阅读说明：本技术 基于混配位纳米薄膜的柔性弯曲传感装置及其制备方法 (Flexible bending sensing device based on mixed position nano film and preparation method thereof ) 是由 张希 王旭晟 刁东风 于 2020-12-09 设计创作，主要内容包括：本发明提供一种基于混配位纳米胶体的柔性弯曲传感装置及其制备方法,柔性弯曲传感装置中的柔性弯曲传感器的混配位纳米薄膜传感层的组分包括混配位金属碳纳米薄膜粉末、液态硅橡胶和聚乙烯吡咯烷酮。混配位金属碳纳米结构在硅橡胶内组成导电网络,当柔性弯曲传感器受到拉伸之后,混配位纳米薄膜传感层内的金属碳纳米颗粒与石墨烯纳晶键合位错滑移,导致混配位熵增效应,使得导电网络的电阻发生较大变化。通过测量柔性弯曲传感器在弯曲过程中的电压变化信号,准确测量柔性弯曲传感器的弯曲角度,同时柔性弯曲传感器具有较好的拉伸性和耐用性,适用于多种应用场景。(The invention provides a flexible bending sensing device based on mixed position nano colloid and a preparation method thereof. The mixed coordination metal carbon nano structure forms a conductive network in the silicon rubber, and when the flexible bending sensor is stretched, metal carbon nano particles in the mixed coordination nano film sensing layer and graphene nano crystal are bonded, dislocated and slipped, so that a mixed coordination entropy increase effect is caused, and the resistance of the conductive network is greatly changed. The bending angle of the flexible bending sensor is accurately measured by measuring the voltage change signal of the flexible bending sensor in the bending process, and meanwhile, the flexible bending sensor has better stretchability and durability and is suitable for various application scenes.)

1. A flexible bend sensing device based on a mixed-position nano film, comprising:

the flexible bending sensor comprises a substrate, a mixed-position nano-film sensing layer arranged on the substrate and an electrode arranged on the mixed-position nano-film sensing layer, wherein the mixed-position nano-film sensing layer comprises mixed-position metal carbon nano-film powder, liquid silicone rubber and polyvinylpyrrolidone;

a rectifying and amplifying unit connected to the electrode;

and the signal output unit is connected with the rectification amplification unit.

2. The flexible bend sensing device of claim 1 wherein the composition of the mixed-coordination nanofilm sensing layer further comprises nanosilver flakes.

3. The flexible bend sensing device of claim 1, wherein the mixed coordination metal carbon nano-film powder comprises metal carbon compound particles and graphene nanocrystals rich in edge states, and the metal carbon compound particles are connected with the graphene nanocrystals through chemical bonding.

4. The flexible bend sensing device of claim 1, wherein the pattern of the mixed-coordination nano-thin film sensing layer comprises a parallel bar pattern, a connection line, and a fold line pattern, the parallel bar pattern and the fold line pattern being connected by the connection line.

5. The flexible bend sensing device of claim 1, wherein the substrate is a PDMS flexible substrate, a PBAT flexible substrate, or a fabric substrate.

6. A method of making a compound-site nanocolloid-based flexible bend sensing device as defined in any one of claims 1 to 5, comprising:

growing a mixed-position metal carbon nano film on a silicon substrate, peeling the mixed-position metal carbon nano film from the silicon substrate, and then grinding to obtain mixed-position metal carbon nano film powder;

uniformly mixing the mixed-site metal carbon nano film powder, liquid silicon rubber and polyvinylpyrrolidone according to a preset proportion to obtain mixed-site metal carbon nano colloid;

forming a mixed coordination nano film sensing layer on the substrate by adopting the mixed coordination metal carbon nano colloid, and forming an electrode on the mixed coordination nano film sensing layer to obtain the flexible bending sensor; providing a rectification amplification unit, and connecting the rectification amplification unit with an electrode of the flexible bending sensor;

and providing a signal output unit, and connecting the signal output unit with the rectifying and amplifying unit.

