation performance and even short circuits between electrodes, posing a risk of failure with long-term implantation. Furthermore, high-precision patterning directly on tubular curved structures is challenging, making it difficult to achieve electrode and wire layouts with micron-level linewidths, thus restricting the miniaturization and multi-channel integration capabilities of the device. Summary of the Invention

[0005] This invention provides a method for fabricating a scaffold with electrodes, which solves the problem of avoiding thermal damage to the non-conductive material layer caused by high-temperature processes during the heat setting of a scaffold substrate with thermally responsive deformation characteristics to form a tubular structure, and solves the problem of easy cracking and failure of the scaffold due to repeated deformation caused by the use of an inorganic brittle insulating layer.

[0006] This invention provides a method for fabricating a scaffold with electrodes, comprising the following steps: Provide a planar precursor for the support structure with thermally responsive deformation characteristics; A conductive layer is formed on the surface of the planar precursor, and the conductive layer is patterned to form at least one electrode unit and at least one wire unit electrically connected to the electrode unit. A non-conductive material layer is formed on at least a portion of the surface of the conductive layer; The planar precursor is placed under constraint and heated to a molding temperature below 300°C to soften it, induce a shape memory phase transition or crystal structure transformation, and then molded into a support structure. The non-conductive material layer maintains structural integrity and insulation properties at the molding temperature. The non-conductive material layer has windows to expose the electrode unit and covers the wire unit.

[0007] Beneficial Effects: By providing a planar precursor with thermally responsive deformation characteristics, a conductive layer is formed on its surface and patterned to construct electrode and wire units. A non-conductive material layer is then formed on the conductive layer surface. Finally, under constraint, the precursor is heated to a molding temperature below 300°C, causing it to soften, undergo shape memory phase transition or crystal structure transformation, and be molded into a support structure. The non-conductive material layer maintains structural integrity and insulation properties at the molding temperature. This method, employing a low-temperature molding process below 300°C, overcomes the limitations of traditional high-temperature molding above 400°C on insulating layer materials, allowing the application of polymer insulating materials that were previously unable to withstand high temperatures, thus expanding the range of material choices. Simultaneously, completing the patterning of the conductive layer in a planar state allows for high-precision electrode and wire layout using precision micro-machining techniques such as photolithography, avoiding the difficulties of directly machining on curved surfaces and improving the positioning accuracy of electrode units and the consistency of feature dimensions of wire units. Furthermore, the low-temperature molding process avoids thermal damage to the interface between the conductive and insulating layers, helping to improve interlayer bonding strength and thus ensuring the overall reliability and long-term stability of the support electrode device.

[0008] In one alternative embodiment, the material of the planar precursor is selected from thermoplastic polymers, shape memory polymers, or low-temperature shape memory alloys. The glass transition temperature of the thermoplastic polymer is 40℃-150℃; The austenitic phase transformation end temperature of the low-temperature shape memory alloy is below 37°C.

[0009] In one alternative embodiment, the thermal decomposition temperature of the non-conductive material layer is higher than the molding temperature.

[0010] In one alternative embodiment, the non-conductive material layer is selected from pyrene, polyimide, polydimethylsiloxane, poly(p-phenylenebenzodioxazole), SU8, or polylactic acid-glycolic acid copolymer, and has a thickness of 0.01 μm to 100 μm.

[0011] In one alternative embodiment, the conductive layer is formed by magnetron sputtering, vapor deposition, chemical vapor deposition or electroplating processes, and has a thickness of 10 nm-5 μm. The patterning process employs laser cutting or photolithography and stripping techniques to make the width of the conductor unit 1μm-500μm.

[0012] In one optional embodiment, the planar precursor has a plurality of pillars and cross-connecting portions connecting the pillars, wherein the width of the pillars is 10μm-500μm and the thickness is 10μm-200μm; The planar precursor is prepared by laser cutting, etching, 3D printing or casting processes.

[0013] In one alternative implementation, the constraint is provided by a mold or forming aid structure that defines the final diameter and curvature of the tubular support structure. The scaffold structure, once shaped, maintains shape stability within the human body temperature range and can be compressed to a smaller profile. After being implanted into the target location in the human body, it autonomously returns to its expanded state at human body temperature.

[0014] In one optional embodiment, the molding temperature is set according to the material type of the planar precursor, so that the planar precursor softens, recovers its shape memory, or undergoes a crystal structure transformation corresponding to its material type, thereby transforming from a planar state into a tubular structure.

