A far-infrared heating drug composite patch with integrated fractal microfluidic network

Abstract

This application provides a far-infrared heating drug composite patch with an integrated fractal microfluidic network, relating to the field of medical patches. The composite patch includes a main layer, a far-infrared colloid layer, and an isolation layer. The far-infrared colloid layer includes a medical pressure-sensitive adhesive matrix and a thermosensitive phase change material and a far-infrared functional material fused to the medical pressure-sensitive adhesive matrix. The phase change temperature of the thermosensitive phase change material is 35-42℃. A fractal microfluidic network is provided on the side of the far-infrared colloid layer closest to the skin. The fractal dimension of the fractal microfluidic network is 1.5-1.8, and the channel width is 10-900μm. By setting the fractal microfluidic network on the far-infrared colloid layer, the maximum fluid contact area can be provided in a limited space. During use, it can ensure that sweat or the accompanying drug is evenly diffused throughout the patch area, effectively alleviating the problem of high allergy rate caused by sweat retention, improving drug delivery efficiency and uniformity. Moreover, the fractal pattern has good flexibility and deformation ability, and it is not easy to wrinkle or fall off when used on joints.

Description

Technical Field

[0001] This invention relates to the field of medical patch products, specifically to a far-infrared heating drug composite patch with an integrated fractal microfluidic network. Background Technology

[0002] In the current field of transdermal drug delivery, medicated plasters have become a common treatment for musculoskeletal diseases and chronic pain due to their convenience, ability to deliver drugs locally and target specific areas, and avoidance of gastrointestinal irritation and the first-pass effect of oral medications. Conventional medicated plasters typically consist of a backing layer, a drug layer, and an isolation layer, relying on passive diffusion through the skin for drug absorption. While some improved versions (such as a far-infrared temperature-sensing patch disclosed in Chinese invention patent CN109999353A and a high-efficiency far-infrared heating film disclosed in CN107933006A) incorporate heating components to aid transdermal delivery, significant drawbacks remain.

[0003] 1. Drug delivery is inefficient and uneven, with transdermal penetration rates often below 15%. Drugs tend to be "concentrated in the center and sparse at the edges" (concentration difference of 2-3 times), leading to fluctuating efficacy and waste, and also easily causing skin irritation.

[0004] 2. Thermotherapy with temperature control (fluctuation of more than ±5℃) has a certain burn rate, and the heat field and drug delivery are not synergistic, resulting in low thermotherapy efficiency;

[0005] 3. The fully fitted structure lacks fluid drainage, leading to sweat retention and increased allergy rates. Furthermore, it has poor flexibility, making it prone to wrinkling and falling off at joints.

[0006] In summary, current conventional far-infrared plaster patches still need improvement in terms of drug delivery, thermotherapy synergy, and skin compatibility. Summary of the Invention

[0007] The purpose of this invention is to provide a far-infrared heating drug composite patch with an integrated fractal microfluidic network, in order to solve the technical problems of existing conventional far-infrared plaster patches in terms of drug delivery, thermotherapy synergy, and skin compatibility.

[0008] Based on the above objectives, this application provides a far-infrared heating drug composite patch with an integrated fractal microfluidic network, comprising a main body layer, a far-infrared colloidal layer, and an isolation layer;

[0009] The main body layer is a membrane structure made of elastic and breathable material;

[0010] The far-infrared colloidal layer is disposed on one side of the main body layer;

[0011] The far-infrared colloidal layer includes a medical pressure-sensitive adhesive matrix and a temperature-sensitive phase change material and a far-infrared functional material fused in the medical pressure-sensitive adhesive matrix. The phase change temperature of the temperature-sensitive phase change material is 35-42℃.

[0012] The far-infrared colloidal layer has a fractal microchannel network on the side close to the skin, the fractal dimension of the fractal microchannel network is 1.5-1.8, and the channel width is 10-900μm;

[0013] The isolation layer is disposed on the side of the far-infrared colloidal layer close to the skin, and the isolation layer does not cover the microchannel network.

[0014] Furthermore,

[0015] The thermosensitive phase change material is an octadecane / silica composite microcapsule with a particle size distribution of 1-100 μm, and its mass percentage in the far-infrared colloidal layer is 5%-20%.

[0016] The far-infrared functional material is carbon quantum dot-modified nano-ceramic powder with an emission band of 8-15μm and an emissivity of ≥90%, and its mass percentage in the far-infrared colloidal layer is 10%-60%.

