Ion gel film with microstructure on the surface, preparation method and ionization sensor

Abstract

The present invention belongs to the field of sensors, and relates to an ion gel film with a microstructure on the surface, a preparation method, and an ion-type sensor. The preparation method comprises: sandblasting on a precursor substrate to obtain a substrate, forming a mixed solution of a polymer and an ionic liquid on the substrate to obtain a wet film, and drying and curing the wet film to obtain an ion gel film, wherein the precursor substrate has an arc-shaped recess array, and the sandblasting conditions include: the sandblasting particle size is 5000 mesh to 10000 mesh, and the sandblasting pressure is 2 bar to 10 bar. The ion gel film is used for an ion-type sensor, which can improve the detection sensitivity of the sensor.

Description

Technical Field

[0001] The invention belongs to the field of sensors, and in particular relates to an ion gel membrane with a microstructure on the surface, a preparation method and an ionization sensor. Background Art

[0002] Supercapacitors based on the double-layer effect have been used in energy storage devices. It has been proposed to use the double-layer capacitance generated between the electrode and the ionic electrolyte for pressure sensing, specifically by setting an ion gel layer between the two electrode plates to form an ionized sensor. Since the electrons in the electrode and the ions in the ion gel layer form a double-layer interface, the ionized sensor has supercapacitor characteristics and has higher sensitivity than traditional parallel plate capacitor sensors. With the development of robot intelligence, electronic skin, wearable health and other fields, higher requirements are placed on pressure and touch sensing, requiring high-sensitivity pressure and touch sensing. However, the sensitivity of current ionized sensors is still limited and cannot meet the requirements for pressure and touch sensing in the above fields.

[0003] It should be noted that this part of the present invention only provides background technology related to the present invention and does not necessarily constitute prior art or known technology. Summary of the invention

[0004] The purpose of the present invention is to overcome the defect of limited sensitivity of existing ionization sensors, and to provide an ion gel membrane with a microstructure on the surface, a preparation method and an ionization sensor. The ion gel membrane is used in the ionization sensor to improve the sensitivity of the sensor.

[0005] In order to achieve the above-mentioned purpose, in a first aspect, the present invention provides a method for preparing an ion gel film having a microstructure on the surface, comprising: sandblasting on a precursor substrate to obtain a substrate, forming a mixed solution of a polymer and an ionic liquid on the substrate to obtain a wet film, and drying and curing the wet film to obtain an ion gel film, wherein the precursor substrate has an array of arc-shaped depressions, and the sandblasting conditions include: a sandblasting particle size of 5000 mesh to 10000 mesh, and a sandblasting pressure of 2 bar to 10 bar.

[0006] In some preferred embodiments, the sandblasting particle size is 5000 mesh to 8000 mesh, and the sandblasting pressure is 5 bar to 10 bar.

[0007] In some preferred embodiments, the sandblasting conditions further include: a sandblasting time of 5s to 10s, a sandblasting flow rate of 0.5kg / min to 2kg / min, a sandblasting distance of 10cm to 15cm, and a sandblasting angle of 45° to 90°.

[0008] In some preferred embodiments, the precursor substrate is selected from a metal plate, a melamine foam plate, an alloy plate, a frosted glass plate, and a polyoxymethylene plate.

[0009] In some preferred embodiments, the polymer includes at least one of PVDF-HFP and PVDF-TrFE-CFE; the anions of the ionic liquid include at least one of hexafluorophosphate anion, tetrafluoroborate anion, bistrifluoromethanesulfonyl imide anion, trifluoromethanesulfonate anion, acetate anion, dicyanamide anion, bromide anion, ethyl sulfate anion, and hydrogen sulfide anion; the cations of the ionic liquid include at least one of 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, and 1-octyl-3-methylimidazolium cation; the solvent of the mixed solution includes at least one of N,N-dimethylformamide, acetone, and N-methylpyrrolidone.

[0010] In some preferred embodiments, in the mixed solution, the ratio of the mass of the ionic liquid to the mass of the polymer is 0.05-1.

[0011] In some preferred embodiments, based on the mass of the mixed solution, the sum of the contents of the polymer and the ionic liquid is 8 wt % to 12 wt %.

