A eutectic gel, its preparation method and use

Abstract

The application discloses a kind of eutectic gel and its preparation method and application;Belong to the technical field of electric pressure sensor.The eutectic gel provided by the application, preparation raw material includes: eutectic solvent, acrylamide, carbon nanotube, carbomer, crosslinking agent and initiator;The eutectic solvent includes choline chloride, gallic acid and water.The eutectic gel provided by the application successfully overcomes the problem of traditional water gel or ionic liquid gel leakage, solvent volatilization, can be made into pressure sensor with complex, accurate microstructure by 3D printing simultaneously, simple, fast and low cost, also has higher ionic conductivity.The application also provides the preparation method and application of the above eutectic gel.

Description

Technical Field

[0001] This invention relates to the field of voltage-induced pressure sensor technology, and in particular to a eutectic gel, its preparation method, and its application. Background Technology

[0002] With the rapid development of flexible electronics, wearable devices, and soft robots, flexible pressure sensors, as core sensing devices, have attracted widespread attention. In the field of flexible sensing technology, ion-electron pressure sensors, as an emerging high-sensitivity sensor, have received considerable attention in recent years. Unlike traditional parallel-plate capacitive sensors that primarily rely on changes in capacitance caused by variations in electrode spacing, ion-electron pressure sensors operate based on the electrical double layer (EDL) effect at the ion-electron interface.

[0003] Specifically, this type of sensor typically consists of an ion-conducting dielectric layer and an electron-conducting electrode. When the two come into contact, the mobile ions at the interface and the electron charges on the electrode surface accumulate under electrostatic attraction, forming an electric double layer with a thickness on the nanometer scale. According to the principle of supercapacitors, the extremely small charge separation distance gives the interface an extremely high capacitance per unit area (e.g., Figure 1 As shown in Figure (a). The pressure response mechanism of the voltage sensor is based on the formation of the double layer at the interface between the ion-conducting dielectric layer and the electron-conducting electrode, and the pressure sensing is achieved by the change in the interface contact area with pressure (e.g. Figure 1 (As shown in Figure (b)). When the voltage-displacement pressure sensor is subjected to external mechanical stimulation, the microstructured ion-conductive dielectric layer material deforms, resulting in a significant change in the effective contact area between it and the electrode. Because the double layer has a huge capacitance per unit area, even a small change in contact area can be converted into a drastic change in the total capacitance signal. This sensing mechanism enables the voltage-displacement pressure sensor to overcome the capacitance limitations of traditional parallel plate pressure sensors, achieving high sensitivity and high signal-to-noise ratio detection of weak mechanical signals.

[0004] To further improve the sensitivity of IPSs (isolated pressure sensors), the current mainstream approach is to construct microstructures (such as pyramids or cylinders) on the dielectric layer or electrode surface through complex photolithography, stencil methods, or high-precision etching processes to increase the effective contact area (A) under pressure. However, manufacturing microstructures using these methods is costly and cumbersome, which seriously hinders the large-scale, low-cost production of IPSs.

[0005] Ion-conducting pressure sensors often use hydrogels or ionic liquid gels as the ion-conducting dielectric layer, whose ion conductivity is highly dependent on the solvent. However, the water content in hydrogels is highly volatile in open environments, easily causing the ion-conducting dielectric layer to dry out and harden, irreversibly losing conductivity and flexibility. This ultimately leads to performance drift or even failure of the ion-conducting pressure sensor, severely affecting the reliability and lifespan of the device. Simultaneously, under continuous or cyclic mechanical stress (especially compression), the hydrogel network structure may experience fatigue or damage, leading to encapsulation failure, solvent leakage, and other problems. This not only contaminates the surrounding environment but also directly causes electrode-dielectric layer interface failure, loss of double-layer capacitance, and complete sensor malfunction. Furthermore, at low temperatures, the water-containing ion-conducting dielectric layer is prone to freezing, severely limiting its application in extreme environments. Moreover, while ionic liquid gels are not easily volatile, leakage can still occur, affecting the performance of the resulting ion-conducting pressure sensor. Additionally, ionic liquids are generally toxic, posing a certain risk when used as wearable sensors.

