Pressure sensor, manufacturing method, and data acquisition system and method

Abstract

A pressure sensor, a manufacturing method, and a data acquisition system and method. The cylindrical array-type flexible pressure sensor comprises an ionic gel dielectric layer (2); the upper surface of the ionic gel dielectric layer (2) is provided with a plurality of column electrodes (1); the lower surface of the ionic gel dielectric layer (2) is provided with a plurality of row electrodes (3); the intersection of each row electrode (3) and each column electrode (1) forms a single sensor unit (4). The sensor and method can solve the problem of lack of touch information in the current digestive endoscopy diagnosis and treatment process, and have the characteristics of high sensitivity and accurate measurement.

Description

Pressure sensor, preparation method, and data acquisition system and method Technical Field

[0001] The present invention belongs to the technical field of sensors and relates to a pressure sensor, a preparation method, and a data acquisition system and method. Background Art

[0002] In traditional medical diagnosis, doctors often perform medical examinations by feeling the patient's tissues, which greatly improves diagnostic efficiency. However, during digestive endoscopy, doctors cannot directly touch the patient's tissues, and existing endoscopic visual feedback technology cannot accurately identify the location and size of the lesion. When doctors use digestive endoscopy in the absence of force feedback, they can easily cause additional damage to the patient's digestive tract tissues.

[0003] Touch is a crucial human function, allowing us to perceive and acquire external information through our skin. This tactile sense allows us to discern information such as the shape, hardness, surface roughness, and temperature of objects we touch, resulting in a more detailed and enriched sensory experience. To mimic the tactile perception of human skin, various pressure sensors have been proposed that can sense and quantify external stimuli by converting them into electronic signals.

[0004] Currently, flexible pressure sensors can be categorized into piezoresistive, piezoelectric, triboelectric, and capacitive types based on their operating principles. Among these four types, capacitive flexible pressure sensors have attracted extensive research due to their simple structure, fast response speed, and low power consumption. Capacitive flexible pressure sensors can be further categorized into traditional capacitive pressure sensors and ion-electromagnetic capacitive pressure sensors based on the dielectric layer. The sensitivity of traditional capacitive pressure sensors is often limited by the incompressibility and low dielectric constant of the elastomer. Furthermore, the capacitance change of traditional capacitive pressure sensors is highly susceptible to parasitic capacitance and environmental noise, limiting their practical applications. Ion-electromagnetic pressure sensors use ion gel as the sensor's dielectric layer, forming a double-layer capacitor at the interface between the electrode and the dielectric layer, significantly improving sensor sensitivity. Compared to other sensor types, ion-electromagnetic pressure sensors offer superior sensing performance and can meet the pressure sensing requirements of a variety of applications. Furthermore, research has shown that introducing microstructures into ion-electromagnetic pressure sensors can further improve their sensing performance.

[0005] Digestive endoscopy is currently one of the most effective and reliable ways to treat digestive system diseases. It can observe abnormal lesions in the digestive tract through accurate and intuitive visual feedback, thereby providing doctors with more accurate diagnostic results. In traditional medical diagnosis, doctors often diagnose patients by touching the patient's tissues with their hands, which greatly improves the efficiency of diagnosis. However, during the digestive endoscopy diagnosis and treatment process, doctors cannot directly touch the patient's tissues, and existing endoscopic visual feedback technology cannot accurately identify the location and size of the lesion area. When doctors use digestive endoscopes in the absence of force feedback, it is easy for the patient's digestive tract tissues to suffer additional damage.

[0006] During digestive endoscopy, doctors insert an endoscope into the patient's body through the natural cavity and use the images provided by the endoscope to perform diagnosis and surgical procedures. This is crucial for locating and treating lesions in the body. However, when doctors use digestive endoscopy without force feedback, this can easily damage the patient's digestive tract tissue. Currently, common flexible pressure sensors include piezoresistive, piezoelectric, triboelectric, and capacitive types.

[0007] In summary, the following problems still exist:

[0008] Lack of tactile information during digestive endoscopy. During digestive endoscopy, doctors cannot directly touch the patient's tissues, and visual feedback cannot accurately identify the location and size of the lesion. In addition, doctors performing surgery without force feedback may cause damage to normal tissues or even vital organs.