[0012] In some preferred embodiments, the arc-shaped depressions in the arc-shaped depression array are evenly spaced, each of the arc-shaped depressions has the same shape, a depth of 8 μm to 150 μm, a diameter of 50 μm to 300 μm, and a center-to-center spacing between adjacent arc-shaped depressions in each row and column of arc-shaped depressions is 58 μm to 450 μm.

[0013] In a second aspect, the present invention provides an ion gel membrane having a microstructure on the surface, which is prepared by the preparation method of the ion gel membrane described in the first aspect, and one side of the surface has an array of arc-shaped protrusions, and the surface of the arc-shaped protrusions has a rough structure, and the rough structure forms the microstructure.

[0014] In some preferred embodiments, the average diameter of the rough structure on the arc-shaped convex surface is 1.5 μm to 3.2 μm.

[0015] In some preferred embodiments, the arc-shaped protrusions in the arc-shaped protrusion array are evenly spaced, each of the arc-shaped protrusions has the same shape, the height of the arc-shaped protrusion is 8μm~150μm, the diameter is 50μm~300μm, and the center distance between adjacent arc-shaped protrusions in each row and column of arc-shaped protrusions is 58μm~450μm.

[0016] In a third aspect, the present invention provides an ionotropic mechanical sensor having electrodes and an ionotropic gel membrane prepared by the preparation method of the first aspect or the ionotropic gel membrane of the second aspect located between two electrodes.

[0017] The preparation method of the ion gel film of the present invention is to perform sandblasting on a precursor substrate having an array of arc-shaped depressions, the sandblasting particle size is 5000 mesh to 10000 mesh, and the sandblasting pressure is 2 bar to 10 bar, so that a specific microstructure (a rough structure forms a microstructure) can be formed on the surface of the arc-shaped depressions of the precursor substrate, and the microstructure has a tiny concave-convex shape. After film formation and curing on the substrate having the specific microstructure, an ion gel film having an array of arc-shaped protrusions on the surface and a specific microstructure on the surface of the arc-shaped protrusions can be obtained, that is, the arc-shaped protrusion surface has a tiny convex-concave shape. The existing polymer ion gel film capacitance sensor relies on force or strain changes to cause film thickness changes, and the film thickness changes cause capacitance changes, converting the capacitance changes into electrical signals, thereby sensing force or strain, and the response amount of capacitance changes caused by unit force or strain changes is small, and the sensitivity is limited. The inventors found that when the surface of the gel film has an array of arc-shaped protrusions, when the capacitive sensor is subjected to force or strain, the contact area between the gel film and the electrode is changed, the capacitance is changed, and the sensitivity of the sensor can be improved. However, the inventors unexpectedly found that when the polymer ion gel film is subjected to a smaller force or strain, the stress curve is hysteresis and the sensitivity is limited. In-depth analysis shows that the reason may be that the smooth and regular arc-shaped protrusion surface film is dense, and when the arc-shaped protrusion is pressed down, the internal molecules squeeze each other, resulting in a strong pressure-bearing capacity. Under small pressure, the lateral internal extrusion stress support causes no obvious deformation, the contact area between the gel film and the electrode changes little, and the initial contact area between the gel film and the electrode is large (when no force is applied), which leads to the fact that when the polymer ion gel film is subjected to When the force or strain is small, as the force increases, the contact area growth rate of the gel film and the electrode is limited, and the sensitivity is limited. The inventor further found that sandblasting under specific conditions is performed on a precursor substrate with an array of arc-shaped depressions, and a specific microstructure is formed on the surface of the arc-shaped depressions. After the film is inverted, a specific microstructure is formed on the surface of the arc-shaped protrusions of the gel film. On the one hand, the mutual extrusion of internal molecules when the arc-shaped protrusions are pressed down can be reduced, and the pressure bearing capacity can be reduced. The deformation when the gel film is subjected to a small force or strain can be increased. On the other hand, the initial contact area of ​​the gel film and the electrode can be reduced, so that when the gel film is subjected to a small force or strain, the contact area growth rate of the gel film and the electrode can be increased as the force increases. In addition, the micro-convex and concave make the surface channel of the ionic liquid widen, which is more conducive to the flow of the ionic liquid, and then the change of capacitance can be more rapidly reflected, and the sensitivity is improved. In summary, the gel film of the present application can improve the sensitivity of the polymer ion gel film when it is subjected to a small force or strain, and can also improve the sensing sensitivity when the polymer ion gel film is subjected to a large force or strain.