7. The preparation method of claim 6, wherein the growing of the mixed coordination metal carbon nano-film on the silicon substrate comprises:

in the vacuum cavity, microwave plasma is used as an irradiation electron source, and a mixed metal carbon nano film is grown on the silicon substrate through direct current magnetron sputtering of the carbon target material and the metal target material.

8. The method according to claim 7, wherein the substrate bias voltage in the vacuum chamber is +0 to 80V, and the current density is 100 to 110mA/cm²The electron flux is (1.25-1.34) x 10²¹mm^-2s^-1。

9. The preparation method according to claim 6, wherein the mass ratio of the mixed coordination metal carbon nano-film powder to the liquid silicone rubber to the polyvinylpyrrolidone is 40-50: 1: 45-55.

10. The method for preparing a sensor layer according to claim 6, wherein the step of forming a mixed-site nano-film sensor layer on a substrate by using the mixed-site metal carbon nano-colloid comprises:

arranging a mask on a substrate, and coating the mixed-position metal carbon nano colloid on the mask to obtain a mixed-position metal carbon nano colloid film;

and curing the mixed-position metal carbon nano colloid film at the temperature of 70-120 ℃ for 25-35 min to form a mixed-position nano film sensing layer on the substrate.

Technical Field

The invention relates to the field of film technology and application and wearable life health equipment, in particular to a flexible bending sensing device based on a mixed position nano film and a preparation method thereof.

Background

At present, photoelectric, resistance-type and capacitance-type flexible sensors have already realized the detection of physiological parameters such as human motion and blood oxygen concentration, and because it has good tensile property, can have better compatibility with the human body, and flexible sensor possesses good detection precision simultaneously, and flexible sensor has very big application potential in wearable field. However, the current research on the flexible sensor still has limitations, on one hand, in order to achieve higher detection accuracy, a part of the flexible sensor needs to adopt a structure with poor tensile property, and on the other hand, the durability of the part of the flexible sensor is poor, and the detection accuracy is reduced after the deformation times reach a certain degree. Thus, the application and popularization of the wearable flexible sensor which is high in precision, high in stretchability and capable of being worn for a long time are hindered. The field of the existing wearable sensor urgently needs a flexible sensor which is simple and convenient to prepare, simple in structure, good in tensile property, repeatability and high in detection precision.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a flexible bending sensor device based on a mixed-position nano colloid and a preparation method thereof, and aims to realize that the flexible bending sensor has better stretchability and durability while improving the detection precision.

The technical scheme of the invention is as follows:

a flexible bend sensing device based on co-location nanofilms, comprising:

the flexible bending sensor comprises a substrate, a mixed-position nano-film sensing layer arranged on the substrate and an electrode arranged on the mixed-position nano-film sensing layer, wherein the mixed-position nano-film sensing layer comprises mixed-position metal carbon nano-film powder, liquid silicone rubber and polyvinylpyrrolidone;

a rectifying and amplifying unit connected to the electrode;

and the signal output unit is connected with the rectification amplification unit.

The flexible bending sensing device is characterized in that the components of the mixed coordination nano film sensing layer further comprise nano silver sheets.

The flexible bending sensing device is characterized in that the mixed coordination metal carbon nano film powder comprises metal carbon compound particles and graphene nanocrystals in rich edge states, and the metal carbon compound particles are bonded and connected with the graphene nanocrystals through chemical bonds.

The flexible bending sensing device is characterized in that the patterns of the mixed coordination nano thin film sensing layer comprise parallel connection strip patterns, connecting lines and fold line patterns, and the parallel connection strip patterns are connected with the fold line patterns through the connecting lines.

The flexible bending sensing device is characterized in that the substrate is a PDMS flexible substrate, a PBAT flexible substrate or a fabric substrate.

