Preparation method of ionizing pressure sensor, pressure sensor, pressure sensing glove and monitoring system

Abstract

The invention provides an ionizing pressure sensor preparation method, a pressure sensor, a pressure sensing glove and a monitoring system, and relates to the technical field of flexible sensors, and the method comprises the following steps: S1, preparing a microstructure electrode by using degradable elastic polyester particles (BEP particles) and PLA particles as raw materials through a method of combining electrostatic spinning and electrostatic spraying; s2, preparing an ionic dielectric layer by using degradable elastic polyester particles and ionic liquid; s3, performing face-to-face assembly on the microelectrode and the ionic dielectric layer to obtain an ionization pressure sensor (NIPS); the nanofiber membrane-based flexible pressure sensor which is low in cost, easy to batch, green and degradable is prepared, meanwhile, the device is combined with a rehabilitation glove, the flexible design enables the pressure sensor to be better attached to the hand, and the wearing comfort and the accurate sensing of hand actions are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible sensors, and more particularly to a method for preparing an ionizing pressure sensor, a pressure sensor, a pressure sensing glove and a monitoring system. Background Art

[0002] At present, due to various reasons, patients have lost the ability to perform fine movements of their hands. In order to accurately assess the degree of hand dysfunction, a variety of detection methods have been adopted, such as neuroelectrophysiological testing and electromyography. Although these testing methods can provide important information about nerve and muscle function, they usually require patients to go to the hospital for examination with professional equipment, and it is difficult to monitor health recovery in real time and accurately. Flexible pressure sensors have shown obvious advantages in detecting the functional status of the hand. This sensor is small and light, can be directly attached to the surface of the skin, and monitors hand movement and posture information in real time by sensing pressure changes on the skin surface. For this reason, it is necessary to develop a flexible pressure sensor that can achieve convenient, real-time and accurate monitoring to achieve early warning and promote rehabilitation.

[0003] However, many studies have been conducted on smart gloves at home and abroad. For example, patent CN116301387A discloses a magnetostrictive smart glove that can monitor the bending angle of finger joints, but because it is mostly made of airtight film, it is not suitable for long-term wear; patent CN118012262A discloses a smart glove operating system composed of ion gel pressure sensors, which can realize a variety of control functions, but its sensitivity is low under low and high pressures, and it does not have the ability to identify small pressures under high pressure, and cannot achieve accurate monitoring.

[0004] Therefore, how to provide a pressure sensor preparation method that can solve the above problems is an issue that those skilled in the art urgently need to solve. Summary of the invention

[0005] In view of this, the present invention provides a method for preparing an ionized pressure sensor, a pressure sensor, a pressure sensing glove and a monitoring system, and prepares a low-cost, easy-to-mass-produce, green and degradable nanofiber membrane-based flexible pressure sensor. At the same time, the device is combined with rehabilitation gloves, and the flexible design makes it fit the hand better, thereby improving the wearing comfort and accurate perception of hand movements.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for preparing an ionization pressure sensor comprises the following steps:

[0008] S1: Using biodegradable elastic polyester particles (BEP particles) and PLA particles as raw materials, microstructure electrodes were prepared by combining electrospinning and electrostatic spraying;

[0009] S2: Preparation of ionic dielectric layer using BEP particles and ionic liquids (ILs);

[0010] S3: The microelectrode and the ionic dielectric layer are assembled face to face to obtain an ionic pressure sensor (NIPS).

[0011] Preferably, the S1 comprises the following steps:

[0012] S11: Preparation of nanofiber membrane using BEP particles;

[0013] S12: preparing high modulus PLA microspheres using PLA particles, and embedding the high modulus PLA microspheres into the surface of the nanofiber membrane to obtain the corresponding microstructure nanofiber membrane;

[0014] S13: Covering the microstructured nanofiber membrane with a screen printing plate, coating the conductive ink material on the microstructured nanofiber membrane with a scraper, and obtaining a microstructured electrode after the microstructured nanofiber membrane is dried.

[0015] Preferably, the S11 comprises the following steps:

[0016] S111: placing BEP particles into a mixed solvent and stirring to obtain a spinning solution;

[0017] S112: Electrospinning the spinning solution using preset spinning conditions to obtain a nanofiber membrane.

[0018] Preferably, the S12 comprises the following steps:

[0019] S121: using the nanofiber membrane obtained in S112 as a base layer, placing PLA particles in a solvent and stirring to obtain a PLA spinning solution, and treating the PLA spinning solution through an integrated electrospinning vortex spray system to obtain PLA microspheres;

[0020] S122: The PLA microspheres are embedded into the surface of the nanofiber membrane using an integrated electrospinning vortex spray system to obtain the corresponding microstructured nanofiber membrane.

