Ceramic, insulated electrode and preparation method thereof, and tumor electric field treatment system

Abstract

The invention provides a ceramic and a preparation method thereof, an insulated electrode prepared from the ceramic, a preparation method of the insulated electrode and a tumor electric field treatment system. The chemical general formula of the ceramic is Pb (0.92-x-y) BaxSrySm < 0.08 > {[Zr (1-a) Tia] 0.95 [Mg (0.99-m) SbmY < 0.01 >] 0.05} O3. The ceramic has a high dielectric constant and low dielectric loss, and the ceramic insulation electrode made of the ceramic has a high capacitance value, a small area and enough thickness so as to ensure the mechanical strength and voltage resistance of the insulation electrode due to the fact that the ceramic insulation electrode is made of a ceramic material with the high dielectric constant; and the insulating electrode can ensure that the electric field intensity is improved, and meanwhile, low-temperature scald to a subject can be avoided when an alternating electric signal is applied for a long time.

Description

Technical Field

[0001] The present invention relates to a ceramic for tumor treatment, a preparation method thereof, an insulating electrode prepared by using the ceramic, a preparation method thereof, and a tumor electrotherapy system, and belongs to the technical field of functional ceramics. Background Art

[0002] At present, the main treatment methods for tumors include surgery, radiotherapy, chemotherapy, etc., but they all have corresponding disadvantages. For example, radiotherapy and chemotherapy will produce side effects and kill normal cells. Using electric fields to treat tumors is also one of the current research frontiers. Tumor electrotherapy is a tumor treatment method that generates a low-intensity, medium-high frequency, alternating electric field through a special electric field generating device to interfere with the mitotic process of tumor cells. Research shows that electrotherapy is effective in the treatment of diseases such as glioblastoma, non-small cell lung cancer, and malignant pleural mesothelioma. The electric field applied by the tumor treatment method can affect the aggregation of tubulin, prevent the formation of the spindle, inhibit the mitotic process, and induce apoptosis of cancer cells.

[0003] The electric energy generated by the signal source in tumor electrotherapy is transmitted to the vicinity of the body through a conductor and then transmitted to the target tissue in a capacitive coupling manner through a pair of insulating electrodes. This kind of electric field only generates displacement current and mainly works according to the dielectric properties of the tissue when acting on the patient's tissue. Dividing tumor cells and normal cells have different polarization characteristics at a specific frequency (such as 100KHz - 500KHz). Under the action of an electric field with a certain electric field intensity and a specific frequency, due to polarization, the pressure at the division junction of dividing tumor cells increases, resulting in the destruction of the dividing tumor cells. Therefore, in medicine, the characteristic that a specific frequency electric field can selectively destroy dividing and proliferating tumor cells without destroying non-dividing normal cells can be used to treat tumors.

[0004] When treating tumors using this principle, a pair of insulating electrodes acting as capacitors serve as the core components. One surface is connected to a signal source through a metal electrode (the metal electrode serves as one electrode surface of the capacitor), a PCB board, and a wire respectively, and the other surface is in close contact with the skin on both sides of the body (the skin can be regarded as the other electrode surface of the capacitor), forming a capacitive coupling mode of insulating electrode - target tissue - insulating electrode. In this case, on the one hand, in order to enable the insulating electrode to closely fit the body skin, the area of the insulating electrode should not be too large; on the other hand, in order to make the field strength destructive force applied to the target tissue sufficient, the pair of insulating electrodes serving as coupling capacitors need to have a sufficiently large capacitance value. According to the principle of series voltage division of capacitors, the larger the capacitance, the smaller the voltage division, and the smaller the voltage drop of the voltage applied by the signal source on the insulating electrode. There are three ways to increase the capacitance of the insulating electrode: 1. Increase the area, 2. Reduce the thickness, 3. Use materials with ultra-high dielectric constants. Among them, increasing the area is not conducive to the fit between the insulating electrode and the body, and reducing the thickness will cause a decrease in mechanical strength and withstand voltage strength, which is not conducive to increasing the field strength. Therefore, selecting an insulating electrode prepared from a material with an ultra-high dielectric constant becomes the best way to increase the electric field strength and improve the inhibition of cell mitosis by electric field therapy in the field of tumor electric field therapy.

