A pressure-sensitive film based on a force-responsive cholesteric main-chain liquid crystal oligomer and a preparation method and application thereof

Abstract

The application discloses a pressure-sensitive film based on force response cholesteric main chain liquid crystal oligomer, and the structure of the pressure-sensitive film based on force response cholesteric main chain liquid crystal oligomer is sequentially PDMS layer, cholesteric liquid crystal oligomer layer and substrate layer from top to bottom; the cholesteric liquid crystal oligomer layer is obtained by reacting diacrylate liquid crystal monomer and dithiol; and the polymerization degree of the cholesteric liquid crystal oligomer layer is 2-10. The pressure-sensitive film based on force response cholesteric main chain liquid crystal oligomer disclosed by the application uses the oligomer with a polymerization degree of 2-10 obtained by polymerizing diacrylate liquid crystal monomer as the cholesteric liquid crystal oligomer layer, so that the visual degree is higher, the threshold of force response is controllable, and there is no liquid component in the pressure-sensitive film, so that the pressure-sensitive film is easier to assemble and more stable.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal materials technology, and in particular to a pressure-sensitive film based on a force-responsive cholesteric phase main chain liquid crystal oligomer, its preparation method, and its application. Background Technology

[0002] Stimulus-responsive materials are those that change their properties (such as shape and optical properties) in response to external stimuli (e.g., electric fields, humidity, temperature, light, or mechanical forces). These materials (including inorganic and organic polymers such as hydrogels, shape memory polymers, and elastomers) are attracting widespread attention in a variety of potential applications, such as tactile, self-cleaning, and macroscopic actuation.

[0003] Liquid crystals (LCs) are materials that lie between ordered solids and isotropic liquids. These materials exhibit birefringence, meaning the refractive index parallel to the long molecular axis differs from the refractive index perpendicular to that axis. Therefore, studying LCs as stimulus-responsive materials that display optical changes is significant. Cholesteric liquid crystals (CLCs) are a particularly interesting liquid crystal phase for studying responsive optical properties. CLCs are obtained by adding chiral dopants to LCs. CLCs possess a periodic helical structure and can reflect light of specific wavelengths.

[0004] Currently, common force-sensitive materials mainly include Fuji pressure measurement films and reconfigurable chiral photonic paper. Fuji pressure measurement films lack elasticity, cannot adhere well to objects, are not reusable, and are costly. Reconfigurable chiral photonic paper is based on the force response of liquid crystal oligomers (CLCs), but the threshold of the force response has not been studied. Research on cholesteric liquid crystal polymers focuses on the polymers themselves, without investigating the threshold of the force response. Furthermore, the preparation of liquid crystal polymers requires liquid components, which increases the complexity of the preparation process and introduces stability issues. Therefore, it is of great significance to develop force-responsive devices that are easy to prepare, flexible, and exhibit different thresholds and sensitivities for force response. Summary of the Invention

[0005] One object of the present invention is to provide the above-mentioned pressure-sensitive film based on force-responsive cholesteric main-chain liquid crystal oligomers, wherein the structure of the pressure-sensitive film based on force-responsive cholesteric main-chain liquid crystal oligomers is, from top to bottom, a PDMS layer, a cholesteric liquid crystal oligomer layer, and a substrate layer.

[0006] in

[0007] The cholesteric phase liquid crystal oligomer layer is obtained by reacting diacrylate liquid crystal monomers and dithiol.

[0008] The degree of polymerization of the cholesteric phase liquid crystal oligomer layer is 2-10;

[0009] Specifically, cholesteric liquid crystal oligomers are generally viscous liquids or semi-solids, which makes them more widely and conveniently applicable. Cholesteric liquid crystals have a helical structure, and the wavelength of the light they reflect is proportional to the pitch. When the degree of polymerization of cholesteric liquid crystal oligomers is higher, the molecular chain length will be longer. Compressing the helical structure to a certain pitch, i.e., reflecting light of a certain wavelength, will require a greater force to produce a visible color change. Therefore, cholesteric liquid crystal oligomers with different degrees of polymerization have different force response thresholds, and the higher the degree of polymerization, the higher the force response threshold. The cholesteric liquid crystal oligomers of this invention have strong oligomer characteristics, are more soluble in solvents, have a higher content of end groups, and can be melted. The response performance is easily manifested. Moreover, this invention uses diacrylate liquid crystal monomers to prepare pressure-sensitive films with a degree of polymerization of 2-10, which have better force response performance than other conventional pressure-sensitive films.