[0015] In one optional embodiment, after the non-conductive material layer is formed, selective windowing is performed on the non-conductive material layer by laser removal, mechanical polishing, or mask avoidance deposition process to expose the electrode unit, so that the wire unit is completely covered by the non-conductive material layer.

[0016] In one alternative embodiment, the electrode-bearing stent prepared by the method described above is used in the preparation of medical devices for nerve signal monitoring, electrical stimulation therapy, or vascular interventional diagnosis and treatment. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a method for fabricating a scaffold with electrodes according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the planar precursor structure in an embodiment of the present invention; Figure 3 This is a schematic diagram of the tubular structure of the support in an embodiment of the present invention; Figure 4 This is a schematic diagram of the layered structure of the support in an embodiment of the present invention; Figure 5 This is a comparison chart of the temperature-performance characteristics of three types of materials in the embodiments of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. Planar precursor; 101. Support column; 102. Cross connection; 2. Conductive layer; 201. Electrode unit; 202. Conductor unit; 3. Non-conductive material layer. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0022] According to an embodiment of the present invention, a method for fabricating a scaffold with electrodes is provided, comprising the following steps: Provide a planar precursor 1 with thermally responsive deformation characteristics; A conductive layer 2 is formed on the surface of the planar precursor 1, and the conductive layer 2 is patterned to form at least one electrode unit 201 and at least one wire unit 202 electrically connected to the electrode unit 201. A non-conductive material layer 3 is formed on at least a portion of the surface of the conductive layer 2; The planar precursor 1 is placed under constraint and heated to a molding temperature below 300°C to soften the planar precursor 1, cause a shape memory phase transition or crystal structure transformation, and is then shaped into a support structure using a mold. The non-conductive material layer 3 maintains structural integrity and insulation performance at the molding temperature. The non-conductive material layer 3 has windows to expose the electrode unit 201 and covers the wire unit 202.

[0023] In this embodiment, a planar precursor 1 with thermally responsive deformation characteristics is provided. A conductive layer 2 is formed on its surface and patterned to construct electrode units 201 and wire units 202. A non-conductive material layer 3 is then formed on the surface of the conductive layer 2. Finally, under constraint, the planar precursor 1 is heated to a molding temperature below 300°C, causing it to soften, undergo shape memory phase transition or crystal structure transformation, and curl into a tubular support structure. The non-conductive material layer 3 maintains structural integrity and insulation performance at the molding temperature. This method, by employing a low-temperature molding process below 300°C, overcomes the limitations of traditional high-temperature molding above 400°C on the insulating layer material, allowing the application of polymer insulating materials that were originally unable to withstand high temperatures, thereby expanding the range of material choices. Simultaneously, completing the patterning of the conductive layer 2 in a planar state allows for high-precision electrode and wire layout using precision micro-machining techniques such as photolithography, avoiding the difficulties of directly machining on curved surfaces and improving the positioning accuracy of the electrode units 201 and the consistency of the feature dimensions of the wire units 202. In addition, the low-temperature molding process avoids thermal damage to the interface between the conductive layer 2 and the insulating layer caused by high temperature, which helps to improve the interlayer bonding strength and thus ensure the overall reliability and long-term stability of the support electrode device.

[0024] In one embodiment, multiple electrode units 201 and wire units 202 electrically connected to the electrode units 201 can be provided, and each wire unit 202 is connected to one electrode unit 201.

[0025] In one embodiment, the material of the planar precursor 1 is selected from thermoplastic polymers, shape memory polymers, or low-temperature shape memory alloys.

[0026] The glass transition temperature of thermoplastic polymers is 40℃-150℃.

[0027] The austenitic phase transformation end temperature of low-temperature shape memory alloys is below 37℃.

[0028] In this embodiment, the material of the planar precursor 1 is selected from thermoplastic polymers, shape memory polymers, or low-temperature shape memory alloys. Specifically, the glass transition temperature of the thermoplastic polymer is limited to 40-150°C, and the austenitic transformation end temperature of the low-temperature shape memory alloy is limited to below 37°C. This allows the preparation method to be compatible with various material systems with different thermal response mechanisms. Thermoplastic polymers achieve softening and shaping through glass transition, shape memory polymers trigger shape recovery through phase transformation temperature, and low-temperature shape memory alloys complete shape fixation using austenitic phase transformation, thus providing diverse material choices for different clinical application needs. The limitation on the glass transition temperature range of thermoplastic polymers ensures that they can fully soften and flow at molding temperatures below 300°C to achieve reliable shaping, while the limitation on the austenitic transformation end temperature of low-temperature shape memory alloys ensures that the shaped stent can maintain shape stability or have superelastic recovery capability under human body temperature conditions, enabling the prepared stent electrode device to better meet the mechanical performance and biocompatibility requirements of vascular interventional devices.