[0005] For example, the insulating electrode disclosed in Chinese Invention Publication Patent No. 112479709 is prepared from a ceramic with a dielectric constant greater than 20,000 and a small dielectric loss. When this insulating electrode is used for tumor electric field therapy with the same applied alternating voltage and the same usage time, due to its preparation from a ceramic with an ultra-high dielectric constant, the capacitance value between the two insulating electrodes increases, and the electric field strength generated between the two insulating electrodes also increases significantly. However, due to the increase in capacitance value, the medium between the two insulating electrodes (the patient tissue between the two insulating electrodes attached to the corresponding body surface of the patient's lesion site) is subjected to a greatly increased alternating electric field, resulting in a much higher temperature rise change in the patient part between the two insulating electrodes than the temperature rise change caused by the heat generation of the dielectric loss of the insulating electrode itself. That is, the temperature rise of the patient caused by the increase in capacitance value of this insulating electrode prepared from an ultra-high dielectric constant ceramic has a greater impact than the temperature rise of the patient caused by the heat generation of the ceramic material itself. When using this insulating electrode for tumor electric field therapy for a long time, the patient's temperature rises too fast. To avoid the patient suffering from low-temperature burns and shortening the electric field therapy time, or to avoid shortening the treatment time will cause the patient to suffer from low-temperature burns.

[0006] Therefore, there is an urgent need for an insulating electrode prepared from a ceramic material that takes into account the improvement of electric field strength, the application of alternating electric signals for a long time, and can avoid the patient suffering from low-temperature burns to meet the above requirements. Summary of the Invention

[0007] The object of the present invention is to provide a ceramic with high dielectric constant and low dielectric loss, a preparation method thereof, an insulating electrode prepared by using the ceramic, a method for preparing the insulating electrode by using the ceramic, and a tumor electrotherapy system.

[0008] Specifically, the present application is realized by the following technical solutions: A ceramic, the chemical general formula of the ceramic material is as follows: Pb (0.92-x-y) Ba x Sr y Sm 0.08 {[Zr (1-a) Ti a 0.95 [Mg (0.99-m) Sb m Y 0.01 0.05}O3.

[0009] According to an embodiment of the present invention, the value ranges of x, y, a, and m in the general formula should satisfy: 0.08 ≤ x + y ≤ 0.1; 0.39 ≤ a ≤ 0.41; 0.55 ≤ m ≤ 0.65.

[0010] The present application also provides the following technical solution: An insulating electrode for tumor electrotherapy, which is prepared from the above ceramic.

[0011] The present application is also realized by the following technical solutions: A preparation method of a ceramic, which is prepared according to the following steps:

[0012] Step 1. Weigh and prepare analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, and Y2O3 according to the stoichiometric ratio, and mix them by wet ball milling for 5 to 10 hours; material: water = 1: 0.3 to 0.8, and obtain a mixture after drying;

[0013] Step 2. Calcinate the mixture material at 800 to 1000 °C for 2 to 6 hours to obtain a pre-synthesized ceramic block;

[0014] Step 3. Add water and PVA aqueous solution to the pre-synthesized ceramic block, and mix and pulverize them by wet ball milling for 18 to 24 hours. Material: water: PVA aqueous solution = 1: 0.1 to 0.5: 0.07 to 0.15. After spray granulation of the pulverized slurry, granulated powder is obtained, and the spray granulation is centrifugal spray granulation;

[0015] Step 4. Press the granulated powder into a ceramic green body by using a molding die;

[0016] Step 5. First degrease the ceramic green body at a temperature of 700 to 900 °C; then sinter it in the range of 1200 to 1320 °C to obtain a ceramic sheet with high dielectric constant. ​​

[0017] According to one embodiment of the present invention, in step 1, the raw materials are weighed and prepared as follows: Pb3O4: 57.5~59.5%; BaCO3: 1.8~3.1%; SrCO3: 1.3~2.3%; ZrO2: 21.3~22.0%; TiO2: 9.1~9.6%; Sb2O3: 1.2~1.5%; MgO: 0.21~0.28%; Sm2O3: 4.25~4.35%; Y2O3: 0.02%.