[0009] Disadvantages of sensors: Piezoresistive pressure sensors are easily affected by external factors and may experience signal drift after long-term use. Piezoelectric pressure sensors cannot measure static pressure. Triboelectric pressure sensors are also susceptible to external factors and cannot measure static pressure. Traditional capacitive sensors have an incompressible dielectric layer, resulting in low sensitivity and being easily affected by parasitic capacitance and the environment, resulting in poor measurement accuracy. Technical issues

[0010] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a pressure sensor, preparation method and data acquisition system and method. The sensor and method can solve the problem of lack of tactile information in the current digestive endoscopy diagnosis and treatment process, and have the characteristics of high sensitivity and accurate measurement. Technical Solutions

[0011] To achieve the above-mentioned objectives, in a first aspect, the present invention discloses a cylindrical array flexible pressure sensor, comprising an ion gel dielectric layer, wherein a plurality of column electrodes are provided on the upper surface of the ion gel dielectric layer, and a plurality of row electrodes are provided on the lower surface of the ion gel dielectric layer, wherein the intersection of each row electrode and each column electrode forms a single sensor unit.

[0012] A plurality of pyramid microstructures are arranged on the surface of the ion gel dielectric layer.

[0013] In a second aspect, the present invention discloses a method for preparing a cylindrical array flexible pressure sensor, comprising the following steps:

[0014] 1) Using polydimethylsiloxane film as the substrate, a stretched silver paste is applied by doctor blade coating on the PDMS film to prepare row and column electrodes;

[0015] 2) Preparation of microstructured ion gel dielectric layer;

[0016] 3) A cylindrical array flexible pressure sensor is manufactured using the ion gel dielectric layer, the row electrodes and the column electrodes.

[0017] The specific operations of step 1) are:

[0018] 11) Mixing a PDMS prepolymer and a curing agent, stirring and removing bubbles to obtain a PDMS mixture, spin-coating the PDMS mixture on a substrate sprayed with a release agent, and curing to form a PDMS film;

[0019] 12) Place the mask with the electrode pattern on the PDMS film prepared in step 11) so that the PDMS film and the mask are in contact with each other. Then, apply the stretched silver paste evenly to the PDMS film with the mask. After curing, remove the mask and cut it to obtain row electrodes and column electrodes.

[0020] In step 11), the mass ratio of PDMS prepolymer to curing agent is (10-12):1.

[0021] In step 2), a solution spin coating method is used to prepare an ion gel dielectric layer with a microstructure.

[0022] In a third aspect, the present invention discloses a method for preparing a cylindrical array flexible pressure sensor, comprising the following steps:

[0023] The column electrodes, the ion gel dielectric layer and the row electrodes are sequentially wound and fixed on the digestive endoscope, so that the cylindrical array flexible pressure sensor is integrated on the digestive endoscope.

[0024] In a fourth aspect, the present invention discloses a data acquisition system, including a microcontroller module, a capacitance measurement module, a row and column scanning module, and a cylindrical array flexible pressure sensor. The cylindrical array flexible pressure sensor is integrated on a digestive endoscope, the cylindrical array flexible pressure sensor is grounded through the row and column scanning module, the cylindrical array flexible pressure sensor is connected to the capacitance measurement module, and the microcontroller module is connected to the output end of the capacitance measurement module and the control end of the row and column scanning module.

[0025] The microcontroller module is connected to a host computer, and the host computer can display the sensor data output by the microcontroller module.

[0026] In a fifth aspect, the present invention discloses a data collection method, comprising the following steps:

[0027] Acquire capacitance information of each row of sensor units in the cylindrical array type flexible pressure sensor detected by a capacitance measurement module;

[0028] The obtained capacitance information of each row of sensor units in the cylindrical array flexible pressure sensor is graphically displayed.

[0029] The obtained capacitance information of each sensor unit in the cylindrical array flexible pressure sensor is graphically displayed. Beneficial effects

[0030] The present invention has the following beneficial effects:

[0031] The pressure sensor, preparation method, and data acquisition system and method described in the present invention use PDMS as a flexible substrate during specific operation. At the same time, a plurality of column electrodes are provided on the upper surface of the ion gel dielectric layer, and a plurality of row electrodes are provided on the lower surface of the ion gel dielectric layer, thereby forming a single sensor unit at the intersection of each row electrode and each column electrode. During measurement, the array-arranged sensor units are used for detection, and the measurement is highly accurate and sensitive, enabling doctors to obtain richer and more detailed tactile information during the operation, thereby improving the efficiency and safety of disease diagnosis and surgical treatment. At the same time, a corresponding data acquisition system is configured, and the capacitance information of each row of sensor units is acquired by cooperating with the row and column scanning module to improve the accuracy and reliability of data acquisition. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a structural diagram of the sensor of the present invention;

