Application of high-dielectric composite material in patch electrode for tumor electric field treatment

Abstract

The invention discloses application of a high-dielectric composite material in a patch electrode for tumor electric field treatment, and relates to the technical field of medical instruments. The high-dielectric composite material comprises a conductive three-dimensional skeleton layer, a high-dielectric inorganic shell layer and a flexible interface layer, the surface of the conductive three-dimensional skeleton layer is coated with the high-dielectric inorganic shell layer, and the conductive three-dimensional skeleton layer and the high-dielectric inorganic shell layer are filled with the flexible interface layer. The composite material provided by the invention has the characteristics of high dielectric, low loss and good heat dissipation performance, is applied to a flexible patch electrode for body surface capacitance coupling of a 100-500 kHz intermediate frequency alternating electric field, can significantly improve the in-vivo electric field intensity and deep coverage on the premise of not increasing the output voltage of equipment, and reduces the power consumption and skin adverse reaction at the same time.

Description

Technical Field

[0001] This invention relates to the technical field of medical devices, and more particularly to the application of a high-dielectric composite material in patch electrodes for tumor electric field therapy. Background Technology

[0002] Tumor treating fields (TTF) is a treatment that uses low-intensity, medium-frequency (100-500 kHz) alternating electric fields to act on human tissues, interfering with the mitotic process of cells and thus inhibiting and destroying rapidly proliferating cells. It is primarily used for the treatment of tumors. This type of tumor treatment is known internationally as alternating electric field therapy or Tumor Treating Fields (TTFields, hereinafter referred to as TTF). It is a technology that developed after 2000. In 2011, TTF treatment for gliomas received FDA approval in the United States, and related treatment devices were launched in Hong Kong in 2018. In 2019, TTF treatment for malignant pleural mesothelioma also received FDA approval. To date, phase III clinical trials for various tumors have yielded promising results, making it a promising tumor treatment technology.

[0003] Existing TTF devices mostly use small-sized rigid ceramic electrode pads. Due to the curvature of the human body, there are warped edges, voids, and stress concentrations, which reduces the effective coupling area and increases the interfacial air gap. This results in a decrease in the equivalent coupling capacitance, and under the condition of limited port voltage, the electric field strength and energy coupling efficiency within the tissue are limited. Furthermore, the thickness and impermeability of rigid ceramic electrode pads can easily cause skin irritation and inflammation, affecting long-term compliance (>18 hours / day). Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an application of a high-dielectric composite material in patch electrodes for tumor electric field therapy. The composite material of this invention features high dielectric strength, low loss, and good heat dissipation. When applied to a flexible patch electrode with surface capacitive coupling of a 100-500 kHz mid-frequency alternating electric field, it can significantly improve the intensity and depth of the electric field within the body without increasing the device's output voltage, while simultaneously reducing power consumption and adverse skin reactions.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides an application of a high-dielectric composite material in a patch electrode for tumor electric field therapy. The high-dielectric composite material includes a conductive three-dimensional framework layer, a high-dielectric inorganic shell layer, and a flexible interface layer. The high-dielectric inorganic shell layer covers the surface of the conductive three-dimensional framework layer, and the flexible interface layer fills the conductive three-dimensional framework layer and the high-dielectric inorganic shell layer.

[0006] The tumors treated in the tumor electric field therapy described in this invention include, but are not limited to: (1) Central nervous system: glioblastoma multiforme (GBM), anaplastic astrocytoma, oligodendroglioma, brain metastases (including primary metastases from the lungs / breast to the brain); (2) Chest: Malignant pleural mesothelioma; lung cancer; (3) Digestive system: pancreatic cancer, liver cancer, biliary tract cancer, stomach cancer, esophageal cancer, colorectal cancer; (4) Urinary and reproductive system: renal cell carcinoma, bladder cancer, prostate cancer, ovarian cancer, endometrial cancer, cervical cancer; (5) Breast and endocrine system: breast cancer, thyroid cancer; (6) Head and neck skin and soft tissue: squamous cell carcinoma of the head and neck, soft tissue sarcoma, melanoma; (7) Bone and metastasis: bone tumors, bone metastases; (8) Pediatric solid tumors: medulloblastoma, neuroblastoma, rhabdomyosarcoma.