[0006] In summary, the sensitivity of traditional voltage-isolated pressure sensors needs further improvement and lacks simple, low-cost microstructure fabrication processes. At the same time, the materials used as dielectric layers in voltage-isolated pressure sensors have issues with stability, leakage, safety, or unsuitability under extreme conditions. Summary of the Invention

[0007] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a eutectic gel that successfully overcomes the problems of leakage and solvent evaporation of traditional hydrogels or ionic liquid gels. It also has the ability to easily, quickly, and cost-effectively form complex and precise microstructures using 3D printing technology, and also has high ionic conductivity.

[0008] The present invention also provides a method for preparing the above-mentioned eutectic gel.

[0009] The present invention also provides an ionization pressure sensor prepared from the above-mentioned eutectic gel.

[0010] The present invention also provides a method for manufacturing the above-mentioned voltage-isolated pressure sensor.

[0011] The present invention also provides applications of the above-mentioned voltage-displacement pressure sensor.

[0012] According to an embodiment of the first aspect of the present invention, a eutectic gel is provided, wherein the raw materials for preparing the eutectic gel include: Eutectic solvents, acrylamide, carbon nanotubes, carbomer, crosslinking agents, and initiators; The eutectic solvent includes choline chloride, gallic acid, and water.

[0013] The eutectic gel according to embodiments of the present invention has at least the following beneficial effects: Eutectic gels are gels made from eutectic solvents, possessing advantages such as good environmental stability, low water loss, green and non-toxic properties, and no leakage, making them suitable for flexible electronic devices. However, their intrinsic ionic conductivity is often lower than that of high-performance ionomer gels, a drawback that limits their application in ionomer pressure sensors requiring high signal strength. Furthermore, traditional eutectic gels have poor processing performance, making it difficult to shape microstructures; moreover, existing eutectic gels lack effective methods for integrating them with customized three-dimensional microstructures. Traditional casting methods are insufficient for constructing complex and precise microstructures, further limiting the potential for improving the performance of ionomer pressure sensors through structural design.

[0014] The eutectic solvent used in this invention is a green, healthy, and harmless solvent that possesses many advantages of ionic liquids, and is also lower in cost and more environmentally friendly; it can be safely applied to wearable scenarios such as human breathing, swallowing, and walking detection.

[0015] The eutectic gel provided by this invention significantly reduces the saturated vapor pressure of the gel through a strong hydrogen bond network formed between choline chloride and gallic acid, causing water molecules to exist in a bound state, thereby endowing it with excellent resistance to water loss in open environments. Simultaneously, the numerous hydroxyl groups in the eutectic solvent form a dense interfacial hydrogen bond anchoring effect with the amide and carboxyl groups on the polyacrylamide (a polymer of acrylamide) and carbomer molecular chains. Combined with the high viscosity of the eutectic solvent itself, this effectively suppresses the phase separation and seepage of the eutectic solvent, especially water, from the polymer network. This solves the technical problem of easy leakage in traditional liquid ionic conductors and also solves the problem of eutectic gel freezing at low temperatures, ensuring long-term stable operation and storage of IPSs in complex environments.

[0016] In the raw materials used in this invention, carbomer acts as a thickener, adjusting the rheological properties of the eutectic gel and significantly improving its processing performance, providing a material basis for microstructure shaping. Under the action of crosslinking agents, initiators, and subsequent UV curing, acrylamide polymerizes to form polyacrylamide, and polyacrylamide and carbomer can also crosslink with each other; the presence of polymers and the multiple crosslinking forms further enhance the mechanical properties of the resulting eutectic gel.

[0017] By uniformly dispersing conductive nanomaterials such as carbon nanotubes in a eutectic gel system, a highly efficient ion / electron synergistic transport network is constructed through the synergistic interaction between carbon nanotubes and other components. This significantly improves the overall ionic conductivity of the eutectic gel, laying a material foundation for obtaining high signal-to-noise ratio sensing signals. Furthermore, carbon nanotubes can also synergistically enhance the mechanical properties of the resulting eutectic gel with other raw materials.

[0018] According to some embodiments of the present invention, in the eutectic solvent, the mass ratio of choline chloride (CAS: 67-48-1), gallic acid (CAS: 149-91-7), and water is 3~3.5:0.5~1:1. Specifically, the mass ratio of choline chloride to water is 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, or 3.5:1; or a range consisting of any two of the above values; the mass ratio of gallic acid to water is 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, or 1:1; or a range consisting of any two of the above values.