[0010] Furthermore, the thickness of the cholesteric phase liquid crystal oligomer layer is 8-15 μm; the thickness of the PDMS layer is 200-250 μm.

[0011] Furthermore, the thickness of the substrate layer is 150-200 μm.

[0012] Preferably, the substrate layer is a flexible substrate, and the material of the substrate layer is selected from one or more of PC (polycarbonate), PET (polyethylene terephthalate), and PP (polypropylene).

[0013] Furthermore, the diacrylate liquid crystal monomer is selected from one or more of the HCM class monomers.

[0014] Another object of the present invention is to disclose a method for preparing the above-mentioned pressure-sensitive film based on a force-responsive cholesteric phase main chain liquid crystal oligomer, wherein the method for preparing the pressure-sensitive film based on a force-responsive cholesteric phase main chain liquid crystal oligomer includes the following steps:

[0015] S1. Dissolve the diacrylate liquid crystal monomer, dithiol, and dipropylamine in a solvent and stir the reaction at 50-60°C for 5-6 hours to obtain an intermediate product.

[0016] S2. The intermediate product, dipropylamine, and n-butanethiol are reacted at 55-65°C to cap the polymer, and the degree of polymerization of the intermediate product is controlled to obtain the cholesteric liquid crystal oligomer.

[0017] S3. The cholesteric liquid crystal oligomer is blended with a surfactant and a solvent and coated onto the substrate layer to form a film, thereby obtaining the cholesteric liquid crystal oligomer layer.

[0018] S4. A layer of PDMS is coated on the cholesteric liquid crystal oligomer layer and a film is formed to obtain the PDMS layer.

[0019] Further, in step S1, the proportion of the diacrylate liquid crystal monomer is 80-85 wt%; the proportion of the dithiol is 14-19 wt%; and the proportion of the dipropylamine is 0.5-2 wt%.

[0020] Further, in step S2, the intermediate product accounts for 86-94 wt%; the dipropylamine accounts for 0.5-1.5 wt%; and the n-butanethiol accounts for 5.5-13 wt%.

[0021] Further, in step S4, the PDMS is prepared by reacting a PDMS precursor and a crosslinking agent at a mass ratio of 7-10:1.

[0022] Furthermore, in step S4, after the PDMS coating is applied, the curing temperature is 60-80℃ and the curing time is 30-60min.

[0023] Preferably, the dithiol is selected from one or more of 2,2'-(1,2-ethylenedioxy)bis(ethanethiol), 1,2-ethylenedithiol, and 1,5-pentanedithiol.

[0024] Preferably, the surfactant is selected from one or more of N-ethylperfluorooctylsulfonamide ethyl acrylate, sodium dioctyl succinate sulfonate, and sodium dodecyl sulfate.

[0025] Preferably, the solvent is selected from one or more of dichloromethane, tetrahydrofuran, and chloroform.

[0026] Another object of the present invention is to disclose the application of the above-mentioned pressure-sensitive membrane based on force-responsive cholesteric main chain liquid crystal oligomers in pressure detection.

[0027] Specifically, when no pressure is applied, the liquid crystal molecules inside the cholesteric liquid crystal oligomer layer of the pressure-sensitive membrane are in a disordered multi-domain state, and the entire film appears white. By applying pressure, the arrangement of liquid crystal molecules can be changed, and the arrangement of liquid crystal molecules changes from a disordered state to an ordered state. The film quickly changes from white to a visible color with a specific reflection wavelength. The pressure-sensitive membrane has higher visual force response performance and has broad research and application prospects in pressure detection, medical and other fields.

[0028] The present invention has at least the following beneficial effects:

[0029] 1. The pressure-sensitive film of the present invention can obtain different reflective colors by adjusting the applied pressure, and has reversible force-induced color-changing characteristics. The pressure-sensitive film has no liquid components, is easier to assemble, more stable, and has a wider range of applications. Compared with traditional force-responsive reflective devices, it does not require thermal, optical, or electrical drive, making it more convenient to use. At the same time, the degree of polymerization of the pressure-sensitive film of the present invention is controllable and easier to adjust, and it has high sensitivity and controllable threshold.

