Giant dielectric ceramic filler flexible capacitive sensor and preparation method thereof
By combining the giant dielectric ceramic filler prepared by ion-doped calcium copper titanate with rubber and silicone rubber, the problems of low sensor sensitivity and increased brittleness were solved, and a flexible sensor with high dielectric constant and low dielectric loss was realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TIANJIN CHENGJIAN UNIV
- Filing Date
- 2024-10-25
- Publication Date
- 2026-04-28
AI Technical Summary
Existing flexible capacitive sensors have low sensitivity, and the large amount of traditional ceramic filler added increases the brittleness of the composite material and the elastic modulus, posing a risk of electrical breakdown.
Using ion-doped calcium copper titanate (CaCu3Ti4O12) as the matrix, the dielectric constant was improved through chemical synthesis, and then combined with natural rubber, silicone rubber and polyurethane to prepare a flexible sensor dielectric layer with giant dielectric properties.
While maintaining a high dielectric constant, the dielectric loss is reduced, the sensor sensitivity is improved, and high sensitivity is achieved with a small amount of filler, avoiding the brittleness problem of traditional ceramic fillers.
Smart Images
Figure HSA0000299779150000011
Abstract
Description
Technical Field
[0001] This invention belongs to the field of flexible sensors, and its purpose is to prepare a flexible capacitive sensor with giant dielectric ceramic filler. Background Technology
[0002] Flexible sensors, as an emerging sensor technology, have received widespread attention in various fields in recent years. Compared with traditional rigid sensors, flexible sensors have better adaptability and flexibility, and can conform to various irregular surfaces. This makes them show great potential in applications such as health monitoring, smart wearable devices, robotics, and flexible electronics.
[0003] Flexible capacitive sensors are sensors capable of operating in dynamic environments such as bending, stretching, and compression, and are widely used in health monitoring, smart wearable devices, robotics, and flexible electronics. The core principle of these sensors is to detect external stimuli using changes in capacitance. With technological advancements, flexible capacitive sensors are showing promising prospects in terms of both performance and application.
[0004] Flexible capacitive pressure sensors typically employ a sandwich structure of electrode layer-dielectric layer-electrode layer. To ensure the sensor's flexibility, the dielectric layer is generally made of an elastomer. Currently, the elastomers used in the development of these sensors include natural rubber, silicone rubber, and polyurethane. Compared to traditional intelligent materials, such as shape memory alloys, dielectric elastomers offer faster response times, higher energy density, and superior electromechanical conversion efficiency. These excellent properties have led to the widespread application of dielectric elastomers, which are playing an increasingly important role in engineering applications such as Braille displays, artificial muscles, bionic robotic arms, and underwater bionic mechanical design.
[0005] However, during the experiments, it was found that the flexible sensor had low sensitivity. Research revealed that filling natural rubber, silicone rubber, and polyurethane with conductive particles such as silver, graphene, and carbon nanotubes can increase the dielectric constant of the dielectric elastomer, thereby reducing the operating voltage and improving sensor sensitivity. However, before the percolation threshold is reached, the addition of conductive filler causes the dielectric constant to continue to rise. But once the percolation threshold is exceeded, the dielectric loss of the composite material increases, and electrical breakdown is more likely to occur, which is detrimental to practical applications.
[0006] In addition, high-dielectric ceramic fillers, such as titanium dioxide (TiO2), barium titanate (BaTiO3), and calcium copper titanate (CaCu3Ti4O3), are added to natural rubber, silicone rubber, and polyurethane. 12It can also significantly improve the dielectric constant of composite materials. However, the disadvantages are also very obvious. A large amount of ceramic filler is often required to increase the dielectric constant of the composite material. A large amount of ceramic filler leads to increased brittleness and increased elastic modulus of the composite material, which can cause great harm to equipment and people.
[0007] Therefore, a giant dielectric ceramic filler with a giant dielectric constant and low dielectric loss was prepared and added to natural rubber, silicone rubber, and polyurethane. Compared with traditional ceramic fillers, the giant dielectric ceramic filler prepared in this experiment requires only a small amount of filler to achieve a dielectric layer with a high dielectric constant and low dielectric loss, and also has a low elastic modulus, resulting in higher sensitivity for the flexible sensor. Summary of the Invention
[0008] To address the shortcomings of existing methods, this invention proposes using calcium copper titanate (CaCu3Ti4O) 12 Using a substrate as the base, the dielectric properties of the substrate are improved by ion doping, and then its dielectric constant is significantly increased by simple chemical synthesis to give it giant dielectric properties, thereby improving the sensitivity of the flexible sensor while maintaining a high dielectric constant.
