Flexible Sensor and Its Design Method

Abstract

The present invention provides a flexible sensor, which relates to the technical field of sensor devices and includes a flexible substrate and a sensing component. The flexible substrate is provided with accommodation cavities, and each accommodation cavity protrudes from one end face of the flexible substrate. Each sensing component is disposed in each accommodation cavity, and the outer wall of each sensing component matches and contacts the inner wall of each accommodation cavity. The resistance value of each sensing component can change with the deformation of each sensing component. The test accuracy is high. Its design method is as follows: fabricate a sensing component specimen to obtain the stress-strain experimental data of the specimen; create a three-dimensional model of the flexible sensor, and the sensing component in the three-dimensional model has the same three-dimensional shape as the specimen; obtain the parameters of the stress-strain function of the specimen through the stress-strain experimental data; apply the parameters of the stress-strain function to the three-dimensional model of the flexible sensor for finite element analysis to obtain the stress distribution of each part of the three-dimensional model under different strains and predict its mechanical properties under various deformations.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor devices, and particularly to a flexible sensor and a design method thereof. Background Art

[0002] At present, with the rapid development of intelligent technologies of industrial products such as robots, the technical research in related fields has also become the focus of people's attention. Precise and rapid perception of the external environment is the basis of intelligence, and flexible sensors are an important means to achieve this function. Integrating flexible sensors into wearable devices to predict users' physiological parameters and quickly and accurately make health assessments, or enabling intelligent robots to more flexibly and comprehensively complete human-computer interaction through wearing such flexible electronic bionic skins. Therefore, the application fields of flexible sensors are very extensive, such as sports, games, medical treatment, military, and scientific research. Graphene, as a new type of two-dimensional nanomaterial, exhibits excellent physical and chemical properties due to its special single-atom layer structure. At the same time, three-dimensional graphene aerogel combines the dual advantages of graphene and three-dimensional network structure, and has significant advantages and broad application prospects as a flexible piezoresistive sensing material.

[0003] Most of the existing flexible sensors adopt a sandwich structure, that is, the flexible sensor is composed of an upper flexible substrate, a lower flexible substrate, and a sensing component. The upper flexible substrate, the lower flexible substrate, and the sensing component are all planar structures, and the sensor component is arranged between the upper flexible substrate and the lower flexible substrate. When the flexible sensor acts on a deformed or irregular surface, it will cause deformation of the flexible substrate, thereby pressing the sensing material and unable to accurately measure the external stress. Therefore, such a structure does not meet the application requirements for the flexible sensor to move towards skinization, and there is an urgent need to develop a flexible sensor with anti-interference performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a flexible sensor and a design method thereof to solve the problems existing in the above-mentioned prior art, with a simple structure and high test accuracy. The design method of the flexible sensor is beneficial to simplifying the design process and improving the accuracy of simulation.

[0005] To achieve the above purpose, the present invention provides the following solution:

[0006] The present invention provides a flexible sensor, including a flexible substrate and at least one sensing component. The flexible substrate is provided with at least one closed receiving cavity, each of the receiving cavities protrudes from one end face of the flexible substrate, each of the sensing components is arranged in each of the receiving cavities, and the outer wall of each of the sensing components matches and contacts the inner wall of each of the receiving cavities. The resistance value of each of the sensing components can change with the deformation of each of the sensing components.

[0007] Preferably, the flexible sensor provided by the present invention further includes a first electrode and a second electrode. There is at least one of each of the first electrode and the second electrode, and a gap is left between each of the first electrodes and each of the second electrodes. The flexible substrate includes a first substrate and a second substrate. The first substrate has the accommodation cavity, and the accommodation cavity protrudes from one end face of the first substrate. The other end of the first substrate is fixedly connected to the second substrate. One end of each of the sensing components away from the protruding direction of each of the accommodation cavities is in contact with one end of a first electrode and one end of a second electrode. The other ends of each of the first electrodes and the other ends of each of the second electrodes are in contact with one end of the second substrate close to the first substrate. The first substrate and the second substrate can clamp each of the sensing components and each of the first electrodes, and the first substrate and the second substrate can clamp each of the sensing components and each of the second electrodes.