[0019] According to some embodiments of the present invention, the mass ratio of the eutectic solvent to acrylamide (CAS: 79-06-1) is 100:60~70. Specifically, it can be 100:60, 100:62, 100:64, 100:65, 100:66, 100:68, 100:70; or a range of values ​​consisting of any two of the above points. Increasing the acrylamide content will reduce the overall printing performance of the resulting eutectic gel, while decreasing the acrylamide content will reduce the overall mechanical properties of the resulting eutectic gel.

[0020] According to some embodiments of the present invention, the mass ratio of the eutectic solvent to the carbon nanotubes is 100:0.1 to 1.2. Specifically, it can be 100:0.1, 100:0.2, 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9, 100:1, 100:1.1, 100:1.2; or a range of values ​​consisting of any two of the above points.

[0021] According to some embodiments of the present invention, the carbon nanotubes include multi-walled carbon nanotubes. The diameter of the carbon nanotubes is distributed in the range of 3–15 nm, the length is distributed in the range of 15–30 μm, and the specific surface area is 250–270 m². 2 Comparable technical effects can be achieved within the range of / g.

[0022] According to some embodiments of the present invention, the mass ratio of the eutectic solvent to carbomer is 100:4~5. For example, it can be 100:4.5.

[0023] According to some embodiments of the present invention, the mass ratio of the eutectic solvent to the crosslinking agent is 100:0.7~0.8. For example, it can be 100:0.75.

[0024] According to some embodiments of the present invention, the crosslinking agent includes MBA (methylenebisacrylamide, CAS: 110-26-9).

[0025] According to some embodiments of the present invention, the mass ratio of the eutectic solvent to the initiator is 100:0.1 to 0.2. For example, it can be 100:0.15. If the amount of the initiator is too large, a large number of bubbles will be generated in the eutectic gel system; conversely, if the amount is too small, the initiation of the reaction will be incomplete.

[0026] According to some embodiments of the present invention, the initiator includes at least one of AAPH (2,2'-azobisisobutylamidine dihydrochloride, CAS: 2997-92-4) and AIBI (azobisisobutyronitrile; CAS: 78-67-1).

[0027] According to an embodiment of a second aspect of the present invention, a method for preparing the eutectic gel described in the first aspect of the present invention is provided, the method comprising mixing and reacting the raw materials for preparing the eutectic gel.

[0028] Since the preparation method adopts all the technical solutions of the eutectic gel in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0029] According to some embodiments of the present invention, the mixing reaction includes the following steps: S1. Mix the eutectic solvent, acrylamide, crosslinking agent and carbon nanotubes; S2. Mix the mixture obtained in step S1 with carbomer; S3. The mixture obtained in step S2 is polymerized under the action of the initiator.

[0030] According to some embodiments of the present invention, in step S1, the mixing time is 1 to 3 hours.

[0031] According to some embodiments of the present invention, in step S1, the mixing includes sequential ultrasonication and stirring. The duration of ultrasonication is 20-40 minutes, specifically 30 minutes; the duration of stirring is 0.5-2.5 hours, specifically 0.5 hours, 1 hour, 1.5 hours, 2 hours, or 2.5 hours.

[0032] According to some embodiments of the present invention, in step S3, the polymerization temperature is 55~80℃. Specifically, it can be 55℃, 60℃, 65℃, 70℃, 75℃, or 80℃; or a range consisting of any two of the above values. In actual production, the polymerization temperature is controlled within the range of 55~65℃ as much as possible to reduce the occurrence of side reactions.

[0033] According to some embodiments of the present invention, in step S3, the polymerization time is 2-3 hours. For example, it can be 2.5 hours. In actual production, this time is not strictly limited, based on the completion of polymerization, but generally the polymerization function can be achieved within 2-3 hours.

[0034] According to an embodiment of a third aspect of the present invention, an isolating pressure sensor is provided, the isolating pressure sensor comprising a first electrode, a dielectric layer and a second electrode disposed in superimposed form; The raw materials for preparing the dielectric layer include the eutectic gel described in the first aspect of the present invention; The dielectric layer surface has a microstructure with localized protrusions.