[0033] FIG2a is a structural diagram of a row electrode;

[0034] FIG2 b is a structural diagram of the column electrodes;

[0035] FIG3 is a structural diagram of an ion gel dielectric layer;

[0036] FIG4 is a structural diagram of the data acquisition system of the present invention;

[0037] FIG5 is a physical picture of the electrode prepared in Example 1;

[0038] Figure 6a is a structural diagram of the electrode in a planar state under a microscope;

[0039] Figure 6b is a structural diagram of the electrode in a cylindrical state under a microscope;

[0040] FIG7 is a physical picture of the ion-coagulated dielectric layer of the pyramid microstructure in Example 1;

[0041] FIG8 is a scanning electron microscope image of the pyramid microstructured ion gel dielectric layer in Example 1;

[0042] FIG9 is a sensitivity test diagram of the sensor in Example 1;

[0043] FIG10 is a graph showing the response time of the sensor in Example 1;

[0044] FIG11 is a graph showing the cyclic stability test of the sensor in Example 1;

[0045] FIG12a is a diagram showing a test result of the sensor described in Example 1 used in tactile perception of the digestive tract;

[0046] FIG12b is another test result diagram of the application of the sensor described in Example 1 in digestive tract tactile perception;

[0047] FIG12c is another test result diagram of the application of the sensor described in Example 1 in tactile perception of the digestive tract.

[0048] Among them, 1 is the column electrode, 2 is the ion gel dielectric layer, 3 is the row electrode, and 4 is the sensor unit. Modes for Carrying Out the Invention

[0049] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0050] The accompanying drawings illustrate schematic diagrams of the structures of the disclosed embodiments of the present invention. These figures are not drawn to scale; for the purpose of clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0051] Example 1

[0052] Referring to Figure 1, the cylindrical array flexible pressure sensor described in the present invention is used in the process of endoscopic diagnosis and treatment and is arranged on a digestive endoscope. The cylindrical array flexible pressure sensor includes an ion gel dielectric layer 2, and a plurality of column electrodes 1 are arranged on the upper surface of the ion gel dielectric layer 2, and a plurality of row electrodes 3 are arranged on the lower surface of the ion gel dielectric layer 2, wherein the intersection position of each row electrode 3 and each column electrode 1 forms a single sensor unit 4.

[0053] During operation, when pressure acts on the cylindrical array flexible pressure sensor of the present invention, the capacitance of the sensor unit 4 changes, thereby achieving pressure measurement.

[0054] Specifically, the cylindrical array-type flexible pressure sensor described in this embodiment includes three rows of electrodes 3 and eight columns of electrodes 1 to form 24 sensor units 4 .

[0055] 2a and 2b, in actual application, the diameter of the colonoscope is 11-14 mm, the circumference of the colonoscope is 34.6-44 mm, and the area range of the single sensor unit 4 is 2.25-4 m 2 The sensor units 4 in the same row are evenly distributed in the circumferential direction of the digestive endoscope, and the spacing between adjacent sensor units 4 in the same column is 1 mm.

[0056] It should be noted that, in the present invention, the sensor units 4 in the same row share the row electrode 3 , and the sensor units 4 in the same column share the column electrode 1 , so as to reduce the number of sensor connections and facilitate application.

[0057] Example 2

[0058] To manufacture the cylindrical array type flexible pressure sensor described in this embodiment, the present invention discloses a method for manufacturing the cylindrical array type flexible pressure sensor, comprising:

[0059] 1) Fabrication of flexible electrodes;

[0060] Using polydimethylsiloxane (PDMS) film as the base material, the stretched silver paste is applied to the PDMS film by the doctor blade method to form a flexible electrode. The specific process is as follows:

[0061] 11) Mix the PDMS prepolymer and curing agent in a mass ratio of (10-12):1, and stir at 1500-2000 rpm in a blender for 1-3 minutes to mix evenly and remove bubbles to obtain a PDMS mixture. Spray a layer of silicone aerosol release agent on a glass slide, pour the PDMS mixture on the glass slide, and spin-coat at 300-500 rpm for 20-40 seconds. Cur the glass slide at 80-90°C for 30 minutes to 1 hour to form a PDMS film.