[0029] In one embodiment, the thermal decomposition temperature of the non-conductive material layer 3 is higher than the molding temperature.

[0030] The non-conductive material layer 3 is selected from pyrene, polyimide, polydimethylsiloxane, poly(p-phenylenebenzodioxazole), SU8 or polylactic acid-glycolic acid copolymer, with a thickness of 0.01 μm to 100 μm.

[0031] In this embodiment, the thermal decomposition temperature of the non-conductive material layer 3 is limited to be higher than the molding temperature. Specifically, Pyrelin, polyimide, polydimethylsiloxane, poly(p-phenylenebenzodioxazole), SU8, or polylactic-co-glycolic acid copolymer are listed as optional materials, with a thickness range of 0.01 μm to 100 μm. By setting the thermal decomposition temperature higher than the molding temperature, it is ensured that the insulating layer does not undergo thermal decomposition, melting, or flow during low-temperature shaping, thereby maintaining its structural integrity and insulation performance, laying the foundation for the long-term stable operation of the stent in blood vessels. The listed polymer materials all possess excellent flexibility and biocompatibility, allowing for the selection of different materials to match mechanical performance or degradation characteristics requirements based on specific application scenarios. The wide range of thickness settings gives designers the freedom to flexibly adjust the insulation layer thickness according to electrode size, wire density, and insulation requirements, satisfying the thinning requirements of miniaturized devices while allowing for the selection of thicker insulation layers to enhance protection capabilities in high-voltage or strong signal isolation scenarios.

[0032] In one embodiment, the non-conductive material layer 3 maintains its insulation integrity without cracking or short circuits between electrodes during repeated deformation of the tubular stent structure between compressed and expanded states. This ensures that the non-conductive material layer 3 maintains its insulation integrity without cracking or short circuits between electrodes during repeated deformation of the tubular stent structure between compressed and expanded states. Addressing the shortcomings of existing technologies where brittle inorganic insulating layers such as SiO are prone to cracking and failure under cyclic deformation of the stent, this invention selects and verifies the reliability of polymer insulating materials under dynamic mechanical loads. This ensures that the insulating layer maintains its physical barrier function and electrical isolation performance in the complex mechanical environment of repeated expansion and contraction with vascular pulsation after implantation. The crack-free characteristic avoids the risk of local electric field concentration or dielectric breakdown caused by microcrack propagation, while the absence of short circuits between electrodes ensures the signal acquisition accuracy and stimulation output accuracy of the multi-channel electrode array. This improves the safety and functional stability of the device after long-term implantation, providing reliable protection for applications with extremely high signal fidelity requirements, such as nerve signal monitoring and electrical stimulation therapy.

[0033] In one embodiment, the conductive layer 2 is formed by magnetron sputtering, vapor deposition, chemical vapor deposition or electroplating, and has a thickness of 10 nm-5 μm.

[0034] The patterning process employs laser cutting or photolithography and stripping techniques to achieve a width of 1μm-500μm for the wire unit 202.

[0035] In this embodiment, high-precision thin-film deposition and patterning technology enables the fabrication of conductive layers 2 with thicknesses ranging from nanometers to micrometers in a planar state. Furthermore, laser or photolithography processes are used to pattern micrometer-linewidth wire units 202. Compared to traditional curved surface processing methods, this can increase wire density by 5 to 10 times, thereby integrating more independent electrode channels on the same scaffold surface. This provides a hardware foundation for high-resolution neurophysiological monitoring and multi-target electrical stimulation therapy. Simultaneously, the combination of dry processes such as magnetron sputtering and evaporation with electroplating allows for the selection of different metal materials, such as gold, platinum, and titanium, or their composite layer structures, according to the functional requirements of the electrodes.

[0036] In one embodiment, the planar precursor 1 has a plurality of pillars 101 and cross-connecting portions 102 connecting the pillars 101. The width of the pillars 101 is 10μm-500μm and the thickness is 10μm-200μm.