The preparation method of the flexible bending sensing device based on the mixed-position nano colloid is characterized by comprising the following steps:

growing a mixed-position metal carbon nano film on a silicon substrate, peeling the mixed-position metal carbon nano film from the silicon substrate, and then grinding to obtain mixed-position metal carbon nano film powder;

uniformly mixing the mixed-site metal carbon nano film powder, liquid silicon rubber and polyvinylpyrrolidone according to a preset proportion to obtain mixed-site metal carbon nano colloid;

forming a mixed coordination nano film sensing layer on the substrate by adopting the mixed coordination metal carbon nano colloid, and forming an electrode on the mixed coordination nano film sensing layer to obtain the flexible bending sensor;

providing a rectification amplification unit, and connecting the rectification amplification unit with an electrode of the flexible bending sensor;

and providing a signal output unit, and connecting the signal output unit with the rectifying and amplifying unit.

The preparation method, wherein the growing of the mixed coordination metal carbon nano film on the silicon substrate comprises:

in the vacuum cavity, microwave plasma is used as an irradiation electron source, and a mixed metal carbon nano film is grown on the silicon substrate through direct current magnetron sputtering of the carbon target material and the metal target material.

In the preparation method, the substrate bias voltage is + 0-80V, and the current density is 100-110 mA/cm in the vacuum cavity²The electron flux is (1.25-1.34) x 10²¹mm^-2s^-1。

The preparation method comprises the step of mixing and coordinating metal carbon nano-film powder, the liquid silicon rubber and the polyvinylpyrrolidone according to a mass ratio of 40-50: 1: 45-55.

The preparation method, wherein the forming of the mixed-coordination nano-film sensing layer on the substrate by using the mixed-coordination metal carbon nano-colloid, comprises:

arranging a mask on a substrate, and coating the mixed-position metal carbon nano colloid on the mask to obtain a mixed-position metal carbon nano colloid film;

and curing the mixed-position metal carbon nano colloid film at the temperature of 70-120 ℃ for 25-35 min to form a mixed-position nano film sensing layer on the substrate.

Has the advantages that: the invention provides a flexible bending sensing device based on mixed position nano colloid and a preparation method thereof. The mixed coordination metal carbon nano structure forms a conductive network in the silicon rubber, and when the flexible bending sensor is stretched, metal carbon nano particles in the mixed coordination nano film sensing layer and graphene nano crystal are bonded, dislocated and slipped, so that a mixed coordination entropy increase effect is caused, and the resistance of the conductive network is greatly changed. The bending angle of the flexible bending sensor is accurately measured by measuring the voltage change signal of the flexible bending sensor in the bending process, and meanwhile, the flexible bending sensor has better stretchability and durability and is suitable for various application scenes.

Drawings

Fig. 1 is a schematic structural diagram of a flexible bending sensing device based on mixed-site nanocolloid.

Fig. 2 is a schematic flow chart of the manufacturing process of the flexible bending sensor of the present invention.

Fig. 3 is a graph showing a variation of resistance value with respect to a stretching ratio during the stretching process of the flexible bending sensor according to the present invention.

FIG. 4 is a schematic view of the microstructure of a co-sited nano-film sensing layer under unstretched and stretched conditions, respectively

Fig. 5 is a graph showing a variation of resistance value with respect to a bending angle during bending of the flexible bending sensor according to the present invention.

FIG. 6 is a curve showing the variation of resistance with the stretching process of the flexible bending sensor of the present invention in the stretching processes from 401 to 406.

Fig. 7 is a graph showing the variation of resistance with the stretching process of the flexible bending sensor according to the present invention after 1000 times of stretching.