[0017] Furthermore, the fractal microfluidic network is generated using the Julia set algorithm. The complex parameter c of the Julia set satisfies Re(c)∈[-0.8,-0.6] and Im(c)∈[0.2,0.3], where Re(c) is the real part of parameter c, i.e., the horizontal coordinate of the corresponding complex plane, and Im(c) is the imaginary part of parameter c, i.e., the vertical coordinate of the corresponding complex plane.

[0018] Furthermore, the fractal microchannel network is generated through the following steps:

[0019] S10. Set the Julia set parameter c = -0.7 + 0.27i, and the maximum number of iterations N = 100; S20. Generate a fractal pattern in the complex plane region [-1.5, 1.5] × [-1.5, 1.5];

[0020] S30. The fractal pattern is binarized, and the connected regions with a fractal dimension of 1.65±0.15 are extracted as microchannel templates.

[0021] Furthermore, it also includes a drug sustained-release unit disposed within the fractal microchannel network to enhance the capillary flow of the liquid.

[0022] Furthermore, the drug sustained-release unit comprises the following components:

[0023] The drug carrier is made of mesoporous silica nanoparticles with a pore size of 2-10 nm.

[0024] Thermoresponsive gel, gel transition temperature 30-35℃;

[0025] Treatment drugs, nonsteroidal anti-inflammatory drugs or extracts of traditional Chinese medicine.

[0026] Furthermore, the inner surface of the fractal microchannel network is hydrophilized by plasma treatment or silane coupling agent modification.

[0027] Furthermore,

[0028] When used as a patch for joint areas, it requires high flexibility to adapt to skin deformation. The fractal microchannel network has a fractal dimension of 1.5-1.6 to reduce branch density and prevent channel breakage when bending.

[0029] When used as a patch for flat areas of the torso, the fractal dimension of the fractal microchannel network is 1.7-1.8, which is used to maximize the contact area;

[0030] When used as a children's patch, the fractal dimension is 1.6, and the overall channel width is enlarged to 500-900μm to reduce the physical pressure of the channel on the skin.

[0031] Furthermore, the thickness of the far-infrared colloidal layer is 0.1mm-5mm, and the depth of the fractal microchannel is 50-150μm.

[0032] Furthermore, the main body layer is made of polyurethane film, polyamide film, silicone rubber film, or TPU film.

[0033] By adopting the above technical solution, the far-infrared heating drug composite patch with integrated fractal microfluidic network provided in this application has the following technical effects compared with the prior art:

[0034] In this solution, the far-infrared colloidal layer includes a medical pressure-sensitive adhesive matrix and a thermosensitive phase change material and a far-infrared functional material fused within the medical pressure-sensitive adhesive matrix. The phase change temperature of the thermosensitive phase change material is 35-42℃. A fractal microchannel network is set on the side of the far-infrared colloidal layer closest to the skin. The fractal dimension of the fractal microchannel network is 1.5-1.8, and the channel width is 10-900μm. By setting a fractal microchannel network on the far-infrared colloidal layer, the maximum fluid contact area can be provided in a limited space. During use, it can ensure that sweat or the accompanying medication is evenly diffused throughout the entire patch area, effectively alleviating the problem of high allergy rate caused by sweat retention, improving drug delivery efficiency and uniformity. Moreover, the fractal pattern has good flexibility and deformation ability, and it is not easy to wrinkle or fall off when used on joints. Attached Figure Description

[0035] 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.

[0036] Figure 1 This is a schematic diagram of the structure of the far-infrared heating drug composite patch with integrated fractal microfluidic network provided in the embodiments of this application;

[0037] Figure 2 This is a planar schematic diagram of the fractal microchannel network in this embodiment;

[0038] Figure 3 This is a photograph of the far-infrared heating drug composite patch in this embodiment;

[0039] Figure 4 This is a liquid distribution diagram of the far-infrared colloidal layer containing the fractal microfluidic network in this embodiment;

[0040] Figure 5 This is a liquid distribution diagram of the far-infrared colloidal layer in existing products;

[0041] Figure 6 This is a liquid distribution diagram of the far-infrared colloidal layer containing a fractal microfluidic network in this embodiment after sweat is expelled.

[0042] Figure 7 This is a liquid distribution diagram of the far-infrared colloidal layer in existing products after sweat is excreted.