[0037] The planar precursor 1 is prepared by laser cutting, etching, 3D printing or casting processes.

[0038] In this embodiment, the precise definition of the precursor geometry and dimensions ensures that the shaped tubular stent has sufficient radial support, flexibility, and fatigue resistance. The mesh structure design of the strut 101 and the cross-connection 102 effectively balances the stent's compression and folding ability with its wall-adhering performance after expansion, enabling it to be delivered to the distal end of the tortuous blood vessel through a microcatheter and stably adhere to the inner wall of the blood vessel after release. Precision processing technologies such as laser cutting and etching can achieve highly consistent repeated manufacturing of microstructures, while 3D printing and casting processes provide the possibility for the design of complex geometries and gradient structures. The setting of the width and thickness range of the strut 101 takes into account the mechanical performance of the stent and the space requirements for electrode placement, ensuring the structural integrity of the stent in the blood vessel and reserving sufficient surface area for the integration of the electrode unit 201 and the lead unit 202.

[0039] In one embodiment, the constraint is provided by a mold or forming aid that defines the final diameter and curvature of the tubular support structure.

[0040] The shaped tubular scaffold structure maintains shape stability within the human body temperature range, can be compressed to a smaller profile, and autonomously returns to its expanded state at human body temperature after being implanted at the target location.

[0041] In this embodiment, the final diameter and curvature of the tubular stent are defined. The shaped stent maintains shape stability within the human body temperature range and can be compressed to a smaller profile and autonomously return to its expanded state at body temperature after implantation at the target location. This technical solution uses a mold or forming auxiliary structure to geometrically constrain the shaping process, ensuring precise control over the deformation process from the planar precursor 1 to the tubular stent. The diameter, curvature, and axial consistency of the final product are guaranteed, meeting the matching requirements of stent size for different vascular anatomy sites. The shape stability of the shaped stent within the human body temperature range ensures its structural integrity during storage, delivery, and inactive states. The ability to be compressed to a smaller profile and autonomously expand at body temperature enables minimally invasive catheter delivery. The expanded wall-adhering performance helps reduce the risk of stent displacement and the probability of late thrombosis, while providing a mechanical basis for stable contact between the electrode unit 201 and the vascular wall tissue, ensuring the effectiveness of signal acquisition or electrical stimulation.

[0042] In one embodiment, the molding temperature is set according to the material type of the planar precursor 1, so that the planar precursor 1 undergoes softening, shape memory recovery or crystal structure transformation according to its material type, thereby transforming from a planar state into a tubular structure.

[0043] In this embodiment, the molding temperature is set according to the material type of the planar precursor 1, causing the planar precursor 1 to soften, recover its shape memory, or undergo a crystal structure transformation corresponding to its material type, thereby transforming it from a planar state into a tubular structure. Thermoplastic polymers are set above their glass transition temperature to achieve flow shaping, shape memory polymers are set above their phase transformation temperature to trigger entropy elastic recovery, and low-temperature shape memory alloys are set within the austenitic phase transformation temperature range to complete crystal structure rearrangement. This allows for compatible processing of multiple material systems within a unified low-temperature process framework below 300°C. This avoids the thermal damage that a single high-temperature process may cause to different materials, and the final mechanical properties and shape memory characteristics of the materials can be optimized by precisely controlling the temperature window, providing process freedom for the personalized design and multifunctional integration of the support electrode device.

[0044] In one embodiment, after the non-conductive material layer 3 is formed, selective windowing is performed on the non-conductive material layer 3 by laser removal, mechanical polishing, or mask avoidance deposition process to expose the electrode unit 201, so that the wire unit 202 is completely covered by the non-conductive material layer 3.

[0045] In this embodiment, after the non-conductive material layer 3 is formed, selective windowing is performed on the insulating layer using laser removal, mechanical polishing, or mask-avoidance deposition processes to expose the electrode unit 201 and ensure that the lead wire unit 202 is completely covered by the non-conductive material layer 3. By implementing selective windowing after the insulating layer is formed, controllable contact between the electrode unit 201 and the external physiological environment is achieved, while ensuring that the lead wire unit 202 is completely covered by the insulating layer and remains electrically isolated from conductive media such as tissue fluid and blood, effectively avoiding signal crosstalk between adjacent leads and the risk of short circuits between electrodes. Laser removal and mechanical polishing processes can achieve micron-level precision control of the windowing position and size, while mask-avoidance deposition can directly form the window area during the insulating layer deposition process. The flexible selection of the three processes can be optimized according to the number, distribution, and size requirements of the electrode units 201, ensuring that the working area of ​​each electrode unit 201 is accurately exposed while the surrounding area remains completely insulated.