[0062] 12) Use a laser cutter to cut a 50 μm thick PET film to form a mask with the desired electrode pattern. Place the mask on the PDMS film prepared in step 11) so that the PDMS film and the mask are aligned. Apply a stretched silver paste evenly to the PDMS film with the mask. Curing at 90-100°C for 4-6 hours, remove the mask, and cut the PDMS film to obtain row electrodes 3 and column electrodes 1.

[0063] 13) Use copper wire, heat-cured silver paste, or conductive silver glue to lead out the row electrode 3 and column electrode 1 of the cylindrical array flexible pressure sensor for subsequent testing. Cure the high-temperature curing silver paste at 90°C for 30 minutes to 1 hour, and cure the conductive silver glue at 60°C for 1 hour to 2 hours.

[0064] 2) preparing an ion gel dielectric layer 2;

[0065] The solution spin coating method is used to prepare the microstructured PVDF-HFP / IL ion gel dielectric layer 2. The specific process is as follows:

[0066] 21) Mix PVDF-HFP and acetone at a mass ratio of 1:(7-9), and stir at 60-70°C for 2-4 hours to fully dissolve the PVDF-HFP to obtain a mixed solution;

[0067] 22) Adding ionic liquid to the mixed solution obtained in step 21), and continuing stirring at room temperature for 1 hour, wherein the mass ratio of PVDF-HFP to ionic liquid is 1.5:(1-1.2);

[0068] 23) Drop the solution obtained in step 22) onto the template with the microstructure, spin-coat it at 300-500 rpm for 15-30 seconds, and then dry it in an oven at 60°C for 30 minutes to 1 hour. After peeling and cutting, the ion gel dielectric layer 2 is obtained.

[0069] In this embodiment, the ionic liquid is 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]).

[0070] In this embodiment, the microstructure template is a template with a pyramid microstructure formed by photolithography. The pyramid microstructure has a square side length of 70 μm, a height of 50 μm, and a side spacing of 40 μm. The results of microstructure template observation under a microscope are shown in FIG3 .

[0071] Example 3

[0072] The method for preparing the cylindrical array flexible pressure sensor of the present invention comprises the following steps:

[0073] The column electrode 1, the ion gel dielectric layer 2 and the row electrode 3 are sequentially wrapped around the digestive endoscope and fixed with PI (polyimide) tape to form a cylindrical array flexible pressure sensor.

[0074] Example 4

[0075] In order to realize data acquisition of the cylindrical array type flexible pressure sensor, the present invention further discloses a data acquisition system, which includes a hardware acquisition circuit and a host computer.

[0076] In this embodiment, the hardware acquisition circuit includes a cylindrical array flexible pressure sensor, a microcontroller module, a capacitance measurement module and a row and column scanning module; the cylindrical array flexible pressure sensor is integrated on the digestive endoscope, the cylindrical array flexible pressure sensor is grounded through the row and column scanning module, the cylindrical array flexible pressure sensor is connected to the capacitance measurement module, and the microcontroller module is connected to the output end of the capacitance measurement module and the control end of the row and column scanning module.

[0077] In this embodiment, the microcontroller module adopts an STM32 single-chip microcomputer, wherein the STM32 single-chip microcomputer is a series of 32-bit microcontroller product series launched by STMicroelectronics, which has the advantages of high performance, low power consumption, multiple peripherals, high integration and easy development. STM32F103C8T6 is selected as the microcontroller of the hardware acquisition circuit.

[0078] In this embodiment, the capacitance measurement module utilizes a PCap01AD chip. The PCap01AD chip can connect to the capacitive sensor in four connection modes: single sensor drift mode, single sensor ground mode, differential sensor drift mode, and differential sensor ground mode. In single sensor drift mode, the PCap01AD chip can connect to up to seven sensors. Due to the large number of sensor units 4 in this embodiment, two PCap01AD chips are used, connected in single sensor ground mode, to measure the capacitance of a cylindrical array flexible pressure sensor. The PCap01AD chip communicates with the microcontroller module via SPI communication, enabling high-speed data transmission and supporting full-duplex communication.