[0021] Preferably, S2 comprises the following steps:

[0022] S21: placing the BEP particles in a mixed solvent, adding an ionic liquid until the particles are completely dissolved, and obtaining a composite spinning solution;

[0023] S22: electrospinning the composite spinning solution using a blended electrospinning method to obtain a corresponding ionic dielectric layer.

[0024] Preferably, the S22 specifically includes: spinning the composite spinning solution using the preset spinning conditions.

[0025] The present invention also provides a pressure sensor, comprising: a pressure sensor obtained by any of the above-mentioned methods for preparing an ionization pressure sensor.

[0026] The present invention also provides a pressure sensing glove, comprising a glove body and a pressure sensor arranged at the joint of the glove body, wherein the pressure sensor is obtained by any of the above-mentioned methods for preparing an ionizing pressure sensor.

[0027] The present invention also provides a hand movement monitoring system, comprising:

[0028] A pressure sensing glove, wherein a pressure sensor is provided at the joint of the pressure sensing glove, wherein the pressure sensor is obtained by the preparation method of the ionization pressure sensor according to any one of claims 1 to 6, and is used to monitor the fine movement data of the user's hand;

[0029] A transmission module, the transmission module is communicatively connected with the pressure sensing glove and is used for transmitting hand fine movement data;

[0030] A processing terminal is communicatively connected to the transmission module and is used for processing the hand fine movement data.

[0031] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method for preparing an ionization pressure sensor and a pressure sensor, which have the following beneficial effects:

[0032] 1. The new ionization sensing technology and anisotropic modulus gradient were used to achieve high-sensitivity and high-resolution pressure sensing in a wide response range, and a low-cost, easy-to-mass-produce, green and degradable nanofiber membrane-based flexible pressure sensor was prepared;

[0033] 2. The device is combined with rehabilitation gloves. The flexible design makes it fit the hand better, improving the wearing comfort and accurate perception of hand movements. This creates a new hand rehabilitation training monitoring tool that can realize convenient, real-time and accurate monitoring of hand movements, which has important innovative significance.

[0034] 3. Simple process and low cost: The preparation method of the present invention is simple, the materials are environmentally friendly and sustainable, and it is easy to carry out large-scale production, which is in line with the development trend of modern manufacturing industry. Compared with traditional monitoring methods, the present invention is comfortable, convenient, accurate and real-time. It has good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0036] Figure 1 The results of observations of pure BEP nanofiber membrane, ILs / degradable elastic polyester particle nanofiber membrane, and PLA / BEP nanofiber membrane provided in the embodiments of the present invention by scanning electron microscopy, wherein a is the SEM image of pure BEP nanofiber membrane, b is the SEM image of ionic liquid ILs / BEP nanofiber membrane, and c is the SEM image of PLA / BEP nanofiber membrane;

[0037] Figure 2 A line graph showing the effect of the doping amount of ionic liquid in the ionic dielectric layer and the thickness of ILs / BEP nanofiber membrane on the sensing performance of the ionic pressure sensor provided in the embodiment of the present invention, where a is the ionic liquid [EMIM] + [PF6] - a is the performance influence line graph of the doping amount, b is the performance influence line graph of the ILs / BEP nanofiber membrane thickness;

[0038] Figure 3 A comparison chart of the sensing performance of CPS, NCPS, IPS, and NIPS provided in an embodiment of the present invention;

[0039] Figure 4 The NIPS pressure response performance test result diagram provided by the embodiment of the present invention, wherein a is a pressure response test result diagram, b is a micro-pressure response test result diagram, and c is a cycle stability test result diagram;

[0040] Figure 5 A schematic diagram of an ionized pressure sensing glove and a monitoring system using the glove provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The embodiment of the present invention discloses a method for preparing an ionization pressure sensor, comprising the following steps:

[0043] S1: Using BEP particles (low modulus degradable elastic polyester, abbreviated as BEP particles) and PLA particles (high modulus polylactic acid) as raw materials, microstructure electrodes were prepared by combining electrospinning and electrostatic spraying;

[0044] S2: preparing an ionic dielectric layer using BEP particles and ionic liquids (abbreviated as ILs);

[0045] S3: Assemble the microelectrode and the ionic dielectric layer face to face to obtain an ionic pressure sensor.