[0035] Since the voltage-displacement pressure sensor employs all the technical solutions of the eutectic gel described in the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments. Furthermore, The voltage-dissociated pressure sensor integrates the intrinsic properties of the eutectic gel and the structural advantages of the dielectric layer, exhibiting high sensitivity (especially over a wide pressure range), fast response and recovery time, excellent cycle stability, and good environmental tolerance, thus meeting the urgent demand for high-performance flexible sensors in wearable electronics, human-computer interaction, intelligent robots, and other fields.

[0036] According to some embodiments of the present invention, the microstructure is at least one of mesh, pyramid, and columnar.

[0037] According to some embodiments of the present invention, the first electrode and the second electrode are carbon cloth.

[0038] According to some embodiments of the present invention, the sensitivity coefficient of the voltage-displacement pressure sensor is ≥1.06 kPa. -1 The test pressure for this sensitivity is 140 kPa.

[0039] According to some embodiments of the present invention, the pressure detection range of the voltage-displacement pressure sensor is ≥800 kPa. For example, it can be 800 kPa, 900 kPa, 1000 kPa, 1100 kPa; or a range consisting of any two of the above values.

[0040] According to some embodiments of the present invention, the detection limit of the voltage-displacement pressure sensor is ≤29Pa.

[0041] Traditional voltage-isolated pressure sensors typically struggle to simultaneously achieve high sensitivity and a wide pressure detection range. The technical solution provided by this invention combines a special microstructure with a dielectric layer made of a special material, achieving full coverage from slight touch (detection limit as low as 29 Pa) to high-voltage loads, thus overcoming the "high-voltage saturation bottleneck" of traditional structures.

[0042] According to some embodiments of the present invention, the response time of the voltage-disconnected pressure sensor within the pressure detection range is ≤1s; the recovery time is ≤1s.

[0043] According to an embodiment of a fourth aspect of the present invention, a method for manufacturing the voltage-isolated pressure sensor described in the third aspect of the present invention is provided, the method comprising the following steps: D1. A dielectric layer with a microstructure is prepared by using DIW printing technology combined with ultraviolet curing technology; D2. Assemble the dielectric layer, the first electrode, and the second electrode by stacking them together.

[0044] Since the manufacturing method employs all the technical solutions of the voltage-displacement pressure sensor described in the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments. Furthermore, Traditional techniques for obtaining microstructures typically rely on complex photolithography or stencil methods, which are costly and difficult to implement on a large scale or for personalized customization. This invention utilizes direct-write 3D printing technology (DIW printing); eliminating the need for complex molds or post-processing, it significantly reduces production costs and time, providing a feasible technical path for the large-scale application of IPSs. Furthermore, the core advantage of the fabrication method provided by this invention lies in its ability to freely design and precisely construct complex three-dimensional microstructures, thereby enabling "programmable" control over the performance (sensitivity, range, response time) of voltage-independent pressure sensors and promoting their development towards integrated and personalized customization; for example, the shape of the microstructure can be quickly customized according to application requirements (such as different body parts).

[0045] This invention proposes and implements the use of 3D printed microstructures as the core dielectric layer. By designing and printing dielectric layer structures with specific shapes (such as square grids or column arrays), controllable and efficient changes in contact area can be achieved under pressure. At the same time, combined with the excellent resilience of the eutectic gel itself, the high-pressure saturation bottleneck of traditional microstructures is broken through, and a wide linear response is achieved over a wide range from low pressure to high pressure, while the sensitivity is significantly improved.

[0046] According to some embodiments of the present invention, in step S1, the ultraviolet light wavelength used in the ultraviolet curing technology is 365nm.

[0047] According to some embodiments of the present invention, in step S1, the curing time in the ultraviolet curing technology is ≥20 minutes. In actual production, this time is not strictly limited, and complete curing is the standard; generally, about 20 minutes is sufficient to achieve the curing function.

[0048] The dielectric layer fabrication process includes sequential single-layer DIW printing and ultraviolet curing. The ultraviolet curing time mentioned above refers to the curing time for single-layer DIW printing.

[0049] The thickness obtained by single-layer DIW printing is 0.4~0.6mm.