[0079] In this embodiment, the sensor units 4 in the same row share the row electrode 3, and the sensor units 4 in the same column share the column electrode 1. Therefore, there are 11 wirings in total for the 24 sensor units 4. The number of wirings can be effectively reduced by sharing the electrodes. In addition, the present invention uses two PCap01AD chips to measure the capacitance of 8 columns at the same time. At this time, an analog switch is used to realize the gating of three rows, and the measurement of the capacitance data of the 3×8 cylindrical array flexible pressure sensor can be completed. The present invention uses a high-speed analog switch TS5A3357 chip to realize the row scanning of the sensor array. The operating voltage of the high-speed analog switch TS5A3357 chip is 1.65-5.5V. Under the control of the STM32 single-chip microcomputer, the row scanning of the sensor array is realized, thereby realizing the collection of capacitance data of the cylindrical array flexible pressure sensor.

[0080] In addition, in this embodiment, the STM32 single chip microcomputer sends the collected sensor data to the host computer through the serial port for digital display and storage. Among them, the present invention uses the CH343 chip to achieve high-speed transmission of sensor array capacitance data.

[0081] Example 5

[0082] Accordingly, the present invention discloses a data collection method, comprising the following steps:

[0083] 1) Acquiring capacitance information of each row of sensor units 4 in the cylindrical array flexible pressure sensor detected by the capacitance measurement module;

[0084] 2) The microcontroller module receives the capacitance information of each row of sensor units 4 in the cylindrical array type flexible pressure sensor output by the capacitance measurement module, and then graphically displays the capacitance information of each row of sensor units 4 in the cylindrical array type flexible pressure sensor through the host computer. The capacitance data of the cylindrical array type flexible pressure sensor is displayed in the form of a three-dimensional bar graph in the host computer, so that the pressure distribution can be observed more intuitively. The sensor digital acquisition scheme is shown in Figure 4.

[0085] Example 6

[0086] The method for preparing the cylindrical array flexible pressure sensor described in this embodiment includes:

[0087] 1) Fabrication of flexible electrodes;

[0088] Using polydimethylsiloxane (PDMS) film as the base material, the stretched silver paste is applied to the PDMS film by the doctor blade method to form a flexible electrode. The specific process is as follows:

[0089] 11) PDMS prepolymer and curing agent were mixed in a mass ratio of 11:1 and stirred in a blender at 1800 rpm for 2 minutes to ensure uniform mixing and remove bubbles, thereby obtaining a PDMS mixture. A layer of silicone aerosol release agent was sprayed on a glass slide, and the PDMS mixture was poured onto the glass slide and spin-coated at 400 rpm for 30 seconds. The glass slide was cured at 85°C for 45 minutes to form a PDMS film.

[0090] 12) Use a laser cutter to cut a 50 μm thick PET film to form a mask with the desired electrode pattern. Place the mask on the PDMS film prepared in step 11) so that the PDMS film and the mask are aligned. Apply a stretched silver paste evenly to the PDMS film with the mask. Curing at 95°C for 5 h, remove the mask, and cut the PDMS film to obtain row electrodes 3 and column electrodes 1.

[0091] 13) Use copper wire, heat-cured silver paste, or conductive silver glue to lead out the row electrode 3 and column electrode 1 of the cylindrical array flexible pressure sensor to facilitate subsequent testing. The high-temperature curing silver paste should be cured at 90°C for 40 minutes, and the conductive silver glue should be cured at 60°C for 1.5 hours.

[0092] 2) preparing an ion gel dielectric layer 2;

[0093] The solution spin coating method is used to prepare the microstructured PVDF-HFP / IL ion gel dielectric layer 2. The specific process is as follows:

[0094] 21) Mix PVDF-HFP and acetone at a mass ratio of 1:8, and stir at 65°C for 3 h to fully dissolve the PVDF-HFP to obtain a mixed solution;

[0095] 22) adding an ionic liquid to the mixed solution obtained in step 21), and continuing stirring at room temperature for 1 hour, wherein the mass ratio of PVDF-HFP to the ionic liquid is 1.5:1.2;

[0096] 23) Drop the solution obtained in step 22) onto the template with the microstructure, spin-coat it at 400 rpm for 25 seconds, and then dry it in an oven at 60°C for 45 minutes. After peeling and cutting, the ion gel dielectric layer 2 is obtained.