[0018] The ion gel membrane of the present invention has an arc-shaped protrusion array on one side of the surface, and the surface of the arc-shaped protrusion has a rough structure. It is used for an ion-type mechanical sensor and has significantly improved sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a scanning electron microscope photograph of the arc-shaped recess array of the substrate of Example 1 of the present invention.

[0021] Figure 2 is a scanning electron microscope photograph of the ion gel membrane of Example 1 of the present invention. DETAILED DESCRIPTION

[0022] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0023] The inventors of the present invention have found that the sensitivity of existing ionization sensors is limited and cannot meet the sensitivity requirements for pressure and tactile sensing in the fields of robot intelligence, electronic skin, wearable health, etc.

[0024] In this regard, in a first aspect, the present invention provides a method for preparing an ion gel film having a microstructure on the surface, comprising: sandblasting on a precursor substrate to obtain a substrate, forming a mixed solution of a polymer and an ionic liquid on the substrate to obtain a wet film, and drying and curing the wet film to obtain an ion gel film, wherein the precursor substrate has an arc-shaped recess array, and the sandblasting conditions include: a sandblasting particle size of 5000 mesh to 10000 mesh, and a sandblasting pressure of 2 bar to 10 bar.

[0025] The preparation method of the ion gel film of the present invention is to perform sandblasting on a precursor substrate having an array of arc-shaped depressions, the sandblasting particle size is 5000 mesh to 10000 mesh, and the sandblasting pressure is 2 bar to 10 bar, so that a specific microstructure (a rough structure forms a microstructure) can be formed on the surface of the arc-shaped depressions of the precursor substrate, and the microstructure has a tiny concave-convex shape. After film formation and curing on the substrate having the specific microstructure, an ion gel film having an array of arc-shaped protrusions on the surface and a specific microstructure on the surface of the arc-shaped protrusions can be obtained, that is, the arc-shaped protrusion surface has a tiny convex-concave shape. The existing polymer ion gel film capacitance sensor relies on force or strain changes to cause film thickness changes, and the film thickness changes cause capacitance changes, converting the capacitance changes into electrical signals, thereby sensing force or strain, and the response amount of capacitance changes caused by unit force or strain changes is small, and the sensitivity is limited. The inventors found that when the surface of the gel film has an array of arc-shaped protrusions, when the capacitive sensor is subjected to force or strain, the contact area between the gel film and the electrode is changed, the capacitance is changed, and the sensitivity of the sensor can be improved. However, the inventors unexpectedly found that when the polymer ion gel film is subjected to a small force or strain, the stress curve is hysteresis and the sensitivity is limited. In-depth analysis shows that the reason may be that the smooth and regular arc-shaped protrusion surface film is dense, and when the arc-shaped protrusion is pressed down, the internal molecules squeeze each other, resulting in a strong pressure-bearing capacity. Under small pressure, the lateral internal extrusion stress support causes no obvious deformation, the contact area between the gel film and the electrode changes little, and the initial contact area between the gel film and the electrode is large (when no force is applied), which leads to a limited growth rate of the contact area between the gel film and the electrode as the force increases when the polymer ion gel film is subjected to a small force or strain. In addition, The squeezed surface may also limit the full flow of the ionic liquid, resulting in limited sensitivity. The inventor further found that sandblasting under specific conditions was performed on a precursor substrate with an array of arc-shaped depressions to form a specific microstructure on the surface of the arc-shaped depressions. After the film was inverted, a specific microstructure was formed on the surface of the arc-shaped protrusions of the gel film. On the one hand, it can reduce the mutual squeezing of internal molecules when the arc-shaped protrusions are pressed down, can reduce the pressure bearing capacity, can increase the deformation when the gel film is subjected to a small force or strain, and on the other hand, it can reduce the initial contact area between the gel film and the electrode, so that when the gel film is subjected to a small force or strain, the growth rate of the contact area between the gel film and the electrode increases with the increase in force. In addition, the micro-convex and concave make the surface channel of the ionic liquid widen, which is more conducive to the flow of the ionic liquid, and thus can more quickly reflect the change in capacitance. The polymer ion gel membrane provided by the present application can increase its sensitivity when it is subjected to a small force or strain, actually reduce the initial contact area between the gel film and the electrode, and can also improve the sensing sensitivity when the polymer ion gel membrane is subjected to a large force or strain.