[0018] According to one embodiment of the present invention, in step 5, the ceramic body is first sintered at a temperature within a range of 1200-1320° C. for 2-4 hours, and then, after cooling to room temperature, is sintered at a temperature within a range of 1220-1290° C. for 2.5 hours.

[0019] According to an embodiment of the present invention, in step 4, a through hole for accommodating the temperature sensor chip is provided in the center of the ceramic body.

[0020] The present application further provides the following technical solution: a method for preparing an insulated electrode, wherein the ceramic sheet obtained by the above-mentioned preparation method is subjected to the following steps:

[0021] Step 6. Grind the ceramic sheet to a thickness of 0.5 to 1.5 mm, and plate a metal electrode on the surface of the side where the ceramic sheet is connected to the flexible circuit board to obtain a ceramic insulating electrode. The pattern of the metal electrode has insulating edges at the inner and outer edges of the ceramic sheet, and the width of the insulating edge is 0.3 to 1.5 mm.

[0022] Step 7. Mount the ceramic insulating electrode on the flexible circuit board, and at the same time mount a temperature sensor chip on the flexible circuit board at the position corresponding to the central through hole of the ceramic sheet, using a reflow soldering process;

[0023] Step 8. Cover the other surface of the mounted insulated electrode that contacts the skin with a layer of hydrogel.

[0024] According to one embodiment of the present invention, the hydrogel is gelatin added with sodium polyacrylate and sodium alginate.

[0025] The present application also provides the following technical solution: an insulating electrode for electric field therapy of tumors, which is made of the above-mentioned ceramic.

[0026] The present application also provides the following technical solution: an insulating electrode for electric field therapy of tumors, which adopts a chemical formula of Pb (0.92-x-y) Ba x Sr y Sm 0.08 {[Zr (1-a) Ti a ] 0.95[Mg (0.99-m) Sb m Y 0.01 0.05}O3 ceramic material and prepared by the above method according to the above.

[0027] The present application also provides the following technical solution: A tumor electrotherapy system, which includes the above-mentioned insulating electrode.

[0028] The present application obtains a ceramic with a high dielectric constant and a small dielectric loss. The present application also provides a preparation method of the ceramic, an insulating electrode prepared by using the ceramic, and a method for preparing an insulating electrode by using the ceramic. The tumor electrotherapy system of the present application uses a ceramic insulating electrode made of the ceramic. Because it uses a ceramic material with a high dielectric constant, it has a small area and sufficient thickness while having a high capacitance value to ensure the mechanical strength and pressure resistance of the insulating electrode; and the ceramic insulating electrode has a low dielectric loss, and when an alternating current signal is applied for a long time, it increases the electric field strength generated between the two insulating electrodes while preventing the subject from being caused by the increase in the electric field strength. Tissue heating causes the temperature to rise too fast, so as to avoid causing low-temperature burns to the subject while ensuring that an alternating current signal is applied for a long time.

[0029] In addition, in the ceramic preparation method of the present application, the ceramic blank after degreasing is sintered twice, which not only improves the strength of the ceramic sheet but also reduces the defective rate of the ceramic sheet product from four to seven per thousand to less than one in ten thousand.

[0030] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Description of the Drawings

[0031] Figure 1 is the process flow chart for preparing the insulating electrode of the present invention;

[0032] Figure 2 is the equivalent circuit schematic diagram of the insulating electrode during operation;

[0033] Figure 3 is the schematic diagram of various ceramic insulating electrodes with different shapes;

[0034] Figures 4A to 4C is a variety of insulating electrode arrays.

[0035] Description of the reference numerals: Insulating electrode 1, silver electrode 2, through hole 3, insulating electrode array 4, flexible circuit board 5, ceramic insulating electrode 6, temperature sensor chip 7. Detailed Embodiments

[0036] ​Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices, systems, devices, and methods consistent with some aspects of the present application.