[0043] Icons: 1-Main layer; 2-Far-infrared colloidal layer; 3-Isolation layer. Detailed Implementation

[0044] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0045] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] The far-infrared heating drug composite patch provided in this application innovatively combines a fractal microfluidic network with a far-infrared colloidal layer, solving the problems of uneven drug distribution, unsafe heat therapy, poor skin compatibility, and limited functionality of conventional plasters, thereby improving transdermal drug delivery efficiency and clinical safety.

[0048] like Figure 1 , Figure 2 and Figure 3 As shown, the far-infrared heating drug composite patch with integrated fractal microfluidic network in this embodiment includes a main body layer 1, a far-infrared colloidal layer 2, and an isolation layer 3.

[0049] Among them, the main body layer 1 adopts a membrane structure made of elastic and breathable material;

[0050] A far-infrared colloidal layer 2 is provided on one side of the main body layer 1;

[0051] The far-infrared colloidal layer 2 includes a medical pressure-sensitive adhesive matrix and a temperature-sensitive phase change material and a far-infrared functional material fused in the medical pressure-sensitive adhesive matrix. The phase change temperature of the temperature-sensitive phase change material is 35-42℃.

[0052] The far-infrared colloidal layer 2 has a fractal microchannel network on the side close to the skin. The fractal dimension of the fractal microchannel network is 1.5-1.8 and the channel width is 10-900μm.

[0053] The isolation layer 3 is disposed on the side of the far-infrared colloidal layer 2 close to the skin, and the isolation layer 3 does not cover the microchannel network.

[0054] In this design, the addition of a thermosensitive phase change material to the far-infrared colloidal layer 2 aims to stabilize the skin contact temperature at 35-42℃, thereby adapting it to a comfortable and safe treatment temperature range for the human body. For example, when the temperature is below 35℃, the thermosensitive phase change material is solid and stores heat.

[0055] When the temperature is between 35-42℃, the material gradually changes from solid to liquid. This process absorbs a lot of heat, thus inhibiting the rapid rise in temperature. When the local skin temperature rises to 42℃ due to far-infrared heating or inflammatory response, the material completely liquefies. The heat absorbed during the previous phase change buffers the temperature rise, avoiding the problem of skin burns that may occur if the temperature exceeds 42℃.

[0056] Meanwhile, the liquid material will further dissipate heat through thermal convection, and together with the fluid conduction of the fractal microchannels (extracting heat from the skin's sweat), the temperature will be maintained below the safe threshold.

[0057] Furthermore, the fractal dimension of the fractal microfluidic network is 1.5-1.8, and the channel width is 10-900μm. It maximizes the contact area with the skin. Within the limited patch space, the fractal microfluidic network significantly increases the contact area between the channel and the skin and the drug, improving the liquid adsorption efficiency. When no drug is being used, the fractal microfluidic network can evenly guide sweat or drugs to the entire patch area, preventing skin irritation or uneven drug concentration caused by excessive local liquid.

[0058] In this scheme, preferably, the medical pressure-sensitive adhesive matrix can be made of acrylate or polyurethane, the thermosensitive phase change material is n-octadecane / silica composite microcapsules with a particle size distribution of 1-100μm and a mass percentage of 5%-20% in the far-infrared colloidal layer 2; the far-infrared functional material is carbon quantum dot modified nano-ceramic powder with an emission band of 8-15μm and an emissivity ≥90% and a mass percentage of 10%-60% in the far-infrared colloidal layer 2.

[0059] It should be noted that the medical pressure-sensitive adhesive matrix is ​​the basic carrier of the colloidal layer. It has stable high-temperature resistance. Even when the temperature rises to 42°C, the pressure-sensitive adhesive still maintains an elastic solid state and will not melt or collapse, thus providing continuous structural support for fractal microchannels.

[0060] In application, for example, when the skin is at 42°C, the octadecane core material inside the composite microcapsule is completely liquefied, but the silica shell will encapsulate the liquid core material, and the liquefaction does not affect the shape of the capsule; the liquefied phase change material only regulates the temperature inside the microcapsule through heat absorption and release, and will not seep out or flow from the medical pressure-sensitive adhesive matrix, nor will it impact the hollow channel structure of the fractal microchannel, and the width (10-900μm) and connectivity of the channel are unaffected.

[0061] In this embodiment, the Julia set is a fractal structure on the complex plane, defined by the iteration function:

[0062] f c (z)=z 2 +c is generated, where z is any point on the complex plane and c is a fixed complex parameter.