[0050] According to an embodiment of the fifth aspect of the present invention, an application of the voltage-disconnected pressure sensor described in the third aspect of the present invention in flexible electronics technology is provided.

[0051] Since the application adopts all the technical solutions of the voltage-displacement pressure sensor of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments.

[0052] According to some embodiments of the present invention, the flexible electronics technology includes at least one of wearable electronics, human-computer interaction, and intelligent robots.

[0053] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0054] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is the pressure response mechanism of an isolation pressure sensor.

[0055] Figure 2 This is the synthesis route of the eutectic gel in Example 1 of the present invention.

[0056] Figure 3 This is an example of the surface morphology of the dielectric layer in an application example of the present invention.

[0057] Figure 4 This is an example of a eutectic gel printable component in the test examples of this invention.

[0058] Figure 5 These are mechanical property diagrams of the eutectic gels obtained in Embodiment 1 and Comparative Examples 1-2 of the present invention.

[0059] Figure 6 This is the sensitivity curve of the voltage-sensitive pressure sensor corresponding to Embodiment 1 of the present invention.

[0060] Figure 7 These are the capacitance curves of the voltage-displacement pressure sensor at different frequencies under a pressure of 28 kPa, corresponding to Embodiment 1 of the present invention.

[0061] Figure 8 The curves are those of the pressure sensor in Embodiment 1 of the present invention, which are compressed for 5 cycles under different pressures.

[0062] Figure 9The response and recovery times of the voltage pressure sensor corresponding to Embodiment 1 of the present invention are given.

[0063] Figure 10 This is the capacitance curve of the voltage-sensitive pressure sensor corresponding to Embodiment 1 of the present invention after 1700 cycles of compression at 140 kPa.

[0064] Figure 11 This is the minimum detection limit of the voltage pressure sensor corresponding to Embodiment 1 of the present invention.

[0065] Figure 12 This is the sensing curve of the voltage-pressure sensor used to detect human respiration in Embodiment 1 of the present invention.

[0066] Figure 13 This is the sensing curve of the voltage-pressure sensor corresponding to Embodiment 1 of the present invention when used to detect swallowing in the human body.

[0067] Figure 14 This is the sensing curve of the voltage-independent pressure sensor used for human body detection during walking, corresponding to Embodiment 1 of the present invention.

[0068] Figure 15 The sensing properties of the eutectic gels obtained in Examples 1 (0.5%), 2 (0.1%), 3 (0.3%) and Comparative Example 4 (0%) of this invention are described.

[0069] Figure 16 The mechanical properties of the eutectic gels obtained in Examples 1 (0.5%), 2 (0.1%), 3 (0.3%), 4 (0.7%) and Comparative Example 4 (0%) of this invention are described. Detailed Implementation

[0070] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0071] Example 1 refer to Figure 2 Based on the route and the raw material composition in Table 1, a eutectic gel was prepared in this example. The specific steps are as follows: S1. Mix choline chloride, gallic acid and water to form a eutectic solvent; Acrylamide, crosslinking agent MBA, carbon nanotubes, and the above-mentioned eutectic solvent were mixed; wherein, the mixing process was to first sonicate for 0.5 h and then continue stirring for 2 h. S3. Mix the mixture obtained in step S2 with carbomer; S4. The mixture obtained in step S3 is polymerized at 60°C for 2.5 h under the action of the initiator.

[0072] Table 1. Composition of raw materials used in the synthesis of eutectic gel in Example 1 choline chloride gallic acid water Acrylamide 5.12g 1.25g 1.6g 5.12g carbon nanotubes Carbomer MBA AAPH 0.068g (0.5wt%) 0.35g 0.057g 0.015g In Table 1, the carbon nanotubes are multi-walled carbon nanotubes with a diameter of 3-15 nm, a length of 15-30 μm, and a specific surface area of ​​260 m². 2 / g. The carbomer model number is S940.

[0073] In this example, the mass percentage of carbon nanotubes = carbon nanotubes / (choline chloride + gallic acid + water + acrylamide + carbon nanotubes + carbomer) = 0.5%.

[0074] Examples 2-4 each prepared a eutectic gel, the specific difference from Example 1 being: The amount of carbon nanotubes was adjusted, and the mass percentage of carbon nanotubes in the eutectic gel was 0.1% in Example 2; 0.3% in Example 3; and 0.7% in Example 4.

