Device and method for preparing crack encapsulation intelligent sensor based on subsidence freezing and thawing

Abstract

The invention discloses a sensor preparation method based on circulating freezing and thawing, relates to the technical field of crack sensor manufacturing, and aims to solve the problem that a conductive crack sensor is manufactured to sense vibration of a spider web by simulating bristle cracks on spider feet. The intensity and the frequency of the vibration are measured according to the principle that the opening and the closing of the crack cause the change of electrical impedance; vibration measurement can be carried out in real time through impedance change caused by crack closure; the problem of vibration measurement in coronary intervention is solved, and the purpose of measuring the vibration characteristic of the blood vessel in the balloon dilatation process is achieved by adopting a modified sensor design.

Description

Technical Field

[0001] The present invention relates to the technical field of crack sensor manufacturing, and in particular to a device and method for manufacturing a crack capsule intelligent sensor based on freeze-thaw cycles. Background Art

[0002] The existing crack sensor crack fabrication method is to first make a complete crack-free dry electrode, then directly mechanically stretch the electrode until the strain exceeds the fracture strain, causing the electrode to break and produce an electrode with a crack structure. The crack formed by this dynamic stretching usually initiates and expands rapidly in the stress concentration area. The stress concentration effect causes very high stress at the crack tip. The sudden change or uneven distribution of the fracture force can easily lead to unpredictable crack paths, and the crack morphology cannot be precisely controlled. The same crack form cannot be repeatedly produced, and ultimately cannot be commercialized. In addition, this crack has macroscopic defects, generally at the millimeter level. Crack electrodes using this method can only be used as displacement sensors with low measurement accuracy. At the same time, because the electrode is thick and has large inertia, it cannot be used as a vibration sensor.

[0003] In existing coronary intervention treatment technologies, balloons are used to support diseased blood vessels. In existing technologies, plain balloon angioplasty (POBA) technology uses a balloon catheter to advance to the stenotic or occluded lesion of the coronary artery, and expands the stenotic blood vessel by expanding the volume of the balloon to restore normal blood flow. Although this technology does not require surgical operation, the blood vessels will have a high restenosis rate after the implementation of this technology (up to 40%-50% chance). In existing technology, coronary angiography (CAG) is generally used to measure the degree of vascular stenosis, but it is impossible to observe the reconstruction effect of damage (such as dissection, thrombosis) at the lesion of the blood vessel wall during the operation; according to existing research results, the mechanical properties of the blood vessels change during balloon expansion, resulting in changes in mechanical vibration properties, so measuring vibration can evaluate the operation effect in real time; however, in today's coronary intervention, there is no mature application that can measure vibration in real time during the operation.

[0004] To solve the vibration measurement problem during coronary intervention, it is necessary to adopt a modified sensor design to achieve the purpose of measuring the vibration characteristics of blood vessels during balloon expansion. Summary of the Invention

[0005] In response to the above-mentioned problems existing in the prior art, the present invention provides a crack-encapsulated intelligent sensor based on freeze-thaw cycles. The bristle cracks on the bionic spider's feet can sense the vibration of the spider web. The design of the present invention utilizes the principle that the sensor cracks open and close with vibration, and the opening and closing of the cracks will cause changes in electrical impedance to measure the intensity and frequency of the vibration; the impedance changes caused by the crack closure can be used to measure vibration in real time.

[0006] The preparation device of the crack capsule intelligent sensor based on cyclic freeze-thaw comprises a liquid nitrogen freeze-thaw gas generating device, a first gas heat pump, a temperature sensor for measuring condensed gas, a crack freeze-thaw device, a temperature sensor for outputting freeze-thaw device, a second gas heat pump, a central control console, a liquid nitrogen vaporization control device and a fiber optic camera for connecting to observe crack extension, a fiber optic bundle for lighting optical fiber and a connecting wire for impedance analysis measurement. The liquid nitrogen freeze-thaw gas generating device is provided with a heat exchange tube, the heat exchange tube is provided with a heating gas inlet / outlet on the liquid nitrogen freeze-thaw gas generating device, and the liquid nitrogen freeze-thaw gas generating device is fixedly connected with a freeze-thaw gas output A first gas heat pump is provided on one side of the freeze-thaw gas output port, the first gas heat pump is fixedly connected to the freeze-thaw gas output port through a pipeline, a temperature sensor for measuring condensed gas is provided on one side of the first gas heat pump, the temperature sensor for measuring condensed gas is fixedly connected to the first gas heat pump through a pipeline, a crack freeze-thaw device is provided on the pipeline between the first gas heat pump and the temperature sensor for measuring condensed gas, the crack freeze-thaw device has a first port and a second port, and the first port of the crack freeze-thaw device is fixedly connected to the pipeline between the first gas heat pump and the temperature sensor for measuring condensed gas through a pipeline;

[0007] A temperature sensor of an output freeze-thaw device is provided on one side of the second port of the crack freeze-thaw device, a second gas heat pump is provided on one side of the temperature sensor of the output freeze-thaw device, the second gas heat pump is fixedly connected to the output freeze-thaw device through a pipeline, and the second port of the crack freeze-thaw device is fixedly connected to the pipeline between the second gas heat pump and the output freeze-thaw device through a pipeline;

[0008] A liquid nitrogen vaporization control device is provided on one side of the liquid nitrogen freeze-thaw gas generating device, and the heating gas inlet / outlet is fixedly connected to the liquid nitrogen vaporization control device through a pipeline. A central console is provided on one side of the liquid nitrogen vaporization control device, and the central console is connected to the first gas heat pump, the second gas heat pump, the temperature sensor for measuring the condensed gas, and the temperature sensor of the output freeze-thaw device through lines. A fiber optic camera for connecting to observe crack propagation, an optical fiber bundle of optical fibers for lighting, and connecting wires for impedance analysis measurement are fixedly connected between the central console and the crack freeze-thaw device; the central console includes an impedance analysis module and a fiber optic camera receiving and intelligent judgment module.