[0007] The aforementioned tumors include both tumors in humans and various solid tumors in pets.

[0008] Preferably, the material of the conductive three-dimensional skeleton layer can be selected from Ni, Ni-Cr alloy, Ni-Co alloy, Cu-Ni alloy, Ti, Ta, Mo, W, stainless steel (Fe-Cr-Ni system), Ni-Mo, Ni-W and their mixed-based foam or metal fiber materials; or from nickel-titanium alloy, titanium-molybdenum alloy, tantalum-niobium alloy metal fabric, woven mesh, knitted mesh or fiber felt. Because the above materials have very high melting points, the skeleton can remain stable during sintering.

[0009] Preferably, the conductive three-dimensional skeleton layer is a three-dimensional conductive skeleton with interconnected openings, having an opening rate of 70-99%, an average pore size of 30-1500 μm, and a thickness of 5-3000 μm.

[0010] The conductive three-dimensional framework layer described in this invention has an surface resistance of ≤1.0 Ω / m at 200 kHz. 2 Preferably ≤0.3Ω / m 2 A continuous conductive network is maintained under sintering in an inert atmosphere (air atmosphere or various common mixed gas atmospheres) at >1000°C.

[0011] Preferably, the monofilament diameter of the metal fabric / woven mesh / knitted mesh / fiber felt is 5-500 μm, and the porosity is 30-90%.

[0012] Preferably, the material of the high-dielectric inorganic shell includes at least one of ferroelectric / relaxed ferroelectric and giant dielectric materials.

[0013] Preferably, the ferroelectric / relaxed ferroelectric material includes at least one of BaTiO3 and its modified solid solution materials, lead-based materials, and bismuth-based ferroelectric materials.

[0014] More preferably, the BaTiO3 and its modified solid solution materials include at least one of Ba(Sn,Ti)O3, Ba(Zr,Ti)O3, Ba(Sr,Ti)O3, and Ba(Ca,Zr,Ti)O3.

[0015] More preferably, the lead-based material includes lead titanate (PbTiO3) and lead zirconate titanate (Pb(Zr)). x Ti 1-x O3 (PZT), Mg-modified lead magnesium niobate Pb (Mg 1 / 3 Nb 2 / 3 )O3-PbTiO3 (PMN-PT), Pb(Zn 1 / 3 Nb 2 / 3 At least one of O3-PbTiO3 (PZN-PT) and Bi-based bismuth titanate lead.

[0016] More preferably, the bismuth-based ferroelectric material includes BiFeO3 and Bi4Ti3O. 12 Na 0.5 Bi 0.5 At least one of TiO3.

[0017] Preferably, the giant dielectric material comprises CaCu3Ti4O 12 SrCu3Ti4O 12 La 0.5 Ba 0.5 At least one of TiO3.

[0018] The high-dielectric inorganic shell material of the present invention requires continuous coating or core-shell structure of the conductive three-dimensional framework layer, with a shell thickness of 5-300 μm, a dielectric constant of ≥1000 at 10-500 kHz, preferably ≥5000, and a loss angle tanδ≤0.2.

[0019] This invention significantly improves the dielectric properties of composite materials by coating the conductive three-dimensional framework layer with a high-dielectric inorganic shell, while interface polarization enhances the dielectric constant.

[0020] Preferably, the material of the flexible interface layer includes PDMS silicone, polyurethane elastomer, epoxy resin and polyetheramine curing system, acrylic resin, polyester, multiblock copolymer (such as SEBS), polyether ester (TPEE), polyimide (PI), and may also include at least one of polyvinylidene fluoride (PVDF) and its copolymers (PVDF-HFP, P(VDF-TrFE)), polyether ether ketone (PEEK), and polyether sulfone (PES).

[0021] Preferably, the material of the flexible interface layer has a viscosity of 100-20000 mPa·s at 25°C. The viscosity described in this invention is obtained by testing using ASTM D1084 / D2196.