[0097] Example 7

[0098] The method for preparing the cylindrical array flexible pressure sensor described in this embodiment includes:

[0099] 1) Fabrication of flexible electrodes;

[0100] Using polydimethylsiloxane (PDMS) film as the base material, the stretched silver paste is applied to the PDMS film by the doctor blade method to form a flexible electrode. The specific process is as follows:

[0101] 11) PDMS prepolymer and curing agent were mixed in a mass ratio of 10:1 and stirred in a blender at 1500 rpm for 1 minute to mix evenly and remove bubbles, thereby obtaining a PDMS mixture. A layer of silicone aerosol release agent was sprayed on a glass slide, and the PDMS mixture was poured onto the glass slide and spin-coated at 300 rpm for 20 seconds. The glass slide was cured at 90°C for 30 minutes to form a PDMS film.

[0102] 12) Use a laser cutter to cut a 50 μm thick PET film to form a mask with the desired electrode pattern. Place the mask on the PDMS film prepared in step 11) so that the PDMS film and the mask are aligned. Apply a stretched silver paste evenly to the PDMS film with the mask. Curing at 90°C for 4 h, remove the mask, and cut the PDMS film to obtain row electrodes 3 and column electrodes 1.

[0103] 13) Use copper wire, heat-cured silver paste, or conductive silver glue to lead out the row electrode 3 and column electrode 1 of the cylindrical array flexible pressure sensor to facilitate subsequent testing. Cure the high-temperature curing silver paste at 90°C for 30 minutes, and cure the conductive silver glue at 60°C for 1 hour.

[0104] 2) preparing an ion gel dielectric layer 2;

[0105] The solution spin coating method is used to prepare the microstructured PVDF-HFP / IL ion gel dielectric layer 2. The specific process is as follows:

[0106] 21) Mix PVDF-HFP and acetone at a mass ratio of 1:7, and stir at 60°C for 2 h to fully dissolve the PVDF-HFP to obtain a mixed solution;

[0107] 22) adding an ionic liquid to the mixed solution obtained in step 21), and continuing stirring at room temperature for 1 hour, wherein the mass ratio of PVDF-HFP to the ionic liquid is 1.5:1.1;

[0108] 23) Drop the solution obtained in step 22) onto the template with the microstructure, spin-coat it at 300 rpm for 15 seconds, and then dry it in an oven at 60°C for 30 minutes. After peeling and cutting, the ion gel dielectric layer 2 is obtained.

[0109] Example 8

[0110] The method for preparing the cylindrical array flexible pressure sensor described in this embodiment includes:

[0111] 1) Fabrication of flexible electrodes;

[0112] Using polydimethylsiloxane (PDMS) film as the base material, the stretched silver paste is applied to the PDMS film by the doctor blade method to form a flexible electrode. The specific process is as follows:

[0113] 11) PDMS prepolymer and curing agent were mixed in a mass ratio of 12:1 and stirred in a blender at 2000 rpm for 3 minutes to ensure uniform mixing and remove bubbles, thereby obtaining a PDMS mixture. A layer of silicone aerosol release agent was sprayed on a glass slide, and the PDMS mixture was poured onto the glass slide and spin-coated at 500 rpm for 40 seconds. The glass slide was cured at 90°C for 1 hour to form a PDMS film.

[0114] 12) Using a laser cutter, cut a 50 μm thick PET film to form a mask with the desired electrode pattern. Place the mask on the PDMS film prepared in step 11) to ensure that the PDMS film and the mask are aligned. Apply a stretched silver paste evenly to the PDMS film with the mask. Curing at 100°C for 6 h, remove the mask, and cut the PDMS film to obtain row electrodes 3 and column electrodes 1.

[0115] 13) Use copper wire, heat-cured silver paste, or conductive silver glue to lead out the row electrode 3 and column electrode 1 of the cylindrical array flexible pressure sensor to facilitate subsequent testing. The high-temperature curing silver paste should be cured at 90°C for 1 hour, and the conductive silver glue should be cured at 60°C for 2 hours.

[0116] 2) preparing an ion gel dielectric layer 2;

[0117] The solution spin coating method is used to prepare the microstructured PVDF-HFP / IL ion gel dielectric layer 2. The specific process is as follows:

[0118] 21) Mix PVDF-HFP and acetone at a mass ratio of 1:9, and stir at 70°C for 4 h to fully dissolve the PVDF-HFP to obtain a mixed solution;

[0119] 22) adding ionic liquid to the mixed solution obtained in step 21), and continuing stirring at room temperature for 1 hour, wherein the mass ratio of PVDF-HFP to ionic liquid is 1.5:1;

[0120] 23) Drop the solution obtained in step 22) onto the template with the microstructure, spin-coat it at 500 rpm for 30 seconds, and then dry it in an oven at 60°C for 1 hour. After peeling and cutting, the ion gel dielectric layer 2 is obtained.