[0063] Specifically, the complex parameter c of the Julia set is constrained to satisfy:

[0064] Re(c)∈[-0.8,-0.6] and Im(c)∈[0.2,0.3];

[0065] Where Re(c) is the real part of parameter c, which corresponds to the horizontal axis coordinate of the complex plane, and Im(c) is the imaginary part of parameter c, which corresponds to the vertical axis coordinate of the complex plane. The purpose is to meet the requirement of fractal dimension of 1.5-1.8 and channel width of 10-900μm.

[0066] It should be noted that the core function of the real part Re(c) is to adjust the sparsity of the branches in the Julia set. The smaller the real part, the denser the branches; the larger the real part, the sparser the branches.

[0067] If Re(c) < -0.8 (e.g., -1), the branches will be excessively dense, and the generated flow channel width may be less than 10 μm, which may lead to the following problems:

[0068] 1. Fluids (sweat or medication) are prone to clogging within fractal microchannels;

[0069] 2. Soft lithography or 3D printing cannot produce precise products.

[0070] If Re(c) > -0.6 (e.g., -0.5) is used, the branches will be too sparse, the number of flow channels will be small, the contact area will be insufficient, and the goal of uniform fluid transmission cannot be achieved.

[0071] In this scheme, Re(c)∈[-0.8,-0.6] is limited to generate Julia sets with appropriate branch density. This ensures that the width of the fractal microchannel is within the manufacturable range of 10-900μm, while maximizing the contact area through a sufficient number of branches to meet the transport efficiency requirements of capillary action.

[0072] The core function of the imaginary part Im(c) is to adjust the structural integrity and complexity (i.e., fractal dimension) of the Julia set. If the imaginary part is too small, the structure is prone to breakage; if the imaginary part is too large, the complexity will exceed the target dimension.

[0073] If Im(c) < 0.2 (e.g., 0.1), the Julia set will exhibit broken branches, resulting in some branches being disconnected from the main structure. This leads to the formation of closed ends in the fractal microchannels, preventing fluid from being transported from the broken points and directly disrupting the uniform distribution function.

[0074] If Im(c) > 0.3 (e.g., 0.4), the complexity of the Julia set will be too high, and the fractal dimension may exceed 1.8, leading to two problems:

[0075] 1. If the flow channel morphology is too complex, eddies are easily generated in the branch intersection area of ​​the fluid, which will reduce the transmission speed.

[0076] 2. A fractal dimension that is too high will increase the rigidity of the patch, making it easier to feel a foreign body sensation when applied to the skin.

[0077] In this scheme, by limiting Im(c)∈[0.2,0.3], the characteristics of maximizing the contact area are satisfied, while also adapting to the flexibility of the patch.

[0078] In this scheme, the fractal microchannel network is generated through the following steps:

[0079] S10. Set the Julia set parameter c = -0.7 + 0.27i, and the maximum number of iterations N = 100;

[0080] S20. Generate a fractal pattern within the complex plane region [-1.5, 1.5] × [-1.5, 1.5].

[0081] S30. The fractal pattern is binarized, and the connected regions with a fractal dimension of 1.65±0.15 are extracted as microchannel templates.

[0082] Specifically, in step S10, the set parameter c = -0.7 + 0.27i aims to select the optimal value from Re(c) ∈ ​​[-0.8, -0.6] and Im(c) ∈ ​​[0.2, 0.3], i.e.:

[0083] The real part Re(c) = -0.7 ensures that the generated fractal branch density is moderate and the channel width can be stabilized at 30-80μm, providing a non-clogging and non-sparse basis for extracting the connected region in step S30;

[0084] The imaginary part Im(c) = 0.27, which ensures that the fractal structure is continuous and unbroken, avoids dead ends of branches, and ensures that the connected region is successfully extracted in the subsequent step S30.

[0085] In step S30, the range of the real axis (i.e., the horizontal axis) is from -1.5 to 1.5, ensuring that the real part Re(z) of all complex numbers is within this range;

[0086] The imaginary axis (vertical axis) ranges from -1.5 to 1.5, ensuring that the imaginary part Im(z) of all complex numbers lies within this interval;

[0087] In step S10, c = -0.7 + 0.27i, the corresponding Julia set can be used to construct continuous structures of microchannels, which are exactly concentrated within [-1.5, 1.5] × [-1.5, 1.5].

[0088] If the region is too small (e.g., [-1,1]×[-1,1]), it is easy to "truncate" the outer branches of the Julia set, resulting in incomplete fractals and missing branches in the subsequent flow channels.