[0022] Preferably, the mass ratio of the conductive three-dimensional framework layer, the high-dielectric inorganic shell layer, and the flexible interface layer is (1-5):(6-14):(3-10), more preferably (2-4):(8-12):(4-8). The conductive three-dimensional framework layer has ultra-high porosity (90-97%) and a limited mass proportion; the high-dielectric inorganic shell layer is a 10-100 μm shell layer, which determines the main dielectric pathway; the flexible interface layer is used to ensure filling, interface, and skin-friendliness. The high-dielectric composite material with the above mass ratio belongs to the "high-dielectric-high-coupling" type, which can be fully filled, maximize coupling capacitance, reduce capacitive reactance, and is suitable for high field strength scenarios.

[0023] Preferably, the mass ratio of the conductive three-dimensional skeleton layer, the high-dielectric inorganic shell layer, and the flexible interface layer is (1-5):(4-10):(5-12), and more preferably (2-4):(5-9):(7-11). The high-dielectric composite material using the above mass ratio is of the "breathable-uniform temperature" type, with semi-injection and perforation. The increased proportion of the flexible interface layer, combined with the addition of thermally conductive filler (BN / AlN 5-20wt%), helps improve the in-plane thermal conductivity of the composite material, making it suitable for products that offer long-term comfort and good heat dissipation under the skin.

[0024] Preferably, the mass ratio of the conductive three-dimensional skeleton layer, the high-dielectric inorganic shell layer, and the flexible interface layer is (1-6):(2-8):(8-14), and more preferably (2-5):(3-7):(9-13). The high-dielectric composite material using the above mass ratio is of the "lightweight-high flexibility" type. The high-dielectric inorganic shell layer has a smaller thickness, and combined with the porous nature of the flexible interface layer, it is suitable for products with large curvature or moving parts.

[0025] Preferably, the method for preparing the high-dielectric composite material includes the following steps: (1) Add the high dielectric inorganic shell material to an organic solvent and stir for 3-4 h, then sonicate for 20-30 min to obtain a mixed solution after uniform dispersion; (2) Electrophoretic deposition is performed using a DC power supply, with a platinum sheet as the positive electrode and a conductive three-dimensional framework layer as the negative electrode. The spacing between the conductive three-dimensional framework layer and the platinum sheet is 10-25 mm. Deposition is carried out at a voltage of 40V. The deposition time is set to 8-10 min for single-sided electroplating, and electroplating is performed once on each side. (3) Under a protective atmosphere, sinter at 1000-1300℃ for 1-2 h, and after cooling, a composite material with a high dielectric inorganic shell layer covering a conductive three-dimensional skeleton layer is obtained. (4) The material of the flexible interface layer is injected into the pores of the composite material with the high dielectric inorganic shell layer covering the conductive three-dimensional skeleton layer to obtain the high dielectric composite material.

[0026] Preferably, polyethyleneimine may be added in step (1), which allows the high-dielectric inorganic shell layer to better coat the surface of the conductive three-dimensional framework layer, thereby improving the performance of the composite material. Furthermore, polyethyleneimine decomposes after high-temperature sintering without affecting the material's performance.

[0027] Preferably, in step (2), the conductive three-dimensional framework layer is preprocessed, and the specific steps are as follows: S1: Immerse the conductive three-dimensional framework layer in acetone solution and ultrasonically clean for 20-30 min; S2: After removing the acetone solution, add deionized water and continue sonication for 10-15 min. S3: Remove deionized water, then add anhydrous ethanol and sonicate for 10-15 minutes for cleaning.

[0028] Secondly, the present invention also provides a patch electrode for tumor electric field therapy, which is made of the above-mentioned high dielectric composite material.

[0029] The patch electrode prepared by this invention is also suitable for other scenarios where AC voltage or alternating electric field needs to be transmitted into the body for treatment.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In this invention, a conductive three-dimensional framework layer forms a continuous conductive network, and a high-dielectric inorganic shell layer uniformly and continuously coats the conductive three-dimensional framework layer, forming a core-shell structure. The flexible interface layer, by filling the pores within the conductive three-dimensional framework layer and the high-dielectric inorganic shell layer, enhances the softness and comfort of the high-dielectric composite material. Therefore, this invention, through the combined use of a conductive three-dimensional framework layer, a high-dielectric inorganic shell layer, and a flexible interface layer, enables the high-dielectric composite material to possess high dielectric strength, low loss, and good heat dissipation characteristics, making it suitable for flexible high-dielectric patch electrodes with surface capacitive coupling in 100-500 kHz mid-frequency alternating electric fields.