[0026] If the sandblasting particle size of the present invention is less than 5000 mesh and the sandblasting pressure is greater than 10 bar, the arc-shaped concave structure on the substrate will be destroyed. If the sandblasting particle size is greater than 10000 mesh and the sandblasting pressure is less than 2 bar, the surface of the arc-shaped concave on the substrate cannot form a specific microstructure, resulting in the surface of the arc-shaped protrusion cannot form a specific microstructure, and cannot effectively reduce the mutual squeezing of internal molecules when the arc-shaped protrusion is pressed down when the gel film is subjected to a small force or strain, and increase the deformation of the gel film, thereby affecting the sensitivity of the sensor. Multiple arc-shaped depressions are arranged in rows and / or columns with intervals between them to form the arc-shaped depression array of the present invention. The arc-shaped depression refers to a depression not larger than 1 / 2 sphere (hemispherical). The present invention does not limit the film-forming method, for example, spraying, template method, scraping method, film pressing method, casting method, leveling method and the like are used. When the leveling method is used, the leveling time is preferably 5 to 10 minutes. The present invention does not limit the wet film drying and curing method, as long as the wet film can be dried and cured. Preferably, the wet film is dried and cured by baking in an oven at 60-80° C. for more than 0.5 h.

[0027] The present invention forms a microstructure on the arc-shaped recessed array by sandblasting. Compared with methods such as cutting, a uniform microstructure can be formed on the surface of the arc-shaped recessed array. The microstructure can be at the micron level, thereby forming a uniform micron-level microstructure on the surface of the arc-shaped protrusion array of the gel film, thereby avoiding inconsistent sensitivity at different points of the gel film, and the surface when squeezed can also ensure sufficient flow of the ionic liquid.

[0028] In some preferred embodiments, the sandblasting particle size is 5000 mesh to 8000 mesh, and the sandblasting pressure is 5 bar to 10 bar. Under this preferred embodiment, the microstructure formed on the arc-shaped concave surface after sandblasting and the microstructure formed on the surface of the arc-shaped protrusion of the ion gel membrane after inverting the membrane are more conducive to reducing the mutual squeezing of internal molecules when the arc-shaped protrusion is pressed down, increasing the deformation of the gel membrane when it is subjected to a small force or strain, reducing the initial contact area between the gel membrane and the electrode, and when the gel membrane is subjected to a small force or strain, as the force increases, the contact area growth rate between the gel membrane and the electrode is increased, thereby improving the sensitivity of the sensor.

[0029] In some preferred embodiments, the sandblasting conditions also include: sandblasting time of 5s~10s, sandblasting flow rate of 0.5kg / min~2kg / min, sandblasting distance of 10~15cm, and sandblasting angle of 45°~90°. Under this preferred scheme, the microstructure formed on the surface of the arc-shaped protrusion of the ion gel membrane after the film is inverted is more conducive to reducing the mutual squeezing of internal molecules when the arc-shaped protrusion is pressed down, increasing the deformation when the gel membrane is subjected to a small force or strain, reducing the initial contact area between the gel membrane and the electrode, and when the gel membrane is subjected to a small force or strain, as the force increases, the contact area growth rate between the gel membrane and the electrode is increased, thereby improving the sensitivity of the sensor; the sandblasting angle is 45°~90°, which is more conducive to improving the uniformity of the microstructure on the arc-shaped depression of the mold or the arc-shaped protrusion of the film formed by the mold. The sandblasting time is, for example, 5s, 6s, 7s, 8s, 9s and 10s, the sandblasting flow rate is, for example, 0.5kg / min, 1kg / min, 1.5kg / min, 2kg / min, the sandblasting distance is, for example, 10cm, 11cm, 12cm, 13cm, 14cm and 15cm, and the sandblasting angle is, for example, 45°, 50°, 60°, 75° and 90°. The sandblasting angle refers to the angle between the sandblasting direction and the horizontal direction.