Detailed Description

The invention provides a flexible bending sensing device based on mixed-position nano colloid and a preparation method thereof, and the invention is further described in detail below in order to make the purpose, technical scheme and effect of the invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, the present invention provides a flexible bending sensing device based on mixed nano-colloids, comprising:

the flexible bending sensor 10 comprises a substrate 11, a mixed coordination nano-film sensing layer 12 arranged on the substrate and electrodes arranged on the mixed coordination nano-film sensing layer 12, wherein the mixed coordination nano-film sensing layer 12 comprises mixed coordination metal carbon nano-film powder, liquid silicone rubber and polyvinylpyrrolidone;

a rectifying and amplifying unit 20, wherein the rectifying and amplifying unit 20 is connected with the electrode;

and a signal output unit 30, wherein the signal output unit 30 is connected with the rectifying and amplifying unit 20.

Specifically, when the flexible bending sensor is bent, the resistance value of the flexible bending sensor changes and is reflected as a change signal of a voltage value, and the signal is collected and stored by the signal collecting unit after being processed by the rectifying and amplifying unit, so that the bending angle is accurately and stably measured. The mixed coordination metal carbon nano-film powder comprises metal carbon compound particles and graphene nano-crystals rich in edge states. The mixed coordination metal carbon nano film powder is obtained by grinding a mixed coordination metal carbon nano film, edge-rich graphene nano crystals and mixed coordination chemically-bonded metal carbon compound particles grow on the surface of a silicon substrate through double-target sputtering of microwave sputtering and direct-current magnetron sputtering by taking microwave plasma as an irradiation electron source, so that the mixed coordination metal carbon nano film with an ultra-smooth surface is formed, and the metal carbon compound particles and the edge-rich graphene nano crystals are connected through chemical bond bonding instead of common doping.

The mixed-position metal carbon nano film powder, the liquid silicon rubber and the polyvinylpyrrolidone are mixed to obtain the mixed-position nano film sensing layer, mixed-position metal carbide particles and the graphene nano crystals in the mixed-position metal carbon nano film powder can form a conductive network in a silicon rubber grid, when the sensor is stretched or bent, the conductive network is deformed and stretched, the contact condition of part of conductive paths is changed, the metal carbon nano particles and the graphene nano crystals are bonded and dislocated, the mixed-position entropy increase effect is caused, and the integral resistance value of the conductive network is changed. By measuring the resistance change, the angular bending can be measured with the flexible bending sensor. In addition, the metal carbide particles and the graphene nanocrystalline are small in cross-linked structure size and random in growth direction, so that a conductive path is formed in the silicon rubber more easily, and the number of the conductive paths is increased. Therefore, on one hand, when the flexible bending sensor is not deformed, the resistance value of the flexible bending sensor is smaller, and the energy consumption of a circuit can be reduced; on the other hand, in the deformation process, dislocation is easier to occur in a mixed position nano structure between the metal carbide particles with smaller size and the graphene nano crystal, so that the mixed position metal carbon nano film flexible bending sensor has larger response in deformation, and the response precision of the flexible bending sensor can be improved.

In one embodiment, the rectifying and amplifying unit 20 includes a blocking capacitor 22 and a two-stage rectifying operational amplifier 21, the blocking capacitor 22 is connected with the electrode, and the two-stage rectifying operational amplifier 21 is connected with the blocking capacitor 21; the signal output unit 30 includes: an analog signal output circuit 31, a digital/analog converter 32, a digital signal output circuit 33, and a bent signal output circuit 34. The electric signal generated by the flexible bending sensor 10 is subjected to signal amplification through the second-stage rectifying operational amplifier 21 after the direct current component of the electric signal is eliminated through the blocking capacitor 22, the amplified electric signal is output to the digital-to-analog converter 32 through the analog signal output circuit 31 and is converted into a digital signal through digital-to-analog conversion, the digital signal is output to the bending signal output circuit 34 through the digital signal output circuit 33, and the bending signal output circuit 34 processes the digital signal and outputs a corresponding bending angle.

