阅读说明：本技术 一种胶原纤维基柔性压力传感材料及其制备方法 (Collagen fiber-based flexible pressure sensing material and preparation method thereof ) 是由 张文博 潘朝莹 马建中 卫林峰 陈珍 于 2021-02-07 设计创作，主要内容包括：本发明公开了一种胶原纤维基柔性压力传感材料及其制备方法,属于柔性传感技术领域。所述制备方法通过将胶原纤维悬浮液与交联剂混合后进行交联反应,制得交联胶原纤维悬浮液；向所得交联胶原纤维悬浮液中加入MXene分散液进行均匀分散,制得MXene/胶原纤维复合悬浮液；对所得MXene/胶原纤维复合悬浮液进行冷冻干燥处理,得到胶原纤维基柔性压力传感材料。所述胶原纤维基柔性压力传感材料具有海绵状多孔结构,包括胶原纤维基底材料,基底材料表面包覆MXene。本发明避免了使用传统合成聚合物作为基底,所述胶原纤维基柔性压力传感材料兼具优异的透气率和高灵敏度。(The invention discloses a collagen fiber-based flexible pressure sensing material and a preparation method thereof, belonging to the technical field of flexible sensing. The preparation method comprises the steps of mixing the collagen fiber suspension with a cross-linking agent and then carrying out cross-linking reaction to prepare a cross-linked collagen fiber suspension; adding MXene dispersion liquid into the obtained crosslinked collagen fiber suspension liquid for uniform dispersion to obtain MXene/collagen fiber composite suspension liquid; and carrying out freeze drying treatment on the obtained MXene/collagen fiber composite suspension to obtain the collagen fiber-based flexible pressure sensing material. The collagen fiber-based flexible pressure sensing material has a spongy porous structure and comprises a collagen fiber base material, wherein MXene is coated on the surface of the base material. The invention avoids using the traditional synthetic polymer as the substrate, and the collagen fiber-based flexible pressure sensing material has excellent air permeability and high sensitivity.)

1. A preparation method of a collagen fiber-based flexible pressure sensing material is characterized in that a collagen fiber suspension is mixed with a cross-linking agent and then subjected to a cross-linking reaction to prepare a cross-linked collagen fiber suspension; adding MXene dispersion liquid into the obtained crosslinked collagen fiber suspension liquid for uniform dispersion to obtain MXene/collagen fiber composite suspension liquid; and carrying out freeze drying treatment on the obtained MXene/collagen fiber composite suspension to obtain the collagen fiber-based flexible pressure sensing material.

2. The method of claim 1, wherein the collagen fiber suspension is obtained by:

extracting collagen fiber from animal skin, and dispersing the obtained collagen fiber in 0.05mol/L acetic acid solution to obtain collagen fiber suspension.

3. The method of claim 1, wherein the cross-linking agent is glutaraldehyde, catechin, myrica extract, larch extract, or genipin.

4. The method for preparing a collagen fiber-based flexible pressure sensing material as claimed in claim 1, wherein the temperature of the crosslinking reaction is 25-45 ℃, the time is 4-24 h, and the pH value is 5-8.

5. The method for preparing a collagen fiber-based flexible pressure sensing material as claimed in claim 1, wherein the mass ratio of the solid content in the collagen fiber suspension to the cross-linking agent is 1 (0.08-0.4).

6. The method of claim 1, wherein MXene is Ti₂C、Ti₃C₂、Mo₂C、Mo₂TiC₂Or Mo₂Ti₂C₃。

7. The method for preparing a collagen fiber-based flexible pressure sensing material as claimed in claim 1, wherein the crosslinked collagen fiber suspension and MXene dispersion are uniformly dispersed for 0.5-2 h and pH 3-5.

8. The method according to claim 1, wherein the mass ratio of the solid content of the crosslinked collagen fiber suspension to the solid content of the MXene dispersion is 1 (0.3-0.7).

9. The collagen fiber-based flexible pressure sensing material is characterized by having a spongy porous structure, wherein the collagen fiber-based flexible pressure sensing material comprises a collagen fiber base material, and MXene is coated on the surface of the base material.

10. The collagen fiber-based flexible pressure sensing material according to claim 9, wherein the sensitivity of the collagen fiber-based flexible pressure sensing material in pressure sensing is 30.58 to 61.99KPa^-1The response time is 0.09-0.5s, the sensing detection range is 0-20 KPa, and the air permeability is 47.9% -58.5%.

