Polysaccharide-based nanofiber membrane, polysaccharide-based piezoresistive membrane material, and preparation method and application thereof

Abstract

This invention relates to the field of piezoresistive sensor technology, and particularly to a polysaccharide-based nanofiber membrane, a polysaccharide-based piezoresistive membrane material, its preparation method, and its applications. The preparation method of the polysaccharide-based nanofiber membrane includes: mixing polysaccharide, a water-soluble polymer, and water at 50–70°C to obtain a spinning precursor solution, followed by electrospinning to obtain the polysaccharide-based nanofiber membrane; wherein the molecular weight of the polysaccharide is 7 × 10⁻⁶. 5 ~12×10 5 g / mol. This invention, by controlling the molecular weight of polysaccharides within the above range and combining it with electrospinning technology, can prepare ultrathin, lightweight polysaccharide-based nanofiber membranes with a three-dimensional conductive network structure, greatly broadening the conductive pathway.

Description

Technical Field

[0001] This invention relates to the field of piezoresistive sensor technology, and in particular to a polysaccharide-based nanofiber membrane, a polysaccharide-based piezoresistive membrane material, its preparation method, and its application. Background Technology

[0002] Precise and continuous wearable electronic devices can facilitate the early predictive monitoring of abnormal physiological changes, including applications in medical diagnostics, human-computer interaction, human motion detection, and Joule heating devices. Pressure sensing, which converts external force into electrical signals or other reactive output signals, is key to wearability, comfort, and flexibility. Typically, pressure sensors are classified into piezoresistive, capacitive, piezoelectric, and triboelectric sensors based on their sensing mechanisms. Piezoresistive sensing, in particular, is favored due to its ease of signal acquisition, simple structure, high sensitivity, and wide pressure range, as it works based on changes in externally applied pressure that are reflected as changes in resistance. Despite significant advancements in piezoresistive sensing, achieving both high sensitivity and excellent cyclic stability to meet the demands of comprehensive human motion detection, ranging from minute human activities (such as pulse signals) to large movements (such as elbow flexion), remains a significant challenge. Traditional flexible piezoresistive sensors mainly embed conductive materials into highly sensitive matrices, such as hydrogels, aerogels, and membranes, effectively designing conductive network pathways for pressure detection. In contrast, membranes have the characteristics of ultra-thin structure and lightweight, making them a promising candidate material for soft electronic and biomedical devices. Currently, there is a great need to develop flexible piezoresistive membrane sensors that are lightweight, breathable, biocompatible, and highly sensitive.

[0003] In the prior art, CN115031879A discloses a flexible pressure sensor based on metal aerogel. This flexible pressure sensor includes a flexible piezoresistive sensing layer and an electrode layer connected to the flexible piezoresistive sensing layer. It utilizes a porous elastic sponge as a support to effectively support the metal aerogel and fixes the metal aerogel with a polymer. It has good conductivity, high sensitivity, and can work continuously for a long time, with the piezoresistive response of the metal aerogel remaining stable. However, the flexible piezoresistive aerogel sensor obtained by this method has poor mechanical properties and unstable structure, which greatly limits the application of piezoresistive sensing in flexible electronics, human health monitoring, and other fields. CN113235310A discloses a method for preparing a piezoresistive sensing fabric, using an air-layer fabric as a filling substrate and MXene two-dimensional material as a filler. It can realize the detection of large-amplitude limb movements and the real-time monitoring of minute pulses and respiratory signals. CN115058886A discloses a method for preparing a flexible nano-alloy piezoresistive sensing fabric. In this invention, the flexible nano-alloy piezoresistive sensing fabric uses fabric as a flexible substrate, nano-alloy as a conductive functional layer, and hydrophobic surface ligands as a protective layer. This not only endows the piezoresistive sensing fabric with good hydrophobicity and self-cleaning ability but also enhances the bonding force between the fabric and the nano-alloy through hydrogen bonding, preventing the nano-alloy from detaching. However, the piezoresistive film materials prepared by the methods in CN113235310A and CN115058886A both use fabric as a substrate. The fabric has large pores and a large specific surface area of ​​fibers, and the conductive materials are expensive, limiting their industrial development.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a polysaccharide-based nanofiber membrane, a polysaccharide-based piezoresistive membrane material, its preparation method, and its application. This polysaccharide-based piezoresistive membrane material has advantages such as being non-toxic, environmentally friendly, and low-cost. At the same time, this polysaccharide-based piezoresistive sensor exhibits excellent sensing performance, including high sensitivity, wide detection range, cycle stability, and fast response time.