[0009] A flexible sensor dielectric layer with high dielectric properties, comprising, by mass parts:
[0010] Natural rubber, silicone rubber, polyurethane: 100 parts
[0011] Crosslinking agent: 1-5 parts of dicumyl peroxide (DCP).
[0012] Giant dielectric ceramic filler: Ion-doped calcium copper titanate (CaCu3Ti4O) 12 ).
[0013] The particles may include germanium (Ge), magnesium (Mg), barium (Ba), zinc (Zn), aluminum (Al), gadolinium (Gd), zirconium (Zr), etc.
[0014] The particle size of the giant dielectric ceramic filler is 30nm-60nm.
[0015] The dielectric layer of the flexible sensor has a dielectric constant of approximately 10 at 1 kHz. 4 -10 6 .
[0016] In this work, the authors propose a strategy involving giant dielectric ceramic fillers. This involves enhancing the dielectric properties of the matrix material through ion doping while simultaneously introducing conductive and insulating materials into the matrix. The former, through its inherent conductivity and high specific surface area, improves the sensitivity of the flexible sensor, while the latter, by coating with an insulating layer, reduces the damage caused by the percolation threshold, thus achieving both high dielectric constant and high sensitivity.
[0017] The method for preparing a dielectric layer includes the following steps:
[0018] By mass fraction, 100 parts each of natural rubber, silicone rubber and polyurethane, 1-5 parts of crosslinking agent and 0.2-0.8 parts of giant dielectric ceramic filler are mixed evenly in a mixer and vulcanized in a vulcanizing machine at a pressure of 10-20 MPa and a temperature of 150-180°C for 25-50 minutes.
[0019] The beneficial effects of this invention are as follows:
[0020] This invention prepares a ceramic filler with giant dielectric properties and fills it into natural rubber, silicone rubber, and polyurethane. The resulting flexible sensor dielectric layer possesses high dielectric constant and low dielectric loss. The giant dielectric ceramic filler used in this experiment is simple to prepare and requires a small amount, greatly improving the current situation where traditional dielectric ceramic fillers cannot simultaneously achieve high dielectric constant and low sensitivity, thus promoting the practical application of flexible capacitive sensors. Attached Figure Description
[0021] Appendix Figure 1 This refers to the sensor's response to finger joint bending. Specific implementation methods
[0022] The present invention will be further described below with reference to specific embodiments. It should be noted that the following are merely examples and not intended to limit its application.
[0023] In this embodiment
[0024] Dielectric constant determination: Dielectric properties were tested at room temperature using an Agilent E4980A impedance meter (USA), with a test frequency range of 10⁻¹⁰. 6 Hz.
[0025] Implementation Method 1:
[0026] First, weigh out a certain amount of calcium carbonate (CaCO3), titanium dioxide (TiO2), and copper oxide (CuO) according to the stoichiometric ratio, and weigh out germanium oxide (GeO) according to the doping ratio. Place these components together with anhydrous ethanol in a ball mill jar and mill for 12-24 hours. Place the resulting mixture of giant dielectric ceramic particles in a 60℃ oven for 24 hours to dry. After drying, grind the mixture into powder. Mix the giant dielectric ceramic particle powder with PVA at a ratio of 1g powder to 1mL 5% PVA and grind. Compress the mixture into tablets using a tablet press. Place the resulting giant dielectric ceramic particle tablets in a muffle furnace for pre-firing at 500℃ for 2 hours with a rising rate of 5℃ / min, followed by pre-firing at 800℃ for 5 hours with a rising rate of 5℃ / min. Grind the pre-firing sample into powder and place it back into the ball mill jar with anhydrous ethanol for 12-24 hours. Place the resulting mixture of giant dielectric ceramic particles in a 60℃ oven for 24 hours to dry. After drying, grind the mixture into powder. Giant dielectric ceramic particles were mixed and ground with PVA at a ratio of 1g powder to 1mL 5% PVA, and then compressed into tablets using a tablet press. The giant dielectric ceramic particle tablets were placed in a muffle furnace and heated to 500℃ for 2 hours with a rising rate of 5℃ / min for debinding, followed by heating to 950℃ for 4 hours with a rising rate of 5℃ / min for final calcination. The calcined sample was then ground into powder to obtain giant dielectric ceramic particles. Next, carboxylated CNT particles were weighed and dispersed in anhydrous ethanol, then ultrasonicated for 30 minutes to ensure uniform dispersion of the CNTs in the solution. An equal proportion of giant dielectric ceramic particles was added to the CNT mixture. The mixture was then continuously stirred with a magnetic stirrer for 12-24 hours to obtain a mixture of giant dielectric ceramic particles and CNTs. Subsequently, the mixture was placed in a 60℃ oven for 24 hours to dry, and then ground into powder to obtain preliminarily modified particles. A certain amount of the prepared preliminary modified particles were taken according to a certain ratio, dispersed in deionized water and stirred. Then, a certain amount of tris(hydroxymethyl)aminomethane (Tris), catechol (Cate), and tetraethylenepentamine (TEPA) were added to obtain a mixture of giant dielectric ceramic filler particles. The mixture of giant dielectric ceramic filler particles was placed in a 60°C oven for 24 hours to dry. After drying, it was removed and ground into powder to form the final giant dielectric ceramic filler particles. The dielectric layer of the flexible sensor is characterized by including its preparation method:
[0027] By mass fraction, select 100 parts of rubber, 1-5 parts of crosslinking agent, and 0.2-0.8 parts of macro-dielectric filler, mix them evenly in a mixer, and then vulcanize at 150-180℃ for 25-50 minutes.