Technical Field

The invention belongs to the technical field of flexible sensing, and relates to a collagen fiber-based flexible pressure sensing material and a preparation method thereof.

Background

With the rapid development of science and technology, electronic products gradually develop towards light weight, flexibility and wearability. The flexible pressure sensor has the advantages of high sensitivity of a common rigid sensor, and also has good flexibility, can be bent at will, and can randomly detect the magnitude and distribution of acting force. They have great application potential in entertainment technology, human-computer interfaces, personal healthcare, and motion monitoring.

Compared with other sensors, the resistance-type flexible pressure sensor has the characteristics of simple preparation process, high sensitivity and the like, and is formed by compounding a flexible polymer matrix and a conductive nano material. He (He, et al. carbon,2019,146:701-708.) prepares a novel conductive composite fiber strain sensor composed of carbon nanotubes and thermoplastic polyurethane elastomer by a wet spinning method, and can be used for monitoring human motion. Wang (Wang, et al advanced Functional Materials,2017,27:1605657.) degummed and dialyzed silkworm cocoon to prepare regenerated silk fibroin aqueous solution, and a silk fiber membrane is prepared by an electrostatic spinning method. The prepared silk nanofiber membrane is carbonized at high temperature in inert atmosphere, and the obtained carbonized silk fiber membrane (CSilkNM) is transferred to a Polydimethylsiloxane (PDMS) film. The whole pressure sensor consists of two CSilkNM/PDMS films which face each other and can be used for monitoring human physiology. Huangxin and the like (CN109163825B) prepares the pressure sensing material by taking animal skins as raw materials through in-situ polymerization and pasting, and the pressure range is 0.027-0.567 KPa^-1The sensitivity is 0.397KPa at most^-1. Also, a leather-based pressure sensor was prepared by a method such as multilayer adhesion of similar leather with a conductive layer or sewing, by means of Roxburgh (CN111084975A) and Hover (CN 108917996A).

The sensor using the traditional polymer as the substrate has compact film formation and poor air permeability, and can cause damage to the skin after being attached to the skin for a long time. And the sensor based on the synthetic polymer material can generate a large amount of non-degradable electronic garbage when being widely used, thereby causing huge damage to the environment and not meeting the requirement of green sustainable development. Meanwhile, the technologies of electrostatic spinning, high-temperature carbonization and the like make the preparation process of the product more complex and the cost higher, and large-scale industrial production is difficult to realize. At present, the pressure sensing material taking animal skin as a raw material has good air permeability and degradability, but the sensor formed by overlapping multiple layers of leather has a large thickness, so that the actual application range of the sensor is limited.

Disclosure of Invention

In order to overcome the disadvantages of the prior art described above, it is an object of the present invention to provide a collagen fiber-based flexible pressure sensing material and a method for preparing the same, which avoid the use of conventional synthetic polymers as a substrate, and which has both excellent air permeability and high sensitivity.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

the invention discloses a preparation method of a collagen fiber-based flexible pressure sensing material, which comprises the steps of mixing a collagen fiber suspension with a cross-linking agent, and then carrying out cross-linking reaction to prepare a cross-linked collagen fiber suspension; adding MXene dispersion liquid into the obtained crosslinked collagen fiber suspension liquid for uniform dispersion to obtain MXene/collagen fiber composite suspension liquid; and carrying out freeze drying treatment on the obtained MXene/collagen fiber composite suspension to obtain the collagen fiber-based flexible pressure sensing material.

Preferably, the collagen fibre suspension is obtained by: extracting collagen fiber from animal skin, and dispersing the obtained collagen fiber in 0.05mol/L acetic acid solution to obtain collagen fiber suspension.

Preferably, the mass concentration of the collagen fiber suspension is 0.8-3%.

Preferably, the cross-linking agent is glutaraldehyde, catechin, myrica extract, larch extract or genipin.

Preferably, the temperature of the crosslinking reaction is 25-45 ℃, the time is 4-24 h, and the pH value is 5-8.

Preferably, the mass ratio of the solid content in the collagen fiber suspension to the cross-linking agent is 1 (0.08-0.4).