[0006] The specific technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a polysaccharide-based nanofiber membrane, comprising: mixing polysaccharide, water-soluble polymer and water at 50-70°C to obtain a spinning precursor solution, and then performing electrospinning to prepare a polysaccharide-based nanofiber membrane.

[0008] The polysaccharide has a molecular weight of 7 × 10⁻⁶. 5 ~12×10 5 g / mol.

[0009] This invention has found that when the spinning precursor solution contains polysaccharides, water-soluble polymers, and water of the above molecular weight, the polysaccharide-based nanofiber membranes prepared by electrospinning have smaller fiber diameters, larger aspect ratios and specific surface areas, and thus can provide more polymerization sites, thereby greatly broadening the conductive pathway.

[0010] Preferably, the polysaccharide is a plant polysaccharide.

[0011] More preferably, the polysaccharide includes one or more of saponin, starch, konjac polysaccharide and nanocellulose.

[0012] Preferably, the water-soluble polymer includes one or more of polyvinyl alcohol, waterborne polyurethane, and polylactic acid.

[0013] More preferably, when the mass ratio of the water-soluble polymer to the polysaccharide is 8-12:0.33-1, the fiber diameter can be further reduced, and the morphology of the polysaccharide-based nanofiber membrane is better.

[0014] Preferably, the spinning precursor solution also contains glycerol; more preferably, the amount of glycerol used is 0.1 to 1 wt%, based on the total amount of the spinning precursor solution.

[0015] The present invention has found that glycerol acts as a plasticizer in the spinning precursor solution system. When the amount of glycerol is controlled within the above range, good nanofiber morphology can be obtained and the mechanical properties of polysaccharide-based nanofiber membranes can be improved.

[0016] Preferably, the electrospinning conditions include: spinning voltage of 15–25 kV, receiving distance of 10–20 cm, and feeding speed of 0.1–0.5 mL / h.

[0017] Preferably, the polysaccharide is purified and pretreated before electrospinning; the pretreatment includes mixing the polysaccharide with water, adding anhydrous ethanol for precipitation, and finally freeze-drying.

[0018] Secondly, the present invention further provides a polysaccharide-based nanofiber membrane, which is prepared by the above-described preparation method.

[0019] Thirdly, the present invention also provides a method for preparing a polysaccharide-based piezoresistive membrane material, which includes: introducing a conductive substance into the polysaccharide-based nanofiber membrane to prepare a polysaccharide-based piezoresistive membrane material.

[0020] The conductive material includes conductive metals, conductive two-dimensional materials, or conductive polymers.

[0021] Preferably, the conductive metal includes silver nanowires; the conductive two-dimensional material includes graphene or carbon nanotubes; and the conductive polymer includes polypyrrole, polyaniline, or poly3,4-ethylenedioxythiophene.

[0022] Preferably, when the conductive material is a conductive metal, the preparation method of the polysaccharide-based piezoresistive membrane material specifically includes the following steps: vacuum filtering the conductive metal onto the surface of the above-mentioned polysaccharide-based nanofiber membrane to obtain the polysaccharide-based piezoresistive membrane material.

[0023] Preferably, when the conductive material is a conductive two-dimensional material, the preparation method of the polysaccharide-based piezoresistive membrane material specifically includes the following steps: immersing the polysaccharide-based nanofiber membrane in the conductive two-dimensional material solution, so that the conductive two-dimensional material is deposited on the surface of the polysaccharide-based nanofiber membrane, thereby obtaining the polysaccharide-based piezoresistive membrane material.