[0028] Implementation Case 1: The preparation method is as described in claim 1. Then, 0.2 phr giant dielectric ceramic filler particles are added to natural rubber, silicone rubber, and polyurethane. A self-made flexible electrode is then coated on both sides of the dielectric layer. After drying, copper wires are fixed to the electrode sides using PI tape. Finally, the sensor is encapsulated with PI tape for protection. Thus, the capacitive sensor based on the flexible giant dielectric ceramic filler dielectric layer is assembled.
[0029] Implementation Case 2: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.4 phr.
[0030] Implementation Case 3: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.6 phr.
[0031] Implementation Case 4: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.8 phr.
[0032] Implementation Method Two:
[0033] First, weigh out a certain amount of calcium carbonate (CaCO3), titanium dioxide (TiO2), and copper oxide (CuO) according to the stoichiometric ratio, and weigh out zirconium oxide (ZrO) according to the doping ratio. Place these components together with anhydrous ethanol in a ball mill jar and ball mill for 12-24 hours. Place the resulting mixture of giant dielectric ceramic particles in a 60℃ oven for 24 hours to dry. After drying, grind the mixture into powder. Mix the giant dielectric ceramic particle powder with PVA at a ratio of 1g powder to 1mL 5% PVA and grind. Compress the mixture into tablets using a tablet press. Place the resulting giant dielectric ceramic particle tablets in a muffle furnace for pre-firing at 500℃ for 2 hours with a rising rate of 5℃ / min, followed by pre-firing at 800℃ for 5 hours with a rising rate of 5℃ / min. Grind the pre-firing sample into powder and place it back into the ball mill jar with anhydrous ethanol for 12-24 hours. Place the resulting mixture of giant dielectric ceramic particles in a 60℃ oven for 24 hours to dry. After drying, grind the mixture into powder. Giant dielectric ceramic particles were mixed and ground with PVA at a ratio of 1g powder to 1mL 5% PVA, and then compressed into tablets using a tablet press. The giant dielectric ceramic particle tablets were placed in a muffle furnace and heated to 500℃ for 2 hours with a rising rate of 5℃ / min for debinding, followed by heating to 950℃ for 4 hours with a rising rate of 5℃ / min for final calcination. The calcined sample was then ground into powder to obtain giant dielectric ceramic particles. Next, carboxylated CNT particles were weighed and dispersed in anhydrous ethanol, then ultrasonicated for 30 minutes to ensure uniform dispersion of the CNTs in the solution. An equal proportion of giant dielectric ceramic particles was added to the CNT mixture. The mixture was then continuously stirred with a magnetic stirrer for 12-24 hours to obtain a mixture of giant dielectric ceramic particles and CNTs. Subsequently, the mixture was placed in a 60℃ oven for 24 hours to dry, and then ground into powder to obtain preliminarily modified particles. A certain amount of the prepared preliminary modified particles were taken according to a certain ratio, dispersed in deionized water and stirred. Then, a certain amount of tris(hydroxymethyl)aminomethane (Tris), catechol (Cate), and tetraethylenepentamine (TEPA) were added to obtain a mixture of giant dielectric ceramic filler particles. The mixture of giant dielectric ceramic filler particles was placed in a 60°C oven for 24 hours to dry. After drying, it was removed and ground into powder to form the final giant dielectric ceramic filler particles. The dielectric layer of the flexible sensor is characterized by including its preparation method:
[0034] By mass fraction, select 100 parts of rubber, 1-5 parts of crosslinking agent, and 0.2-0.8 parts of macro-dielectric filler, mix them evenly in a mixer, and then vulcanize at 150-180℃ for 25-50 minutes.