[0009] Furthermore, the crack freeze-thaw device includes a sealing base, a freeze-thaw gas overflow spring switch, an inner ring cylinder, an outer ring cylinder, a curved sample carrier, a freeze-thaw sample, a sample cover and a sealing top cover, wherein a plurality of fixing columns are fixedly connected between the sealing base and the sealing top cover, and the outer ring cylinder is fixedly connected to the sealing top cover;

[0010] The sealing base is provided with a convex ring, and the convex ring is provided with a stepped groove. The thickness of the stepped groove close to the end face of the convex ring is consistent with the wall thickness of the inner ring cylinder, and the thickness of the stepped groove away from the end face of the convex ring is less than the wall thickness of the inner ring cylinder;

[0011] The sealing base is provided with an inner ring cylinder, which is slidably connected to the stepped groove of the convex ring of the sealing base. Condensed water is provided in the stepped groove on the side away from the end face of the convex ring, and the upper liquid level of the condensed water is flush with the boundary of the stepped groove;

[0012] An outer ring cylinder is provided on the inner ring cylinder, the inner diameter of the outer ring cylinder is consistent with the outer diameter of the inner ring cylinder, an oblique groove is provided on the outer side of the inner ring cylinder, and an oblique groove is provided on the inner side of the outer ring cylinder, the oblique groove and the oblique groove have the same inclination, and a roller is provided between the oblique groove and the oblique groove, the roller is rotatably connected in the oblique groove, and the roller is rollingly connected on the oblique groove;

[0013] The outer ring cylinder is provided with an inner groove, the inner ring cylinder is fixedly connected to a curved sample carrier, the outer ring cylinder is fixedly connected to a sample cover, a freeze-thaw sample is provided between the sample carrier and the sample cover, pins are provided on both sides of the freeze-thaw sample, and the pins are placed in the inner groove;

[0014] The optical fiber bundle for connecting the optical fiber camera for observing crack propagation, the optical fiber for illumination, and the connecting wires for impedance analysis measurement pass through the sealed top cover;

[0015] A freeze-thaw gas overflow reed pipe is fixedly connected in the middle of the sealing base, and the freeze-thaw gas overflow reed pipe is provided with a gap; the first port is arranged on the sealing base and is fixedly connected to the freeze-thaw gas overflow reed pipe, and the second port is fixedly connected to the inner ring cylinder.

[0016] Furthermore, the fiber optic camera for observing crack extension, the fiber optic bundle for lighting, and the connecting wires for impedance analysis measurement include a first fiber optic LED lamp, a second fiber optic LED lamp, and a fiber optic camera. The sample cover is provided with a first fiber optic LED lamp hole, a second fiber optic LED lamp hole, and a fiber optic camera hole that cooperate with the first fiber optic LED lamp, the second fiber optic LED lamp, and the fiber optic camera. The pins on both sides of the freeze-thaw sample are connected to the fiber optic camera for observing crack extension, the fiber optic bundle for lighting, and the connecting wires for impedance analysis measurement through a data transmission line.

[0017] Furthermore, the freeze-thaw sample includes a conductive film, and a plurality of extension paths are provided on the conductive film, the extension paths include a main body and a branch, the extension paths include a plurality of defects, the branch of the extension path includes defect one, defect two, defect three, defect four and defect five, the defect one is located near the main body of the branch of the extension path, the defects one, two, three, four and five are arranged in sequence on the branch of the extension path, the depths of the defects one, two, three, four and five gradually decrease, the data of the depth reduction of the defects one, two, three, four and five gradually increase, the spacing between adjacent defects one, two, three, four and five gradually increase, and the data of the increased spacing between adjacent defects one, two, three, four and five gradually increase.

[0018] Furthermore, the defect spacing within one of the expansion paths gradually increases from the beginning to the end according to a gradient.

[0019] Furthermore, the terminal defect is set as a semicircular defect structure, the center of the terminal defect corresponds to the end position of the expansion path, and the direction of the semicircular defect structure of the terminal defect extending from the center to both sides is ultimately opposite to the direction of the expansion path from the beginning to the end;

[0020] The crack propagation direction is opposite to the predetermined crack propagation path, which prevents the crack from further extending toward the boundary and from penetrating the coating. This prevents undesirable crack propagation in the conductive coating under the influence of boundary conditions and reduces the risk of sensor instability.

[0021] The preparation method of the intelligent sensor of fissure capsule based on freeze-thaw cycle includes the following steps:

[0022] S1: prepare substrate material;

[0023] S1.1: Obtain the substrate material;

[0024] S1.2: The substrate material is prepared into a thin film;

[0025] S1.3: The film is treated to improve surface affinity;

[0026] S2: Processing substrate materials;

[0027] S3: preparing conductive paste;

[0028] S3.1: The conductive paste material A and Ti 3 C 2 T x MXene, material A and Ti 3 C 2 T xMXenes are mixed to obtain a mixture;

[0029] S3.1.1: Substance A includes but is not limited to micron-sized or nanometer-sized silver particles, carbon nanotubes, and single or multilayer graphene;

[0030] S3.2: Mixing the mixture in S3.1 with a binder to obtain a conductive paste;

[0031] S4: evenly coating the conductive paste in S3.2 on the base material in S2.2 to obtain a conductive film; controlling the temperature and humidity to place the conductive film in a vacuum chamber for drying and curing;

[0032] S4.1: Prefabricated vacancy defects that determine the initiation and trend of subsequent cracks are fabricated on the conductive film in S4 by laser lithography;

[0033] S4.1.1: Determine the laser power and pulse duration based on the approximately linear relationship between the defect depth and the energy and pulse number of the laser pulses;

[0034] Conductive slurry is coated on the film to prepare a conductive film, and the laser printing of the conductive film is controlled to generate a specific defect structure. The stress concentration generated at the defect location of the conductive film will guide the initiation and expansion of cracks, making the crack structure formed on the conductive film precisely controllable and producing a highly consistent product.

[0035] S5: cyclic freeze-thaw of the conductive film using a preparation device for a crack capsule-integrated intelligent sensor based on cyclic freeze-thaw;

[0036] S5.1: Initially freeze the conductive film using the output condensing gas;

[0037] S5.1.1: Freeze the conductive film to reduce the difficulty of crack initiation and propagation. As the temperature decreases, the sample becomes more brittle and the condensed water solidifies and expands. The increased stress is concentrated around the defect, and cracks initially form along the defect.

[0038] S5.1.1: Control the cooling rate to adjust the size of the silicone rubber and cool the material to the set temperature, controlling the temperature between 30 and -50 degrees Celsius;

[0039] S5.2: Refrigeration is stopped, and the gas heat pump 6 inputs high-temperature gas to the crack freeze-thaw device 4 to slow down the crack growth rate;

[0040] S5.2.1: Control the thawing rate so that the crack propagates uniformly and the propagation progress is controllable;

[0041] S5.3: Modulate crack depth and length through repeated freeze-thaw cycles;

[0042] S5.3.1: During repeated freeze-thaw cycles, fine-tune the temperature schedule to control crack development;

[0043] By controlling the fracture strain of the electrode material through temperature changes, the difficulty of crack generation and the expansion rate can be regulated, so that a conductive film that is difficult to crack expand under normal conditions can reduce the expansion difficulty after temperature changes, realize crack expansion, and produce a product. The crack structure of the product is stable and not easy to be destroyed during use, and maintains highly robust signal detection; on the conductive film formed by the combined action of temperature and defect structure, the crack structure is precisely controllable, so that the final product has high consistency and good stability, and solves the problems of large size, unevenness, uncontrollability and instability of crack structure prepared by existing mechanical stretching.