In one embodiment, the components of the mixed-site nano-film sensing layer further comprise nano-silver flakes. The mixed coordination nano film sensing layer is provided with a proper amount of nano silver sheets, so that the response of the flexible bending sensor to bending can be improved, and the detection precision is further improved.

In one embodiment, the pattern of the mixed-site nano-film sensing layer comprises a parallel bar pattern, a connecting line and a fold line pattern, wherein the parallel bar pattern and the fold line pattern are connected through the connecting line.

Specifically, referring to fig. 2, the pattern of the mixed-position nano-film sensing layer includes a parallel bar pattern, a connecting line, and a fold line pattern, the parallel bar pattern is formed by connecting a plurality of bar lines in parallel, the fold line pattern is formed by connecting a plurality of fold lines, the parallel bar pattern is located in the middle of the mixed-position nano-film sensing layer, the fold line pattern is located at two sides of the parallel bar pattern, the parallel bar pattern and the fold line pattern are connected in series through the connecting line, and electrodes are prepared at two ends of the series connection. The parallel strip-shaped patterns play a main sensing role, the bending curvature of the parallel strip-shaped patterns is maximum, and the number of conductive paths can be increased by arranging a plurality of strip-shaped lines in parallel, so that the response is improved; the fold line pattern has the function of improving the mechanical strength of the device, and meanwhile, after the fold line pattern is stretched, the mixed position entropy increase generated in the conductive path is smaller, so that the resistance change is smaller, and the fold line pattern is suitable for serving as a circuit; the connecting wire functions as a lead wire, and the metal electrode is used for being connected with the conductive lead.

In one embodiment, the substrate is a PDMS flexible substrate, a PBAT flexible substrate, or a fabric substrate.

In one embodiment, the present invention further provides a method for preparing a flexible bending sensor device based on mixed-site nanocolloid, wherein the method comprises the following steps:

s10, growing a mixed-position metal carbon nano film on a silicon substrate, peeling the mixed-position metal carbon nano film from the silicon substrate, and then grinding to obtain mixed-position metal carbon nano film powder;

s20, uniformly mixing the mixed metal carbon nano film powder with liquid silicon rubber and polyvinylpyrrolidone according to a preset proportion to obtain mixed metal carbon nano colloid;

s30, forming a mixed-coordination nano-film sensing layer on the substrate by adopting the mixed-coordination metal carbon nano-colloid, and forming an electrode on the mixed-coordination nano-film sensing layer to obtain the flexible bending sensor;

s40, providing a rectifying and amplifying unit, and connecting the rectifying and amplifying unit with the electrode of the flexible bending sensor;

and S50, providing a signal output unit, and connecting the signal output unit with the rectification amplification unit.

Specifically, referring to fig. 2, a microwave plasma magnetron sputtering technique is used, plasma generated by microwave induction is used as an irradiation electron source, the electron density in the vacuum chamber is controlled, and a mixed metal carbon nano-film is grown on the surface of the cavity-type silicon substrate by sputtering a metal target material and a carbon target material with direct current. The ultrahigh electron flux induces and grows a large amount of edge-state-rich graphene nano crystals, the edges of the graphene nano crystals have higher energy, and the nucleation of metal carbide particles is facilitated, so that the metal carbide particles mostly start to grow in a mixed position from the edges of the graphene nano crystals. On one hand, the growth of the metal carbide particles is the chemical bonding of metal and carbon, and the growth rate of the graphene nanocrystals is influenced, so that the size of the graphene nanocrystals is reduced; on the other hand, the metal carbide particles can be used as a good catalyst for the growth of the graphene nano-crystal, the directional growth condition of the graphene nano-crystal can be changed, and based on the effects of the two aspects, the mixed site structure of the metal carbide particles and the graphene nano-crystal forms a special mixed site metal carbon nano-film with an ultra-smooth surface.