[0031] 2. This invention can significantly improve therapeutic efficacy and reduce energy consumption. The electric field strength at the tumor site is a decisive factor in the effectiveness of TTF treatment. Due to the limitations of wearable devices in terms of applied voltage, increasing the field strength within the body encounters a bottleneck. This invention, through a large, flexible patch that fits perfectly against the body and has a high dielectric constant, can significantly increase the electric field strength at the tumor site, thereby enhancing therapeutic efficacy. Simultaneously, since the device operates for at least 18 hours a day, the frequency of battery replacement is a crucial consideration affecting patient compliance. This invention achieves the same internal electric field as current high-voltage devices using a lower voltage, thus reducing device power consumption.

[0032] 3. The patch processing steps described in this invention are fewer, less costly, and lighter. Competing products use a multi-layer bonding process, while this invention employs an integrated processing method, resulting in lower cost and weight compared to competing products. This can help address patients' financial difficulties and improve their adherence to treatment.

[0033] 4. The high-dielectric composite material described in this invention is fully breathable, which can suppress the side effects of scalp irritation and offers strong customization capabilities. Existing product design and processing technology dictate that a significant portion of competing products are not breathable, while the patch described in this invention allows for easy perforation, making the entire patch breathable and thus suppressing scalp irritation during treatment. Furthermore, the flexible patch electrode of this invention can be directly cut and processed, greatly reducing the difficulty of secondary processing and thus supporting personalized customization. Attached Figure Description

[0034] Figure 1 This is a scanning electron microscope image of the cross-section of the nickel foam in Example 1.

[0035] Figure 2 This is a scanning electron microscope image of the cross-section of the barium titanate plated in Example 1.

[0036] Figure 3 This is a scanning electron microscope image of the cross-section of the material after high-temperature sintering in Example 1.

[0037] Figure 4 This is a scanning electron microscope image of the cross-section of the material after gel casting in Example 1.

[0038] Figure 5 This is a simulation model diagram used to test the electric field strength in the human brain.

[0039] Figure 6 This is a true simulation of the electric field generated in the human brain by a rigid electrode (2cm in diameter).

[0040] Figure 7 This is a true-to-life image simulating the electric field generated in the human brain by a rigid electrode (4cm in diameter).

[0041] Figure 8This is a true-to-life image simulating the electric field generated in the human brain by a flexible patch electrode (2cm in diameter).

[0042] Figure 9 This is a true-to-life image simulating the electric field generated in the human brain by a flexible patch electrode (4cm in diameter).

[0043] Figure 10 This is a comparison chart of temperature changes between flexible patch electrodes and rigid electrodes.

[0044] Figure 11 This is a picture of a rabbit being tested for skin surface temperature. Detailed Implementation

[0045] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the scope of protection and implementation of the present invention are not limited thereto.

[0046] Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0047] Example 1 A method for preparing a high-dielectric composite material includes the following steps: (1) Pretreatment of nickel foam is carried out, and the specific steps are as follows: S1: Place the nickel foam in a beaker, add acetone solution to immerse the nickel foam, and ultrasonically clean for 30 min; S2: After removing the acetone solution, add deionized water and continue sonication for 15 min; S3: Remove deionized water, then add anhydrous ethanol and sonicate for 15 minutes for cleaning.

[0048] (2) Add 1g of barium titanate powder and 0.5g of polyethyleneimine to a beaker, then add 50mL of isopropanol, stir at room temperature for 4 h, then sonicate for 30 min, and obtain a mixed solution after uniform dispersion.

[0049] (3) Electrophoretic deposition was performed using a DC power supply, with a platinum sheet as the positive electrode and pretreated nickel foam as the negative electrode. The distance between the nickel foam and the platinum sheet was 10 mm, and deposition was carried out at a voltage of 40 V. The deposition time was set to 10 min for single-sided electroplating, and electroplating was performed once on each side.