[0046] In one embodiment, a method for preparing an electrode-bearing scaffold using polylactic acid as the scaffold planar precursor material 1 is described.

[0047] First, a polylactic acid (PLA) film was prepared as a planar precursor 1 for the support structure using a solution casting process. The film thickness was 80 μm, and its glass transition temperature was 60-65 °C, meeting the requirements for thermal response deformation characteristics. The film was then processed into a planar mesh structure with multiple pillars 101 and cross-connecting portions 102 connecting the pillars 101 using a laser cutting process. The width of the pillars 101 was 200 μm, and the diameter of the cross-connecting portions 102 was 400 μm.

[0048] Subsequently, a gold layer with a thickness of 300 nm is deposited as a conductive layer 2 on the surface of the polylactic acid planar precursor 1 using a magnetron sputtering process. The gold layer is then patterned using a laser cutting process to form an electrode unit 201 with a diameter of 300 μm and a wire unit 202 with a width of 20 μm, and the electrode unit 201 and the wire unit 202 are electrically isolated from each other.

[0049] Next, a non-conductive material layer 3 with a thickness of 3 μm is formed on the surface of the patterned conductive layer 2 using a Parylene C vapor deposition process. The thermal decomposition temperature of Parylene C is much higher than the subsequent forming temperature. After deposition, the insulating layer is selectively windowed using a laser removal process to expose the electrode unit 201, while ensuring that the wire unit 202 is completely covered by the non-conductive material layer 3.

[0050] Then, the planar precursor 1, with the conductive layer 2 and insulating layer prepared, is encased in a 4mm diameter stainless steel mold. The mold provides constraint to define the final diameter and curvature of the tubular scaffold structure. The mold is heated to 70°C, a temperature below 300°C and above the glass transition temperature of polylactic acid (PLA), causing the PLA planar precursor 1 to soften and undergo plastic deformation under the mold constraint, curling and shaping into a tubular scaffold structure. During heating, the Perylene C insulating layer maintains structural integrity and insulation properties at the 70°C molding temperature. After cooling and demolding, the tubular scaffold electrode device is obtained. This device maintains shape stability within the human body temperature range and can be compressed to a smaller profile. After implantation, it can spontaneously return to its expanded state at body temperature.

[0051] Finally, the fabricated tubular stent electrode device was subjected to cyclic compression-expansion tests to simulate the repeated deformation environment within blood vessels. The test results showed that the phenelzine C insulating layer maintained its insulation integrity without cracking or short circuits between electrodes during repeated deformation, verifying the reliability of the non-conductive material layer 3 under dynamic mechanical loads.

[0052] In one embodiment, a method for fabricating a scaffold with electrodes using a shape memory polymer as the scaffold planar precursor 1 material is provided.

[0053] First, a copolymer of polycaprolactone and thermoplastic polyurethane is used as the planar precursor 1 material, where polycaprolactone serves as the crystallizable soft segment and thermoplastic polyurethane as the hard segment, with the soft segment melting temperature designed to be 55℃. A 100μm thick film is prepared as the planar precursor 1 using a hot pressing process. Subsequently, it is stretched 200% longitudinally at 60℃ to orient the molecular chains, and then rapidly cooled to room temperature to fix it into a temporary planar shape. At this point, the soft segment crystallizes and locks in deformation, while the hard segment provides a physical cross-linking network to maintain the structure, meeting the thermal response deformation characteristics requirements of shape memory polymers. The film is then processed into a planar mesh structure with multiple pillars 101 and cross-connecting portions 102 connecting the pillars 101 using laser cutting or etching processes. The width of the pillars 101 is 150μm.

[0054] Subsequently, a platinum layer with a thickness of 200 nm is deposited as a conductive layer 2 on the surface of the shape memory polymer planar precursor 1 using a magnetron sputtering process. The platinum layer is then patterned using photolithography and lift-off processes to form electrode units 201 with a diameter of 300 μm and wire units 202 with a width of 20 μm, and the electrode units 201 and wire units 202 are electrically isolated from each other.