Preferably MXene is Ti₂C、Ti₃C₂、Mo₂C、Mo₂TiC₂Or Mo₂Ti₂C₃。

Preferably, the mass concentration of the MXene dispersion liquid is 0.5-3%.

Preferably, the stirring time for uniformly dispersing the crosslinked collagen fiber suspension and the MXene dispersion liquid is 0.5-2 h, and the pH value is 3-5.

Preferably, the mass ratio of the solid content in the crosslinked collagen fiber suspension to the solid content in the MXene dispersion is 1 (0.3-0.7).

The invention discloses a collagen fiber-based flexible pressure sensing material which has a spongy porous structure and comprises a collagen fiber base material, wherein MXene is coated on the surface of the base material.

Preferably, the sensitivity of the collagen fiber-based flexible pressure sensing material in pressure sensing is 30.58-61.99 KPa^-1The response time is 0.09-0.5s, the sensing detection range is 0-20 KPa, and the air permeability is 47.9% -58.5%.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a preparation method of a collagen fiber-based flexible pressure sensing material, which takes collagen fibers as reaction raw materials, has the advantages of low cost, no toxicity and degradability, and the structure of the collagen fibers is formed by mutually weaving hydrophilic collagen and water-insoluble collagen, so that the collagen fiber-based flexible pressure sensing material has ultrahigh flexibility, scalability, water permeability and air permeability; meanwhile, crosslinking agent is used for crosslinking the collagen fibers so as to improve the mechanical strength of the collagen fibers and reduce the functional groups of the collagen fibers; MXene can be covered on the surface of the collagen fiber through hydrogen bonds, and the stability of the coating structure is improved through freeze drying treatment. Therefore, the preparation method of the invention takes the collagen fiber as the substrate, can exert the advantages of good flexibility, green and no pollution of the collagen fiber, ensures that the finally prepared collagen fiber-based flexible pressure sensing material has good flexibility and air permeability, and simultaneously avoids the generation of a large amount of electronic waste. Wherein, the three-dimensional porous structure of the collagen fiber is utilized, and a new structure is not required to be added to the material when the pressure sensing material is manufactured, so that a plurality of manufacturing processes can be avoided. The invention combines the natural collagen fiber and MXene by simple stirring, has simple preparation process, low energy consumption and low cost, avoids using the traditional synthetic polymer as a substrate, and is beneficial to large-scale industrial production.

Further, the collagen fibers derived from animal skins are selected, and based on the wide source, the cost investment can be effectively controlled. In addition, the collagen fiber is derived from leather, has a more uniform structure, is more suitable for being combined with MXene conductive materials and the like, and further satisfies the requirement of constructing a sensor with target performance under the condition of thinner thickness.

Furthermore, the cross-linking agent is used for cross-linking the collagen fibers, so that the mechanical strength of the collagen fibers is improved, and the collagen fibers can better meet the requirements of practical application; the crosslinking degree is controlled, so that the number of functional groups of the collagen fibers can be controlled, the dispersion and combination of the collagen fibers and MXene are promoted, and the MXene is distributed on the surfaces of the collagen fibers more uniformly. Meanwhile, a cross-linking agent from natural plants is selected, so that the concept of green environmental protection is further implemented.

The invention also discloses a collagen fiber-based flexible pressure sensing material with a spongy porous structure, which is characterized in that the collagen fiber is used as a base material, the unique 3D porous network structure of the collagen fiber can promote multi-scale (nano, micron and macro scale) deformation, so that the collagen fiber-based flexible pressure sensing material can adapt to the shape (i.e. conformability) of human skin through a plurality of effective contact sites, and the mechanical strength required by the collagen fiber-based flexible pressure sensing material is ensured through the crosslinking process. Meanwhile, MXene and collagen fiber are combined through hydrogen bonds (MXene has oxygen-containing and fluorine-containing functional groups and rich active sites, so that the MXene can interact with functional groups on various polymer chains to be stably combined), the surface of the substrate material is coated with MXene, and the MXene has good conductivity and mechanical property, so that the conductivity is given to the MXene on the basis of not damaging the mechanical property of the collagen fiber, and a porous conductive network is constructed.