[0037] The ceramic of the present application for tumor electrotherapy has a high dielectric constant (e.g., about 5000) and a low dielectric loss (e.g., <0.08) at a relatively high frequency; the insulating electrode made of this ceramic can have a large capacitance (e.g., greater than 10 nF), a low dielectric loss, and a high breakdown voltage strength at a small area and appropriate thickness, which can ensure an increase in the electric field strength required for tumor electrotherapy while considering the temperature rise caused by heat generation when an alternating electric signal is applied for a long time, and avoid hypothermia burns of the subject so that it can be allowed to be applied with an alternating electric signal for a long time; this insulating electrode also facilitates real-time monitoring of the temperature of the insulating electrode, has a certain elasticity, can be in close contact with the skin, and has biocompatibility.

[0038] The chemical general formula of the ceramic material of the present application is as follows:

[0039] Pb (0.92-x-y) Ba x Sr y Sm 0.08 {[Zr (1-a) Ti a 0.95 [Mg (0.99-m) Sb m Y 0.01 0.05}O3

[0040] Among them, x represents the molar fraction of Ba in the component, y represents the molar fraction of Sr in the component, and 0.08 ≤ x + y ≤ 0.1; a represents the molar fraction of Ti in the component, and 0.39 ≤ a ≤ 0.41; m represents the molar fraction of Sb in the component, and 0.55 ≤ m ≤ 0.65.

[0041] The following is the specific chemical general formula of some preferred embodiments of the ceramic material of the present application:

[0042] Chemical formula 1: Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg (0.39 Sb 0.6 Y 0.01 ​​​​0.05}O3.

[0043] Chemical formula 2: Pb 0.84 Ba 0.03 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3.

[0044] Chemical formula 3: Pb 0.84 Ba 0.5 Sr 0.03 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3.

[0045] Chemical formula 4: Pb 0.84 Ba 0.04 Sr 0.04 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3.

[0046] Chemical formula 5: Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.59 Ti 0.41 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3.

[0047] Chemical formula 6: Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.61 Ti 0.39 0.95 [Mg 0.39 Sb 0.6 Y 0.01 ​​​​​​​​​​0.05}O3。

[0048] Chemical formula 7: Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.44 Sb m0.55 Y 0.01 0.05}O3。

[0049] Chemical formula 8: Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.34 Sb m0.65 Y 0.01 0.05}O3。

[0050] This application also provides an insulating electrode for tumor electric field therapy, which is prepared from the above-mentioned ceramic according to the following method.

[0051] Refer to Figure 1 As shown, this application also provides a preparation method of using the above-mentioned ceramic and a method of using the ceramic to prepare an insulating electrode, including the following steps:

[0052] Step 1. Weigh and prepare raw materials such as analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3, etc. according to the stoichiometric ratio of each chemical formula (Pb3O4: 57.5 - 59.5%; BaCO3: 1.8 - 3.1%; SrCO3: 1.3 - 2.3%; ZrO2: 21.3 - 22.0%; TiO2: 9.1 - 9.6%; Sb2O3: 1.2 - 1.5%; MgO: 0.21 - 0.28%; Sm2O3: 4.25 - 4.35%; Y2O3: about 0.02%); Mix them by wet ball milling for 5 - 10 hours; Preferably, the mixing time is 8 hours; The ratio of material to water = 1:0.3 - 0.8, preferably, the ratio of material to water = 1:0.5, and obtain a mixture after drying;

[0053] Step 2. Calcinate the mixture material obtained in Step 1 at 800 - 1000 °C for 2 - 6 hours; Preferably, the calcination temperature is 900 °C and the holding time is 4 hours to obtain a pre-synthesized ceramic block;

[0054] ​​​​Step 3. Add water and PVA aqueous solution to the pre-synthesized ceramic mass obtained in Step 2, and perform wet ball milling, pulverizing, and mixing for 18 - 24 hours; preferably, the pulverizing time is 20 hours; the ratio of material: water: PVA aqueous solution = 1: 0.1 - 0.5: 0.07 - 0.15, preferably, the ratio of material: water: PVA aqueous solution = 1: 0.3: 0.1. After pulverizing, the slurry is spray granulated to obtain granulated powder, and the spray granulation is centrifugal spray granulation;