[0121] Embodiment 9

[0122] The flexible sensor electrode prepared in this experiment is a PDMS / silver paste flexible electrode, and the ion gel dielectric layer 2 is a dielectric layer with a pyramid microstructure PVDF-HFP / 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]). The specific preparation process is as follows:

[0123] 1) Preparation of flexible electrodes;

[0124] 11) Mix polydimethylsiloxane (PDMS) prepolymer and curing agent in a mass ratio of 10:1. Stir the mixture in a blender at 2000 rpm for 1 min to ensure uniform mixing and remove bubbles. This yields a PDMS mixture. Spin-coat the PDMS mixture at 500 rpm for 40 seconds onto a glass slide coated with a silicone release agent. Heat-cure the mixture in an oven at 90°C for 30 minutes to obtain a PDMS film.

[0125] 12) Preparation of electrode pattern mask;

[0126] A laser cutting machine is used to cut the PET film to prepare a mask of the required electrode shape to obtain a mask.

[0127] 13) Preparation of flexible electrodes by scraping method;

[0128] Place the mask on the solidified PDMS film, fit the mask to the PDMS film, drop the stretched silver paste on the mask, and then scrape it to evenly coat the silver paste on the PDMS film. Then place it in a 90°C oven, heat and cure it for 4 hours, then remove the mask and use a knife to cut it into the required electrodes.

[0129] 14) Wiring;

[0130] The PDMS / silver paste flexible electrode was connected to the conductive lead through conductive silver glue, and then placed in a 60°C oven. After curing for 1 hour, it was taken out and polyimide tape was attached to the conductive silver glue to prevent the wire from falling off during use, which facilitated subsequent testing and application. Figure 5 shows the prepared electrode.

[0131] In the planar state, the resistance of a single row electrode 3 is 3Ω, and the resistance of a single column electrode 1 is 1.4Ω. In the bent state, the resistance of a single row electrode 3 is 4.4Ω, and the resistance of a single column electrode 1 is 2Ω.

[0132] Under a microscope, the electrodes in the planar state and the cylindrical state were observed respectively, and the observation results under the microscope were obtained as shown in Figures 6a and 6b. Figure 6a shows the electrode in the planar state, and Figure 6b shows the electrode in the cylindrical state. According to the observation results, it can be seen that the stretched silver paste is evenly and continuously coated on the PDMS film without breakage, ensuring good conductivity of the electrode.

[0133] 2) Preparation of pyramid microstructured dielectric layer;

[0134] 21) PVDF-HFP and acetone were mixed in a mass ratio of 1:7 and stirred at 500 rpm at 65°C for 2 h to completely dissolve the PVDF-HFP in the acetone. Then, [EMIM][TFSI] ionic liquid was added to the mixed solution at a ratio of 3:2. The mixture was stirred at 500 rpm at room temperature for 1 h to form a mixed solution of PVDF-HFP, acetone, and ionic liquid.

[0135] 22) The mixed solution obtained in step 21) was spin-coated at 400 rpm for 20 seconds onto a silicon wafer with a pyramid microstructure. After complete evaporation of the solvent, the film was peeled off and cut into a 10 mm × 45 mm film. Figure 7 shows the prepared PVDF-HFP / IL ion gel dielectric layer 2. The morphology of the pyramid microstructured ion gel dielectric layer 2 was characterized using a scanning electron microscope, as shown in Figure 8.

[0136] 3) Sensor packaging;

[0137] The prepared electrodes and the ion gel dielectric layer 2 are packaged on a digestive endoscope in a sandwich structure to form a cylindrical array flexible pressure sensor.

[0138] 4) Performance test of cylindrical array flexible pressure sensor, the specific results are as follows:

[0139] 41) The sensitivity test results are shown in Figure 9. As shown in Figure 9, the cylindrical array flexible pressure sensor shows a sensitivity of 0.39 kPa in the pressure range of 0-40 kPa. -1 sensitivity.