[0024] Preferably, when the conductive material is a conductive polymer, the preparation method includes: immersing the polysaccharide-based nanofiber membrane in a mixed solution of the monomer, catalyst, and solvent of the conductive polymer at 0-7°C, so that the conductive polymer is polymerized in situ on the polysaccharide-based nanofiber membrane, thereby obtaining a polysaccharide-based piezoresistive membrane material.

[0025] The solvent includes lower alcohols, preferably methanol or ethanol;

[0026] And / or, when the conductive polymer is polypyrrole, the catalyst is a ferric salt; preferably FeCl3·6(H2O);

[0027] When the conductive polymer is polyaniline, the catalyst is a ferrous salt;

[0028] When the conductive polymer is poly(3,4-ethylenedioxythiophene), the catalyst is copper powder.

[0029] In this invention, the polysaccharide-based nanofiber membrane has a high specific surface area, which can provide sufficient polymerization sites; using the polysaccharide-based nanofiber membrane as the substrate of the piezoresistive material, the conductive polymer is polymerized in situ on the nanofiber surface, which can further expand the conductive path and improve the sensing performance.

[0030] Preferably, the mass ratio of the monomer of the conductive polymer to the catalyst is (5-12):1; for example, the mass ratio of the monomer of the conductive polymer to the catalyst can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1 and 12:1, etc.

[0031] Fourthly, the present invention provides a polysaccharide-based piezoresistive membrane material, which is prepared by the above-described preparation method.

[0032] Fifthly, the present invention provides a polysaccharide-based piezoresistive sensor containing the polysaccharide-based piezoresistive film material.

[0033] In a sixth aspect, the present invention also provides a method for preparing a polysaccharide-based piezoresistive sensor, comprising: encapsulating the polysaccharide-based piezoresistive film material and the gold interdigitated electrode with polyimide tape, and leading out two electrode wires on both sides of the gold interdigitated electrode.

[0034] Based on the above technical solution, the beneficial effects of the present invention are as follows:

[0035] This invention, by controlling the molecular weight of polysaccharides within the aforementioned range and combining it with electrospinning technology, enables the preparation of ultrathin, lightweight polysaccharide-based nanofiber membranes with a three-dimensional conductive network structure, significantly broadening the conductive pathway. Furthermore, the polysaccharide-based piezoresistive membrane material, made from polysaccharides, is natural, non-toxic, biodegradable, and biocompatible, showing broad market application prospects. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a SEM image of the polysaccharide-based nanofiber membrane prepared in Example 1 of this invention;

[0038] Figure 2 This is an electrothermal diagram of the soapberry polysaccharide-based piezoresistive film material prepared in Example 1 of this invention;

[0039] Figure 3 This is a flowchart of the preparation of a piezoresistive sensor using polysaccharides as raw materials in Example 1 of the present invention;

[0040] Figure 4 Scanning electron microscope image of the polysaccharide-based nanofiber membrane prepared in Example 7 of this invention;

[0041] Figure 5 Scanning electron microscope (SEM) images of the saponin-based piezoresistive membrane materials prepared in Examples 1-6 of this invention;

[0042] Figure 6 Transmission electron microscope image of the saponin-based piezoresistive film material prepared in Example 1 of this invention;

[0043] Figure 7 Fourier transform infrared spectrum of the saponin-based piezoresistive membrane material prepared in Example 1 of this invention;

[0044] Figure 8 Contact angle diagrams of the saponin-based piezoresistive membrane materials prepared in Examples 1-6 of this invention;

[0045] Figure 9 Sensitivity diagram of the saponin-based piezoresistive sensor prepared in Example 1 of this invention;

[0046] Figure 10 The response time diagram of the saponin-based piezoresistive sensor prepared in Example 1 of this invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] Unless otherwise specified, all raw materials used in the embodiments are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0049] Example 1

[0050] This embodiment first provides a polysaccharide-based nanofiber membrane, the preparation method of which includes the following steps:

[0051] (1) Dissolve 0.5g GSP (Gleditsia sinensis polysaccharide) in 300mL of distilled water, stir continuously at 80℃ for 2-4h, then add 200mL of anhydrous ethanol to precipitate, and collect the white GSP raw material by freeze drying; wherein, the molecular weight of the saponin polysaccharide is 8.935×10 5 g / mol;

[0052] (2) Weigh 31.25g of 16% PVA (polyvinyl alcohol) solution, 16.5g of 0.1% GSP solution, and 0.5g of GL (glycerol). After stirring at 60℃ for 6h, pour the solution into a syringe. Set the spinning voltage to 20kV, the receiving distance to 15cm, the feeding speed to 0.3mL / h, and the spinning solution volume to 3μl to prepare a saponin-based nanofiber membrane (PGG). The cellulose diameter was measured to be approximately 666nm. The SEM image of the polysaccharide-based nanofiber membrane is shown below. Figure 1 .

[0053] This embodiment further provides a polysaccharide-based piezoresistive film material, the preparation method of which includes the following steps:

[0054] Weigh 8.4g of pyrrole monomer solution and 4.8347g of FeCl3·6(H2O) and dissolve them in 40ml and 30ml of anhydrous ethanol solution, respectively. PGG is pre-soaked in pyrrole alcohol solution, and ferric chloride alcohol solution is pre-cooled at 4℃. After 30min, PGG is removed, ferric chloride alcohol solution is poured into pyrrole alcohol solution and stirred rapidly. The solution turns black. PGG obtained in step (3) is placed back into pyrrole solution and placed at 4℃ for in-situ polymerization of polypyrrole on PGG, thus obtaining the saponin-based piezoresistive membrane material (i.e., PGG@PPy 7:1). The electrothermal diagram of the saponin-based piezoresistive membrane material prepared in Example 1 is shown in [reference needed]. Figure 2 .

[0055] This embodiment also provides a polysaccharide-based piezoresistive sensor, the preparation method of which includes the following steps:

[0056] By combining the saponin polysaccharide-based piezoresistive film material PGG@PPy with the gold interdigitated electrodes, and encapsulating the upper and lower layers with polyimide tape, and extending two electrode lines from both ends of the electrodes, a saponin polysaccharide-based piezoresistive sensor can be obtained.

[0057] The flowchart for preparing polysaccharide-based piezoresistive sensors using saponin as a raw material is shown below. Figure 3 .

[0058] Examples 2-6

[0059] The following examples provide a polysaccharide-based piezoresistive membrane material, which is prepared using the same method as in Example 1, except that the molar ratio of the pyrrole monomer to FeCl3·6(H2O) is as shown in Table 1:

[0060] Table 1

[0061]

[0062] Example 7

[0063] This embodiment first provides a polysaccharide-based nanofiber membrane, which is prepared in the same way as in Example 1, except that glycerol is not added.

[0064] The cellulose diameter was measured to be approximately 462 nm; the SEM image of the polysaccharide-based nanofiber membrane without glycerol is shown below. Figure 4 The results showed that, compared with Example 7, the addition of glycerol helped to obtain better fiber morphology, and the mechanical properties of the fiber membrane prepared in Example 1 were significantly improved.

[0065] Example 8

[0066] This embodiment provides a polysaccharide-based piezoresistive film material, the preparation method of which includes the following steps:

[0067] Add 100 μl of aqueous silver nanowires to 500 ml of deionized water, sonicate for 30 minutes, vacuum filter onto the surface of the polysaccharide-based nanofiber membrane prepared in Example 1, and vacuum dry at 60°C for 4 hours to obtain the soapberry polysaccharide-based piezoresistive membrane material.

[0068] Comparative Example 1

[0069] This comparative example provides a polysaccharide-based nanofiber membrane, prepared using the same method as in Example 1, except that the polysaccharide is hydroxyethyl cellulose with a molecular weight of 7.5 × 10⁻⁶. 4 g / mol. Tests showed the fiber diameter to be approximately 1–2 μm.

[0070] As can be seen, compared with the example, the fiber diameter is significantly larger. Consequently, the specific surface area of ​​the polysaccharide-based nanofiber membrane prepared therefrom will inevitably be smaller than that of the polysaccharide-based nanofiber membrane prepared in the example, thus affecting its conductivity and resulting in poor sensing performance.