[0008] Preferably, the flexible sensor provided by the present invention further includes at least one support component. One end of each of the support components is fixedly connected to one end of the second substrate close to the first substrate, and the other end of one of the support components is in contact with both the first electrode and the second electrode. The first substrate and the second substrate can clamp each of the sensing components, each of the first electrodes, and each of the second electrodes through each of the support components and each of the accommodation cavities.

[0009] Preferably, both the accommodation cavity and the sensing component are multiple, and the multiple accommodation cavities and the multiple sensing components are both arranged in an array.

[0010] Preferably, the flexible sensor provided by the present invention further includes a plurality of transverse wires and a plurality of longitudinal wires. A plurality of the first electrodes located in a horizontal row are connected to one transverse wire, and a plurality of the second electrodes located in a vertical row are connected in series through a plurality of longitudinal wires. Both the transverse wires and the longitudinal wires are spiral wires.

[0011] Preferably, the material of each of the sensing components is three-dimensional graphene, and the accommodation cavity is cylindrical.

[0012] The present invention also provides a design method for a flexible sensor, including:

[0013] S1: Fabricate the sensing component specimen, test and record the stress of the sensing component specimen under different strains and obtain the stress-strain experimental data of the sensing component specimen; create a three-dimensional model of the flexible sensor, and the three-dimensional shape of the sensing component in the three-dimensional model of the flexible sensor is the same as the three-dimensional shape of the sensing component specimen.

[0014] S2: Obtain the parameters of the stress-strain function of the sensing component specimen from the stress-strain experimental data of the sensing component specimen;

[0015] S3: Apply the parameters of the stress-strain function curve of the sensing component specimen to the 3D model of the flexible sensor for finite element analysis to obtain the stress distribution of each part of the 3D model of the flexible sensor under different strains;

[0016] S4: Predict the mechanical properties of the flexible sensor under various deformations based on the stress distribution of each part of the 3D model of the flexible sensor under different strains.

[0017] Preferably, S1 includes: obtaining the stress-strain experimental data of the sensing component specimen through a universal testing machine;

[0018] S2 includes: performing finite element analysis on the stress-strain experimental data of the sensing component specimen to obtain the stress-strain curve of the sensing component specimen, the stress-strain function curve of the sensing component specimen, and the parameters of the stress-strain function of the sensing component specimen.

[0019] The present invention has achieved the following technical effects compared with the prior art:

[0020] For the flexible sensor provided by the present invention, the sensing component is arranged in the accommodation cavity. When the flexible sensor deforms, the deformation mainly occurs at the connection between the accommodation cavity and the flexible substrate, and the deformation of the part protruding from the flexible substrate of the accommodation cavity is very small, which is not easy to cause compression on the built-in sensing component, so that the influence of external forces is small, thereby improving the accuracy of the test. The present invention also provides a design method for the flexible sensor. Traditional design methods all start from the compressible elastic material itself, making the compressible elastic material into different hole structures to predict the mechanical behavior of the compressible elastic material under different hole structures; this embodiment starts from the compressible elastic porous material (such as three-dimensional graphene), ignores the porous structure, and is based on the experimental data of the material under a specific hole structure to predict the mechanical changes of the compressible elastic porous material (such as three-dimensional graphene) with a specific structure. Therefore, this method does not have the disadvantages caused by the uncertainty of the porous structure and the difficulty of modeling, which is beneficial to simplifying the design process and improving the accuracy of simulation. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Schematic diagram of the structure of the flexible sensor in Example 1 (array structure);

[0023] Figure 2 Schematic diagram of the structure of the flexible sensor in Example 1 (single structure);

[0024] Figure 3 Schematic diagram of the layout of the horizontal wire and the vertical wire in Example 1;

[0025] Figure 4 Schematic diagram of the strain of the existing sandwich - structure flexible sensor in Example 1 under finite - element analysis in the state of being stretched by 2 mm;

[0026] Figure 5 Schematic diagram of the strain of the flexible sensor in Example 1 under finite - element analysis in the state of being stretched by 2 mm;

[0027] Figure 6 Schematic diagram of the strain of the existing sandwich - structure flexible sensor in Example 1 under finite - element analysis in the state of being stretched by 6 mm;

[0028] Figure 7 Schematic diagram of the strain of the flexible sensor in Example 1 under finite - element analysis in the state of being stretched by 6 mm;