[0050] (4) Under a nitrogen atmosphere, the temperature was raised from room temperature to 1300℃ and kept at that temperature for 2 hours. After cooling, a composite material of barium titanate coated nickel foam was obtained.

[0051] (5) Adhesive casting - epoxy resin (AB glue) The composite material of barium titanate-coated nickel foam was dried at 100°C for 30 minutes; the epoxy resin (AB glue, source: Shenzhen Yikai Electronics) was placed in a vacuum to degas for 10 minutes until the foam disappeared. The dried barium titanate-coated nickel foam composite material is placed on a liquid receiving tray, and epoxy resin (AB glue) is slowly poured in until the barium titanate-coated nickel foam composite material is completely immersed. A vacuum is drawn and maintained for 5 minutes to allow the air in the pores of the barium titanate-coated nickel foam composite material to escape. Then, it is slowly returned to normal pressure. The pressure difference is used to drive the epoxy resin (AB glue) into the pores of the barium titanate-coated nickel foam composite material, thus obtaining the high dielectric composite material.

[0052] like Figure 1-4 As shown, the present invention uses scanning electron microscopy to capture the material structure diagrams after nickel foaming, barium titanate electroplating, sintering, and gel casting, respectively, showing that the materials were successfully composited at each step.

[0053] In this embodiment, the mass ratio of the nickel foam, barium titanate, and epoxy resin is 3:8:5.

[0054] Example 2 The difference from Example 1 is that the mass ratio of the foamed nickel, barium titanate, and epoxy resin is 1:6:5.

[0055] Example 3 The difference from Example 1 is that the mass ratio of the foamed nickel, barium titanate, and epoxy resin is 5:14:3.

[0056] Example 4 The difference from Example 1 is that the high dielectric composite material includes Ni-Cr alloy foam and CaCu3Ti4O. 12 The three components—polyurethane elastomer, polyurethane elastomer, and polyurethane elastomer—are in a mass ratio of 1:5:3.

[0057] Example 5 The difference from Example 1 is that the high dielectric composite material includes nickel-titanium alloy metal fabric, lead titanate, and PDMS silicone, with a mass ratio of 3:4:7.

[0058] Comparative Example 1 The difference from Example 1 is that the mass ratio of the foamed nickel, barium titanate, and epoxy resin is 1:8:20.

[0059] Comparative Example 2 The difference from Example 1 is that the mass ratio of the foamed nickel, barium titanate, and epoxy resin is 5:10:1.

[0060] Comparative Example 3 The difference from Example 1 is that an equal mass of foamed Cu is used instead of foamed nickel.

[0061] Comparative Example 4 The difference from Example 1 is that an equal mass of titanium dioxide is used instead of barium titanate.

[0062] Comparative Example 5 The difference from Example 1 is that an equal mass of polytetrafluoroethylene is used instead of epoxy resin.

[0063] Experiment 1: Dielectric Constant and Dielectric Loss Test The dielectric constants of the high-dielectric composite materials prepared in Examples 1-5 and Comparative Examples 1-5 were tested respectively. The testing standard was as follows: all samples were cut into flat plates with a thickness of approximately 1.0 mm and an area of ​​20 mm × 20 mm. After being vacuum dried at 80℃ for 2 h, silver electrodes were formed on both sides of the samples by sputtering. The dielectric constant and dielectric loss were tested according to GB / T 1409-2006 "Determination of Dielectric Constant and Dielectric Loss Factor of Solid Electrical Insulating Materials" standard, using the parallel plate capacitance method. The tests were conducted at 25℃ and 50% relative humidity using an LCR meter (Keysight E4980A, with matching parallel plate capacitance test fixture) in the frequency range of 100-500 kHz. The dielectric constant and dielectric loss data listed in Table 1 are values ​​measured at a frequency of 200 kHz.

[0064] The test results are shown in Table 1.

[0065] Table 1 As shown in Table 1, the present invention employs a conductive three-dimensional skeleton layer, a high-dielectric inorganic shell layer, and a flexible interface layer in combination to give the composite material the characteristics of high dielectric and low loss, making it suitable for flexible high-dielectric patch electrodes with surface capacitive coupling in 100-500 kHz mid-frequency alternating electric fields.