[0030] In some preferred embodiments, the precursor substrate is selected from one of metal plates, melamine foam plates, alloy plates, frosted glass plates, and polyoxymethylene plates. On the basis of sandblasting the precursor substrate, the sandblasting particle size is 5000 mesh to 10000 mesh, and the sandblasting pressure is 2 bar to 10 bar, under this preferred scheme, the precursor substrate is selected from one of metal plates, melamine foam plates, alloy plates, frosted glass plates, and polyoxymethylene plates, and the microstructure formed is more conducive to reducing the mutual squeezing of internal molecules when the arc-shaped protrusion is pressed down, increasing the deformation when the gel film is subjected to a small force or strain, reducing the initial contact area between the gel film and the electrode, and when the gel film is subjected to a small force or strain, as the force increases, the contact area growth rate between the gel film and the electrode is increased, and the sensitivity of the sensor is improved. The metal plate of the present invention is, for example, a photolithography metal plate.

[0031] In some preferred embodiments, the polymer includes at least one of PVDF-HFP and PVDF-TrFE-CFE; the anions of the ionic liquid include at least one of hexafluorophosphate anion, tetrafluoroborate anion, bistrifluoromethanesulfonyl imide anion, trifluoromethanesulfonate anion, acetate anion, dicyanamide anion, bromide anion, ethyl sulfate anion, and hydrogen sulfide anion; the cations of the ionic liquid include at least one of 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, and 1-octyl-3-methylimidazolium cation; the solvent of the mixed solution includes at least one of N,N-dimethylformamide, acetone, and N-methylpyrrolidone. There is an arc-shaped protrusion on the precursor substrate, and sandblasting is performed on the precursor substrate. The sandblasting particle size is 5000 mesh to 10000 mesh and the sandblasting pressure is 2 bar to 10 bar. Under this preferred embodiment, the polymer is selected from the above polymer and the ionic liquid is selected from the above ionic liquid, which is more conducive to improving the sensing sensitivity.

[0032] In some preferred embodiments, in the mixed solution, the ratio of the mass of the ionic liquid to the mass of the polymer is 0.05 to 1. The precursor substrate has an arc-shaped protrusion, and sandblasting is performed on the precursor substrate. The sandblasting particle size is 5000 mesh to 10000 mesh, and the sandblasting pressure is 2 bar to 10 bar. Under this preferred solution, the conductivity of the polymer ion gel film can be improved, thereby further improving the sensitivity of the capacitive sensor, and the resilience of the polymer ion gel film can be further improved. After the gel film is used in the capacitive sensor, the friction between molecules is reduced, and the energy dissipation of the gel film after being subjected to force or strain is reduced, thereby reducing the hysteresis of the detection, improving the accuracy of the sensing force or strain, and reducing the sensing error.

[0033] In some preferred embodiments, based on the mass of the mixed solution, the sum of the content of the polymer and the ionic liquid is 8wt% to 12wt%. Under this preferred embodiment, it is more conducive to forming complete arc-shaped protrusions and microstructures on the surface of the arc-shaped protrusions on the surface of the ion gel membrane after the membrane is inverted, thereby improving the sensitivity of the sensor and avoiding inconsistent strength, resilience and sensitivity at different points of the gel membrane.

[0034] In some preferred embodiments, the arc-shaped depressions in the arc-shaped depression array are arranged evenly at intervals, each of the arc-shaped depressions has the same shape, the depth of the arc-shaped depressions is 8μm~150μm, the diameter is 50μm~300μm, and the center spacing of adjacent arc-shaped depressions in each row and column of arc-shaped depressions is 58μm~450μm. Under this preferred scheme, the arc-shaped depressions in the arc-shaped depression array are arranged evenly at intervals, and the shape of each arc-shaped depression is the same, which is more conducive to avoiding inconsistent strength, resilience and sensitivity at different points of the gel film, the depth of the arc-shaped depression is 8μm~150μm, the diameter is 50μm~300μm, and the center spacing of adjacent arc-shaped depressions in each row and column of arc-shaped depressions is 58μm~450μm, which is more conducive to improving the response amount of capacitance change caused by unit force or strain change, improving sensitivity, and reducing detection hysteresis. The diameter of the arc-shaped depression refers to the diameter of the opening. The center distance between adjacent arc-shaped recesses in each row and column of arc-shaped recesses refers to the distance between the centers of two openings of adjacent arc-shaped recesses.

[0035] In a second aspect, the present invention provides an ion gel membrane having a microstructure on its surface, wherein one side of the surface has an array of arc-shaped protrusions, and the surface of the arc-shaped protrusions has a rough structure, which forms the microstructure, and the microstructure is a tiny convex and concave shape.