Further, the collagen fiber-based flexible pressure sensing material functions based on a porous conductive network with a spongy porous structure. When pressure acts on the collagen fiber-based pressure sensing material, the porous structure of the collagen fiber-based pressure sensing material is more compact, the contact and connection of MXene are increased, the resistance of the MXene is reduced, and the current is increased. When the pressure is released, the porous structure returns to the initial state, the gap is increased, the contact and connection between MXene are reduced, and the current is reduced. I.e. the pressure signal can be converted into an electrical signal. The gradual change of the porous structure enables the porous structure to have higher sensitivity and deformability, so that the collagen fiber-based flexible pressure sensing material has excellent air permeability and high sensitivity, and has great application potential in the aspects of intelligent wearable equipment such as electronic skin, virtual reality, health monitoring and the like.

Drawings

FIG. 1 is a schematic structural view of a collagen fiber-based flexible pressure sensing material according to the present invention;

FIG. 2 is a schematic flow chart of a preparation method of the present invention;

FIG. 3 is an SEM image of a collagen fiber-based flexible pressure-sensing material in example 1 of the present invention;

FIG. 4 is a graph showing the relationship between the pressure and the rate of change in current of the collagen fiber-based flexible pressure sensing material in example 1 of the present invention;

FIG. 5 is a graph showing the sensing effect of the collagen fiber-based flexible pressure sensing material according to example 1 of the present invention;

FIG. 6 is an enlarged view of 18.8-20 s shown in FIG. 5.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some embodiments of the invention are shown.

The invention discloses a collagen fiber-based flexible pressure sensing material, the structure of which is shown in figure 1, wherein MXene two-dimensional conductive material is introduced based on the porous structure of collagen fiber, and the MXene can be covered on the surface of the collagen fiber through hydrogen bonds to form a spongy collagen fiber-based flexible pressure sensing material containing a porous structure conductive network. The preparation process of the collagen fiber-based flexible pressure sensing material is shown in figure 2 and comprises the following steps:

(1) dispersing 0.8-3 g of collagen fibers extracted from animal skin into 100g of 0.05mol/L acetic acid solution, and stirring for 4 hours at 25 ℃ to prepare the collagen fiber suspension. Wherein the animal skin comprises Corii Sus Domestica, Corii Caprae Seu Ovis, and Corii bovis Seu Bubali.

(2) Mixing the obtained collagen fiber suspension with the mass concentration of 0.8-3% with a cross-linking agent, and stirring the mixture at the pH value of 5-8 and the temperature of 25-45 ℃ for a cross-linking reaction for 4-24 hours to prepare a cross-linked collagen fiber suspension, wherein the mass ratio of the solid content in the collagen fiber suspension to the cross-linking agent is 1 (0.08-0.4); wherein the cross-linking agent is one of glutaraldehyde, catechin, myrica tannin extract, larch tannin extract and genipin.

(3) Adding 0.5-3% by mass of MXene dispersion liquid into the obtained crosslinked collagen fiber suspension, adjusting the pH value to 3-5, and stirring for 0.5-2 h to obtain MXene/collagen fiber composite suspension liquid, wherein the mass ratio of the solid content in the crosslinked collagen fiber suspension liquid to the solid content in the MXene dispersion liquid is 1 (0.3-0.7);

(4) and (3) putting the obtained MXene/collagen fiber composite suspension into an appliance, and freeze-drying at-40 to-20 ℃ and 0.1Pa for 12-48 h to obtain the collagen fiber-based flexible pressure sensing material with a spongy porous structure.

Specifically, the shape of the obtained collagen fiber-based flexible pressure sensing material can be a cuboid, a cylinder and other shapes, and the specific shape is changed according to the appliance for containing the suspension during freeze drying.

Specifically, in the embodiment of the invention, the sensitivity of the obtained collagen fiber-based flexible pressure sensing material in pressure sensing is 30.58-61.99 KPa^-1The response time is 0.09-0.5s, the sensing detection range is 0-20 KPa, and the air permeability is 47.9% -58.5%.

Wherein the air permeability test operation comprises: filling a certain amount of distilled water in the wide-mouth bottle, and sealing the mouth of the wide-mouth bottle by using the obtained collagen fiber-based flexible pressure sensing material; standing at room temperature (20-30 ℃, 50-70 RH%) for 24h, and calculating the air permeability by taking the unsealed opening as a control; air permeability is 24h water loss/24 h contrast water loss x 100%.