[0046] In a specific embodiment, S1 comprises the following steps:

[0047] S11: Preparation of nanofiber membrane using BEP particles;

[0048] S12: preparing high modulus PLA microspheres using PLA particles, and embedding the high modulus PLA microspheres into the surface of the nanofiber membrane to obtain the corresponding microstructure nanofiber membrane;

[0049] S13: Paste the screen printing plate on the microstructure nanofiber membrane using conductive ink material, and obtain the microstructure electrode after the microstructure nanofiber membrane is dried.

[0050] In a specific embodiment, S11 includes the following steps:

[0051] S111: weighing a certain amount of BEP particles, putting them into a mixed solvent and stirring them to obtain a spinning solution, wherein the amount of BEP particles added may be 5-10 g, preferably 8 g, depending on the concentration of the spinning solution; the mixed solvent may be formed by dichloromethane / hexafluoroisopropanol (DCM / HFIP), wherein the mixing ratio may be 10 / 0, 9 / 1, 8 / 2, 7 / 3, 6 / 4, 5 / 5;

[0052] S112: electrospinning the spinning solution using preset spinning conditions to obtain a nanofiber membrane, wherein the spinning time can be 1-4 hours, and the optimal spinning time is 2 hours.

[0053] Specifically, the spinning conditions include spinning voltage (which can be 14-22 kV), injection speed (which can be 1 mL / h-3.0 mL / h), spinning distance (which can be 12 cm-18 cm), and roller speed (which can be 200 rpm-800 rpm). The preferred spinning conditions are a spinning voltage of 18 kV, an injection speed of 2.0 mL / h, a spinning distance of 15 cm, and a roller speed of 500 rpm, and the preferred spinning conditions are used as preset spinning conditions.

[0054] In a specific embodiment, S12 includes the following steps:

[0055] S121: using the nanofiber membrane obtained in S112 as a base layer, placing PLA particles in a solvent and stirring to obtain a PLA spinning solution, and treating the PLA spinning solution through an integrated electrospinning vortex spray system to obtain PLA microspheres;

[0056] S122: The PLA microspheres are embedded into the surface of the nanofiber membrane using an integrated electrospinning vortex spray system to obtain the corresponding microstructured nanofiber membrane.

[0057] Specifically, in S122, generally speaking, the lower the concentration of the PLA solution, the larger the particle size of the corresponding PLA microspheres, the greater the number of PLA microspheres, and the more corresponding microstructures are formed. At the same time, the size of the PLA microspheres increases with the decrease of the PLA concentration. The optimal value is PLA-0.25 / BEP NMs, and the modulus gradient is 1.6μm-5.4μm. At this time, the prepared microstructure electrode has the best sensing performance for assembling devices.

[0058] In a specific embodiment, S2 includes the following steps:

[0059] S21: placing the BEP particles in a mixed solvent, adding an ionic liquid until the particles are completely dissolved, and obtaining a composite spinning solution;

[0060] S22: electrospinning the composite spinning solution using a blended electrospinning method to obtain a corresponding ionic dielectric layer.

[0061] In a specific embodiment, S22 specifically includes: spinning the composite spinning solution using preset spinning conditions.

[0062] Specifically, the weight of the BEP particles in S21 can be 3.6 g, the mixed solvent can be a mixture of dichloromethane / hexafluoroisopropanol (DCM / HFIP, with a mixing ratio of 8 / 2-wt / wt), and the ionic liquid (ILs) can be any one of an imidazole ionic liquid, a pyridine ionic liquid, and a quaternary ammonium ionic liquid, preferably an imidazole ionic liquid, including 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIM] + [PF6] - ), the addition amount of the corresponding ionic liquid can be 2-20wt%, and stirred at room temperature for 3h until it is completely dissolved to obtain ILs / BEP composite spinning solutions with different ratios.

[0063] In S22, the composite spinning solution can be placed in a 10 mL syringe, and a series of ILs / BEP NMs nanofiber membranes (denoted as ILs / BEP-x) can be prepared by conventional co-blending electrospinning technology under preset spinning conditions (spinning voltage 20 kV, spinning speed 0.8 mL / h, spinning distance 12 cm, receiver roller speed 500 rpm), which is the ionic dielectric layer.

[0064] An embodiment of the present invention also provides a pressure sensor, including: obtained by the ion-type pressure sensor preparation method described in any of the above embodiments, wherein the pressure sensor is assembled by an ultrasonic resonance integrated assembly method, and has a unique sandwich structure (wherein the upper and lower layers are microstructured electrode layers; the middle layer is an ionic dielectric layer).

[0065] An embodiment of the present invention further provides a pressure sensing glove, comprising a glove body and pressure sensors arranged at the joints of the glove body, wherein the pressure sensor is obtained by the method for preparing the ionizing pressure sensor described in any one of the above embodiments.