[0036] The ion gel membrane of the present invention has an arc-shaped protrusion array on one side of the surface, and the surface of the arc-shaped protrusion has a rough structure. It is used for an ion-type mechanical sensor and has significantly improved sensitivity.

[0037] In some preferred embodiments, the average diameter of the rough structure on the surface of the arc-shaped protrusion is 1.5 μm to 3.2 μm. The average diameter refers to the average diameter of the grooves in the tiny convex and concave shapes. Under this preferred embodiment, it is more conducive to reducing the mutual squeezing of internal molecules when the arc-shaped protrusion is pressed down, reducing the pressure bearing capacity, increasing the deformation when the gel film is subjected to a small force or strain, and reducing the initial contact area between the gel film and the electrode. Therefore, when the gel film is subjected to a small force or strain, as the force increases, the contact area growth rate between the gel film and the electrode is increased, and the sensitivity of the polymer ion gel film when subjected to a small force or strain is improved.

[0038] In some preferred embodiments, the arc-shaped protrusions in the arc-shaped protrusion array are arranged evenly at intervals, each of the arc-shaped protrusions has the same shape, the height of the arc-shaped protrusion is 8μm~150μm, the diameter is 50μm~300μm, and the center spacing of adjacent arc-shaped protrusions in each row and column of arc-shaped protrusions is 58μm~450μm. Under this preferred solution, the arc-shaped protrusions in the arc-shaped protrusion array are arranged evenly at intervals, and each of the arc-shaped protrusions has the same shape, which is more conducive to avoiding inconsistent strength, resilience and sensitivity at different points of the gel film. The arc-shaped protrusions have a height of 8μm~150μm and a diameter of 50μm~300μm, and the center spacing of adjacent arc-shaped protrusions in each row and column of arc-shaped protrusions is 58μm~450μm, respectively, which is more conducive to improving the response amount of capacitance change caused by unit force or strain change, improving sensitivity, and reducing detection hysteresis. The diameter of the arc-shaped protrusion refers to the diameter of the bottom surface of the protrusion. The center distance between adjacent arc-shaped protrusions in each row and column of arc-shaped protrusions refers to the distance between the centers of two bottom surfaces of adjacent arc-shaped protrusions.

[0039] In a third aspect, the present invention provides an ionotropic mechanical sensor having electrodes and an ionotropic gel membrane prepared by the preparation method of the first aspect or the ionotropic gel membrane of the second aspect located between two electrodes.

[0040] The present invention is further described in detail below with reference to specific embodiments.

[0041] Example 1

[0042] A method for preparing an ion gel membrane comprises the following steps:

[0043] Step 1: sandblasting on a metal precursor substrate to obtain a metal substrate, the metal precursor substrate having an arc-shaped depression array formed by arc-shaped depressions of the same shape, the average depth of the arc-shaped depressions is 25 μm, the average diameter is 150 μm, the arc-shaped depressions in the arc-shaped depression array are evenly spaced, and the center spacing between adjacent arc-shaped depressions in each row and each column of arc-shaped depressions is 190 μm on average. The sandblasting particle size is 8000 mesh, the sandblasting pressure is 8 bar, the sandblasting time is 10 s, the sandblasting flow rate is 1 kg / min, the sandblasting distance is 12 cm, and the sandblasting angle is 55°; the morphology of the metal substrate of the present invention is shown in Figure 1 ;

[0044] Step 2: Wipe the metal substrate obtained in step 1 with alcohol to remove moisture and oil on the surface, and form a film of a mixed solution of a polymer and an ionic liquid on the metal substrate by a leveling method, wherein the polymer is PVDF-HFP, the ionic liquid is 1-ethyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt, and the solvent of the mixed solution is N,N-dimethylformamide. Based on the mass of the mixed solution, the content of the polymer is 6wt%, the content of the ionic liquid is 4wt%, the content of the solvent is 90wt%, the ratio of the mass of the ionic liquid to the mass of the polymer is 0.66, and the sum of the contents of the polymer and the ionic liquid is 10wt%;

[0045] Step 3: Place the wet film formed in step 2 and the metal substrate in a 70° C. oven and bake for 1 hour. The wet film is dried and solidified to obtain an ion gel film. The ion gel film is peeled off from the substrate to obtain a separate ion gel film.