[0035] Implementation Case 1: The preparation method is as described in claim 1. Then, 0.2 phr giant dielectric ceramic filler particles are added to natural rubber, silicone rubber, and polyurethane. A self-made flexible electrode is then coated on both sides of the dielectric layer. After drying, copper wires are fixed to the electrode sides using PI tape. Finally, the sensor is encapsulated with PI tape for protection. Thus, the capacitive sensor based on the flexible giant dielectric ceramic filler dielectric layer is assembled.
[0036] Implementation Case 2: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.4 phr.
[0037] Implementation Case 3: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.6 phr.
[0038] Implementation Case 4: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.8 phr.
[0039] Implementation Method 3:
[0040] First, weigh out a certain amount of calcium carbonate (CaCO3), titanium dioxide (TiO2), and copper oxide (CuO) according to the stoichiometric ratio, and weigh out gadolinium trioxide (Gd2O3) according to the doping ratio. Place these components together with anhydrous ethanol into a ball mill jar and ball mill for 12-24 hours. Place the resulting mixture of giant dielectric ceramic particles in a 60℃ oven for 24 hours to dry. After drying, grind the mixture into powder. Mix the giant dielectric ceramic particle powder with PVA at a ratio of 1g powder to 1mL 5% PVA and grind the mixture. Press the mixture into tablets using a tablet press. Place the resulting giant dielectric ceramic particle tablets in a muffle furnace for pre-firing at 500℃ for 2 hours with a rising rate of 5℃ / min, followed by pre-firing at 800℃ for 5 hours with a rising rate of 5℃ / min. Grind the pre-firing sample into powder and place it back into the ball mill jar with anhydrous ethanol for 12-24 hours. The resulting mixture of giant dielectric ceramic particles was placed in a 60℃ oven for 24 hours to dry. After drying, it was ground into powder. The giant dielectric ceramic particle powder was mixed with PVA at a ratio of 1g powder to 1mL 5% PVA and ground. The mixture was then compressed into tablets using a tablet press. The giant dielectric ceramic particle tablets were placed in a muffle furnace and subjected to calcination at 500℃ for 2 hours with a rising rate of 5℃ / min, followed by calcination at 950℃ for 4 hours with a rising rate of 5℃ / min. The calcined sample was then ground into powder to obtain the giant dielectric ceramic particles. Next, carboxylated CNT particles were weighed and dispersed in anhydrous ethanol, and then ultrasonicated for 30 minutes to ensure uniform dispersion of the CNTs in the solution. An equal proportion of giant dielectric ceramic particles was added to the CNT mixture. Then, the mixture was continuously stirred with a magnetic stirrer for 12-24 hours to obtain the mixture of giant dielectric ceramic particles and CNTs. Subsequently, the mixture of giant dielectric ceramic particles and CNTs was placed in a 60°C oven for 24 hours to dry. After drying, it was removed and ground into powder to obtain preliminary modified particles. A certain amount of the prepared preliminary modified particles was taken according to a certain ratio, dispersed in deionized water and stirred. A certain amount of tris(hydroxymethyl)aminomethane (Tris), catechol (Cate), and tetraethylenepentamine (TEPA) were then added to obtain a mixture of giant dielectric ceramic filler particles. The mixture of giant dielectric ceramic filler particles was placed in a 60°C oven for 24 hours to dry. After drying, it was removed and ground into powder to obtain the final giant dielectric ceramic filler particles. The dielectric layer of the flexible sensor is characterized by including its preparation method:
[0041] By mass fraction, select 100 parts of rubber, 1-5 parts of crosslinking agent, and 0.2-0.8 parts of macro-dielectric filler, mix them evenly in a mixer, and then vulcanize at 150-180℃ for 25-50 minutes.
[0042] Implementation Case 1: The preparation method is as described in claim 1. Then, 0.2 phr giant dielectric ceramic filler particles are added to natural rubber, silicone rubber, and polyurethane. A self-made flexible electrode is then coated on both sides of the dielectric layer. After drying, copper wires are fixed to the electrode sides using PI tape. Finally, the sensor is encapsulated with PI tape for protection. Thus, the capacitive sensor based on the flexible giant dielectric ceramic filler dielectric layer is assembled.