[0066] Experiment 2: Investigation of the electric field intensity generated in the brain by flexible patch electrodes and rigid electrodes 1. Modeling parameter settings (1) Outer radius of head (including scalp): R head =92 mm; (2) Scalp thickness: 3 mm; (3) Skull thickness: 7 mm; (4) Cerebrospinal fluid thickness: 2 mm; (5) Radius of brain parenchyma: 80 mm (innermost layer); (6) Tumor: radius r tumor =10 mm, located in the brain about 20 mm below the scalp; (7) Gel thickness: 1mm (cylinder, covering between ceramic and scalp); (8) The ceramic patch has a thickness of 1mm, but different values ​​for diameter and dielectric constant.

[0067] 2. Taking glioma as an example, the finite element electric field intensity simulation in the brain uses a 200KHz frequency, sine wave, and 50Vpp voltage to be transmitted to the skin surface through a dielectric ceramic sheet and gel patch, and then further transmitted to the tumor site in the brain.

[0068] The electric field strength generated at brain tumor sites by rigid and flexible ceramic sheets of different sizes (2 cm and 4 cm in diameter) was compared. Since the human brain is approximately spherical, a spherical model was used to represent the brain for easier comparison of the properties of rigid and flexible ceramics. (See model image). Figure 5 The flexible ceramic sheet used in the test was the high-dielectric composite material prepared in Example 1.

[0069] This invention is only intended to illustrate the difference in the magnitude of the electric field intensity in the brain caused by properties such as the fit of hard and flexible ceramics to the head. Therefore, only one pair of ceramic electrodes is selected for simulation comparison to obtain intuitive comparison results. It does not represent the magnitude of the electric field intensity in the brain during actual tumor electric field therapy (in actual use, dozens of ceramic electrodes are usually used to form an electric field transducer array to enhance the electric field intensity of brain tumors).

[0070] like Figure 6-7 As shown, hard ceramics with diameters of 2cm and 4cm, due to their inflexibility, cannot conform to the curvature of the head, resulting in severe edge warping. This means that only a small portion of the ceramic in close contact with the skin generates an electric field, with a maximum electric field strength of ~4×10⁻⁶. 4 The electric field strength of V / m appears in the scalp area where the ceramic adheres tightly, and this extremely high electric field strength in such a small area can easily damage the skin. At the same time, regardless of the size of the hard ceramic, the electric field strength inside the tumor (at the very center) is relatively small, approximately 0.57 V / m.

[0071] Flexible ceramics, such as Figure 8-9 As shown, because it can closely conform to the curvature of the head, the maximum electric field intensity at the scalp site where the ceramic adheres is one order of magnitude smaller than that of hard ceramic. Furthermore, as the ceramic area increases (diameter from 2cm to 4cm), the maximum electric field intensity at the scalp site gradually decreases, protecting the scalp from electric field damage. Simultaneously, with the increase in ceramic area, the electric field intensity inside the tumor (at its very center) is 15 V / m and 26 V / m, respectively, which are 26 and 46 times that of the hard electrode, demonstrating a significant comparative advantage.

[0072] Experiment 3: Investigation of the heat dissipation properties of flexible patch electrodes and rigid electrodes like Figure 11 As shown, hair was removed from two opposite areas on the rabbit's back to make the skin surface smooth. After thorough cleaning, hair was removed from each area, which was 4cm in size. 2 Rigid and flexible electrodes of varying sizes were attached to the rabbit skin surface using gel. The instrument was then turned on, and a 200kHz sine wave was generated by a signal generator (Tektronix AFG31102). The voltage amplitude was then increased to 50Vpp by a high-voltage amplifier (Aigtek, ATA-2041), and finally, voltage was distributed to each electrode via a voltage distribution module. An orthogonal electric field mode was used, with each electrode alternating for 1 second. This setting is a classic parameter commonly used in electric field therapy for gliomas, as detailed in the references (CNS Neurosci Ther. 2021;27:1587-1604 and TumorDiscovery 2025, 4(2), 55-65). Thermocouples were attached between the ceramic electrodes and the rabbit skin to record temperature changes in real time. The flexible electrode used in the test was made from the high-dielectric composite material prepared in Example 1.