[0029] Figure 8 Schematic diagram of the strain of the existing sandwich - structure flexible sensor in Example 1 under finite - element analysis in the state of being stretched by 10 mm;

[0030] Figure 9 Schematic diagram of the strain of the flexible sensor in Example 1 under finite - element analysis in the state of being stretched by 10 mm;

[0031] Figure 10 Schematic diagram of the strain of the existing sandwich - structure flexible sensor in Example 1 under finite - element analysis in the state where the arc length remains unchanged and the chord length is shortened by 2 mm;

[0032] Figure 11 Schematic diagram of the strain of the flexible sensor in Example 1 under finite - element analysis in the state where the arc length remains unchanged and the chord length is shortened by 2 mm;

[0033] Figure 12 Schematic diagram of the strain of the existing sandwich - structure flexible sensor in Example 1 under finite - element analysis in the state where the arc length remains unchanged and the chord length is shortened by 6 mm;

[0034] Figure 13 Schematic diagram of the strain of the flexible sensor in Example 1 under finite - element analysis in the state where the arc length remains unchanged and the chord length is shortened by 6 mm;

[0035] Figure 14Schematic diagram of strain of the existing sandwich - structure flexible sensor in Example 1 under the state where the arc length remains unchanged and the chord length is shortened by 10 mm in finite - element analysis;

[0036] Figure 15 Schematic diagram of strain of the flexible sensor in Example 1 under the state where the arc length remains unchanged and the chord length is shortened by 10 mm in finite - element analysis;

[0037] Figure 16 Stress - strain curve of the flexible sensor in Example 1 under 10 repeated compressions at 60% strain;

[0038] Figure 17 Stress - strain curves of the flexible sensor in Example 1 at 10%, 20%, 30%, 40%, 50%, 60%, 70% and 80% strain respectively;

[0039] Figure 18 Current - voltage curve of the flexible sensor in Example 1;

[0040] Figure 19 Current change rate of the flexible sensor in Example 1 at 5% - 80% strain;

[0041] Figure 20 Response time of the flexible sensor in Example 1;

[0042] Figure 21 Current change rate of the flexible sensor in Example 1 under 1000 consecutive compressions at 40% strain;

[0043] Figure 22 Resistance change rate curves of the flexible sensor in Example 1 when stretched at different scales along the horizontal or vertical direction;

[0044] Figure 23 Resistance change rate curves of the flexible sensor in Example 1 when bent with different - scale chord changes and unchanged arc length along the horizontal or vertical direction;

[0045] Figure 24 Stress - strain experimental curve and stress - strain function curve (fitting curve) of the flexible sensor in Example 2;

[0046] Figure 25 Stress - strain experimental data (experimental curve) and stress - strain curve (fitting curve) diagram of the sensing component specimen in Example 2;

[0047] In the figure: 100 - flexible sensor, 1 - flexible substrate; 101 - first substrate; 102 - second substrate; 2 - sensing component; 3 - accommodation cavity; 4 - first electrode; 5 - second electrode; 6 - support component; 7 - lateral wire; 8 - longitudinal wire. Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] The purpose of the present invention is to provide a flexible sensor and its design method to solve the problems existing in the above-mentioned prior art, with a simple structure and high test accuracy.

[0050] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0051] Embodiment 1

[0052] As Figure 1-2 shown, this embodiment provides a flexible sensor 100, including a flexible substrate 1 and at least one sensing component 2. The flexible substrate 1 is provided with at least one closed accommodation cavity 3. Each accommodation cavity 3 protrudes from one end face of the flexible substrate 1. Each sensing component 2 is disposed in each accommodation cavity 3, and the outer wall of each sensing component 2 matches and contacts the inner wall of each accommodation cavity 3. The shape of the sensing component 2 is exactly the same as the shape of the inner wall of the accommodation cavity 3, that is, the outer wall of each sensing component 2 is in full contact with the inner wall of each accommodation cavity 3. The resistance value of each sensing component 2 can change with the deformation of each sensing component 2. By disposing the sensing component 2 in the accommodation cavity 3, when the flexible sensor 100 is deformed, the deformation mainly occurs at the connection between the accommodation cavity 3 and the flexible substrate 1. The deformation amount of the part of the accommodation cavity 3 protruding from the flexible substrate 1 is very small and is not likely to cause compression to the built-in sensing component 2, so that the influence of external forces is small, thereby improving the test accuracy. The flexible sensor 100 provided in this embodiment has a bubble film structure and can be applied to a deformed surface, with excellent anti-interference performance. Preferably, each sensing component 2 is made of a porous-structured compressible elastic material. When each sensing component 2 is squeezed, the contact area of the porous inner wall becomes larger, the number of conductive paths increases, and the resistance decreases; when the squeezing force is removed, each sensing component 2 returns to its original shape, and the resistance value changes accordingly.