[0140] 42) The response / time test results are shown in FIG10 . As can be seen from FIG10 , the response / recovery time of the cylindrical array flexible pressure sensor is 46 ms.

[0141] 43) The results of the cyclic stability test are shown in FIG11 . As can be seen from FIG11 , the capacitance signal of the cylindrical array flexible pressure sensor does not drift significantly after 1200 loading / unloading cycles, indicating that the cylindrical array flexible pressure sensor has good stability.

[0142] 44) Application of cylindrical array flexible pressure sensor in tactile perception of the digestive tract. The cylindrical array flexible pressure sensor is integrated on a digestive endoscope and moved in an intestinal model. During the movement, the cylindrical array flexible pressure sensor comes into contact with the intestine and is subjected to pressure. The capacitance change data of this process is collected by a digital acquisition system. Figures 12a-12c show different states of the digestive endoscope moving in the digestive tract. The results show that the cylindrical array flexible pressure sensor has good tactile perception capabilities.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A cylindrical array flexible pressure sensor, characterized in that: The invention comprises an ion gel dielectric layer (2), wherein a plurality of column electrodes (1) are arranged on the upper surface of the ion gel dielectric layer (2), and a plurality of row electrodes (3) are arranged on the lower surface of the ion gel dielectric layer (2), wherein the intersection of each row electrode (3) and each column electrode (1) forms a single sensor unit (4).

2. The cylindrical array flexible pressure sensor according to claim 1, characterized in that: A plurality of pyramid microstructures are arranged on the surface of the ion gel dielectric layer (2).

3. A method for preparing the cylindrical array flexible pressure sensor according to claim 1, characterized in that: The following steps are involved: 1) Using polydimethylsiloxane film as the base material, a stretched silver paste is scraped onto the PDMS film to prepare row electrodes (3) and column electrodes (1); 2) preparing an ion gel dielectric layer with a microstructure (2); 3) A cylindrical array type flexible pressure sensor is manufactured using the ion gel dielectric layer (2), the row electrodes (3) and the column electrodes (1).

4. The method for preparing the cylindrical array flexible pressure sensor according to claim 3, characterized in that: The specific operations of step 1) are: 11) mixing the PDMS prepolymer and the curing agent, stirring and removing bubbles to obtain a PDMS mixture, spin-coating the PDMS mixture on a substrate sprayed with a release agent, and forming a PDMS film after curing; 12) placing the mask with the electrode pattern on the PDMS film prepared in step 11) so that the PDMS film and the mask are in contact with each other, and then evenly scraping the stretched silver paste on the PDMS film with the mask. After curing, the mask is removed and cut to obtain row electrodes (3) and column electrodes (1).

5. The method for preparing the cylindrical array flexible pressure sensor according to claim 4, characterized in that: In step 11), the mass ratio of PDMS prepolymer to curing agent is (10-12):

1.

6. The method for preparing the cylindrical array flexible pressure sensor according to claim 3, characterized in that: In step 2), a solution spin coating method is used to prepare an ion gel dielectric layer (2) having a microstructure.

7. A method for preparing the cylindrical array flexible pressure sensor according to claim 1, characterized in that: The following steps are involved: The column electrodes (1), the ion gel dielectric layer (2) and the row electrodes (3) are sequentially wound and fixed on a digestive endoscope, so that the cylindrical array type flexible pressure sensor is integrated on the digestive endoscope.

8. A data acquisition system, characterized in that: It includes a microcontroller module, a capacitance measurement module, a row and column scanning module and the cylindrical array type flexible pressure sensor as described in claim 1, wherein the cylindrical array type flexible pressure sensor is integrated on a digestive endoscope, the cylindrical array type flexible pressure sensor is grounded through the row and column scanning module, the cylindrical array type flexible pressure sensor is connected to the capacitance measurement module, and the microcontroller module is connected to the output end of the capacitance measurement module and the control end of the row and column scanning module.

9. The pressure data detection system according to claim 8, characterized in that: The microcontroller module is connected to a host computer, and the host computer can display the sensor data output by the microcontroller module.

10. A data collection method, characterized in that: The following steps are involved: Acquire capacitance information of each row of sensor units (4) in the cylindrical array type flexible pressure sensor according to claim 1 detected by a capacitance measurement module; The acquired capacitance information of each row of sensor units (4) in the cylindrical array type flexible pressure sensor is graphically displayed.

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