[0030] 2. By using specific diacrylate liquid crystal monomers, cholesteric phase liquid crystal oligomers with a degree of polymerization of 2-10 are prepared. The pressure-sensitive membrane made from these oligomers can have its threshold controlled by adjusting the degree of polymerization. Compared with common pressure-sensitive membranes, these oligomers have superior force response performance, better sensitivity, and more obvious color changes, enabling rapid visualization of pressure signals. Attached Figure Description

[0031] Figure 1 These are schematic diagrams of the pressure-sensitive membranes in Embodiments 1-3 of the present invention;

[0032] Figure 2 This is a schematic diagram of the arrangement of cholesteric liquid crystal molecules in the pressure-sensitive membrane of Embodiments 1-3 of the present invention with and without pressure.

[0033] Figure 3 These are external schematic diagrams of the pressure-sensitive membrane in Embodiments 1-3 of the present invention when no pressure is applied and when pressure is applied;

[0034] Figure 4 This is a transmission spectrum of the pressure-sensitive membrane color change and red shift over time under pressure and without pressure in Embodiment 1 of the present invention;

[0035] Figure 5 This is a transmission spectrum of the pressure-sensitive membrane color change and red shift over time under pressure and without pressure in Embodiment 2 of the present invention;

[0036] Figure 6 This is a transmission spectrum of the pressure-sensitive membrane color change and red shift over time under pressure and without pressure applied, as shown in Embodiment 3 of the present invention.

[0037] In the figure: 1. PDMS layer; 2. Cholesteric liquid crystal oligomer layer; 3. Substrate layer. Detailed Implementation

[0038] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0039] The substrate material in this embodiment of the invention is a PC (polycarbonate) substrate.

[0040] The diacrylate liquid crystal monomers, HCM-009 and HCM-006, were purchased from Jiangsu Hecheng New Materials Co., Ltd.

[0041] The dithiol was EDDET, purchased from Sigma-Aldrich.

[0042] Dipropylamine (DPA) was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0043] n-Butyl mercaptan, purchased from Sigma-Aldrich.

[0044] N-Ethylperfluorooctylsulfonamide ethyl acrylate was purchased from Shenzhen Ruijie Biotechnology Co., Ltd.

[0045] Dichloromethane, purchased from Tianjin Zhiyuan Chemical Reagent Co., Ltd.

[0046] Tetrahydrofuran, purchased from Sigma-Aldrich.

[0047] PDMS, purchased from DOW CORNING, brand name DC184;

[0048] DC184 comprises a PDMS precursor and a crosslinking agent, wherein the mass ratio of the PDMS precursor to the crosslinking agent is 9:1.

[0049] The HCM021 used in the comparative example of this invention was purchased from Jiangsu Hecheng New Materials Co., Ltd.

[0050] Example 1

[0051] A pressure-sensitive film based on a force-responsive cholesteric main chain liquid crystal has the following structure: PDMS layer 3 (200 μm) / cholesteric liquid crystal oligomer layer 2 (12 μm) / substrate layer 1 (175 μm).

[0052] Its preparation method includes the following steps:

[0053] S1. Dissolve 77.4 wt% HCM-009, 6.9 wt% HCM-006, 14.9 wt% EDDET, and the balance DPA in dichloromethane and stir at 50 °C for 6 h to obtain the intermediate product.

[0054] S2. 86.5 wt% of the intermediate product, 0.8 wt% of DPA and the balance n-butanethiol were reacted at 60 °C to end-cap the product. The reaction was stirred for more than 12 h. The degree of polymerization of the intermediate product was controlled to be 3. The solvent was evaporated to obtain the cholesteric phase liquid crystal oligomer.

[0055] S3. 99 wt% of the cholesteric liquid crystal oligomer is blended with the balance of N-ethylperfluorooctylsulfonamide ethyl acrylate and tetrahydrofuran, and coated onto the substrate layer 3 at 50°C to form a film, thereby obtaining the cholesteric liquid crystal oligomer layer 2.