[0053] The flexible sensor 100 provided in this embodiment further includes a first electrode 4 and a second electrode 5. There is at least one first electrode 4 and at least one second electrode 5. A gap is left between each first electrode 4 and each second electrode 5. The flexible substrate 1 includes a first substrate 101 and a second substrate 102. The first substrate 101 has a receiving cavity 3. The receiving cavity 3 protrudes from one end face of the first substrate 101. The other end of the first substrate 101 is fixedly connected to the second substrate 102. One end of each sensing component 2 away from the protruding direction of each receiving cavity 3 is in contact with one end of a first electrode 4 and one end of a second electrode 5. The other ends of each first electrode 4 and the other ends of each second electrode 5 are in contact with one end of the second substrate 102 close to the first substrate 101. The first substrate 101 and the second substrate 102 can clamp each sensing component 2 and each first electrode 4, and the first substrate 101 and the second substrate 102 can clamp each sensing component 2 and each second electrode 5, so as to ensure good contact between each sensing component 2 and the first electrode 4 and the second electrode 5, and avoid inaccurate test results. Preferably, both the first electrode 4 and the second electrode 5 are semi-circular conductive copper foils, and the outer edges of the first electrode 4 and the second electrode 5 do not protrude beyond the outer edge of the sensing component 2. Preferably, the projections of the outer edges of the first electrode 4 and the second electrode 5 on the second substrate 102 coincide with the outer edge of the sensing component 2.

[0054] The flexible sensor 100 provided in this embodiment further includes at least one support component 6. One end of each support component 6 is fixedly connected to one end of the second substrate 102 close to the first substrate 101. The other end of one support component 6 is in contact with both the first electrode 4 and the second electrode 5. The first substrate 101 and the second substrate 102 can clamp each sensing component 2, each first electrode 4, and each sensing component 2 and each second electrode 5 through each support component 6 and each receiving cavity 3. The support component 6 enables the first electrode 4, the second electrode 5 and the sensing component 2 to be tightly connected, preventing short circuits. Preferably, there is one support component 6.

[0055] There are multiple receiving cavities 3 and multiple sensing components 2, and the multiple receiving cavities 3 and the multiple sensing components 2 are both arranged in an array. The array structure of the flexible sensor 100 enables the flexible sensor 100 to measure large-area pressure signals.

[0056] As Figure 3 shown, the flexible sensor 100 provided in this embodiment further includes a transverse wire 7 and a longitudinal wire 8. Preferably, the transverse wire 7 and the longitudinal wire 8 are enameled wires to avoid short circuits between the transverse wire 7 and the longitudinal wire 8. There are multiple transverse wires 7 and multiple longitudinal wires 8. Multiple first electrodes 4 in a horizontal row are connected to one transverse wire 7, and multiple second electrodes 5 in a vertical row are connected in series through multiple longitudinal wires 8. Both the transverse wire 7 and the longitudinal wire 8 are spiral wires. The spiral wire structure enhances the stretchable performance of the array of the flexible sensor 100, thereby making the performance more stable.

[0057] The material of each sensing component 2 is three-dimensional graphene, and the accommodating cavity 3 is cylindrical, so that the flexible sensor 100 has good anti-interference performance.

[0058] As Figures 4-9 shown, the existing sandwich-structured flexible sensors of the same size and the flexible sensor 100 in this embodiment are respectively stretched by 2 mm, 6 mm, and 10 mm, and finite element analysis calculations are performed on the two types of flexible sensors 100. As the stretching amount increases, the strain of the sensing components 2 of the two types of flexible sensors increases, and at the same stretching amount, the strain of each sensing component 2 of the same flexible sensor 100 is equal; however, at each stretching length, each sensing component 2 in the flexible sensor 100 in this embodiment has a smaller strain; this shows that the flexible sensor 100 in this embodiment has better anti-stretching interference performance.