[0055] Next, a non-conductive material layer 3 with a thickness of 2 μm is formed on the surface of the patterned conductive layer 2 using a Parylene C vapor deposition process. The thermal decomposition temperature of Parylene C is much higher than the subsequent forming temperature. After deposition, the insulating layer is selectively windowed using a laser removal process to expose the electrode unit 201, while ensuring that the wire unit 202 is completely covered by the non-conductive material layer 3.

[0056] Then, the planar temporary shape precursor, with the conductive layer 2 and insulating layer prepared, was encased in a 4mm diameter stainless steel mold. The mold provided constraint to limit the final diameter and curvature of the tubular scaffold structure. The mold was heated to 60°C, a temperature below 300°C but above the soft segment melting temperature, causing the soft segments to crystallize and melt, restoring the mobility of the molecular chain segments, and spontaneously returning to the permanent shape (tubular) under entropy elastic drive. Simultaneously, the mold constraint ensured geometric accuracy. After holding at this temperature for 10 minutes, the shape was cooled and solidified. During the heating process, the Perylene C insulating layer maintained structural integrity and insulation properties at the 60°C molding temperature. After cooling and demolding, the tubular scaffold electrode device was obtained. This device, with soft segments recrystallizing at temperatures far below the melting temperature, stably maintained its tubular shape and shape stability within the human body temperature range. It could be compressed to a smaller profile and, after implantation, could spontaneously return to its expanded state at body temperature.

[0057] Finally, the fabricated tubular stent electrode device was subjected to cyclic compression-expansion tests to simulate the repeated deformation environment within blood vessels. The test results showed that the phenelzine C insulating layer maintained its insulation integrity without cracking or short circuits between electrodes during repeated deformation, verifying the reliability of the non-conductive material layer 3 under dynamic mechanical loads.

[0058] In one embodiment, this embodiment provides a method for preparing a scaffold with electrodes using a nickel-rich titanium-nickel low-temperature shape memory alloy as the scaffold planar precursor material 1.

[0059] First, a Ti-51Ni alloy thin film was prepared as a planar precursor 1 using magnetron sputtering. The film thickness was 100 μm, and its austenitic phase transformation termination temperature was approximately 28 °C, which is lower than 37 °C, meeting the thermal response deformation characteristics requirements of low-temperature shape memory alloys. The film was then processed into a planar mesh structure with multiple pillars 101 and cross-connecting portions 102 connecting the pillars 101 using laser cutting. The width of the pillars 101 was 200 μm, and the diameter of the cross-connecting portions 102 was 400 μm.

[0060] Subsequently, a platinum layer with a thickness of 200 nm is deposited as a conductive layer 2 on the surface of the nickel-titanium alloy planar precursor 1 using an electron beam evaporation process. The platinum layer is then patterned using photolithography and lift-off processes to form electrode units 201 with a diameter of 300 μm and wire units 202 with a width of 20 μm, and the electrode units 201 and wire units 202 are electrically isolated from each other.

[0061] Next, a non-conductive polyimide material layer 3 with a thickness of 5 μm is formed on the surface of the patterned conductive layer 2 using a spin-coating process, followed by imidization at 200°C for 2 hours. The thermal decomposition temperature of polyimide is much higher than the subsequent molding temperature, satisfying the requirement that the thermal decomposition temperature is higher than the molding temperature. After curing, the insulating layer is selectively windowed using a photolithography process to expose the electrode unit 201, while ensuring that the wire unit 202 is completely covered by the non-conductive material layer 3.

[0062] Then, the planar precursor 1, with the conductive layer 2 and insulating layer prepared, is encased in a 4mm diameter stainless steel mold. The mold provides constraint to define the final diameter and curvature of the tubular support structure. The entire mold is heated to 200°C in a nitrogen-protected environment. This temperature is below 300°C and above the austenitic phase transformation temperature range of the nickel-titanium alloy, causing the nickel-titanium alloy to undergo a crystal structure transformation and complete shape shaping. After holding at this temperature for 2 hours, it is cooled. During the heating process, the polyimide insulating layer maintains its structural integrity and insulation properties at the 200°C molding temperature. After cooling and demolding, the tubular support electrode device is obtained. This device exhibits superelastic shape memory characteristics at a body temperature of 37°C, enabling it to autonomously return to its expanded state after being compressed to a reduced profile at body temperature, and maintains shape stability within the body temperature range.