[0089] If the area is too large (e.g., [-3,3]×[-3,3]), the excess part will not belong to the blank points of the Julia set, making processing more difficult and resulting in the effective fractals in the final pattern being too small to fit the size of the plaster (i.e., far-infrared colloidal layer 2).

[0090] In step S30, only if c falls within this interval (i.e., c = -0.7 + 0.27i) can a connected region with a dimension of 1.65 ± 0.15 be generated, ensuring that qualified templates can be selected through step S30.

[0091] The far-infrared heating drug composite patch provided in this embodiment also includes a drug sustained-release unit, which is disposed within a fractal microchannel network to enhance the capillary flow of the liquid.

[0092] Preferably, the drug sustained-release unit comprises the following components: a drug carrier, a thermoresponsive gel, and a therapeutic drug; wherein the drug carrier is made of mesoporous silica nanoparticles with a pore size of 2-10 nm; the thermoresponsive gel has a transition temperature of 30-35 °C; and the therapeutic drug is a nonsteroidal anti-inflammatory drug or a traditional Chinese medicine extract.

[0093] In the far-infrared heating drug composite patch provided in this embodiment, the inner surface of the fractal microchannel network is hydrophilicated. This hydrophilication treatment is achieved through plasma treatment or modification with a silane coupling agent. In practical applications, since the width of the fractal microchannels is only 10-900 μm, if skin debris or drug particles (such as microparticles of traditional Chinese medicine extracts) adsorb onto the inner wall, blockage can easily occur, leading to channel failure. In this solution, the hydrophilic treatment of the inner surface of the fractal microchannel network can isolate direct contact between particles and the wall surface, reducing particle adsorption and thus extending the service life of the channels.

[0094] In the far-infrared heating drug composite patch provided in this embodiment, different fractal microchannel networks can be processed into composite patches according to the characteristics of different parts of the body, so as to adapt to the treatment of different parts of the body. Specifically:

[0095] When used as a patch for joints, the area requires high flexibility to adapt to skin deformation. The fractal dimension of the fractal microchannel network is 1.5-1.6, which is used to reduce the branch density and prevent channel breakage when bending.

[0096] When used as a patch for flat areas of the torso, the fractal dimension of the fractal microchannel network is 1.7-1.8, which is used to maximize the contact area;

[0097] When used as a children's patch, the fractal dimension is 1.6, and the overall channel width is enlarged to 500-900μm to reduce the physical pressure of the channel on the skin.

[0098] In the far-infrared heating drug composite patch provided in this embodiment, preferably, the thickness of the far-infrared colloidal layer 2 is 0.1mm-5mm, and the depth of the fractal microchannel is 50-150μm.

[0099] In the far-infrared heating drug composite patch provided in this embodiment, the main layer 1 is made of polyurethane film, polyamide film, silicone rubber film or TPU film.

[0100] The performance of this product is explained below based on experimental data.

[0101] 1. Comparative Analysis of the Distribution Properties of Colloidal Liquids

[0102] Figure 4 This diagram shows the liquid distribution of the far-infrared colloidal layer containing a fractal microchannel network in this product. Figure 5 The liquid distribution diagram of the far-infrared colloidal layer of the existing product is shown;

[0103] The total volume of liquid in the comparative analysis simulation experiment was 3 mL. The simulation assumed that a total of 3 mL of liquid was distributed on the entire surface of the colloid. After the 3 mL of liquid was distributed within 10-30 minutes, the liquid distribution and the proportion of the liquid distribution area on the entire surface of the colloid (liquid distribution area / total colloid area * 100) were compared between the two cases.

[0104] Comparison of liquid distribution area percentage in two cases

[0105]

[0106] As can be seen from the above experiments, this product, by adding a fractal microchannel network to the colloidal layer, can make sweat or drugs spread evenly in the colloidal layer compared to existing products.

[0107] 2. Comparative Analysis of Colloidal Liquid Excretion Properties

[0108] Figure 6 This image shows the liquid distribution of the far-infrared colloidal layer containing a fractal microchannel network after sweat is expelled. Figure 7The diagram shows the liquid distribution of the far-infrared colloidal layer of an existing product after sweat excretion.

[0109] The total amount of sweat in the excretion analysis simulation was 5 mL. The simulated 42℃ far-infrared heating pressure-sensitive adhesive was distributed on the entire surface of the adhesive. Then, from 0 to 60 minutes, the sweat was calculated at the time when sweat began to appear and when it was excreted from the skin. The sweat distribution and the proportion of liquid distribution area on the entire far-infrared adhesive surface (liquid distribution area / total adhesive area * 100) were compared between the two conditions.