[0044] S6: When the crack depth-total capacitance of the conductor reaches the required value, the heating / cooling is canceled.

[0045] Through repeated thermal cycles, the crack gradually expands and eventually forms a fatigue crack. The crack depth and length form slowly, and its development process is uniform and controllable. The crack propagation path and fractal morphology can be adjusted by controlling the thermal cycle parameters. Finally, a crack similar to the bristle crack on the spider's leg is formed. The crack can be as small as micrometer or even nanometer. When the crack closes, Figure 10 (a) is used as an electrode, as shown in Figure 10 As shown in (b), when an excitation voltage is applied across the device, the crack opens and closes under the action of external vibration, forming a capacitive switch.

[0046] Furthermore, the material of the substrate includes but is not limited to expandable silicon-based compounds and rubber; the substrate is prepared into a thin film, and the film preparation method includes but is not limited to spin coating and blade coating;

[0047] The treatment for improving surface affinity includes but is not limited to plasma treatment and chemical modification.

[0048] Furthermore, the surface treatment of the film is performed by soaking the substrate material in a 15% aqueous solution of the surface modifier for 2 hours; rinsing with deionized water and then drying with nitrogen for later use.

[0049] Furthermore, the laser power and pulse time are as follows: the laser used is an ultraviolet laser source with a maximum power of 3W, a frequency range of 10-100kHz, and a minimum focused spot diameter line width of 0.01mm; for different substrate materials, the frequency and spot size are adjusted in the experiment to produce the corresponding depth.

[0050] Beneficial effects of the present invention:

[0051] The preparation method of the crack capsule intelligent sensor based on freeze-thaw cycle is based on the freeze-thaw cycle principle. According to the book "Fracture of Brittle Solids", the crack propagation rate is determined by the following formula

[0052] v=v0a[exp(-ΔU + / kT)-exp(-ΔU - / kT)]

[0053] v: crack growth rate; v0: fundamental vibration frequency of the material atomic lattice; ΔU + : activation energy required for crack growth; ΔU - : activation energy required for crack contraction, k: Boltzmann constant, a: interatomic distance or characteristic dimension of crack tip.

[0054] The formula indicates that the spatial arrangement of defect points determines the activation energy of crack propagation, and the temperature determines the speed of crack propagation. The spatial arrangement of defect points and temperature changes jointly determine the crack propagation process, so that cracks can initiate and propagate according to the preset defect points.

[0055] When the conductive material changes with temperature, it will transform from brittle to ductile, that is, it will show shrinkage brittleness at low temperature, the fracture strain value will decrease, and the material will easily break under stress, or cracks will develop along defects; at higher temperatures, it will show ductile plasticity, the fracture strain value will increase, and strain will occur under stress to maintain the stability of the overall structure, making it difficult to crack; by changing the temperature of the material, the initiation and expansion of cracks can be controlled.

[0056] At the same time, in terms of physical essence, the development of cracks comes from stress concentration at defects. When there are defects inside the material, heat conduction will be uneven, and a temperature gradient will appear at the defect. The temperature gradient will produce the effect of expansion when heated and contraction when cooled. During the process, the strain changes at different positions are inconsistent, that is, during the heating and cooling process, the material in the space around the defect expands or contracts at different rates. The additional stress generated by thermal expansion or cold contraction will be concentrated in the local area of the defect to promote the formation of cracks. Specifically, in the crack initiation stage, a physical circuit of temperature increase-defect activation-stress concentration-crack initiation is formed; in the crack development stage, a physical circuit of temperature reduction-temperature gradient formation-stress concentration-crack extension is formed.

[0057] Cracks are thermally activated using controlled temperatures, triggering crack initiation and growth through temperature changes (heating, cooling, and thermal cycling). Thermal stresses arise from uneven thermal expansion of the material, phase transitions, and thermal fatigue caused by thermal cycling. These thermal stresses cause changes in the atomic lattice structure around the defect, leading to crack initiation and growth.

[0058] The invention relates to a device and method for preparing a crack capsule-based intelligent sensor based on freeze-thaw cycles. The sensor is used to make a balloon, which can measure both resistance and capacitive reactance on the same conductive membrane. When the crack is normally closed, it can be used as an electrode. When voltage is applied to both ends of the membrane, it can be used as a vibration sensor, saving sensor layout space and solving the problem of simultaneous multi-modal electroacoustic measurement in vivo.

[0059] The present invention uses defect positioning and repeated freezing and thawing to effectively control the growth of cracks in the conductive film. Compared with the brittle cracks produced by existing stretching, the crack generation method of the present invention transforms between brittle and plastic, achieving the effect of precise development of crack extension.

[0060] Compared with traditional wide cracks, the cracks of the present invention are small, and the size of the prepared cracks can be limited to the micrometer or even nanometer level. An electric field tunneling effect can be formed at the cracks; and the cracks can be used as high-frequency vibration sensors.

[0061] The present invention adopts a crack electrical sensing method and uses a conductive film as a vibration sensor. The sensitivity of the vibration pickup of the present invention uses the film thickness to control the acoustic inertia: the thicker the film, the less sensitive it is to high-frequency vibration signals. This makes the invention have the advantages of a wide range of selectable frequency parameters and easy design.

[0062] During coronary intervention, electroacoustic sensors installed at the same point in space can ensure the robustness of the signal. For the sake of signal integrity, the expansion and contraction of the airbag placed in the body will be repeated at irregular intervals. Repeated freezing and thawing can increase the elastic limit of the conductive film material. The crack structure of the conductive film is stable and will not be affected by expansion or damage. It can be used multiple times for a long time, providing a prerequisite for repeated actions of collecting electroacoustic signals at the same point.