[0046] An ion gel membrane, one side surface of the ion gel membrane has an array of arc-shaped protrusions, the surface of the arc-shaped protrusions has a microstructure in the form of a rough structure, the arc-shaped protrusions in the array of arc-shaped protrusions are evenly spaced, each of the arc-shaped protrusions has the same shape, the average height of the arc-shaped protrusions is 25 μm, the diameter is 150 μm, and the center spacing between adjacent arc-shaped protrusions in each row and column of arc-shaped protrusions is 190 μm on average. The morphology of the ion gel membrane of the present invention is shown in Figure 2 , after Figure 2 The roughness of the sample was analyzed and the average diameter of the arc-shaped surface roughness structure was about 2 μm.

[0047] An ion-type mechanical sensor comprises two parallel-arranged pole plates, between which is arranged the aforementioned ion gel membrane which is parallel to the pole plates.

[0048] Example 2

[0049] Refer to Example 1, except that in step 1 of the preparation method, the sandblasting particle size is 10000 mesh.

[0050] Example 3

[0051] Refer to Example 1, except that in step 1 of the preparation method, the sandblasting pressure is 4 bar.

[0052] Example 4

[0053] Refer to Example 1, except that in step 1 of the preparation method, the sandblasting time is 4 s.

[0054] Example 5

[0055] Referring to Example 1, the difference is that in step 2 of the preparation method, based on the mass of the mixed solution, the content of the polymer is 4wt%, the content of the ionic liquid is 6wt%, and the ratio of the mass of the ionic liquid to the mass of the polymer is 1.5.

[0056] Example 6

[0057] Referring to Example 1, the difference is that in step 2 of the preparation method, based on the mass of the mixed solution, the content of the polymer is 9.6wt%, the content of the ionic liquid is 0.4wt%, and the ratio of the mass of the ionic liquid to the mass of the polymer is 0.042.

[0058] Example 7

[0059] Referring to Example 1, the difference is that in step 1 of the preparation method, the average depth of the arc-shaped depression is 5 μm, the average diameter is 10 μm, and the average center distance between adjacent arc-shaped depressions in each row and column of arc-shaped depressions is 13 μm. The average height of the arc-shaped protrusions of the ion gel membrane is 5 μm, the diameter is 10 μm, and the average center distance between adjacent arc-shaped protrusions in each row and column of arc-shaped protrusions is 13 μm.

[0060] Comparative Example 1

[0061] Refer to Example 1, except that in step 1 of the preparation method, the sandblasting particle size is 12000 mesh.

[0062] Comparative Example 2

[0063] Refer to Example 1, except that in step 1 of the preparation method, the sandblasting pressure is 1 bar.

[0064] Comparative Example 3

[0065] Referring to Example 1, the difference is that no sandblasting is performed in the preparation method, and the mixed solution of the polymer and the ionic liquid is directly formed into a film on the metal precursor substrate.

[0066] The ion-type mechanical sensors obtained in the above embodiments and comparative examples were tested for hysteresis and sensitivity, and the results are shown in Table 1, where the pressure test range is 0~1Mpa. The above performance was measured using a MARK-10 brand F105Easy electric measuring table combined with a FS05-20 tension and compression sensor, and the hysteresis and sensitivity data were obtained by referring to the measurement method in the "Technical Specifications for Distributed Thin Film Pressure Sensors". Hysteresis indicates the ability of the gel film to recover deformation, and sensitivity indicates the increase rate of the contact area between the gel film and the electrode as the pressure increases.

[0067] Table 1

[0068]

[0069] Comparing Comparative Examples 1 to 3 and the embodiment, the precursor substrate having the arc-shaped recess array is sandblasted, the sandblasting particle size is 5000 mesh to 10000 mesh, and the sandblasting pressure is 2 bar to 10 bar, which can improve the sensing sensitivity.