[0059] As Figures 10-15 shown, the existing sandwich-structured flexible sensors of the same size and the flexible sensor 100 in this embodiment are respectively subjected to bending deformations with an unchanged arc length and a chord length shortened by 2 mm, 6 mm, and 10 mm, and finite element analysis calculations are performed on the two types of flexible sensors. As the change amount of the chord length increases, the strain of the sensing components 2 of the two types of flexible sensors 100 increases; at the same stretching amount, the strain of each row of sensing components 2 perpendicular to the bending chord variable direction of the same flexible sensor 100 is equal, and the closer to the middle, the greater the strain of the sensing component 2. However, at each bending deformation state, each sensing component 2 in the flexible sensor 100 in this embodiment has a smaller strain. This shows that the flexible sensor 100 in this embodiment has better anti-bending interference performance.

[0060] As Figure 16 shown, the flexible sensor 100 in this embodiment is repeatedly compressed 10 times at 60% strain, and the stress values during the 10 compressions are recorded to obtain the stress-strain curve of the flexible sensor 100 during each compression. The stress-strain curves of the flexible sensor 100 under multiple compressions are basically the same, indicating that the flexible sensor 100 in this embodiment has good mechanical stability and compression recovery.

[0061] As Figure 17As shown, the flexible sensor 100 in this embodiment is tested under strains of 10%, 20%, 30%, 40%, 50%, 60%, 70% and 80% respectively, and stress-strain curves under each strain are obtained. It can be obtained that in the unloading stage, the stress-strain curves under each strain return to zero, indicating that the flexible sensor 100 in this embodiment does not undergo irreversible deformation under strains of 0% - 80% and has good repeatability. This shows that the flexible sensor 100 in this embodiment has good measurement effects within the strain range of 0 - 80%, and the sensing unit has a wide strain detection range.

[0062] As Figure 18 shown, by measuring the voltage and current of the flexible sensor 100 in this embodiment, the current-voltage curve of the flexible sensor 100 in this embodiment is obtained. The slope of the current-voltage curve is the resistance of the flexible sensor 100. The results show that the resistance value of the flexible sensor 100 in this embodiment is stable (a constant value), indicating that the flexible sensor 100 in this embodiment has a stable resistance value, providing a basic guarantee for accurate detection.

[0063] As Figure 19 shown, the current change rate of the flexible sensor 100 in this embodiment is tested under strains of 5% - 80%. The difference in the current change rate under different strains is clearly visible, that is, under different stresses, the flexible sensor 100 in this embodiment has significantly different response signals (current change rate), indicating that there is a one-to-one correspondence between the two, and the magnitude of the force applied to the sensor can be determined according to the response signal value. According to Ohm's law, the current change rate is proportional to the resistance change rate. Therefore, it shows that the flexible sensor 100 in this embodiment has the ability to detect different stresses or strains.

[0064] As Figure 20 shown, the response time of the flexible sensor 100 in this embodiment is tested to be 9.91 ms, indicating that the flexible sensor 100 in this embodiment has a small response time, can quickly sense the stimulus signal, and can identify signals with less action time or fast change frequency.

[0065] As Figure 21 shown, the current change rate of the flexible sensor 100 in this embodiment is tested under 40% strain and continuous compression for 1000 times. The results show that after multiple compressions, the flexible sensor 100 in this embodiment still has a stable and consistent response signal under the same strain, indicating that the flexible sensor 100 in this embodiment has good stability and reliability and can continuously detect sensing signals multiple times.

[0066] As Figure 22As shown in the figure, when the flexible sensor 100 in this embodiment is stretched at different scales along the horizontal or vertical columns, it is found that the resistance change rate of each column of sensing units perpendicular to the stretching direction is the same. As the stretching scale increases, the resistance change rate also increases.

[0067] As Figure 23 shown in the figure, when the flexible sensor 100 in this embodiment is bent with different scale chord changes and the arc length remains unchanged along the horizontal or vertical columns, it is found that the resistance change rate of each column of the flexible sensor 100 perpendicular to the chord in the bent state is the same. As the bending scale increases, the resistance change rate also increases; the closer to the middle, the greater the bending deformation, resulting in a larger resistance change rate of the flexible sensor 100 in the column closer to the middle.