[0063] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0065] Figure 1 Schematic diagram of the structure of the sensor preparation device based on freeze-thaw cycle according to the present invention;

[0066] Figure 2 Schematic diagram of the cross-sectional structure of the liquid nitrogen freeze-thaw gas generating device of the present invention;

[0067] Figure 3Schematic diagram of the dispersed structure of the crack freeze-thaw device;

[0068] Figure 4 It is a perspective structural diagram of the outer ring cylinder;

[0069] Figure 5 Schematic diagram of the cross-sectional structure of the inner ring cylinder and the outer ring cylinder;

[0070] Figure 6 Schematic diagram of the cross-sectional structure of the curved sample carrier, freeze-thaw sample, and sample cover;

[0071] Figure 7 Schematic diagram of the enlarged structure of the freeze-thaw sample;

[0072] Figure 8 Control process for crack parameters;

[0073] Figure 9 To control the freeze-thaw process;

[0074] Figure 10 (a) is the freeze-thaw temperature control process;

[0075] Figure 10 (b) The film impedance change process measured by impedance analysis;

[0076] Figure 10 (c) Partially preset defect structure on the film;

[0077] Figure 10 (d) is the crack expansion result;

[0078] Figure 11 This is a schematic diagram of the structure of a balloon used for coronary intervention;

[0079] 1-Liquid nitrogen freeze-thaw gas generating device, 2-First gas heat pump, 3-Temperature sensor for measuring condensed gas, 4-Crack freeze-thaw device, 5-Temperature sensor for output freeze-thaw device, 6-Second gas heat pump, 7-Central console, 8-Liquid nitrogen vaporization control device, 9-Fiber optic camera for observing crack propagation, fiber optic bundle for illumination, and connecting wires for impedance analysis measurement, 101-Heating gas inlet / outlet, 102-Heat exchange tube, 103-Freeze-thaw gas outlet, 401-Sealing base, 402-Freeze-thaw gas overflow spring switch, 403-Inner ring cylinder, 404-Curved sample carrier , 405-outer ring cylinder, 406-freeze-thaw sample, 407-sample cover, 408-sealed top cover, g1-inner groove, g2-bevel groove, 407a-first fiber optic LED lamp hole, 407b-fiber optic camera hole, 407c-second fiber optic LED lamp hole, h1-defect one, h2-defect two, h3-defect three, h4-defect four, h5-defect five, 91-coronary intervention uses the front end of the balloon, 92-balloon equipped with a cracked capsule intelligent sensor, 93-coronary intervention structure, 94-coronary intervention surgery external connector, S1-port for balloon inflating, S2-entrance for interventional treatment drugs. DETAILED DESCRIPTION

[0080] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0081] Example 1

[0082] The sensor preparation device based on cyclic freeze-thaw comprises a liquid nitrogen freeze-thaw gas generating device 1, a first gas heat pump 2, a temperature sensor 3 for measuring condensed gas, a crack freeze-thaw device 4, a temperature sensor 5 for outputting freeze-thaw device, a second gas heat pump 6, a central control console 7, a liquid nitrogen vaporization control device 8, and an optical fiber camera for connecting to observe crack propagation, an optical fiber bundle for lighting optical fiber, and a connecting wire 9 for impedance analysis measurement. The liquid nitrogen freeze-thaw gas generating device 1 is provided with a heat exchange tube 102, and the heat exchange tube 102 is provided with a heating gas inlet / outlet 101 on the liquid nitrogen freeze-thaw gas generating device 1. The liquid nitrogen freeze-thaw gas generating device 1 is fixedly connected with a freeze-thaw gas output port 103. A first gas heat pump 2 is provided on one side of the freeze-thaw gas output port 103, and the first gas heat pump 2 is fixedly connected to the freeze-thaw gas output port 103 through a pipeline. A temperature sensor 3 for measuring condensed gas is provided on one side of the first gas heat pump 2, and the temperature sensor 3 for measuring condensed gas is fixedly connected to the first gas heat pump 2 through a pipeline. A crack freeze-thaw device 4 is provided on the pipeline between the first gas heat pump 2 and the temperature sensor 3 for measuring condensed gas, and the crack freeze-thaw device 4 is provided with a first port and a second port. The first port of the crack freeze-thaw device 4 is fixedly connected to the pipeline between the first gas heat pump 2 and the temperature sensor 3 for measuring condensed gas through a pipeline.

[0083] A temperature sensor 5 of an output freeze-thaw device is provided on one side of the second port of the crack freeze-thaw device 4, and a second gas heat pump 6 is provided on one side of the temperature sensor 5 of the output freeze-thaw device. The second gas heat pump 6 is fixedly connected to the output freeze-thaw device through a pipeline, and the second port of the crack freeze-thaw device 4 is fixedly connected to the pipeline between the second gas heat pump 6 and the output freeze-thaw device through a pipeline;

[0084] A liquid nitrogen vaporization control device 8 is provided on one side of the liquid nitrogen freeze-thaw gas generating device 1, and the heating gas inlet / outlet 101 is fixedly connected to the liquid nitrogen vaporization control device 8 through a pipeline. A central console 7 is provided on one side of the liquid nitrogen vaporization control device 8. The central console 7 is connected to the first gas heat pump 2, the second gas heat pump 6, the temperature sensor 3 for measuring the condensed gas, and the temperature sensor 5 for the output freeze-thaw device through lines. A fiber optic camera for observing crack propagation, an optical fiber bundle of optical fibers for illumination, and a connecting wire 9 for impedance analysis measurement are fixedly connected between the central console 7 and the crack freeze-thaw device 4; the central console 7 includes an impedance analysis module and an optical fiber camera receiving and intelligent judgment module;

[0085] The crack freeze-thaw device 4 includes a sealed base 401, a freeze-thaw gas overflow spring tube 402, an inner ring cylinder 403, an outer ring cylinder 405, a curved sample carrier 404, a freeze-thaw sample 406, a sample cover 407 and a sealed top cover 408. Several fixing columns are fixedly connected between the sealed base 401 and the sealed top cover 408, and the outer ring cylinder 405 is fixedly connected to the sealed top cover 408.

[0086] The sealing base 401 is provided with a convex ring, and the convex ring is provided with a stepped groove. The thickness of the stepped groove close to the end face of the convex ring is consistent with the wall thickness of the inner ring cylinder 403, and the thickness of the stepped groove away from the end face of the convex ring is less than the wall thickness of the inner ring cylinder 403.

[0087] The sealing base 401 is provided with an inner ring cylinder 403, which is slidably connected to the stepped groove of the convex ring of the sealing base 401. Condensate is provided in the stepped groove on the side away from the end face of the convex ring, and the upper liquid level of the condensate is flush with the boundary of the stepped groove.

[0088] An outer ring cylinder 405 is provided on the inner ring cylinder 403. The inner diameter of the outer ring cylinder 405 is consistent with the outer diameter of the inner ring cylinder 403. An oblique groove is provided on the outer side of the inner ring cylinder 403. An oblique groove g2 is provided on the inner side of the outer ring cylinder 405. The oblique groove g2 has the same slope as the oblique groove. A roller is provided between the oblique groove g2 and the oblique groove. The roller is rotatably connected in the oblique groove and rollingly connected on the oblique groove g2.