[0071] Test example

[0072] 1. Characterization Analysis Methods

[0073] Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are important methods for characterizing the morphology of nanomaterials. This invention uses field emission scanning electron microscopy (FESEM) and transmission electron microscopy to analyze the microstructure of a saponin-based piezoresistive film material.

[0074] Fourier transform infrared spectroscopy (FTIR) is an effective means of obtaining functional groups on the surface of sample materials. In this invention, a Nicolet Nexus 470 infrared spectrometer was used to analyze the functional groups of polypyrrole on the surface of saponin-based piezoresistive film material.

[0075] This invention uses an electrochemical workstation (CHI600E, Shanghai Huachen Instrument Co.) and a universal tensile testing machine (Zwell / Roell, Germany) to evaluate the piezoresistive performance of a polysaccharide-based piezoresistive sensor. When a given stress is applied by the universal tensile testing machine, the resistance value of the polysaccharide-based piezoresistive sensor changes, which is displayed as a change in current signal on the electrochemical workstation.

[0076] 2. Characterization Analysis Results

[0077] 2.1 Figure 5 These are scanning electron microscope (SEM) images of the saponin-based piezoresistive film materials prepared in Examples 1-6 of this invention. Figure 5It can be seen that when the amount of pyrrole used is relatively small, it will affect the tightness of the bonding between PPy and PGG fibers to a certain extent; while too much and too fast polymerization of a large number of polypyrrole particles can easily block some fiber pores, affecting the polymerization of pyrrole inside the nanofiber structure to a certain extent.

[0078] 2.2 Figure 6 This is a transmission electron microscope (TEM) image of the soapberry polysaccharide-based piezoresistive film material prepared in Example 1 of the present invention. Figure 6 As can be seen, polypyrrole adheres perfectly to the nanofibers, encapsulating the PGG nanofibers internally to form a conductive nanofiber structure similar to a "shell-core". The image clearly shows the dark outer contour of the fiber and the lighter-colored internal structure, namely the polypyrrole "shell" and PGG "core" double-layer structure, proving the successful preparation of the saponin-based piezoresistive membrane material.

[0079] 2.3 Figure 7 This is the Fourier transform infrared spectrum of the soapberry polysaccharide-based piezoresistive membrane material prepared in Example 1 of the present invention. From... Figure 7 It can be seen that, compared with PVA and PGG, the PGG@PPy 7:1 prepared in Example 1 has a better growth rate at 1550 cm⁻¹. -1 A strong tensile vibration peak was observed at 1160 cm⁻¹, representing the asymmetric vibration of the pyrrole ring. -1 and 1308cm -1 The characteristic peaks correspond to the CN and CC tensile vibrations of the pyrrole ring, proving the presence of polypyrrole and the successful preparation of the saponin-based piezoresistive membrane material.

[0080] 2.4 Figure 8 The contact angle diagrams are for the saponin-based piezoresistive membrane materials prepared in Examples 1-6 of this invention. Figure 8 This demonstrates that the saponin-based piezoresistive membrane material possesses excellent hydrophobic properties.

[0081] 2.5 Figure 9 The sensitivity diagram of the saponin-based piezoresistive sensor prepared in Example 1 shows a sensitivity of 7.09 kPa in the range of 2.34–34.36 kPa. -1 The sensitivity is 52.42 kPa within the range of 34.36–128.46 kPa. -1 When the stress is low, the piezoresistive film material of the three-dimensional network structure is compressed, the internal pores decrease, and the change in the contact area between the piezoresistive film material and the electrode is minimal, resulting in low sensitivity at the beginning of stress application. However, as the stress increases, the piezoresistive film material is compressed to a certain extent, increasing the contact area with the electrode, thus producing higher sensitivity. This demonstrates the excellent sensing performance of the saponin-based piezoresistive sensor prepared in Example 1 of this invention. In this invention, the saponin-based piezoresistive sensors prepared in the other examples also exhibit considerable effectiveness and high sensitivity.