[0068] As Figure 24 shown in the figure, taking the flexible sensor 100 in the array arrangement state (such as Figure 1 the state) as the test sample, test and record the voltage signal during the whole process of applying a specific stress, holding the stress, and removing the stress to any one of the flexible sensors 100 in the flexible sensor 100 in the array arrangement state; test multiple flexible sensors 100 in the flexible sensor 100 in the array arrangement state, and integrate the data to obtain its voltage waveform diagram. This waveform diagram clearly records the change of the voltage of the flexible sensor 100 during the process of applying force and removing force, indicating that the flexible sensor 100 provided in this embodiment can detect continuously changing external stimuli in real time.

[0069] Embodiment 2

[0070] As Figure 25 shown in the figure, this embodiment provides a design method for a flexible sensor 100, including:

[0071] S1: Fabricate a specimen of the sensing component 2. The sensing component 2 is preferably three-dimensional graphene. Test and record the stress of the sensing component 2 specimen under different strains and obtain the stress-strain experimental data of the sensing component 2 specimen; create a three-dimensional model of the flexible sensor 100, and the three-dimensional shape of the sensing component 2 in the three-dimensional model of the flexible sensor 100 is the same as the three-dimensional shape of the sensing component 2 specimen.

[0072] S2: Obtain the parameters of the stress-strain function of the sensing component 2 specimen through the stress-strain experimental data of the sensing component 2 specimen.

[0073] S3: Apply the parameters of the stress-strain function curve of the sensing component 2 specimen to the three-dimensional model of the flexible sensor 100 for finite element analysis to obtain the stress distribution of each part of the three-dimensional model of the flexible sensor 100 under different strains.

[0074] S4: Predict the mechanical properties of the flexible sensor 100 under various deformations based on the stress distribution of each part of the three-dimensional model of the flexible sensor 100 under different strains.

[0075] Preferably, COMSOL software is used for finite element analysis to establish a hyperelastic material model and simulate the compression of the hyperelastic material (specimen of the sensing component 2), so as to obtain the stress distribution of each part of the three-dimensional model of the flexible sensor 100 under different strains. The specific finite element analysis method is a prior art and will not be elaborated here.

[0076] Table 1 shows the material parameters of the compressible hyperelastic material model, where α, β, and μ are the Storakers material parameters. The Storakers material parameters are a prior art and will not be elaborated here.

[0077] Parameter 1 2 α 13.145 1.9658 β -0.41452 -0.44645 μ 805.83 kPa 1.4721 kPa

[0078] Table 1

[0079] The sensing mechanism of the sensing component 2 is that under the action of stress, the pores deform, resulting in an increase in the contact area of the inner wall of the pores, an increase in the conductive paths, and a decrease in the resistance; in the state where the structures of all parts of the material are unified, the strain state can illustrate the deformation of the pores of the material, and then illustrate its resistance change. Through the above design method, the mechanical properties of the flexible sensor 100 with different structures under various deformations can be predicted, and then the mechanical behavior of the flexible sensor 100 with different structures can be inferred, so as to obtain the flexible sensor 100 that meets the corresponding requirements and reduce the R & D cost and development cycle of the flexible sensor 100.

[0080] Traditional design methods all start from compressible elastic materials such as graphene itself, making the compressible elastic materials into different pore structures to predict the mechanical behavior of the compressible elastic materials under different pore structures; this embodiment starts from compressible elastic porous materials (such as three-dimensional graphene), ignores the porous structure, and is based on the experimental data of the materials under specific pore structures to predict the mechanical behavior of the compressible elastic porous materials (such as three-dimensional graphene) with specific structures. Therefore, this method does not have the disadvantages caused by the uncertainty of the porous structure and the difficulty in modeling, which is beneficial to simplifying the design process and improving the accuracy of simulation.

[0081] Preferably, S1 further includes: obtaining the stress-strain experimental data of the specimen of the sensing component 2 through a universal testing machine;

[0082] S2 further includes: performing finite element analysis on the stress-strain experimental data of the specimen of the sensing component 2 to obtain the stress-strain curve of the specimen of the sensing component 2, the stress-strain function curve of the specimen of the sensing component 2, and the parameters of the stress-strain function of the specimen of the sensing component 2. The specific finite element analysis method is a prior art and will not be elaborated here.