[0066] An embodiment of the present invention further provides a hand movement monitoring system, comprising:

[0067] A pressure sensing glove, wherein a pressure sensor is provided at the joint of the pressure sensing glove, wherein the pressure sensor is obtained by the preparation method of the ionization pressure sensor described in any one of the above embodiments, and is used to monitor the fine movement data of the user's hand;

[0068] A transmission module, the transmission module is communicatively connected with the pressure sensing glove and is used for transmitting hand fine movement data;

[0069] A processing terminal is communicatively connected to the transmission module and is used for processing the hand fine movement data.

[0070] In order to verify the reliability of the pressure sensor provided by the embodiment of the present invention, the obtained ionization pressure sensor was observed for microscopic morphology using a JEM-7500F scanning electron microscope. Under the conditions of an accelerating voltage of 5 kV and a current of 10 μA, a clear surface morphology image was obtained by adjusting the lens magnification.

[0071] The results of pure BEP nanofiber membrane, ILs / nanofiber membrane, and PLA / BEP nanofiber membrane were observed by scanning electron microscopy. Figure 1 shown. Figure 1 a is the SEM image of the pure BEP nanofiber membrane, from which it can be seen that the sample is composed of three-dimensional porous nanofibers stacked together, with a smooth fiber surface and uniform diameter distribution (Mean = 1.1341 ± 0.228 μm). Figure 1 b is a nanofiber membrane doped with ionic liquid. After the addition of ionic liquid, the fibers become uneven in thickness, but still maintain a good porous structure. Figure 1c is a nanofiber membrane obtained in an embodiment of the present invention. As can be seen from the figure, PLA microspheres are evenly sprayed on the surface of the nanofiber membrane. The PLA microspheres form more microstructures on the fiber membrane, which is beneficial to reducing the initial capacitance value. At the same time, its greater rigidity enables it to further compress the ionic dielectric layer under high pressure, thereby further improving the sensitivity and response range through a "rigid and flexible" approach.

[0072] The obtained ion-type pressure sensor was subjected to pressure sensing test to explore the effects of the doping amount of ionic liquid in the ionic dielectric layer and the thickness of the ILs / BEP nanofiber membrane on the sensing performance of the ion-type pressure sensor.

[0073] like Figure 2 As shown in the figure, in order to further improve the sensing performance of the sensor, the effects of the doping amount of ionic liquid in the ionic dielectric layer and the thickness of the ILs / BEP nanofiber membrane on the sensing performance of the ion-type pressure sensor were investigated. Figure 2 As shown in Figure a, the sensitivity of the sensor increases with the increase of the ionic liquid doping amount, and the highest responsiveness is shown when the ionic liquid doping amount is 15%. Therefore, the optimal doping amount of the ionic liquid is determined to be 15%. The sensing performance of the ionization pressure sensor is also affected by the thickness of the fiber membrane. Figure 2 b is the effect of fiber membranes of different thicknesses on sensor sensitivity. As can be seen from the figure, the thinner the ionic dielectric layer, the better the sensing performance. However, if the ionic dielectric layer is too thin, ionic liquid leakage is likely to occur, resulting in a decrease in sensor performance. Therefore, when the thickness of the ILs / BEP nanofiber membrane is about 26 μm, the sensor sensitivity is the highest.

[0074] In order to demonstrate the influence of ionic liquid and PLA microspheres on the sensing performance of the sensor, the present invention embodiment is compared with the sensor without microstructure (IPS), without ionic liquid (NCPS) and without microstructure and ionic liquid (CPS) to highlight the advantages of the NIPS sensor obtained in the present invention embodiment. For specific results, see Figure 3 As shown. Figure 3 It can be clearly seen that compared with the other three sensors, the sensitivity of NIPS has been greatly improved.