[0055] Step 4. Use the corresponding molding die to dry press the granulated powder obtained in Step 3 under a pressure of about 2 tons per square centimeter to obtain a ceramic green body with the corresponding shape, size, and thickness. In order to be able to monitor the temperature of its own working state in real time after making a ceramic insulating electrode, a through hole capable of accommodating a temperature sensing chip is left at the central part of the green body. The shape of the ceramic green body can be regular shapes such as circular, square, rectangular, regular hexagon, etc., preferably, the shape is circular; the through hole can be in shapes such as circular, rectangular, square, etc., and the size of the through hole should be such that the temperature sensing chip can be placed after sintering; preferably, the central through hole is circular. Preferably, the diameter of the circular ceramic sheet is 15 - 25 mm, preferably, the diameter is 20 mm; the central through hole is a circular hole with a diameter of 2.5 - 5 mm, preferably, the diameter of the through hole is 3 mm.

[0056] Step 5. First degrease the ceramic green body obtained in Step 4 at a temperature of 700 - 900 °C, preferably, the degreasing temperature is 750 - 850 °C; then put it into a closed crucible and keep it warm for 2 - 4 hours in the range of 1200 - 1320 °C for the first sintering, preferably, the sintering temperature is 1230 - 1300 °C, and the holding time is 2.5 hours; after cooling to room temperature, put it into the closed crucible again and keep it warm for 2.5 hours in the range of 1220 - 1290 °C for the second sintering to obtain a ceramic sheet with a high dielectric constant.

[0057] Step 6. Grind the ceramic sheet obtained in Step 5 to a thickness of 0.5 - 1.5 mm, preferably, grind it to a thickness of 1.0 mm; coat a metal electrode with a certain size on the surface of the side of the ceramic sheet connected to the flexible circuit board to obtain a ceramic insulating electrode. The metal electrode can use metal materials such as gold, silver, copper, etc. that are easy to solder; the method of coating the metal electrode can be sputtering, evaporation plating, electroless plating, printing and sintering infiltration, etc., preferably, use the process of printing and sintering a silver electrode, and the process of sintering the silver electrode is 800 °C, holding for 30 minutes; the printed metal electrode pattern leaves insulating edges at both the inner and outer edges of the ceramic sheet, and the width of the insulating edge is 0.3 - 1.5 mm, preferably, it is 1 mm.

[0058] Step 7. Mount the ceramic insulating electrode obtained in Step 6 on the flexible printed circuit board. Meanwhile, mount a temperature sensor chip at the position corresponding to the central through-hole of the ceramic sheet on the flexible printed circuit board. The mounting is by means of reflow soldering chip mounting process. Preferably, the ceramic insulating electrodes are mounted in an array form.

[0059] Step 8. Cover the other surface of the mounted ceramic insulating electrode obtained in Step 7 that is in contact with the skin with a layer of hydrogel having elasticity and good biocompatibility. Preferably, the hydrogel is gelatin added with sodium polyacrylate and sodium alginate.

[0060] By subjecting the plastic-extruded ceramic blank to two sinterings, the present invention can not only improve the strength of the ceramic sheet, but also reduce the manufacturing defect rate of the ceramic sheet from four to seven per thousand to one in ten thousand.

[0061] This application also provides a tumor electric field therapy system including an insulating electrode prepared from the above-mentioned ceramic. The insulating electrode is prepared from the above-mentioned ceramic according to the above method.

[0062] The technical solution provided by this application will be further elaborated below through specific embodiments.