[0089] The outer ring cylinder 405 is provided with an inner groove g1, the inner ring cylinder 403 is fixedly connected to a curved sample carrier 404, the outer ring cylinder 405 is fixedly connected to a sample cover 407, a freeze-thaw sample 406 is provided between the sample carrier and the sample cover 407, and pins are provided on both sides of the freeze-thaw sample 406, and the pins are placed in the inner groove g1;

[0090] The optical fiber bundle for connecting the optical fiber camera for observing crack propagation, the optical fiber for illumination, and the connecting wire 9 for impedance analysis measurement pass through the sealing top cover 408;

[0091] A freeze-thaw gas escape spring tube 402 is fixedly connected to the middle of the sealing base 401, and the freeze-thaw gas escape spring tube 402 has a gap. The first port is provided on the sealing base 401 and is fixedly connected to the freeze-thaw gas escape spring tube 402, and the second port is fixedly connected to the inner ring cylinder 403.

[0092] The fiber optic camera for observing crack growth, the fiber optic bundle for illumination, and the connecting wire 9 for impedance analysis measurement include a first fiber optic LED lamp, a second fiber optic LED lamp, and a fiber optic camera. The sample cover 407 is provided with a first fiber optic LED lamp hole 407a, a second fiber optic LED lamp hole 407c, and a fiber optic camera hole 407b that cooperate with the first fiber optic LED lamp, the second fiber optic LED lamp, and the fiber optic camera. The pins on both sides of the freeze-thaw sample 406 are connected to the fiber optic camera for observing crack growth, the fiber optic bundle for illumination, and the connecting wire 9 for impedance analysis measurement through a data transmission line.

[0093] The freeze-thaw sample 406 includes a conductive film, and a plurality of extension paths are provided on the conductive film. The extension paths include a main body and a branch portion. The extension paths include a plurality of defects. The branch portion of the extension path includes defect one h1, defect two h2, defect three h3, defect four h4 and defect five h5. The defect one h1 is located at the branch portion of the extension path close to the main body. The defect one h1, defect two h2, defect three h3, defect four h4 and defect five h5 are arranged in sequence on the branch portion of the extension path. The depths of the defect one h1, defect two h2, defect three h3, defect four h4 and defect five h5 gradually decrease. The data of the depth reduction of the defect one h1, defect two h2, defect three h3, defect four h4 and defect five h5 gradually increase. The spacing between adjacent defects one h1, defect two h2, defect three h3, defect four h4 and defect five h5 gradually increase. The data of the depth increase of adjacent defects one h1, defect two h2, defect three h3, defect four h4 and defect five h5 gradually increase.

[0094] The preparation method of the intelligent sensor for crack capsule fusion based on freeze-thaw cycle includes the following steps:

[0095] Step 1: Prepare the expandable silicone base material into a thin film by spin coating, and use surface modification methods, including plasma treatment or chemical modification, to improve the affinity of the film surface so that the conductive material can be more evenly attached.

[0096] Step 2: According to the required sensitivity coefficient, select micron-sized silver particles or carbon nanotubes, graphene, disperse them in a dispersion and perform ultrasound to finally obtain a mixed solution of conductive particles. Mix the mixed solution with a binder to form a conductive silver paste, and evenly coat the conductive paste on the film base material.

[0097] Step 3: Use UV laser lithography to print pit defects on the coated conductive film. The laser power and pulse time determine the vacancy depth to guide the subsequent crack development, such as Figure 7The defects on a crack branch are sequentially set as defect one, defect two, defect three, defect four and defect five; from the main part of the crack to the edge of the crack, the defects become shallower and the radius gradually decreases. In order to control the tail end of each branch crack to stop developing, a series of photolithographic shallow pits are used to form an arc-shaped defect at the tail end. With the subsequent freeze-thaw process, the crack will develop along the defect and eventually become a beam tree morphology crack with fractal characteristics.

[0098] Step 4: Liquid nitrogen freeze-thaw gas generation device such as Figure 3 As shown, an air heating throttle is set in the liquid nitrogen freeze-thaw gas generating device, and the heated air passes through Figure 2 The middle joint 101 is introduced into the heat exchange pipe 102 in the liquid nitrogen freeze-thaw gas generating device. The liquid nitrogen in contact with the heat exchange pipe 102 boils and vaporizes into nitrogen after being heated. The nitrogen enters the freeze-thaw gas outlet 103. Figure 1 The crack freeze-thaw device 4 has a first gas heat pump 2 and a temperature sensor 3 for measuring condensed gas located between the freeze-thaw gas outlet 103 and the crack freeze-thaw device 4. The temperature measured by the temperature sensor 3 determines the degree of opening and closing of the first gas heat pump 2. Condensed gas flows through the gas pipeline 402 and enters the freeze-thaw gas overflow reed switch 402. Reed switch 402 has a slit for gas to escape. The gas at the top expands and vaporizes, forming a low-temperature atmosphere at the bottom of the curved sample carrier 404, ultimately causing a freeze-thaw effect on the sample on the curved sample carrier 404. Nitrogen gas after passing through the freeze-thaw device 4 is discharged through the second gas heat pump 6. The timing and degree of opening and closing of the second gas heat pump 6 are determined by data measured by the temperature sensor 5. During the crack formation process, the power of the first and second gas heat pumps 2 and 6 controls the flow rate and temperature of the gas entering and exiting the crack freeze-thaw device 4, thereby controlling the nitrogen stagnation time, achieving low-temperature atmosphere control in the crack freeze-thaw device 4, and thus controlling the crack freeze-thaw rate.

[0099] An oblique groove is arranged on the outside of the inner ring cylinder 403, and the angle of the oblique groove is consistent with the angle of the oblique groove g2 on the outer ring cylinder 405. The outer diameter of the inner ring cylinder 403 is the same as the inner diameter of the outer ring cylinder 405. The inner ring cylinder 403 is inside the outer ring cylinder 405, and the inner ring cylinder 403 is placed in the stepped groove of the sealing base 401; before freezing and thawing, condensed water is injected into the groove of the lower layer of the stepped groove of the sealing base 401 until the liquid level is at the junction of the two layers of the stepped groove interface, and the inner ring cylinder 403 is placed, and the groove space of the stepped groove of the sealing base 401 is closed; then the outer ring cylinder 40 is inserted into the outer ring cylinder 403. 5. Rollers are placed in the inclined groove g2. In the later stage of cooling, as the condensed water turns into a solid state, its volume expands and squeezes the inner ring cylinder 403 to move upward. At the same time, due to the presence of the rollers in the inclined groove g2, the inner ring cylinder 403 has a tendency to rotate and rise, generating a tangential displacement of the order of microns. This displacement causes shear stress to form between the sample carrier 404 and the sample cover 407. Therefore, the frozen atmosphere is subjected to the combined effect of compression-shear composite stress in the freeze-thaw sample 406 between the sample carrier 404 and the sample cover 407. This composite stress provides the driving force for the multi-directional development of cracks.

[0100] The curved surface angles of the sample carrier 404 and the sample cover 407 can be replaced simultaneously, and the shear stress tendency and stress component value borne by the freeze-thaw sample 406 can be controlled, thereby controlling the strain value and crack growth rate of the freeze-thaw sample 406.