[0075] The pressure response test of the prepared NIPS was carried out, such as Figure 4 As shown in a, the NIPS sensor has an ultra-wide response range of up to 1200 kPa. The prepared sensor exhibits an ultra-high sensitivity of 546.58 kPa-1 under a pressure of 0-10 kPa; when the pressure is loaded at 10-40 kPa, the sensitivity is 542.78 kPa -1 ; When loaded with 40-600kPa, the sensitivity is 92.83kPa -1, in the high pressure range (600-1200kPa), it still shows a high sensitivity (16.69kPa -1 ). The sensor mainly uses the EDL capacitance formed between the microstructure electrode layer and the ionic dielectric layer to perform pressure sensing. When the pressure increases, the microstructure on the interface is deformed, resulting in an increase in the contact area and an increase in the EDL capacitance value, thereby achieving pressure sensing. At the same time, the presence of high modulus PLA microspheres, while reducing the initial contact area, amplifies the degree of deformation and delays deformation saturation. In order to explore whether the NIPS sensor still has the ability to detect tiny pressures under high pressure, the embodiment of the present invention applies four weights with different pressure levels (0.01N, 0.02N, 0.03N and 0.1N) to the sensor in sequence after the initial application of a 500g weight (such as Figure 4 b). The resulting capacitance change is obvious, proving that the sensor has the ability to discern subtle changes. For pressure sensors, excellent stability after long-term operation is also an important indicator in practical applications. The device was tested for 10,000 cycles of stability under a pressure of 1 kPa (as shown in Figure 2). Figure 4 c), the device does not show obvious signal deviation and fluctuation, indicating that it has good stability and ability to be used for a long time.

[0076] like Figure 5 The figure shows an ion-type flexible pressure sensing glove and its wireless transmission function for assisting the treatment of patients with hand dysfunction. As can be seen from the figure, the glove can recognize hand movements. For patients with hand dysfunction, smart gloves can provide an effective rehabilitation method. By real-time monitoring of fine hand movements, doctors can more accurately assess the patient's rehabilitation progress and develop a more appropriate rehabilitation plan. At the same time, patients can also understand their hand movements through feedback from smart gloves, so as to better participate in rehabilitation training and improve rehabilitation effects.

[0077] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0078] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing an ionization pressure sensor, characterized in that: The following steps are involved: S1: Using BEP particles and PLA particles as raw materials, microstructure electrodes were prepared by combining electrospinning and electrostatic spraying; S2: preparing an ionic dielectric layer using BEP particles and ionic liquid; S3: Assemble the microelectrode and the ionic dielectric layer face to face to obtain an ionic pressure sensor.

2. The method for preparing an ionization pressure sensor according to claim 1, characterized in that: The S1 comprises the following steps: S11: Preparation of nanofiber membrane using BEP particles; S12: preparing high modulus PLA microspheres using PLA particles, and embedding the high modulus PLA microspheres into the surface of the nanofiber membrane to obtain the corresponding microstructure nanofiber membrane; S13: Covering the microstructured nanofiber membrane with a screen printing plate, coating the conductive ink material on the microstructured nanofiber membrane with a scraper, and obtaining a microstructured electrode after the microstructured nanofiber membrane is dried.

3. The method for preparing an ionization pressure sensor according to claim 2, characterized in that: The S11 comprises the following steps: S111: placing BEP particles into a mixed solvent and stirring to obtain a spinning solution; S112: Electrospinning the spinning solution using preset spinning conditions to obtain a nanofiber membrane.

4. The method for preparing an ionization pressure sensor according to claim 3, characterized in that: The S12 comprises the following steps: S121: using the nanofiber membrane obtained in S112 as a base layer, placing PLA particles in a solvent and stirring to obtain a PLA spinning solution, and treating the PLA spinning solution through an integrated electrospinning vortex spray system to obtain PLA microspheres; S122: The PLA microspheres are embedded into the surface of the nanofiber membrane using an integrated electrospinning vortex spray system to obtain the corresponding microstructured nanofiber membrane.

5. The method for preparing an ionization pressure sensor according to claim 3, characterized in that: The S2 comprises the following steps: S21: placing the BEP particles in a mixed solvent, adding an ionic liquid until the particles are completely dissolved, and obtaining a composite spinning solution; S22: electrospinning the composite spinning solution using a blended electrospinning method to obtain a corresponding ionic dielectric layer.

6. The method for preparing an ionization pressure sensor according to claim 5, characterized in that: The S22 specifically includes: spinning the composite spinning solution using the preset spinning conditions.

7. A pressure sensor, characterized in that: include: The method for preparing the ionization pressure sensor is obtained by any one of claims 1 to 6.

8. A pressure sensing glove, characterized in that: It comprises a glove body and a pressure sensor arranged at the joint of the glove body, wherein the pressure sensor is obtained by the preparation method of the ionization pressure sensor according to any one of claims 1 to 6.

9. A hand movement monitoring system, characterized in that: include: A pressure sensing glove, wherein a pressure sensor is provided at the joint of the pressure sensing glove, wherein the pressure sensor is obtained by the preparation method of the ionization pressure sensor according to any one of claims 1 to 6, and is used to monitor the fine movement data of the user's hand; A transmission module, the transmission module is communicatively connected with the pressure sensing glove and is used for transmitting hand fine movement data; A processing terminal is communicatively connected to the transmission module and is used for processing the hand fine movement data.

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