[0082] 2.6 Figure 10 The figure shows the response time of the saponin-based piezoresistive sensor prepared in Example 1. The figure displays a fast response time (26 ms) and recovery time (19 ms), confirming the fast response performance of the saponin-based piezoresistive sensor prepared in Example 1 of this invention. In this invention, the saponin-based piezoresistive sensors prepared in the other examples also exhibit considerably fast response performance.

[0083] 3. Conductivity

[0084] The resistance values ​​of the piezoresistive film materials obtained in Examples 1-7 are shown in Table 2:

[0085] Table 2

[0086] serial number Resistance (kΩ) Example 1 (PGG@PPy 7:1) 0.06 Example 2 (PGG@PPy 1:1) -- Example 3 (PGG@PPy 3:1) 38.00 Example 4 (PGG@PPy 5:1) 2.86 Example 5 (PGG@PPy 9:1) 0.23 Example 6 (PGG@PPy 12:1) 0.36

[0087] In this invention, the conductivity of the polysaccharide-based piezoresistive membrane material comes from the conductive polymer. That is, the amount of conductive polymer used will affect the conductivity of the piezoresistive membrane. However, this invention has found that more is not necessarily better. When the molar ratio of conductive polymer monomer to catalyst is 5:1 to 12:1, the conductivity is better.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a polysaccharide-based piezoresistive membrane material, characterized in that, include: Polysaccharide, water-soluble polymer and water are mixed at 50~70 °C to obtain a spinning precursor solution, and then electrospinning is performed to prepare polysaccharide-based nanofiber membranes. A conductive material is introduced into the polysaccharide-based nanofiber membrane to prepare a polysaccharide-based piezoresistive membrane material. The polysaccharide has a molecular weight of 7 × 10⁻⁶. 5 ~12×10 5 g / mol; The mass ratio of the water-soluble polymer to the polysaccharide is 8~10:0.33~1; The spinning precursor solution also contains glycerol, and the amount of glycerol used is 0.1~1 wt% based on the total amount of the spinning precursor solution. The conductive material includes conductive metals, conductive two-dimensional materials, or conductive polymers.

2. The method for preparing the polysaccharide-based piezoresistive membrane material according to claim 1, characterized in that, The polysaccharides include one or more of saponin, starch, konjac polysaccharides, and nanocellulose.

3. The method for preparing the polysaccharide-based piezoresistive membrane material according to claim 1 or 2, characterized in that, The water-soluble polymer includes one or more of polyvinyl alcohol, waterborne polyurethane, and polylactic acid.

4. The method for preparing the polysaccharide-based piezoresistive membrane material according to claim 1, characterized in that, The conductive material is a conductive polymer, and the preparation method of the polysaccharide-based piezoresistive membrane material includes: immersing the polysaccharide-based nanofiber membrane in a mixed solution of the conductive polymer monomer, catalyst and solvent at 0~7ºC, so that the conductive polymer is polymerized in situ on the polysaccharide-based nanofiber membrane, thereby obtaining the polysaccharide-based piezoresistive membrane material. The solvent includes lower alcohols.

5. The method for preparing the polysaccharide-based piezoresistive membrane material according to claim 4, characterized in that, The solvent is methanol or ethanol; When the conductive polymer is polypyrrole, the catalyst is a ferric salt; When the conductive polymer is polyaniline, the catalyst is a ferrous salt; When the conductive polymer is poly(3,4-ethylenedioxythiophene), the catalyst is copper powder.

6. The method for preparing the polysaccharide-based piezoresistive membrane material according to claim 5, characterized in that, When the conductive polymer is polypyrrole, the catalyst is FeCl3·6(H2O).

7. The method for preparing the polysaccharide-based piezoresistive membrane material according to claim 4, characterized in that, The molar ratio of the conductive polymer monomer to the catalyst is (5~12):

1.

8. A polysaccharide-based piezoresistive membrane material, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 7.

9. A polysaccharide-based piezoresistive sensor, characterized in that, It contains the polysaccharide-based piezoresistive membrane material as described in claim 8.

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