[0063] Example 1

[0064] For the chemical formula Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg (0.39 Sb 0.6 Y 0.01 0.05 ​​}Ceramic materials of O3, according to the stoichiometric ratio: Pb3O4: 57.5 - 59.5%; BaCO3: 1.8 - 3.1%; SrCO3: 1.3 - 2.3%; ZrO2: 21.3 - 22.0%; TiO2: 9.1 - 9.6%; Sb2O3: 1.2 - 1.5%; MgO: 0.21 - 0.28%; Sm2O3: 4.25 - 4.35%; Y2O3: about 0.02%. Weigh the raw materials and mix them evenly in a ball mill barrel using the wet ball milling process. Specifically, the ratio of material to water is 1:0.5, and the mixing time is 8 hours. Place the dried mixed powder in a crucible and calcine it at 900°C for 4 hours. Add deionized water and PVA aqueous solution to the calcined pre-synthesized material block and crush it using the wet ball milling process. Specifically, the ratio of material to water to PVA aqueous solution is 1:0.3:0.1, and the crushing time is 20 hours. The crushed slurry is spray granulated to obtain granulated powder with good fluidity. Specifically, the spray granulation method is centrifugal spray granulation. The so-called granulated powder with good fluidity should have a particle size between 80 mesh and 350 mesh. Place the granulated powder in a mold and press it into a green body with a certain shape and thickness under a pressure of about 2 tons per square centimeter. Specifically, the green body is circular with a circular through-hole 3 in the center. After the green body is degassed at 800°C, it is placed in a sealed crucible for sintering. Specifically, the sintering temperature is 1250°C, and the holding time is 2.5 hours. After cooling to room temperature, it is placed in a sealed crucible again and sintered at 1250°C for 2.5 hours for secondary sintering. The outer diameter of the sintered ceramic sheet is 20 mm, the diameter of the middle through-hole is 3 mm, and the thickness is greater than 1.1 mm. Grind the sintered ceramic sheet with a thickness greater than 1.1 mm on both sides to the required thickness. Specifically, the ceramic sheet is ground to a thickness of 1.0 mm. Coat one surface of the ground ceramic sheet with a metal electrode 2. Specifically, use the method of screen printing and firing infiltration to coat a silver electrode. There is a 1-mm-wide insulating edge 1 left between the metal silver electrode coating and the inner and outer edges of the ceramic ring. Mount the ceramic insulating electrode with a single-sided coated metal silver electrode on a flexible printed circuit board, and at the same time, mount a temperature sensor chip at the position corresponding to the through-hole 3 of the ceramic sheet on the flexible printed circuit board. Specifically, mount it by reflow soldering in a 3×3 array. Cover the side of the mounted insulating electrode array that contacts the skin with a layer of hydrogel with elasticity and good biocompatibility. Specifically, the hydrogel is gelatin added with 0.3% - 0.7% sodium polyacrylate and 6% - 8% sodium alginate. The insulating electrode used in the tumor electric field treatment system is obtained through the above steps. Figure 2 For a pair of such insulating electrodes, the equivalent circuit schematic diagrams of insulating electrode A and insulating electrode B Figure 3 For various shapes of this insulating electrode Figure 4A 、 Figure 4B And Figure 4C Show various array forms of this insulating electrode.

[0065] Example 2

[0066] For the ceramic material with the chemical formula Pb 0.84 Ba 0.03 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3, weigh out the raw materials of analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3, etc. according to the stoichiometric ratio, and the preparation process is the same as that in Example 1.

[0067] Example 3

[0068] For the ceramic material with the chemical formula Pb 0.84 Ba 0.5 Sr 0.03 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3, weigh out the raw materials of analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3, and the preparation process is the same as that in Example 1.

[0069] Example 4

[0070] For the ceramic material with the chemical formula Pb 0.84 Ba 0.04 Sr 0.04 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3, weigh out the raw materials of analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3, and the preparation process is the same as that in Example 1.

[0071] Example 5

[0072] For the ceramic material with the chemical formula Pb 0.82 Ba 0.05 Sr​​​​​​0.05 Sm 0.08 {[Zr 0.59 Ti 0.41 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3 ceramic material, weigh analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3 raw materials according to the stoichiometric ratio, and the preparation process is the same as that in Example 1.

[0073] Example 6

[0074] For the ceramic material with the chemical formula Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.61 Ti 0.39 0.95 [Mg 0.39 Sb 0.6 Y 0.01 0.05}O3 ceramic material, weigh analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3 raw materials according to the stoichiometric ratio, and the preparation process is the same as that in Example 1.