[0110] Comparison of liquid distribution area percentages in the two cases:

[0111]

[0112] As can be seen from the above experiments, this product, by adding a fractal microchannel network to the colloidal layer, can enable sweat to fully disperse and be discharged from the colloidal layer compared to existing products.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated fractal microfluidic network far-infrared heating medicine composite patch, characterized in that, The main body layer, the far infrared colloid layer and the isolation layer are included. The main body layer is made of a film type structure of an elastic and breathable material. The far infrared colloid layer is arranged on one side of the main body layer. The far infrared colloid layer comprises a medical pressure-sensitive adhesive matrix and a temperature-sensitive phase change material and a far infrared functional material fused in the medical pressure-sensitive adhesive matrix, and the phase change temperature of the temperature-sensitive phase change material is 35-42℃. The far infrared colloid layer is provided with a fractal micro-channel network on the side close to the skin, and the fractal dimension of the fractal micro-channel network is 1.5-1.8, and the channel width is 10-900μm. The isolation layer is arranged on the side of the far infrared colloid layer close to the skin, and the isolation layer does not cover the micro-channel network. The fractal micro-channel network is generated by a Julia set algorithm, and the complex parameter c of the Julia set satisfies Re(c)∈[-0.8,-0.6] and Im(c)∈[0.2,0.3], wherein Re(c) is the real part of the parameter c, that is, the horizontal axis coordinate of the complex plane, and Im(c) is the imaginary part of the parameter c, that is, the vertical axis coordinate of the complex plane.

2. The far infrared heating drug composite patch integrated with a fractal micro-channel network according to claim 1, wherein the temperature-sensitive phase change material is n-octadecane / silicon dioxide composite microcapsules with a particle size distribution of 1-100μm, and the mass percentage in the far infrared colloid layer is 5%-20%; and the far infrared functional material is carbon quantum dot modified nano ceramic powder with an emission band of 8-15μm and an emissivity of ≥90%, and the mass percentage in the far infrared colloid layer is 20%-60%.

3. The far infrared heating drug composite patch integrated with a fractal micro-channel network according to claim 1, wherein the fractal micro-channel network is generated by the following steps: S10. Set the Julia set parameter c = -0.7 + 0.27i, and the maximum iteration number N = 100; S20. Generate a fractal pattern in the complex plane region [-1.5,1.5]×[-1.5,1.5]; S30. Perform binaryzation processing on the fractal pattern, and extract the connected region with a fractal dimension of 1.65±0.15 as a micro-channel template. Further comprising a drug release unit arranged in the fractal micro-channel network for enhancing capillary flow of liquid.

5. The far infrared heating drug composite patch integrated with a fractal micro-channel network according to claim 4, wherein the drug release unit comprises the following components:

4. The far infrared heating medicine composite patch of integrated fractal microchannel network according to claim 1, characterized in that, A drug carrier, which is mesoporous silica nanoparticles with a pore size of 2-10nm; A thermal response gel with a gel transition temperature of 30-35℃; A therapeutic drug, which is a non-steroidal anti-inflammatory drug or a traditional Chinese medicine extract.

6. The far infrared heating drug composite patch integrated with a fractal micro-channel network according to claim 1, wherein the inner surface of the fractal micro-channel network is subjected to hydrophilization treatment, and the hydrophilization treatment is performed by plasma treatment or silane coupling agent modification.

7. The far infrared heating drug composite patch integrated with a fractal micro-channel network according to claim 1, wherein ​ ​ ​ ​ As a joint site patch, high flexibility is required to adapt to skin deformation, the fractal dimension of the fractal micro-channel network is 1.5-1.6, which is used to reduce the branch density and avoid the fracture of the channel when bending; As a torso flat site patch, the fractal dimension of the fractal micro-channel network is 1.7-1.8, which is used to maximize the contact area; As a child patch, the fractal dimension is 1.6, and the overall width of the channel is enlarged to 500-900μm, which is used to reduce the physical compression of the channel to the skin.

8. The far infrared heating medicine composite patch of integrated fractal microchannel network according to claim 1, characterized in that, The thickness of the far-infrared colloid layer is 0.1mm-5mm, and the depth of the fractal micro-channel is 50-150μm.

9. The far infrared heating medicine composite patch of integrated fractal microchannel network according to claim 1, characterized in that, The main body layer adopts polyurethane film, polyamide film, silicone rubber film or TPU film.

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