Example 1:

the preparation method comprises the steps of selecting sheep skin collagen fibers as a base material, mixing 10g of collagen fiber suspension with the mass concentration of 0.8% with 0.032g of 25% glutaraldehyde aqueous solution (the mass ratio of the solid content in the collagen fiber suspension to a crosslinking agent is 1:0.4) at the pH value of 5.5, stirring at 25 ℃ for 4h, and stirring at 45 ℃ for 4h to obtain the crosslinked collagen fiber suspension. Adding 1.4 mass percent of Ti into the obtained cross-linked collagen fiber suspension₃C₂3.14g of dispersion liquid (the mass ratio of the solid content in the crosslinked collagen fiber suspension to the solid content in the MXene dispersion liquid is 1:0.5), fully mixing, adjusting the pH value to 3, stirring for 1h to obtain Ti₃C₂Collagen fiber composite suspension. Subjecting the obtained Ti to₃C₂The/collagen fiber composite suspension is put into a 25mL beaker and is frozen and dried for 24h at the temperature of minus 30 ℃ and the pressure of 0.1Pa, and the collagen fiber-based flexible pressure sensing material with a spongy porous structure is obtainedThe SEM image is shown in FIG. 3. As can be seen from fig. 3, the collagen fiber-based flexible pressure sensing material is a porous structure with MXene wrapped collagen fibers.

And connecting copper sheets at two ends of the obtained collagen fiber-based flexible pressure sensing material through conductive silver paste, connecting the copper sheets to a digital source meter through a lead, and recording the current change under the action of pressure. FIG. 4 shows the current change rate of the sensing material under different pressures at a voltage of 1V, and it can be seen from the graph that the current response of the collagen fiber-based flexible pressure sensing material is different under different pressures, so the current change rate is different, and the sensitivity is as high as 61.99KPa^-1The pressure in the range of 0 to 3KPa can be detected. Fig. 5 shows the current change of the collagen fiber-based flexible pressure sensing material under the same pressure, which proves that the collagen fiber-based flexible pressure sensing material has good sensing performance. FIG. 6 is an enlarged view of 18.8-20 s in FIG. 5, showing that the response time of the collagen fiber-based flexible pressure sensing material is 0.15 s. The air permeability of the obtained collagen fiber-based flexible pressure sensing material is 58.5%.

Example 2:

selecting oxhide collagen fibers as a base material, mixing 10g of collagen fiber suspension with the mass concentration of 1% with 0.012g of genipin (the mass ratio of the solid content in the collagen fiber suspension to the cross-linking agent is 1:0.12) at the pH value of 6, and stirring for 24h at the temperature of 25 ℃ to prepare the cross-linked collagen fiber suspension. Adding Mo with the mass fraction of 0.5 percent into the obtained cross-linked collagen fiber suspension₂Ti₂C₃8.96g of dispersion liquid (the mass ratio of the solid content in the crosslinked collagen fiber suspension to the solid content in the MXene dispersion liquid is 1:0.4), fully mixing, adjusting the pH value to 5, stirring for 1.5h to obtain Mo₂Ti₂C₃Collagen fiber composite suspension. The obtained Mo₂Ti₂C₃And putting the/collagen fiber composite suspension into a 25mL beaker, and freeze-drying for 40h at-40 ℃ and 0.1Pa to obtain the collagen fiber-based flexible pressure sensing material with the spongy porous structure. The sensitivity of the obtained collagen fiber-based flexible pressure sensing material is 30.58KPa^-1The pressure in the range of 0-20 KPa can be detected, the response time is 0.5s, and the air permeability is 56.3%.

Example 3:

selecting pigskin collagen fiber as a base material, mixing 5g of collagen fiber suspension with the mass concentration of 3% with 0.012g of catechin (the mass ratio of the solid content in the collagen fiber suspension to the cross-linking agent is 1:0.08) at the pH value of 5, and stirring for 10h at 35 ℃ to prepare the cross-linked collagen fiber suspension. Adding Ti with the mass fraction of 0.78 percent into the obtained cross-linked collagen fiber suspension₂C dispersion liquid 5.7g (mass ratio of solid content in cross-linked collagen fiber suspension liquid to solid content in MXene dispersion liquid is 1:0.3), fully mixing, adjusting pH value to 4, stirring for 0.5h to obtain Ti₂C/collagen fiber composite suspension. Subjecting the obtained Ti to₂And (3) putting the C/collagen fiber composite suspension into a 25mL beaker, and freeze-drying for 48h at-20 ℃ and 0.1Pa to obtain the collagen fiber-based flexible pressure sensing material with the spongy porous structure. The sensitivity of the obtained collagen fiber-based flexible pressure sensing material is 45.24KPa^-1The pressure in the range of 0-2 KPa can be detected, the response time is 0.09s, and the air permeability is 47.9%.