[0073] like Figure 10 As shown, within 30 minutes of operation, a pair of rigid electrodes can reach and maintain a temperature of 40.3°C, while the flexible electrode can reach and maintain a temperature of 38.5°C, which fully demonstrates that the heat generation and dissipation of the flexible electrode are superior to those of the traditional rigid electrode.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. The application of a high-dielectric composite material in patch electrodes for tumor electric field therapy, characterized in that, The high-dielectric composite material includes a conductive three-dimensional framework layer, a high-dielectric inorganic shell layer, and a flexible interface layer. The high-dielectric inorganic shell layer covers the surface of the conductive three-dimensional framework layer, and the flexible interface layer fills the conductive three-dimensional framework layer and the high-dielectric inorganic shell layer.

2. The application as described in claim 1, characterized in that, The material of the conductive three-dimensional skeleton layer is selected from Ni, Ni-Cr alloy, Ni-Co alloy, Cu-Ni alloy, Ti, Ta, Mo, W, stainless steel, Ni-Mo, Ni-W and their mixed-based foam or metal fiber materials; Alternatively, the material of the conductive three-dimensional skeleton layer is selected from nickel-titanium alloy, titanium-molybdenum alloy, tantalum-niobium alloy metal fabric, woven mesh, knitted mesh or fiber felt.

3. The application as described in claim 1, characterized in that, The conductive three-dimensional framework layer has an opening rate of 70-99%, an average pore size of 30-1500 μm, and a thickness of 5-3000 μm.

4. The application as described in claim 1, characterized in that, The material of the high-dielectric inorganic shell includes at least one of ferroelectric / relaxed ferroelectric and giant dielectric materials.

5. The application as described in claim 4, characterized in that, The ferroelectric / relaxed ferroelectric material includes at least one of BaTiO3 and its modified solid solution materials, lead-containing materials, and bismuth-based ferroelectric materials. And / or, the giant dielectric material includes CaCu3Ti4O 12 SrCu3Ti4O 12 La 0.5 Ba 0.5 At least one of TiO3.

6. The application as described in claim 1, characterized in that, The thickness of the high-dielectric inorganic shell is 5-300 μm.

7. The application as described in claim 1, characterized in that, The flexible interface layer is made of at least one of PDMS silicone, polyurethane elastomer, epoxy resin and polyetheramine curing system, acrylic resin, polyester, multiblock copolymer, polyether ester, polyimide, polyvinylidene fluoride, polyether ether ketone, and polyether sulfone.

8. The application as described in claim 1, characterized in that, The mass ratio of the conductive three-dimensional skeleton layer, the high-dielectric inorganic shell layer and the flexible interface layer is (1-5):(6-14):(3-10). Alternatively, the mass ratio of the conductive three-dimensional framework layer, the high-dielectric inorganic shell layer, and the flexible interface layer is (1-5):(4-10):(5-12). Alternatively, the mass ratio of the conductive three-dimensional skeleton layer, the high-dielectric inorganic shell layer, and the flexible interface layer is (1-6):(2-8):(8-14).

9. The application as described in claim 1, characterized in that, The preparation method of the high dielectric composite material includes the following steps: (1) Add the high dielectric inorganic shell material to an organic solvent and stir for 3-4 h, then sonicate for 20-30 min to obtain a mixed solution after uniform dispersion; (2) Electrophoretic deposition is performed using a DC power supply, with a platinum sheet as the positive electrode and a conductive three-dimensional framework layer as the negative electrode. The spacing between the conductive three-dimensional framework layer and the platinum sheet is 10-25 mm. Deposition is carried out at a voltage of 40V. The deposition time is set to 8-10 min for single-sided electroplating, and electroplating is performed once on each side. (3) Under a protective atmosphere, sinter at 1000-1300℃ for 1-2 h, and after cooling, a composite material with a high dielectric inorganic shell layer covering a conductive three-dimensional skeleton layer is obtained. (4) The material of the flexible interface layer is injected into the pores of the composite material with the high dielectric inorganic shell layer covering the conductive three-dimensional skeleton layer to obtain the high dielectric composite material.

10. A patch electrode for tumor electric field therapy, made of the high dielectric composite material as described in any one of claims 1-9.

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