And then stripping the mixed-position metal carbon nano film from the silicon substrate by adopting a mechanical vibration stripping method through an electric carving knife, grinding the mixed-position metal carbon nano film into uniform mixed-position metal carbon nano film powder through a grinding tool, fully and uniformly stirring the liquid silicon rubber for 10min, adding the mixed-position metal carbon nano film powder and polyvinylpyrrolidone into the liquid silicon rubber, and fully stirring the mixture for 30min to obtain the mixed-position metal carbon nano film colloid. And finally, carrying out spin coating on the mixed-position metal carbon nano film colloid on the flexible substrate to form a mixed-position nano film sensing layer, forming an electrode on the mixed-position nano film sensing layer, and preparing a metal positive electrode and a metal negative electrode on the mixed-position nano film sensing layer by adopting a magnetron sputtering or ultraviolet lithography technology to obtain the flexible bending sensor.

And finally, connecting the rectification amplification unit with the electrode, and connecting the signal output unit with the rectification amplification unit.

Further, the step S30 includes:

s31, arranging a mask on the substrate, and coating the mixed-position metal carbon nano colloid on the mask to obtain a patterned mixed-position metal carbon nano colloid film;

s32, curing the patterned mixed-position metal carbon nano colloid film at the temperature of 70-120 ℃ for 25-35 min, and forming a mixed-position nano thin film sensing layer on the substrate.

Specifically, referring to fig. 2, the mixed metal carbon nano-film colloid is printed into a mixed nano-film sensing layer with a preset structure by using a mask and a layered printing method. The method comprises the steps of covering a steel mask plate with a hollowed preset pattern on a substrate, then coating mixed-position metal carbon nano film colloid on the steel mask plate to enable the colloid to be filled into the hollowed pattern, and scraping redundant colloid by using a film scraping knife to obtain the patterned mixed-position metal carbon nano film. And (3) after the steel mask plate is removed, placing the patterned mixed-position metal carbon nano colloid film on a heating platform, heating to 70-120 ℃, and preserving heat for 25-35 minutes (preferably, preserving heat for 30 minutes at 100 ℃), so that the mixed-position metal carbon nano colloid film is cured, and a mixed-position nano film sensing layer is formed on the substrate.

The mixed coordination nano thin film sensing layer comprises two groups of parallel strip-shaped patterns, connecting lines and fold line patterns, the parallel strip-shaped patterns are formed by connecting a plurality of strip lines in parallel, the fold line patterns are formed by a plurality of fold lines, the parallel strip-shaped patterns are positioned in the middle of the mixed coordination nano thin film sensing layer, the fold line patterns are positioned on two sides of the parallel strip-shaped patterns, the parallel strip-shaped patterns and the fold line patterns are formed by connecting the connecting lines in series, and metal electrodes are prepared at two ends of the series connection. The parallel strip-shaped patterns positioned in the middle of the mixed position nano film sensing layer play a main sensing role, the bending curvature of the parallel strip-shaped patterns is maximum, and the number of conductive paths can be increased through the parallel arrangement of a plurality of strip-shaped lines, so that the response is improved; the fold line pattern has the function of improving the mechanical strength of the device, and meanwhile, after the fold line pattern is stretched, the mixed position entropy increase generated in the conductive path is smaller, so that the resistance change is smaller, and the fold line pattern is suitable for serving as a circuit; the metal electrode is used for being connected with the conductive lead.

In one embodiment, the substrate bias voltage in the vacuum chamber is + 0-80V, and the ultrahigh current density is 100-110 mA/cm²The ultra-high electron flux is (1.25-1.34) x 10²¹mm^-2s^-1. Preferably, the substrate bias voltage is + 0-80V, and the ultrahigh current density is 100mA/cm²Ultrahigh electron flux of 1.25X 10²¹mm^-2s^-1So that the prepared coordination metal carbon nano film has better conductivity.

In one embodiment, the preset ratio is that the mass ratio of the metal carbon nano-film powder to the liquid silicone rubber to the polyvinylpyrrolidone is 40-50: 1: 45-55.