[0075] Comparative Example 1 This example prepared a eutectic gel, which differs from Example 1 in that: Gallic acid in Example 1 was replaced with an equal mass of oxalic acid (CAS: 144-62-7).

[0076] Comparative Example 2 This example prepared a eutectic gel, which differs from Example 1 in that: Gallic acid in Example 1 was replaced with an equal mass of citric acid (CAS: 77-92-9).

[0077] Comparative Example 3 This example prepared a eutectic gel, which differs from Example 1 in that: The raw materials used in the preparation do not include carbomer.

[0078] Comparative Example 4 This example prepared a eutectic gel, which differs from Example 1 in that: The raw materials used in the preparation do not include carbon nanotubes.

[0079] Application examples This example demonstrates the fabrication of a voltage-isolation pressure sensor, which comprises a first electrode, a dielectric layer, and a second electrode stacked together. The dielectric layer is prepared from the eutectic gel obtained in Example 1, and its surface morphology is as follows. Figure 3 As shown.

[0080] The first and second electrodes are made of carbon cloth, and commercially available carbon cloth can achieve similar technical effects.

[0081] The fabrication process of the voltage-independent pressure sensor is as follows: D1. A dielectric layer with a microstructure is prepared using DIW printing technology combined with UV curing technology; specifically, The wavelength of the ultraviolet light used for curing is 365 nm; the curing time is 20 min. During the preparation of the dielectric layer, curing is performed once after each printed layer; the thickness of a single layer is 0.5 mm.

[0082] The dielectric layer is a 2×2cm square, consisting of a 1mm thick substrate and a 1mm thick microstructure on top of it. The microstructure is a raised small square, with a width and height of 0.5mm.

[0083] The DIW printing technology uses a 3mm print pitch and a 21G printhead.

[0084] D2. Assemble the dielectric layer, the first electrode, and the second electrode by stacking them together.

[0085] Test case The first aspect of this example verifies the printability of the eutectic gels obtained in the examples and comparative examples, specifically: Components with different microstructures were prepared using the same methods as in Application Example 1. Specific microstructures include... Figure 4 As shown, pentagrams and regular letter shapes can be printed. The results show that the eutectic gels obtained in Examples 1-3, Comparative Examples 1-2, and Comparative Example 4 can be used to prepare parts with arbitrary microstructures using DIW printing technology; however, the eutectic gel obtained in Comparative Example 3 loses its printability due to the absence of carbomer; in Example 4, the printing performance is slightly reduced due to the higher content of carbon nanotubes and the higher viscosity of the system.

[0086] The second aspect of this example tested the mechanical properties of the eutectic gels obtained in the embodiments and comparative examples. The specific testing method involved using a pressure machine and a corresponding workstation. The test results are as follows: Figure 5 and Figure 16 As shown in the figure. The results show that compared with the eutectic gel obtained in Example 1, the mechanical properties of the eutectic gels obtained in Comparative Examples 1 and 2 are significantly reduced; therefore, it can be predicted that the eutectic sols obtained in Comparative Examples 1 and 2 are prone to structural collapse during long-term, cyclic pressurization-release processes. The results also show that with the increase of carbon nanotube content, the mechanical properties of the obtained eutectic gels show a trend of first increasing and then decreasing. Combining the above results, it can be concluded that in the eutectic gel provided by the present invention, the eutectic solvent and other components have a certain synergistic effect, which can jointly improve the mechanical properties of the eutectic gel.