[0043] Implementation Case 2: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.4 phr.
[0044] Implementation Case 3: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.6 phr.
[0045] Implementation Case 4: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.8 phr.
[0046] Implementation Method Four:
[0047] First, weigh out a certain amount of calcium carbonate (CaCO3), titanium dioxide (TiO2), and copper oxide (CuO) according to the stoichiometric ratio, and weigh out alumina (Al2O3) according to the doping ratio. Place these components together with anhydrous ethanol in a ball mill jar and mill for 12-24 hours. Place the resulting mixture of giant dielectric ceramic particles in a 60℃ oven for 24 hours to dry. After drying, grind the mixture into powder. Mix the giant dielectric ceramic particle powder with PVA at a ratio of 1g powder to 1mL 5% PVA and grind. Compress the mixture into tablets using a tablet press. Place the resulting giant dielectric ceramic particle tablets in a muffle furnace for pre-firing at 500℃ for 2 hours with a rising rate of 5℃ / min, followed by pre-firing at 800℃ for 5 hours with a rising rate of 5℃ / min. Grind the pre-firing sample into powder and place it back into the ball mill jar with anhydrous ethanol for 12-24 hours. Place the resulting mixture of giant dielectric ceramic particles in a 60℃ oven for 24 hours to dry. After drying, grind the mixture into powder. Giant dielectric ceramic particles were mixed and ground with PVA at a ratio of 1g powder to 1mL 5% PVA, and then compressed into tablets using a tablet press. The giant dielectric ceramic particle tablets were placed in a muffle furnace and heated to 500℃ for 2 hours with a rising rate of 5℃ / min for debinding, followed by heating to 950℃ for 4 hours with a rising rate of 5℃ / min for final calcination. The calcined sample was then ground into powder to obtain giant dielectric ceramic particles. Next, carboxylated CNT particles were weighed and dispersed in anhydrous ethanol, then ultrasonicated for 30 minutes to ensure uniform dispersion of the CNTs in the solution. An equal proportion of giant dielectric ceramic particles was added to the CNT mixture. The mixture was then continuously stirred with a magnetic stirrer for 12-24 hours to obtain a mixture of giant dielectric ceramic particles and CNTs. Subsequently, the mixture was placed in a 60℃ oven for 24 hours to dry, and then ground into powder to obtain preliminarily modified particles. A certain amount of the prepared preliminary modified particles were taken according to a certain ratio, dispersed in deionized water and stirred. Then, a certain amount of tris(hydroxymethyl)aminomethane (Tris), catechol (Cate), and tetraethylenepentamine (TEPA) were added to obtain a mixture of giant dielectric ceramic filler particles. The mixture of giant dielectric ceramic filler particles was placed in a 60°C oven for 24 hours to dry. After drying, it was removed and ground into powder to form the final giant dielectric ceramic filler particles. The dielectric layer of the flexible sensor is characterized by including its preparation method:
[0048] By mass fraction, select 100 parts of rubber, 1-5 parts of crosslinking agent, and 0.2-0.8 parts of macro-dielectric filler, mix them evenly in a mixer, and then vulcanize at 150-180℃ for 25-50 minutes.
[0049] Implementation Case 1: The preparation method is as described in claim 1. Then, 0.2 phr giant dielectric ceramic filler particles are added to natural rubber, silicone rubber, and polyurethane. A self-made flexible electrode is then coated on both sides of the dielectric layer. After drying, copper wires are fixed to the electrode sides using PI tape. Finally, the sensor is encapsulated with PI tape for protection. Thus, the capacitive sensor based on the flexible giant dielectric ceramic filler dielectric layer is assembled.
[0050] Implementation Case 2: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.4 phr.
[0051] Implementation Case 3: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.6 phr.
[0052] Implementation Case 4: The preparation method is the same as that in Implementation Case 1, except that the number of giant dielectric ceramic filler particles is 0.8 phr.
[0053] To verify the effectiveness of the present invention, the inventors provided mouse click response and knuckle bending response of the germanium-doped giant dielectric ceramic particle flexible sensor prepared according to the above embodiment one, as shown below. Figure 1 As shown.