Specifically, the adding proportion of the mixed metal carbon nano film powder, the liquid silicon rubber and the polyvinylpyrrolidone affects the measurement accuracy and the tensile property of the flexible bending sensor, if the metal carbon nano film powder is too much, the tensile property of the flexible bending sensor is reduced, and if the metal carbon nano film powder is too much and too little, the response accuracy of the sensor is affected, so that the flexible bending sensor with better tensile property and higher response accuracy can be obtained by setting a proper configuration proportion. Preferably, the preset proportion is that the mass ratio of the mixed metal carbon nano film powder to the liquid silicon rubber to the polyvinylpyrrolidone is 44:1:50

Furthermore, a proper amount of nano silver sheets can be added into the obtained mixed-position metal carbon nano colloid to improve the response of the flexible bending sensor to bending and improve the detection precision. Preferably, the mass ratio of the mixed metal carbon nano film powder to the liquid silicon rubber to the polyvinylpyrrolidone to the nano silver sheet is 44:1:50: 5.

The flexible bending sensor prepared in this example was subjected to a tensile test, a bending test, and a durability test to test its tensile property, bending property, and durability, specifically as follows:

under the original state of the flexible bending sensor, the original resistance value R of the flexible bending sensor is measured₀。

In the tensile test, the flexible bending sensor is placed on a uniaxial tensile testing machine, and the resistance value R of the flexible bending sensor under different bending angles is measured₁And subtracting the original resistance value to obtain a resistance change value delta R, and the resistance change value delta R/R of the flexible bending sensor₀The change with the stretching ratio is shown in fig. 3, and it can be seen from fig. 3 that the resistance change value increases with the increase of the stretching ratio, and the resistance change is obvious at different stretching ratios. The maximum elongation of the flexible bending sensor according to the invention can be up to 300% (not shown in fig. 3). FIG. 4 is a schematic view of the microstructure of a flexible bend sensor in unstretched and stretched conditions, respectively, as can be seenWhen stretched, the distance between the co-located metallic carbon nano-film powder particles increases, which may result in an increase in electrical resistance.

In the bending test, a flexible bending sensor is placed on a uniaxial bending test machine, and the resistance change value delta R/R₀The variation with the bending angle θ is shown in fig. 5. As can be seen from fig. 5, the resistance change value increases with the increase of the bending angle, and the resistance change value is more obvious at different bending angles.

In the durability test, the flexible bending sensor was placed on a uniaxial tensile tester, stretched from an original length to 100%, and then restored to the original length, and a real-time resistance value was recorded, and repeated 1000 times, to measure the durability and response stability of the flexible bending sensor, and the results are shown in fig. 6 and 7. As can be seen from fig. 6, the flexible bending sensor of the present embodiment has stable stretching performance, the rate of change in the resistance change value remains stable after 400 stretches, and as can be seen from fig. 7, the change in the resistance change value hardly changes during 1000 stretches. The flexible bending sensor can still keep higher corresponding stability and has better durability.

In summary, the present invention provides a flexible bending sensing device based on mixed nano colloid and a preparation method thereof, wherein the components of the mixed nano film sensing layer of the flexible bending sensor in the flexible bending sensing device include mixed metal carbon nano film powder, liquid silicone rubber and polyvinylpyrrolidone. The mixed coordination metal carbon nano structure forms a conductive network in the silicon rubber, and when the flexible bending sensor is stretched, metal carbon nano particles in the mixed coordination nano film sensing layer and graphene nano crystal are bonded, dislocated and slipped, so that a mixed coordination entropy increase effect is caused, and the resistance of the conductive network is greatly changed. The bending angle of the flexible bending sensor is accurately measured by measuring the voltage change signal of the flexible bending sensor in the bending process, and meanwhile, the flexible bending sensor has better stretchability and durability and is suitable for various application scenes.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.