[0070] Comparing Examples 1 to 4, the sandblasting particle size is 5000 mesh to 8000 mesh, the sandblasting pressure is 5 bar to 10 bar, and the sandblasting time is 5s-10s, which is more conducive to improving the sensitivity of the sensor. Comparing Examples 1, 5 and 6, in the mixed solution, the ratio of the mass of the ionic liquid to the mass of the polymer is not higher than 1, which is more conducive to reducing the hysteresis of the sensor, and is not lower than 0.05, which is more conducive to improving the sensitivity of the sensor. Comparing Examples 1 and 7, the depth of the arc-shaped depression of the substrate is The height of the arc-shaped depressions is 8μm~150μm, the diameter is 50μm~300μm, the center distance between adjacent arc-shaped depressions in each row and each column is 58μm~450μm respectively, the height of the arc-shaped protrusions of the gel film is 8μm~150μm, the diameter is 50μm~300μm, the center distance between adjacent arc-shaped protrusions in each row and each column is 58μm~450μm respectively, which is more conducive to improving the sensitivity of the sensor and reducing the hysteresis of the sensor.

[0071] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing an ion gel membrane having a microstructure on the surface, characterized in that: include: Sandblasting is performed on a precursor substrate to obtain a substrate, a mixed solution of a polymer and an ionic liquid is formed on the substrate to obtain a wet film, and the wet film is dried and solidified to obtain an ion gel film, wherein the precursor substrate has an arc-shaped recess array, and the sandblasting conditions include: a sandblasting particle size of 5000 mesh to 10000 mesh, and a sandblasting pressure of 2 bar to 10 bar; The polymer includes at least one of PVDF-HFP and PVDF-TrFE-CFE; In the mixed solution, the ratio of the mass of the ionic liquid to the mass of the polymer is 0.05-1; The arc-shaped depressions have a depth of 8 μm to 150 μm, a diameter of 50 μm to 300 μm, and a center distance between adjacent arc-shaped depressions in each row and column of arc-shaped depressions is 58 μm to 450 μm.

2. The preparation method according to claim 1, characterized in that: The sandblasting particle size is 5000 mesh to 8000 mesh, and the sandblasting pressure is 5 bar to 10 bar.

3. The preparation method according to claim 1, characterized in that: The sandblasting conditions also include: a sandblasting time of 5s to 10s, a sandblasting flow rate of 0.5kg / min to 2kg / min, a sandblasting distance of 10cm to 15cm, and a sandblasting angle of 45° to 90°.

4. The preparation method according to any one of claims 1 to 3, characterized in that The precursor substrate is selected from a metal plate, a melamine foam plate, an alloy plate, a frosted glass plate, and a polyoxymethylene plate.

5. The preparation method according to claim 1, characterized in that: The anions of the ionic liquid include at least one of hexafluorophosphate anion, tetrafluoroborate anion, bistrifluoromethanesulfonyl imide anion, trifluoromethanesulfonate anion, acetate anion, dicyanamide anion, bromide anion, ethyl sulfate anion, and hydrogen sulfide anion; the cations of the ionic liquid include at least one of 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, and 1-octyl-3-methylimidazolium cation; and the solvent of the mixed solution includes at least one of N,N-dimethylformamide, acetone, and N-methylpyrrolidone.

6. The preparation method according to claim 1, characterized in that: Based on the mass of the mixed solution, the sum of the contents of the polymer and the ionic liquid is 8wt% to 12wt%.

7. The preparation method according to claim 1, characterized in that: The arc-shaped recesses in the arc-shaped recess array are arranged evenly at intervals, and each of the arc-shaped recesses has the same shape.

8. An ion gel membrane having a microstructure on the surface, characterized in that: It is prepared by the preparation method of the ion gel membrane according to any one of claims 1 to 7, and one side surface of the ion gel membrane has an array of arc-shaped protrusions, and the surface of the arc-shaped protrusions has a rough structure, and the rough structure forms the microstructure.

9. The ion gel membrane according to claim 8, characterized in that The average diameter of the rough structure on the arc-shaped convex surface is 1.5 μm to 3.2 μm.

10. The ion gel membrane according to claim 8, characterized in that The arc-shaped protrusions in the arc-shaped protrusion array are arranged evenly at intervals, each of the arc-shaped protrusions has the same shape, the height of the arc-shaped protrusion is 8μm~150μm, the diameter is 50μm~300μm, and the center distance between adjacent arc-shaped protrusions in each row and column of arc-shaped protrusions is 58μm~450μm.

11. An ionization type mechanical sensor, characterized in that: The invention comprises an electrode plate and an ion gel membrane prepared by the preparation method according to any one of claims 1 to 7 or an ion gel membrane according to any one of claims 8 to 10 located between two of the electrode plates.

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