[0056] S4. Under the condition of 1000 r / s rotation speed, a layer of PDMS is coated on the cholesteric phase liquid crystal oligomer layer 2 for 20 s. Then, it is placed in a vacuum pump to remove air bubbles for 10 min and cured on a hot stage at 80°C for 30 min to obtain the PDMS layer 1.

[0057] Example 2

[0058] A pressure-sensitive film based on a force-responsive cholesteric main chain liquid crystal has the following structure: PDMS layer 3 (200 μm) / cholesteric liquid crystal oligomer layer 2 (12 μm) / substrate layer 1 (175 μm).

[0059] Its preparation method includes the following steps:

[0060] S1. Dissolve 74.2 wt% HCM-009, 7.2 wt% HCM-006, 17.2 wt% EDDET, and the balance DPA in dichloromethane and stir at 50 °C for 6 h to obtain the intermediate product.

[0061] S2. 91.0 wt% of the intermediate product, 1.3 wt% of DPA and the balance n-butanethiol were reacted at 60 °C for end-capping. The reaction was stirred for more than 12 h. The degree of polymerization of the intermediate product was controlled to be 5. The solvent was evaporated to obtain the cholesteric phase liquid crystal oligomer.

[0062] S3. 99 wt% of the cholesteric liquid crystal oligomer is blended with the balance of N-ethylperfluorooctylsulfonamide ethyl acrylate and tetrahydrofuran, and coated onto the substrate layer 3 at 50°C to form a film, thereby obtaining the cholesteric liquid crystal oligomer layer 2.

[0063] S4. Under the condition of 1000 r / s rotation speed, a layer of PDMS is coated on the cholesteric phase liquid crystal oligomer layer 2 for 20 s. Then, it is placed in a vacuum pump to remove air bubbles for 10 min and cured on a hot stage at 80°C for 30 min to obtain the PDMS layer 1.

[0064] Example 3

[0065] A pressure-sensitive film based on a force-responsive cholesteric main chain liquid crystal has the following structure: PDMS layer 3 (200 μm) / cholesteric liquid crystal oligomer layer 2 (12 μm) / substrate layer 1 (175 μm).

[0066] Its preparation method includes the following steps:

[0067] S1. Dissolve 73.1 wt% HCM-009, 7.3 wt% HCM-006, 18.2 wt% EDDET, and the balance DPA in dichloromethane and stir at 50 °C for 6 h to obtain the intermediate product.

[0068] S2. 93.1 wt% of the intermediate product, 1.4 wt% of DPA and the balance n-butanethiol were reacted at 60 °C to cap the product. The reaction was stirred for more than 12 h. The degree of polymerization of the intermediate product was controlled to be 7. The solvent was evaporated to obtain the cholesteric liquid crystal oligomer.

[0069] S3. 99 wt% of the cholesteric liquid crystal oligomer is blended with the balance of N-ethylperfluorooctylsulfonamide ethyl acrylate and tetrahydrofuran, and coated onto the substrate layer 3 at 50°C to form a film, thereby obtaining the cholesteric liquid crystal oligomer layer 2.

[0070] S4. Under the condition of 1000 r / s rotation speed, a layer of PDMS is coated on the cholesteric phase liquid crystal oligomer layer 2 for 20 s. Then, it is placed in a vacuum pump to remove air bubbles for 10 min and cured on a hot stage at 80°C for 30 min to obtain the PDMS layer 1.

[0071] Figure 1 These are schematic diagrams of the pressure-sensitive membranes in Embodiments 1-3 of the present invention;

[0072] according to Figure 1 It can be seen that layer 1 is a PDMS layer; layer 2 is a cholesteric liquid crystal oligomer layer; and layer 3 is a substrate layer.

[0073] Figure 2 This is a schematic diagram of the arrangement of cholesteric liquid crystal molecules in the pressure-sensitive membrane of Embodiments 1-3 of the present invention with and without pressure.

[0074] according to Figure 2 It can be seen that when no pressure is applied, the liquid crystal molecules inside the cholesteric phase liquid crystal oligomer layer are in a disordered multi-domain state. By applying pressure, the arrangement of liquid crystal molecules can be changed, and the arrangement of liquid crystal molecules changes from a disordered state to an ordered state. Moreover, this ordered state will quickly return to a disordered state at 80°C, which makes the pressure-sensitive film have good repeatability.