[0087] The third aspect of this example tested the performance of the disconnected pressure sensor obtained in the application example, specifically the performance of the disconnected pressure sensors corresponding to Examples 1-3 and Comparative Example 4. The test method involved using an inductance-capacitance-resistance (LCR) meter coupled with a universal testing machine to apply a reverse voltage to the disconnected pressure sensor. The capacitance signal changes of the disconnected pressure sensor during step-compression and cyclic compression processes were measured to examine its pressure sensing performance, including sensitivity, test range, response speed, and repeatability. The test results showed that the pressure sensor corresponding to Example 1 had a range of 1000 kPa, and within the range of 140 kPa (the effective range of the microstructure), its sensitivity reached 1.06 kPa. -1 The sensitivity of Comparative Example 4 was 0.2 kPa. -1 The sensitivity of Example 2 is 0.35 kPa. -1 The sensitivity of Example 3 was 0.63 kPa. -1 Furthermore, as the amount of carbon nanotubes used increases, the sensing performance of the resulting voltage-induced pressure sensor gradually improves; specific test results are as follows: Figure 6 and Figure 15 As shown. Figure 7 These are the capacitance curves of the voltage-displacement pressure sensor at different frequencies under a pressure of 28 kPa. Figure 8 The curves show that the performance remained basically consistent throughout the multiple cycles, indicating that the voltage-displacement pressure sensor has good stability and can respond to different pressures and frequencies. Figure 9 These are the response and recovery times of the voltage-displacement pressure sensor corresponding to Example 1, both of which are less than 1 second. Figure 10 The curve shows the cyclic stability of the sensor after 1700 cycles of compression at 140 kPa. It is basically stable, indicating that the voltage-disconnected pressure sensor has good long-term stability and is expected to maintain stable performance after 1700 cycles. Figure 11 This is the minimum detection limit of the voltage pressure sensor, which can detect minute pressures as low as 29 Pa. Figures 12-14 The data shows the sensor curves obtained when the ionized pressure sensor corresponding to Example 1 is used to detect breathing, swallowing, and walking in the human body. All the above data demonstrate that the eutectic gel provided by this invention can be used as a dielectric layer preparation and raw material for ionized sensors, and can be used to prepare various microstructures with stable performance and a wide response range.

[0088] Based on the above test results, it can be seen that the eutectic gel provided by the present invention has a synergistic effect among the raw materials, which enables it to have good mechanical properties on the basis of 3D printing performance. Furthermore, the voltage-isolated pressure sensor made from it has good sensitivity and stability, and a wide response frequency and pressure range, which has broad application prospects in human motion detection.

[0089] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A eutectic gel, characterized in that, The raw materials for preparing the eutectic gel include: Eutectic solvents, acrylamide, carbon nanotubes, carbomer, crosslinking agents, and initiators; The eutectic solvent includes choline chloride, gallic acid, and water.

2. The eutectic gel according to claim 1, characterized in that, The mass ratio of the eutectic solvent to carbon nanotubes is 100:0.1~1.2; And / or, the mass ratio of the eutectic solvent to carbomer is 100:4~5; And / or, the mass ratio of the eutectic solvent to acrylamide is 100:60~70.

3. The eutectic gel according to claim 1, characterized in that, The mass ratio of the eutectic solvent to the crosslinking agent is 100:0.7~0.8; And / or, the mass ratio of the eutectic solvent to the initiator is 100:0.1~0.

2.

4. The eutectic gel according to any one of claims 1 to 3, characterized in that, In the eutectic solvent, the mass ratio of choline chloride, gallic acid, and water is 3~3.5:0.5~1:

1.

5. The eutectic gel according to any one of claims 1 to 3, characterized in that, The crosslinking agent includes MBA; And / or, the initiator includes at least one of AAPH and AIBI.

6. A method for preparing a eutectic gel as described in any one of claims 1 to 5, characterized in that, The preparation method includes mixing and reacting the raw materials for the preparation of the eutectic gel.

7. The preparation method according to claim 6, characterized in that, The mixing reaction includes the following steps: S1. Mix the eutectic solvent, acrylamide, crosslinking agent and carbon nanotubes; S2. Mix the mixture obtained in step S1 with carbomer; S3. The mixture obtained in step S2 is polymerized under the action of the initiator.

8. An independent pressure sensor, characterized in that, The voltage-isolated pressure sensor includes a first electrode, a dielectric layer, and a second electrode stacked together. The raw material for preparing the dielectric layer includes the eutectic gel as described in any one of claims 1 to 5; The dielectric layer surface has a microstructure with localized protrusions.

9. A method for manufacturing an isoelectric pressure sensor as described in claim 8, characterized in that, The manufacturing method includes the following steps: D1. A dielectric layer with a microstructure is prepared by using DIW printing technology combined with ultraviolet curing technology; D2. Assemble the dielectric layer, the first electrode, and the second electrode by stacking them together.

10. An application of the voltage-disconnected pressure sensor as described in claim 8 in flexible electronics technology.

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