[0101] Step 5: Lower the ambient temperature and control the freezing rate to freeze the film gradually. Figure 6 The optical fiber camera in the optical fiber camera hole 407b and the first optical fiber LED lamp in the first optical fiber LED lamp hole 407a and the second optical fiber LED lamp in the second optical fiber LED lamp hole 407c illuminate the observation. The combination of the optical fiber camera, the first optical fiber LED lamp and the second optical fiber LED lamp is Figure 2 The central console 7 controls and receives signals from the optical fiber bundle 9 for connecting the optical fiber camera for observing crack propagation, the optical fiber for illumination, and the connecting wires 9 for impedance analysis measurement.

[0102] like Figure 8 The crack observation process shown in FIG; during the crack generation process, as shown in FIG. Figure 1 The liquid nitrogen vaporization control device 8 controls the liquid nitrogen evaporation volume and evaporation rate, and the central control console 7 controls the gas temperature and flow rate before and after entering the crack freeze-thaw device 4, while observing and controlling the changes in the crack morphology, ultimately achieving a basically linear relationship between the crack length development and the refrigeration rate.

[0103] like Figure 9The intelligent control logic flow of crack growth is shown in FIG. 1 . During the crack propagation process, the DIC method is used. The central console 7 is connected to a fiber optic camera to record the crack development in real time. In order to enhance the DIC grayscale gradient distribution, as shown in FIG. Figure 6 As shown, the first fiber optic LED lamp and the second fiber optic LED lamp on both sides are arranged alternately with red and blue LED lamps, and the positions of the two-color LED lamps are corresponding to the positions of the first fiber optic LED lamp hole 407a and the second fiber optic LED lamp hole 407c in the cross-sectional view of the sample cover 407; a stroboscopic function is used to change the LED flash frequency according to the real-time thickness of the crack, such as using a low frequency for a major crack and a high frequency for a fine crack; in order to prevent the influence of frost on the end faces of the fiber optic camera and the LED lamp, a concave-convex lens is provided at the lower end of the sample cover 407 to fit the frozen-thawed sample 406; the grayscale gradient distribution is described by the crack fractal characteristics (fractal dimension), the development of the crack is judged by the inverse combined Gauss-Newton iteration method (ICGN algorithm), and the impedance measurement module is used to measure the impedance change of the conductor online.

[0104] The center console 7 collects real-time data on temperature, slit length, and crack fractal characteristics. This normalized crack fractal data is then fed into a predictive support vector machine (SVM) model to predict the next crack development morphology, including crack depth and length changes. Based on the model's predicted crack morphology, the freezing equipment temperature is adjusted in real time to control the crack formation rate and superposition morphology. The adjusted temperature parameters and freezing rate are then fed into the next model training cycle to optimize the model. The freezing rate is then adjusted based on the predicted results.

[0105] The central console 7 continuously updates the SVM model based on the collected data and the feedback loop, improving prediction accuracy. The updated model is used to further optimize parameters such as freezing temperature and rate, enhancing crack quality and sensor performance. After multiple successful freeze-thaw parameter labeling, mature support vector machine parameters are obtained. This lays the foundation for the repeatable production of crack sensors in the future.

[0106] Example 2

[0107] Step 1: Select a medical-grade silicone film (NuSil MED-6015) with a thickness of 50 microns. To improve its adhesion, oxygen plasma treatment can introduce polar groups on the film surface. The elastic modulus is required to be set between 5-10 MPa, usually between 0.4-0.5.

[0108] Step 2: According to the size of the preset crack, select micron-sized silver particles and disperse them on the Ti 3 C 2 T x The MXene dispersion was ultrasonicated and the Ti 3 C 2 Tx A mixed solution of MXene / silver particles is mixed with a binder to form a conductive silver paste, which is then evenly coated on the film substrate. The conductive film is dried and cured by controlling the temperature to 45 degrees Celsius and the humidity to 15%, ensuring film thickness and uniformity.

[0109] The solidification temperature of the condensed water is regulated by adjusting the ratio of distilled water, sodium acetate, low-concentration polyethylene glycol (PEG) and ethanol. In this embodiment, the solidification temperature of the condensed water is set to -25°C, and the composition of the condensed water is: 50% distilled water, 30% ethanol and 20% PEG400.

[0110] Step 3: Use a UV laser lithography machine to print defects on the film. The laser power is controlled at 0.5 watts and the excitation time varies from 15 microseconds to 50 microseconds.

[0111] Step 4: If Figure 10 (a) Adjust the liquid nitrogen evaporation rate and set the initial freezing target temperature to -35 degrees ( Figure 10 (Point B in (a)), the sample is cooled by 0.3 degrees per minute from room temperature to the target temperature, the sample becomes more brittle and prone to crack propagation; the condensed water at the bottom gradually solidifies and expands in volume, the tangential stress on the sample gradually increases, causing the sample to strain and promote crack propagation; after reaching the target temperature, maintain it for 30 minutes ( Figure 10 (a) BC point), and then increase the input nitrogen temperature, gradually increase the temperature from -35 degrees to 10 degrees, ( Figure 10 (CD point in (a)), the plasticity of the sample is enhanced, preventing the crack from continuing to expand and producing an unexpected morphology; then it is kept at 10 degrees for 15 minutes ( Figure 10 (DE point in (a)), the condensed water at the bottom is partially liquefied, and the sample is subjected to stress unloading; then the freezing target temperature is set at -55 degrees, and the temperature is reduced by 0.4 degrees per minute, and the sample is cooled from 10 degrees to -55 degrees; ( Figure 10 (Point EF in (a)), thus forming a closed freeze-thaw process.

[0112] To avoid uneven crack expansion. The two ends of the sensor are connected to the impedance measurement module to measure the impedance change online. Preliminary experiments show that within a freezing cycle, the impedance measurement module measures the impedance ( Figure 10 (b)) The tip is elevated ( Figure 10 (b) BC segment), and the local physical picture of the initial crack growth is as follows Figure 10 (c) Figure 10 (c) is the sample before freeze-thaw, and (d) is the sample after freeze-thaw. The setting of defects guides the development of cracks. After the sample temperature is increased, the cracks close. In order to further promote the formation of cracks, the freezing temperature of the second and even later deep freeze-thaw cycles ( Figure 10(FG segment in (a)) is lower than the freezing temperature of the previous freeze-thaw cycle ( Figure 10 As the deep freeze-thaw cycle progresses, the impedance ( Figure 10 The EF segment value in (b) is significantly increased, reflecting the occurrence of a wider growth layer of the crack.