[0063] Finally, the fabricated tubular stent electrode device was subjected to cyclic compression-expansion tests to simulate the repeated deformation environment within blood vessels. The test results showed that the polyimide insulating layer maintained its insulation integrity without cracking or short circuits between electrodes during repeated deformation, verifying the reliability of the non-conductive material layer 3 under dynamic mechanical loads.

[0064] In one embodiment, the electrode-bearing stent prepared by the electrode-bearing stent preparation method is used in the preparation of medical devices for nerve signal monitoring, electrical stimulation therapy, or vascular interventional diagnosis and treatment.

[0065] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for fabricating a scaffold with electrodes, characterized in that, Includes the following steps: Provide a planar precursor for a support structure with thermally responsive deformation characteristics (1); A conductive layer (2) is formed on the surface of the planar precursor (1), and the conductive layer (2) is patterned to form at least one electrode unit (201) and at least one wire unit (202) electrically connected to the electrode unit (201). A non-conductive material layer (3) is formed on at least a portion of the surface of the conductive layer (2); The planar precursor (1) is placed under constraint and heated to a molding temperature below 300°C to soften the planar precursor (1), cause a shape memory phase transition or crystal structure transformation, and is molded into a support structure using a mold; wherein, the non-conductive material layer (3) maintains structural integrity and insulation performance at the molding temperature, the non-conductive material layer (3) has a window for exposing the electrode unit (201), and the non-conductive material layer (3) covers the wire unit (202).

2. The method for preparing a scaffold with electrodes according to claim 1, characterized in that, The material of the planar precursor (1) is selected from thermoplastic polymers, shape memory polymers, or low-temperature shape memory alloys; The glass transition temperature of the thermoplastic polymer is 40℃-150℃; The austenitic phase transformation end temperature of the low-temperature shape memory alloy is below 37°C.

3. The method for preparing a scaffold with electrodes according to claim 1, characterized in that, The thermal decomposition temperature of the non-conductive material layer (3) is higher than the molding temperature.

4. The method for preparing a scaffold with electrodes according to claim 3, characterized in that, The non-conductive material layer (3) is selected from pyrene, polyimide, polydimethylsiloxane, poly(p-phenylenebenzodioxazole), SU8 or polylactic acid-hydroxyacetic acid copolymer, and has a thickness of 0.01 μm-100 μm.

5. The method for preparing a scaffold with electrodes according to claim 1, characterized in that, The conductive layer (2) is formed by magnetron sputtering, vapor deposition, chemical vapor deposition or electroplating processes, and has a thickness of 10 nm-5 μm. The patterning process employs laser cutting or photolithography and stripping techniques to make the width of the wire unit (202) 1μm-500μm.

6. The method for preparing a scaffold with electrodes according to claim 1, characterized in that, The planar precursor (1) has multiple pillars (101) and cross-connecting parts (102) connecting the pillars (101). The width of the pillars (101) is 10μm-500μm and the thickness is 10μm-200μm. The planar precursor (1) is prepared by laser cutting, etching, 3D printing or casting processes.

7. The method for preparing a scaffold with electrodes according to claim 1, characterized in that, The constraint is provided by a mold or forming aid structure, which defines the final diameter and curvature of the tubular support structure; The scaffold structure, once shaped, maintains shape stability within the human body temperature range and can be compressed to a smaller profile. After being implanted into the target location in the human body, it autonomously returns to its expanded state at human body temperature.

8. The method for preparing a support with electrodes according to claim 1, characterized in that, The molding temperature is set according to the material type of the planar precursor (1), so that the planar precursor (1) softens, recovers its shape memory, or undergoes a crystal structure transformation corresponding to its material type, thereby transforming from a planar state into a tubular structure.

9. The method for preparing a scaffold with electrodes according to claim 1, characterized in that, After the non-conductive material layer (3) is formed, selective windowing is performed on the non-conductive material layer (3) by laser removal, mechanical grinding or mask avoidance deposition process to expose the electrode unit (201) so that the wire unit (202) is completely covered by the non-conductive material layer (3).

10. The method for preparing an electrode-bearing scaffold according to any one of claims 1 to 9, characterized in that, The prepared electrode-embedded stent can be used in the fabrication of medical devices for nerve signal monitoring, electrical stimulation therapy, or vascular interventional diagnosis and treatment.

Images