Claims
1. A flexible capacitive sensor with giant dielectric ceramic filler and its preparation method, characterized in that: The preparation method comprises the following steps performed in sequence: (1) First, weigh a certain amount of calcium carbonate (CaCO3), titanium dioxide (TiO2) and copper oxide (CuO), weigh a certain amount of the drug corresponding to the doping element according to the doping ratio, and put them into a ball mill jar together with anhydrous ethanol. The ball milling time is 12-24h. (2) Place the mixture of giant dielectric ceramic particles in a 60°C oven for 24 hours. After drying, take it out and grind it into powder. (3) The giant dielectric ceramic particles powder and PVA are mixed and ground according to the ratio, and then pressed into tablets using a tablet press. (4) Place the giant dielectric ceramic particles in a muffle furnace for debinding and pre-firing. Grind the pre-firing sample into powder and put it into a ball mill jar with anhydrous ethanol for 12-24 hours. (5) Place the mixture of giant dielectric ceramic particles in a 60°C oven for 24 hours. After drying, take it out and grind it into powder. (6) The giant dielectric ceramic particles and PVA are mixed and ground according to the ratio, and then pressed into tablets using a tablet press. (7) Place the giant dielectric ceramic particles in a muffle furnace for debinding and final firing, and grind the final fired sample into powder. (8) Next, a certain amount of carboxylated CNTs particles are weighed and dispersed in anhydrous ethanol, and then vibrated in an ultrasonic instrument to make the CNTs uniformly dispersed in the solution. (9) A certain amount of giant dielectric ceramic particles were added to the CNTs mixture. Then, the mixture was continuously stirred using a magnetic stirrer to obtain the giant dielectric ceramic particles and CNTs mixture. Subsequently, the giant dielectric ceramic particles and CNTs mixture was placed in a 60°C oven for 24 hours. After drying, it was taken out and ground into powder to obtain the preliminary modified particles. (10) Take a certain amount of the prepared preliminary modified particles, disperse them in deionized water and stir, and then add a certain amount of tris(hydroxymethyl)aminomethane (Tris), catechol (Cate) and tetraethylenepentamine (TEPA) to obtain a mixture of giant dielectric ceramic filler particles. (11) Place the mixture of giant dielectric ceramic filler particles in a 60°C oven for 24 hours. After drying, take it out and grind it into powder. (12) The dielectric layer in the flexible capacitive sensor is characterized by the following preparation method: by mass fraction, 100 parts of rubber, 1-5 parts of crosslinking agent, and 0.2-0.8 parts of giant dielectric filler are mixed evenly by a mixer and then vulcanized at 150-180°C for 25-50 minutes. (13) The assembly of the flexible capacitive sensor is characterized by including its preparation method: First, the prepared giant dielectric ceramic filler is cut into small pieces to serve as the dielectric layer of the sensor. Then, flexible electrodes are coated on both sides of the dielectric layer to serve as electrode layers. Copper wires are then fixed to the electrode sides with PI tape. Finally, the sensor is encapsulated with PI tape for protection. Thus, the capacitive sensor based on the flexible giant dielectric ceramic filler dielectric layer is assembled. (14) Then measure the capacitance change of the flexible capacitive sensor under different pressure sources.
2. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (1), the amounts of calcium carbonate (CaCO3), titanium dioxide (TiO2), and copper oxide (CuO) are calculated according to stoichiometric ratios.
3. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (3), the ratio of giant dielectric ceramic particles to PVA is 1g powder to 1mL 5% PVA.
4. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (4), the glue removal conditions for the giant dielectric ceramic particles are 500℃ for 2 hours and the rising rate is 5℃ / min. The pre-firing conditions for the giant dielectric ceramic particles are 800℃ for 5 hours and the rising rate is 5℃ / min.
5. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (6), the ratio of giant dielectric ceramic particles to PVA is 1g powder to 1mL 5% PVA.
6. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (7), the debinding conditions for the giant dielectric ceramic particles are 500℃ for 2 hours and the rising rate is 5℃ / min. The final firing conditions for the giant dielectric ceramic particles are 950℃ for 4 hours and the rising rate is 5℃ / min.
7. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (8), the ultrasound time is 30 minutes.
8. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (9), the mass ratio of carboxylated CNTs to CCTO is 1:
1.
9. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (10), the amount of CCTO-CNTs used is in a mass ratio of Cate, TEPA and Tris of 1:0.014:0.008:0.
006.
10. The method for preparing the giant dielectric ceramic filler according to claim 1, characterized in that: In step (13), the flexible electrode is composed of 6-11g of silicone rubber, 6-11g of dimethyl silicone oil, 3-8g of carbon black, 200-600ml of n-heptane, and 0.5-2g of curing agent.