[0113] Step 5: Multiple freeze-thaw cycles

[0114] During the thawing process, the cracks partially close due to the material's elastic recovery. Repeated freeze-thaw cycles are used to adjust the depth and length of the cracks. Repeating the freeze-thaw process optimizes the crack morphology. Fine-tuning the temperature flow over multiple cycles gradually controls the crack's development.

[0115] According to the sensor requirements, the final shape of the crack is optimized by adjusting factors such as freezing temperature and conductive particle distribution. Figure 10 (a) is the freezing temperature control diagram. After multiple freeze-thaw controls, the final result is as follows: Figure 7 The same crack sensor as the freeze-thaw sample 406;

[0116] The signal stability of the vibration sensor is determined by the controllability of the crack, while the size, length and depth of the crack determine the capacitive reactance of the vibration sensor and the robustness of the signal.

[0117] A coronary intervention balloon is prepared using a medical-grade silicone film as a substrate, including a crack capsule-closed intelligent sensor based on freeze-thaw cycles, including a coronary intervention balloon front end 91, a balloon 92 equipped with a crack capsule-closed intelligent sensor, a coronary intervention structure 93, an external connector for coronary intervention surgery 94, a port S1 for balloon inflation, and an interventional drug inlet S2. The proximal end of the coronary intervention node is fixedly connected to the external connector for coronary intervention surgery, and the external connector for coronary intervention surgery is provided with a port for balloon inflation and an interventional drug inlet. The distal end of the coronary intervention structure is provided with a coronary intervention balloon front end, and the coronary intervention structure is fixedly connected to a balloon equipped with a crack capsule-closed intelligent sensor near the front end of the coronary intervention balloon.

[0118] In specific clinical operations, Figure 11 The coronary intervention balloon combined with the crack intelligent sensor made in combination with the present invention is extended to the diseased part of the blood vessel, and gas is injected into the S1 channel in the figure using a syringe. The gas reaches the balloon equipped with the crack capsule combined with the intelligent sensor through the gas microchannel on the catheter wall 93 of the coronary intervention structure. When the balloon equipped with the crack capsule combined with the intelligent sensor just touches the blood vessel, the sensor acts as an electrode for electrical impedance measurement. The gas is continuously injected, and the crack on the sensor opens slightly. The vibration of the coronary blood vessel drives the crack to produce a switching effect, thereby measuring the acoustic impedance of the blood vessel.

[0119] Therefore, the same sensitive material can be used for electrical impedance / acoustic impedance measurement at different usage stages of the membrane device. For the sake of signal integrity, the expansion and contraction of the airbag placed in the body will be repeated at irregular intervals. The present invention provides a prerequisite for the repeated action of collecting electroacoustic signals at the same point.

[0120] Example 3

[0121] The application of the present invention's intelligent sensor based on freeze-thaw crack sac in saccular structures includes but is not limited to coronary intervention balloons, and also includes tracheal catheter balloons. The sensor of the present invention is installed on tracheal catheter balloons with narrow spaces in the body and narrow installation space. It can measure accurate hemodynamic signs through electroacoustic coupling sensing, so that the measured signal is more stable than that on the body surface.

[0122] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0123] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A device for preparing a fissure capsule intelligent sensor based on freeze-thaw cycles, characterized by: The invention comprises a liquid nitrogen freeze-thaw gas generating device, a first gas heat pump, a temperature sensor for measuring condensed gas, a crack freeze-thaw device, a temperature sensor for outputting a freeze-thaw device, a second gas heat pump, a central control console, a liquid nitrogen vaporization control device, and an optical fiber camera for connecting to observe crack extension, an optical fiber bundle for lighting optical fiber, and connecting wires for impedance analysis measurement. The liquid nitrogen freeze-thaw gas generating device is provided with a heat exchange tube, and the heat exchange tube is provided with a heating gas inlet / outlet on the liquid nitrogen freeze-thaw gas generating device. The liquid nitrogen freeze-thaw gas generating device is fixedly connected with a freeze-thaw gas output port. The freeze-thaw gas output port A first gas heat pump is provided on one side, and the first gas heat pump is fixedly connected to the freeze-thaw gas output port through a pipeline. A temperature sensor for measuring condensed gas is provided on one side of the first gas heat pump, and the temperature sensor for measuring condensed gas is fixedly connected to the first gas heat pump through a pipeline. A crack freeze-thaw device is provided on the pipeline between the first gas heat pump and the temperature sensor for measuring condensed gas, and the crack freeze-thaw device has a first port and a second port. The first port of the crack freeze-thaw device is fixedly connected to the pipeline between the first gas heat pump and the temperature sensor for measuring condensed gas through a pipeline. A temperature sensor of an output freeze-thaw device is provided on one side of the second port of the crack freeze-thaw device, a second gas heat pump is provided on one side of the temperature sensor of the output freeze-thaw device, the second gas heat pump is fixedly connected to the output freeze-thaw device through a pipeline, and the second port of the crack freeze-thaw device is fixedly connected to the pipeline between the second gas heat pump and the output freeze-thaw device through a pipeline; A liquid nitrogen vaporization control device is provided on one side of the liquid nitrogen freeze-thaw gas generating device, and the heating gas inlet / outlet is fixedly connected to the liquid nitrogen vaporization control device through a pipeline. A central console is provided on one side of the liquid nitrogen vaporization control device, and the central console is connected to the first gas heat pump, the second gas heat pump, the temperature sensor for measuring the condensed gas, and the temperature sensor of the output freeze-thaw device through lines. A fiber optic camera for connecting to observe crack propagation, an optical fiber bundle of optical fibers for lighting, and connecting wires for impedance analysis measurement are fixedly connected between the central console and the crack freeze-thaw device; the central console includes an impedance analysis module and a fiber optic camera receiving and intelligent judgment module.