Example 4:

selecting sheep skin collagen fibers as a base material, mixing 10g of collagen fiber suspension with the mass concentration of 0.9% with 0.018g of myrica rubra extract (the mass ratio of the solid content in the collagen fiber suspension to the cross-linking agent is 1:0.2) at the pH value of 7, and stirring for 4h at 45 ℃ to prepare the cross-linked collagen fiber suspension. Adding 1.3 mass percent of Mo into the obtained cross-linked collagen fiber suspension₂3.323g of C dispersion liquid (the mass ratio of the solid content in the crosslinked collagen fiber suspension to the solid content in the MXene dispersion liquid is 1:0.4), fully mixing, adjusting the pH value to 3, stirring for 2h to obtain Mo₂C/collagen fiber composite suspension. Subjecting the obtained Ti to₃C₂And putting the/collagen fiber composite suspension into a 25mL beaker, and freeze-drying the suspension for 30h at-35 ℃ and 0.1Pa to obtain the collagen fiber-based flexible pressure sensing material with the spongy porous structure. The sensitivity of the obtained collagen fiber-based flexible pressure sensing material is 57.58KPa^-1The pressure in the range of 0-20 KPa can be detected, the response time is 0.25s, and the air permeability is 51.7%.

Example 5:

selecting and using oxhide glueThe fibril was used as a base material, and 8g of a collagen fiber suspension having a mass concentration of 1% was mixed with 0.0096g of larch tannin extract at a pH of 8 (the mass ratio of the solid content in the collagen fiber suspension to the crosslinking agent was 1:0.12), and the mixture was stirred at 30 ℃ for 20 hours to prepare a crosslinked collagen fiber suspension. Adding 2.1 mass percent of Mo into the obtained cross-linked collagen fiber suspension₂TiC₂2.987g of dispersion (the mass ratio of the solid content in the crosslinked collagen fiber suspension to the solid content in the MXene dispersion is 1:0.7), fully mixing, adjusting the pH value to 3.5, stirring for 1.5h to obtain Mo₂TiC₂Collagen fiber composite suspension. The obtained Mo₂Ti₂C₃And putting the/collagen fiber composite suspension into a 25mL beaker, and freeze-drying for 36h at-40 ℃ and 0.1Pa to obtain the collagen fiber-based flexible pressure sensing material with the spongy porous structure. The sensitivity of the obtained collagen fiber-based flexible pressure sensing material is 52.76KPa^-1The pressure in the range of 0-20 KPa can be detected, the response time is 0.4s, and the air permeability is 48.1%.

Example 6:

selecting pigskin collagen fibers as a base material, mixing 10g of collagen fiber suspension with the mass concentration of 3% with 0.036g of catechin (the mass ratio of the solid content in the collagen fiber suspension to the cross-linking agent is 1:0.12) at the pH value of 5, stirring at 35 ℃ for 12h, and stirring at 45 ℃ for 12h to obtain the cross-linked collagen fiber suspension. Adding 3 percent of Ti by mass into the obtained cross-linked collagen fiber suspension₂4.48g of C dispersion liquid (the mass ratio of the solid content in the crosslinked collagen fiber suspension to the solid content in the MXene dispersion liquid is 1:0.4), fully mixing, adjusting the pH value to 4, stirring for 1h, and obtaining Ti₂C/collagen fiber composite suspension. Subjecting the obtained Ti to₂And (3) putting the C/collagen fiber composite suspension into a 25mL beaker, and freeze-drying for 48h at-30 ℃ and 0.1Pa to obtain the collagen fiber-based flexible pressure sensing material with the spongy porous structure. The sensitivity of the obtained collagen fiber-based flexible pressure sensing material is 49.81KPa^-1The pressure in the range of 0-5 KPa can be detected, the response time is 0.1s, and the air permeability is 53.4%.

Specifically, in the above examples of the present invention, the MXene dispersion was prepared using water as a solvent.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.