[0075] Figure 3 These are external schematic diagrams of the pressure-sensitive membrane in Embodiments 1-3 of the present invention when no pressure is applied and when pressure is applied;

[0076] according to Figure 3 It can be seen that the cholesteric phase liquid crystal oligomer film appears white when no pressure is applied. When pressure is applied, the film quickly changes from white to a visible color with a specific reflection wavelength, indicating that the pressure-sensitive film has higher visual force response performance.

[0077] Comparative Example 1

[0078] The raw materials and preparation method for a pressure-sensitive film based on a force-responsive cholesteric main-chain liquid crystal are the same as in Example 2, except that the degree of polymerization of the cholesteric liquid crystal oligomer is 15.

[0079] Comparative Example 2

[0080] The raw materials and preparation method for a pressure-sensitive film based on a force-responsive cholesteric main chain liquid crystal are the same as in Example 2, except that HCM-009 is replaced with HCM021.

[0081] Test Example 1

[0082] Stress response test

[0083] Test method:

[0084] Steel balls weighing 20g, 30g, and 50g were dropped freely from a height of 20cm onto the pressure-sensitive films of Examples 1-3 and Comparative Examples 1-2, respectively. The color changes of the pressure-sensitive films after pressure was applied were observed, and the changes in the reflectance band of the pressure-sensitive films of Examples 1-3 at different times were measured using a marine spectrometer.

[0085] The test results are shown in Table 1. Figure 4-6 As shown:

[0086] Table 1. Color changes of the pressure-sensitive films in Examples 1-3 and Comparative Examples 1-2 after applying pressure.

[0087]

[0088]

[0089] Table 1 shows the color changes of the pressure-sensitive membranes in Examples 1-3 after applying pressure, as well as the magnitude of the applied pressure. 20g, 30g, and 50g steel balls were all dropped freely from 20cm. The larger the mass of the steel ball, the greater the pressure applied to the pressure-sensitive membrane after the drop. Due to the difference in the degree of polymerization of the cholesteric phase liquid crystal oligomer layer in Examples 1-3, the pressure required to produce the color change in Examples 1-3 was different.

[0090] As shown in Table 1, the degree of polymerization of the cholesteric phase liquid crystal oligomer layer in Example 1 is 3. A 20g steel ball will show obvious color change after being dropped freely from 20cm. The obvious color change will still occur after the mass of the steel ball is increased to 30g and 50g.

[0091] Example 2: The degree of polymerization of the cholesteric phase liquid crystal oligomer layer is 5. A 20g steel ball dropped freely from 20cm does not change color, leaving only a slight white mark. When the mass of the steel ball increases to 30g, a significant color change occurs, and the same significant color change still occurs when the mass of the steel ball increases to 50g.

[0092] In Example 3, the degree of polymerization of the cholesteric phase liquid crystal oligomer layer was 7. A 20g steel ball dropped freely from 20cm did not change color or leave a white mark. When the mass of the steel ball increased to 30g, no obvious color change occurred, but a slight white mark was left. A significant color change occurred when the mass of the steel ball increased to 50g.

[0093] The pressure-sensitive film of Comparative Example 1 did not change color. We speculate that this is because the degree of polymerization of the cholesteric liquid crystal oligomer in Comparative Example 1 increased, and it lost the characteristics of the main chain cholesteric liquid crystal oligomer, thus affecting its force response performance.

[0094] In Comparative Example 2, by replacing HCM-009 with HCM021, only a 50g steel ball dropped freely from 20cm left a white mark, indicating that the threshold of the pressure-sensitive membrane increased and the force response performance was affected.

[0095] Figure 4 , Figure 5 , Figure 6 The figures show the ocean transmission spectra of the pressure-sensitive membranes in Examples 1-3 before and after pressure was applied. As shown, the membrane rapidly changes from white to blue when pressure is applied, and then gradually red-shifts over time, changing from blue to green, yellow, orange, and red. The colors are linearly related to time. The time information provided by the colors in the spectrum indicates the time when pressure was applied.