2. The device for preparing the freeze-thaw cycle-based fissure capsule intelligent sensor according to claim 1, characterized in that: The crack freeze-thaw device includes a sealing base, a freeze-thaw gas overflow spring tube, an inner ring cylinder, an outer ring cylinder, a curved sample carrier, a freeze-thaw sample, a sample cover, and a sealing top cover. A plurality of fixing columns are fixedly connected between the sealing base and the sealing top cover, and the outer ring cylinder is fixedly connected to the sealing top cover. The sealing base is provided with a convex ring, and the convex ring is provided with a stepped groove. The thickness of the stepped groove close to the end face of the convex ring is consistent with the wall thickness of the inner ring cylinder, and the thickness of the stepped groove away from the end face of the convex ring is less than the wall thickness of the inner ring cylinder; The sealing base is provided with an inner ring cylinder, which is slidably connected to the stepped groove of the convex ring of the sealing base. Condensed water is provided in the stepped groove on the side away from the end face of the convex ring, and the upper liquid level of the condensed water is flush with the boundary of the stepped groove; An outer ring cylinder is provided on the inner ring cylinder, the inner diameter of the outer ring cylinder is consistent with the outer diameter of the inner ring cylinder, an oblique groove is provided on the outer side of the inner ring cylinder, and an oblique groove is provided on the inner side of the outer ring cylinder, the oblique groove and the oblique groove have the same inclination, and a roller is provided between the oblique groove and the oblique groove, the roller is rotatably connected in the oblique groove, and the roller is rollingly connected on the oblique groove; The outer ring cylinder is provided with an inner groove, the inner ring cylinder is fixedly connected to a curved sample carrier, the outer ring cylinder is fixedly connected to a sample cover, a freeze-thaw sample is provided between the sample carrier and the sample cover, pins are provided on both sides of the freeze-thaw sample, and the pins are placed in the inner groove; The optical fiber bundle for connecting the optical fiber camera for observing crack propagation, the optical fiber for illumination, and the connecting wires for impedance analysis measurement pass through the sealed top cover; A freeze-thaw gas overflow reed pipe is fixedly connected in the middle of the sealing base, and the freeze-thaw gas overflow reed pipe is provided with a gap; the first port is arranged on the sealing base and is fixedly connected to the freeze-thaw gas overflow reed pipe, and the second port is fixedly connected to the inner ring cylinder.

3. The device for preparing the freeze-thaw cycle-based fissure capsule intelligent sensor according to claim 2, characterized in that: The fiber optic camera for observing crack extension, the fiber optic bundle for lighting, and the connecting wires for impedance analysis measurement include a first fiber optic LED lamp, a second fiber optic LED lamp, and a fiber optic camera. The sample cover is provided with a first fiber optic LED lamp hole, a second fiber optic LED lamp hole, and a fiber optic camera hole that cooperate with the first fiber optic LED lamp, the second fiber optic LED lamp, and the fiber optic camera. The pins on both sides of the freeze-thaw sample are connected to the fiber optic camera for observing crack extension, the fiber optic bundle for lighting, and the connecting wires for impedance analysis measurement through a data transmission line.

4. The device for preparing a freeze-thaw cycle-based fissure capsule intelligent sensor according to claim 3, characterized in that: The freeze-thaw sample includes a conductive film, and a plurality of extension paths are provided on the conductive film. The extension paths include a main body and a branch part. The extension paths include a plurality of defects. The branch part of the extension path includes defect one, defect two, defect three, defect four and defect five. The defect one is located in the branch part of the extension path close to the main body. The defects one, two, three, four and five are arranged in order on the branch part of the extension path. The depths of the defects one, two, three, four and five gradually decrease. The data of the depth reduction of the defects one, two, three, four and five gradually increase. The distance between adjacent defects one, two, three, four and five gradually increases. The data of the increased distance between adjacent defects one, two, three, four and five gradually increase.

5. The device for preparing the freeze-thaw cycle-based fissure capsule intelligent sensor according to claim 4, characterized in that: The defect spacing in one of the expansion paths increases gradually from the beginning to the end according to a gradient.

6. The device for preparing a freeze-thaw cycle-based fissure capsule intelligent sensor according to claim 5, characterized in that: The terminal defect is set as a semicircular defect structure, the center of the terminal defect corresponds to the end position of the expansion path, and the direction of the semicircular defect structure of the terminal defect extending from the center to both sides is ultimately opposite to the direction of the expansion path from the head end to the end.

7. A method for preparing a freeze-thaw cycle-based fracture capsule intelligent sensor according to claim 6, characterized in that: The steps include: S1: prepare substrate material; S1.1: Obtain the substrate material; S1.2: The substrate material is prepared into a thin film; S1.3: The film is treated to improve surface affinity; S2: Processing substrate materials; S3: preparing conductive paste; S3.1: The conductive paste material A and Ti 3 C 2 T x MXene, material A and Ti 3 C 2 T x MXenes are mixed to obtain a mixture; S3.1.1: Substance A includes but is not limited to micron-sized or nanometer-sized silver particles, carbon nanotubes, and single or multilayer graphene; S3.2: Mixing the mixture in S3.1 with a binder to obtain a conductive paste; S4: evenly coating the conductive paste in S3.2 on the base material in S2.2 to obtain a conductive film; controlling the temperature and humidity to place the conductive film in a vacuum chamber for drying and curing; S4.1: Prefabricated vacancy defects that determine the initiation and trend of subsequent cracks are fabricated on the conductive film in S4 by laser lithography; S4.1.1: Determine the laser power and pulse duration based on the approximately linear relationship between the defect depth and the energy and pulse number of the laser pulses; S5: cyclic freeze-thaw of the conductive film using a preparation device for a crack capsule-integrated intelligent sensor based on cyclic freeze-thaw; S5.1: Initially freeze the conductive film using the output condensing gas; S5.1.1: Freeze the conductive film to reduce the difficulty of crack initiation and propagation. As the temperature decreases, the sample becomes more brittle and the condensed water solidifies and expands. The increased stress is concentrated around the defect, and cracks initially form along the defect. S5.1.1: Control the cooling rate to adjust the size of the silicone rubber and cool the material to the set temperature, controlling the temperature between 30 and -50 degrees Celsius; S5.2: Stop refrigeration, and use the gas heat pump to input high-temperature gas into the crack freeze-thaw device to slow down the crack growth rate; S5.2.1: Control the thawing rate so that the crack propagates uniformly and the propagation progress is controllable; S5.3: Modulate crack depth and length through repeated freeze-thaw cycles; S5.3.1: During repeated freeze-thaw cycles, fine-tune the temperature schedule to control crack development; S6: When the crack depth-total capacitance of the conductor reaches the required value, the heating / cooling is canceled.

8. The method for preparing the freeze-thaw cycle-based fissure capsule intelligent sensor according to claim 7, characterized in that: The material of the substrate includes but is not limited to expandable silicon-based compounds and rubber; the substrate is prepared into a thin film, and the film preparation method includes but is not limited to spin coating and blade coating; The treatment for improving surface affinity includes but is not limited to plasma treatment and chemical modification.

9. The method for preparing the freeze-thaw cycle-based fissure capsule intelligent sensor according to claim 7, characterized in that: The film surface treatment comprises the following steps: placing the substrate material in a 15% surface modifier aqueous solution and soaking it for 2 hours; rinsing it with deionized water, and then drying it with nitrogen gas for later use.

10. The method for preparing the freeze-thaw cycle-based crack capsule intelligent sensor according to claim 7, characterized in that: The laser power and pulse time are as follows: the laser used is an ultraviolet laser source with a maximum power of 3W, a frequency range of 10-100kHz, and a minimum focus spot diameter and line width of 0.01mm.

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