[0075] Example 7

[0076] For the ceramic material with the chemical formula Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 [Mg 0.44 Sb m0.55 Y 0.01 0.05}O3 ceramic material, weigh analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3 raw materials according to the stoichiometric ratio, and the preparation process is the same as that in Example 1.

[0077] Example 8

[0078] For the ceramic material with the chemical formula Pb 0.82 Ba 0.05 Sr 0.05 Sm 0.08 {[Zr 0.6 Ti 0.4 0.95 ​​​​​​​[Mg 0.34 Sb m0.65 Y 0.01 0.05}O3 ceramic material, weigh out analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, Y2O3 raw materials according to the stoichiometric ratio, and the preparation process is the same as that of Example 1.

[0079] To further illustrate the advantages of the ceramics and insulating electrodes of this application, in addition to preparing 8 ceramic examples with the above chemical formulas 1 to 8, this application also prepared 6 ceramic comparative examples outside the defined range. The ceramic components of the 8 examples and 6 comparative examples are specifically shown in Table 1.

[0080] Table 1: Chemical compositions of examples and comparative examples

[0081]

[0082]

[0083] For the ceramic chips obtained from the ceramic materials of Examples 1 to 8 and Comparative Examples 1 to 6, use an LCR tester to measure the dielectric loss and dielectric constant of each single piece, and the test conditions are 28°C and 200 KHz; use a withstand voltage tester to measure its AC withstand voltage strength, and the performance parameters are shown in Table 2.

[0084] Table 2: Performance parameters of ceramic insulating electrodes

[0085]

[0086]

[0087] Combining Table 1 and Table 2, it can be concluded that when the mole fraction x of Ba, the mole fraction y of Sr, the mole fraction a of Ti, and the mole fraction m of Sb satisfy 0.08 ≤ x + y ≤ 0.1, 0.39 ≤ a ≤ 0.41, and 0.55 ≤ m ≤ 0.65, the dielectric constant of the ceramic is between 4820 - 5500, and the dielectric loss is between 0.073 and 0.08. And when the mole fraction a of Ti and the mole fraction m of Sb remain unchanged, the dielectric constant and dielectric loss of the ceramic both increase with the increase of the mole fraction x of Ba or the mole fraction y of Sr; when the mole fraction x of Ba, the mole fraction y of Sr, and the mole fraction a of Ti remain unchanged, the dielectric constant and dielectric loss of the ceramic both increase with the increase of the mole fraction m of Sb; when the mole fraction x of Ba, the mole fraction y of Sr, and the mole fraction m of Sb remain unchanged, the dielectric constant and dielectric loss of the ceramic both decrease with the increase of the mole fraction a of Ti.

[0088] ​Examples 1, 4, and 8 were selected and their capacitances, dielectric constants, and dielectric losses at different frequencies at room temperature were tested. The parameters are shown in Table 3.

[0089] Table 3: Performance parameters of Examples 1, 4, and 8 at different frequencies

[0090]

[0091] At room temperature (25 °C) and under the test conditions where the test frequency is between 100 kHz and 600 kHz. For Example 1, between adjacent test frequencies, the change rate of capacitance is less than or equal to 1.8%; the change rate of dielectric constant is less than or equal to 1.8%; the change rate of dielectric loss is less than or equal to 2.3%. For Example 4, between adjacent test frequencies, the change rate of capacitance is less than or equal to 1.6%; the change rate of dielectric constant is less than or equal to 1.5%; the change rate of dielectric loss is less than or equal to 2.7%. For Example 8, between adjacent test frequencies, the change rate of capacitance is less than or equal to 1.6%; the change rate of dielectric constant is less than or equal to 1.6%; the change rate of dielectric loss is less than or equal to 2.6%. At different test frequencies, the capacitances, dielectric constants, and dielectric losses of Examples 1, 4, and 8 are highly stable and have small change rates.

[0092] The above is only the preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of protection of the present application.

Claims

1. A ceramic, characterized in that, The chemical general formula of the ceramic material is as follows: Pb (0.92-x-y) Ba x Sr y Sm 0.08 {[Zr (1-a) Ti a 0.95 [Mg (0.99-m) Sb m Y 0.01 0.05}O3.​​ 2. The ceramic according to claim 1, wherein In the general formula, the value ranges of x, y, a, and m should satisfy: 0.08 ≤ x + y ≤ 0.1; 0.39 ≤ a ≤ 0.41; 0.55 ≤ m ≤ 0.