[0096] Test Example 2

[0097] Response time test

[0098] Test method: Use a stopwatch to accurately record the time when a 50g steel ball falls freely from a height of 20cm onto the pressure-sensitive membranes of Examples 1-3 and Comparative Examples 1-2, and the time when the pressure-sensitive membrane changes from white to a visible color under the pressure of the steel ball. The time difference between the two is the response time.

[0099] The test results are shown in Table 2:

[0100] Table 2 shows the response times of the pressure-sensitive membranes in Examples 1-3 and Comparative Examples 1-2 after pressure is applied.

[0101]

[0102] As can be seen from Table 2, the response time of the pressure-sensitive membranes in Examples 1-3 is all within 20s, while the color change of the pressure-sensitive membrane in Comparative Example 1 cannot be observed, lacking response time; while the pressure-sensitive membrane in Comparative Example 2 has a longer response time due to the replacement of HCM-009, which greatly affects the force response performance of the pressure-sensitive membrane.

[0103] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0104] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A pressure-sensitive membrane based on a force-responsive cholesteric phase main chain liquid crystal oligomer, characterized in that, The structure of the pressure-sensitive film based on force-responsive cholesteric main chain liquid crystal oligomers, from top to bottom, consists of a PDMS layer, a cholesteric liquid crystal oligomer layer, and a substrate layer. in The cholesteric phase liquid crystal oligomer layer is obtained by reacting diacrylate liquid crystal monomers and dithiol. The degree of polymerization of the cholesteric phase liquid crystal oligomer layer is 2-10; The method for preparing the pressure-sensitive film based on the force-responsive cholesteric phase main chain liquid crystal oligomer includes the following steps: S1. Dissolve the diacrylate liquid crystal monomer, dithiol, and dipropylamine in a solvent and stir the mixture at 50-60 °C for 5-6 h to obtain an intermediate product; S2. The intermediate product, dipropylamine, and n-butanethiol are reacted at 55-65 °C to cap the polymer, and the degree of polymerization of the intermediate product is controlled to obtain the cholesteric liquid crystal oligomer. S3. The cholesteric liquid crystal oligomer is blended with a surfactant and a solvent and coated onto the substrate layer to form a film, thereby obtaining the cholesteric liquid crystal oligomer layer. S4. A layer of PDMS is coated on the cholesteric liquid crystal oligomer layer and a film is formed to obtain the PDMS layer.

2. The pressure-sensitive membrane based on a force-responsive cholesteric main-chain liquid crystal oligomer according to claim 1, characterized in that, The thickness of the cholesteric phase liquid crystal oligomer layer is 8-15 µm; the thickness of the PDMS layer is 200-250 µm.

3. The pressure-sensitive membrane based on a force-responsive cholesteric main-chain liquid crystal oligomer according to claim 1, characterized in that, The diacrylate liquid crystal monomer is selected from one or more of the HCM class monomers.

4. The pressure-sensitive membrane based on a force-responsive cholesteric main-chain liquid crystal oligomer according to claim 1, characterized in that, In step S1, the proportion of the diacrylate liquid crystal monomer is 80-85 wt%; the proportion of the dithiol is 14-19 wt%; and the proportion of the dipropylamine is 0.5-2 wt%.

5. The pressure-sensitive membrane based on a force-responsive cholesteric main-chain liquid crystal oligomer according to claim 1, characterized in that, In step S2, the intermediate product accounts for 86-94 wt%; the dipropylamine accounts for 0.5-1.5 wt%; and the n-butanethiol accounts for 5.5-13 wt%.

6. The pressure-sensitive membrane based on a force-responsive cholesteric main-chain liquid crystal oligomer according to claim 1, characterized in that, In step S4, the PDMS is prepared by reacting a PDMS precursor and a crosslinking agent at a mass ratio of 7-10:

1.

7. The pressure-sensitive membrane based on a force-responsive cholesteric main-chain liquid crystal oligomer according to claim 1, characterized in that, In step S4, after the PDMS coating is applied, the curing temperature is 60-80 ℃ and the curing time is 30-60 min.

8. The application of the pressure-sensitive membrane based on force-responsive cholesteric main-chain liquid crystal oligomers as described in any one of claims 1-7 in pressure detection.

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