[0083] By comparing the coincidence degree between the stress-strain function curve of the specimen of the sensing component 2 and the stress-strain experimental data of the specimen of the sensing component 2, the fitting effect is compared to ensure the accuracy of the parameters.

[0084] In the present invention, specific examples are used to illustrate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A flexible sensor, characterized in that: It includes a flexible substrate and at least one sensing component. The flexible substrate is provided with at least one closed receiving cavity. Each of the receiving cavities protrudes from one end face of the flexible substrate. Each of the sensing components is disposed in each of the receiving cavities, and the outer wall of each of the sensing components matches and contacts the inner wall of each of the receiving cavities. The resistance value of each of the sensing components can change with the deformation of each of the sensing components; It further includes a first electrode and a second electrode. There is at least one of each of the first electrode and the second electrode. A gap is left between each of the first electrodes and each of the second electrodes. The flexible substrate includes a first substrate and a second substrate. The first substrate has the receiving cavity, and the receiving cavity protrudes from one end face of the first substrate. The other end of the first substrate is fixedly connected to the second substrate. One end of each of the sensing components away from the protruding direction of each of the receiving cavities contacts one end of a first electrode and one end of a second electrode. The other ends of each of the first electrodes and the other ends of each of the second electrodes contact one end of the second substrate close to the first substrate. The first substrate and the second substrate can clamp each of the sensing components and each of the first electrodes, and the first substrate and the second substrate can clamp each of the sensing components and each of the second electrodes; When the flexible sensor is deformed, the deformation mainly occurs at the connection between the receiving cavity and the flexible substrate, and the deformation amount of the part of the receiving cavity protruding from the flexible substrate is very small; The receiving cavity is cylindrical, and the sensing component is cylindrical.

2. The flexible sensor according to claim 1, wherein: It further includes at least one support component. One end of each of the support components is fixedly connected to one end of the second substrate close to the first substrate. The other end of a support component contacts both the first electrode and the second electrode. The first substrate and the second substrate can clamp each of the sensing components and each of the first electrodes, and each of the sensing components and each of the second electrodes through each of the support components and each of the receiving cavities.

3. The flexible sensor according to claim 1, wherein: There are multiple receiving cavities and multiple sensing components. The multiple receiving cavities and the multiple sensing components are both arranged in an array.

4. The flexible sensor according to claim 3, wherein: It further includes a plurality of transverse wires and a plurality of longitudinal wires. The plurality of first electrodes in a horizontal row are connected to one transverse wire. The plurality of second electrodes in a vertical row are connected in series through a plurality of longitudinal wires. The transverse wires and the longitudinal wires are both spiral wires.

5. The flexible sensor according to claim 1, characterized in that: The material of each of the sensing components is three-dimensional graphene.

6. A design method of the flexible sensor according to any one of claims 1-5, characterized in that: It includes: S1: Fabricate the sensing component specimen, test and record the stress of the sensing component specimen under different strains and obtain the stress-strain experimental data of the sensing component specimen; create a three-dimensional model of the flexible sensor, and the three-dimensional shape of the sensing component in the three-dimensional model of the flexible sensor is the same as the three-dimensional shape of the sensing component specimen; S2: Obtain the parameters of the stress-strain function of the sensing component specimen through the stress-strain experimental data of the sensing component specimen; S3: Apply the parameters of the stress-strain function of the sensing component specimen to the 3D model of the flexible sensor for finite element analysis to obtain the stress distribution of each part of the 3D model of the flexible sensor under different strains; S4: Predict the mechanical properties of the flexible sensor under various deformations based on the stress distribution of each part of the 3D model of the flexible sensor under different strains.

7. The design method of the flexible sensor according to claim 6, wherein: S1 further includes: obtaining the stress-strain experimental data of the sensing component specimen through a universal testing machine; S2 further includes: performing finite element analysis on the stress-strain experimental data of the sensing component specimen to obtain the stress-strain curve of the sensing component specimen, the stress-strain function curve of the sensing component specimen, and the parameters of the stress-strain function of the sensing component specimen.

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