65.

3. A method for preparing a ceramic, characterized in that, It is prepared according to the following steps: Step 1. Weigh and prepare analytical pure Pb3O4, BaCO3, SrCO3, ZrO2, TiO2, Sb2O3, MgO, Sm2O3, and Y2O3 according to the stoichiometric ratio, and mix them by wet ball milling for 5 - 10 hours; Ratio of material to water = 1:0.3 - 0.8, and after drying, a mixture is obtained; Step 2. Calcinate the mixture material at 800 - 1000 °C for 2 - 6 hours to obtain a pre-synthesized ceramic block; Step 3. Add water and PVA aqueous solution to the pre-synthesized ceramic block and mix them by wet ball milling and pulverizing for 18 - 24 hours. Ratio of material to water to PVA aqueous solution = 1:0.1 - 0.5:0.07 - 0.

15. After spray granulation of the pulverized slurry, granulated powder is obtained. The spray granulation is centrifugal spray granulation; Step 4. Press the granulated powder using a molding die to obtain a ceramic green body; Step 5. First, degrease the ceramic green body at a temperature of 700 - 900 °C; then sinter it in the range of 1200 - 1320 °C to obtain a ceramic sheet with a high dielectric constant.

4. The method for preparing the ceramic according to claim 3, wherein In Step 1, the weighing and preparation method of each raw material is as follows: Pb3O4: 57.5 - 59.5%; BaCO3: 1.8 - 3.1%; SrCO3: 1.3 - 2.3%; ZrO2: 21.3 - 22.0%; TiO2: 9.1 - 9.6%; Sb2O3: 1.2 - 1.5%; MgO: 0.21 - 0.28%; Sm2O3: 4.25 - 4.35%; Y2O3: 0.02%.

5. The preparation method of the ceramic according to claim 3, wherein, In Step 5, the ceramic green body is first sintered for the first time by holding it at a temperature in the range of 1200 - 1320 °C for 2 - 4 hours. After cooling to room temperature, it is sintered for the second time by holding it at a temperature in the range of 1220 - 1290 °C for 2.5 hours.

6. The method for preparing the ceramic according to claim 3, wherein, In Step 4, a through hole for accommodating a temperature sensor chip is provided at the central part of the ceramic green body.

7. A method for preparing an insulating electrode, characterized in that, For the ceramic sheet obtained by the preparation method according to Claim 3, the following steps are carried out: Step 6. Grind the ceramic sheet to a thickness of 0.5 - 1.5 mm, and coat a metal electrode on the surface of the side where the ceramic sheet is connected to the flexible circuit board to obtain a ceramic insulated electrode. The pattern of the metal electrode has insulating edges left at both the inner and outer edges of the ceramic sheet, and the width of the insulating edge is 0.3 - 1.5 mm; Step 7. Mount the ceramic insulated electrode on the flexible circuit board, and at the same time, mount a temperature sensor chip at the position corresponding to the central through hole of the ceramic sheet on the flexible circuit board. The mounting is by reflow soldering chip mounting process; Step 8. Cover a layer of hydrogel on the other surface of the mounted insulated electrode that contacts the skin.

8. The method for preparing an insulating electrode according to claim 7, characterized in that, The hydrogel is gelatin added with sodium polyacrylate and sodium alginate.

9. An insulating electrode for treating tumors by means of electric fields, characterized in that: It is prepared from the ceramic according to Claim 1.

10. An insulating electrode for treating tumors with electric fields, characterized in that, It uses a ceramic material with a chemical general formula of Pb (0.92-x-y) Ba x Sr y Sm 0.08 {[Zr (1-a) Ti a 0.95 [Mg (0.99-m) Sb m Y 0.01 0.05}O3 and is prepared by the method according to any one of claims 7 to 8.​​ 11. A tumor electrotherapy system, characterized in that: It includes the insulated electrode according to any one of Claims 9 to 10.

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