Preparation method and application of flexible stress angle sensor

Abstract

The invention relates to the technical field of nano materials, and provides a preparation method and application of a flexible stress angle sensor. The invention aims to overcome the defects of low sensitivity, small detection range, rigidity and the like of the existing stress angle sensor and improve the application of the sensor in the field of flexible electronics. According to the main scheme, the method comprises the steps that georgette fabric is subjected to high-temperature carbonization, a fabric material with good conductivity is obtained, then two pieces of carbonized georgette are cut into appropriate sizes and placed on a polydimethylsiloxane substrate in a staggered stacking mode at a certain angle, wires are led out of the two ends of the georgette, and the georgette fabric is obtained. And finally, coating is carried out through polydimethylsiloxane to obtain the flexible stress angle sensor. The flexible stress angle sensor is used in the fields of soft robots, man-machine interaction, mechanical sensing and the like, has the advantages of being ingenious in design, reasonable in structure, simple in process, rich in raw material source, low in cost, high in stability and easy to industrially amplify, and achieves rapid preparation of the flexible stress angle sensor with high sensitivity, high anti-interference performance and a full-angle detection range. The method has high commercial and practical values.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomaterials, and in particular relates to a preparation method and application of a flexible stress angle sensor that senses carbon fibers stacked at different angles. Background Art

[0002] A stress angle sensor is a sensor that can simultaneously measure stress and angle. It can simultaneously detect changes in stress and angle on an object and output these information as electrical signals. When an object is subjected to external force, its internal electrical parameters, such as resistance or capacitance, change, enabling stress measurement. Stress angle sensors, on the other hand, use methods such as the Hall effect and photoelectric effect to measure angles. Stress angle sensors are often used in aerospace, automotive, human-computer interaction, electronic skin, and soft robotics. Currently, stress angle sensors are often complex to design, particularly requiring chips to process the output signals. This significantly increases the installation difficulty and cost of their use. Furthermore, some stress angle sensors suffer from limitations such as an inability to quickly detect dynamic changes, the need for temperature compensation, and size and weight restrictions. Flexible angle sensors also struggle to measure angles across the entire plane. These factors significantly hinder the practical application of stress angle sensors. Therefore, it is crucial to design stress angle sensors that are highly sensitive, resistant to interference, low-cost, and flexible to install and maintain.

[0003] Through the above analysis, the problems and defects of the existing technology are: rigidity, low precision, weak dynamic measurement and anti-interference capabilities, and high manufacturing and maintenance costs. Therefore, it is very important to develop a stress angle sensor that is flexible, has strong dynamic measurement and anti-interference capabilities, responds quickly, has low cost, and has convenient signal output. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a preparation method and application of a flexible stress angle sensor.

[0005] The present invention is implemented as follows: a method for preparing a flexible stress angle sensor comprises the following steps:

[0006] Step 1: ironing the georgette fabric with high-temperature steam, then cutting it into strips using a laser cutting machine, and placing the strips in a tube furnace for heat treatment to remove moisture from the fabric;

[0007] Step 2: Further heat treatment of the georgette fabric removes small organic molecules from the fabric, resulting in a smooth, black, pre-carbonized fabric. The black fabric is then removed and carefully separated to prevent adhesion caused by volatilization of the organic matter. Increasing the heat treatment temperature graphitizes the protein in the fabric, resulting in a highly conductive material.

[0008] Step 3: Cut two pieces of carbonized georgette into appropriate sizes, place them on a polydimethylsiloxane base in a staggered stack at a certain angle, lead wires to both ends of the georgette, and finally coat them with polydimethylsiloxane.

[0009] Furthermore, in step 1, the size of the georgette fabric is 250 mm*70 mm.

[0010] Furthermore, the heat treatment temperature in step 1 is 300° C., and high-purity nitrogen is introduced into the tubular furnace.

[0011] Furthermore, during the high temperature treatment in step 2, the fabric is clamped between two quartz plates.

[0012] Furthermore, the heat treatment temperature in step 2 is 600° C., and high-purity nitrogen is introduced into the tubular furnace.

[0013] Furthermore, the carbonized georgette in step 3 has a size of 50 mm*5 mm.

[0014] Furthermore, the misalignment angle in step 3 is 45°.

[0015] The present invention also provides a stress direction identification sensor, which is prepared using the above-mentioned flexible stress angle sensor.

[0016] The present invention also provides a human-computer interaction flexible electronic device, characterized in that the flexible electronic device is prepared using the above-mentioned flexible stress angle sensor.

[0017] The present invention also provides a soft robot perception system, which is prepared using the above-mentioned flexible stress angle sensor.

[0018] The flexible stress angle sensor and its preparation method provided by the present invention achieve high sensitivity, high anti-interference, and omnidirectional angle measurement functions through the synergistic effects of material selection, process optimization, and surface modification. Specifically, they have the following technical advantages:

[0019] 1. High sensitivity

[0020] The soft strain sensor constructed with carbonized georgette as the sensing material has the characteristics of high sensitivity, which is due to the ultra-thin plain weave structure of carbonized georgette (such as Figure 2 As shown in the figure, in particular, the silk yarns in the horizontal and vertical directions are twisted structures. After carbonization, the twisted structure is slightly deformed, and the internal fibers begin to break, resulting in a sharp change in resistance, thereby obtaining a sensitive electrical change signal.

[0021] 2. All-round angle measurement

[0022] The present invention solves the problems of traditional sensors' rigidity and inability to detect full-plane angles by combining two stress sensors with different angles and assembling them through a flexible substrate. A single angle stress sensor can only detect within the range of 0-90°, while assembling two angle stress sensors with a 45° offset (see the structural diagram) Figure 3 It can realize the detection of the full plane angle range of 0-180°.

[0023] 3. Good anti-interference performance

[0024] Using the material's own resistance as the sensing signal and through wired connection, it avoids electromagnetic or electrostatic signal interference generated by the instrument or environment. It can quickly and accurately obtain the resistance value corresponding to each stress direction, and combine with the dual sensor system to quickly determine the direction of stress application.

[0025] 4. There are also stress direction sensors in the prior art, which are conducive to being widely used in projects such as rock blasting, but most of these sensors are large sensors with rigidity and complex structures. The application field of the present invention is mainly the field of flexible electronics, and the application scenarios are soft robots, electronic skin, human-computer interaction, etc. The sensor needs to have the characteristics of flexibility, low energy consumption, anti-interference and high sensitivity. The design of the present invention solves the problems of weak anti-interference, rigidity and low sensitivity of traditional stress direction sensors. At the same time, carbonized georgette is abundant in source and low in price, which further reduces production and maintenance costs. The sensor is encapsulated by polydimethylsiloxane, which not only solves the problem of sensor rigidity, but also improves the stability of sensor use.

[0026] 5. The technical solution to be protected by the present invention has an ingenious design, a reasonable structure, a simple process, abundant sources of raw materials, low cost, high stability, and is easy to scale up industrially; the materials used in the solution of the present invention are abundant in source and easy to obtain; and the prepared flexible stress direction sensor has good stability and high sensitivity, and its own flexibility makes it easy to further combine with other flexible electronic devices to construct a flexible detection system in the later stage.

[0027] 6. The technical solution to be protected by the present invention has the advantages of flexibility, dynamic measurement and strong anti-interference, rapid response, low cost and convenient signal output.

[0028] 7. The expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: The present invention can quickly realize the rapid preparation of flexible stress angle sensors, which are not affected by environmental factors during the detection process, have the characteristics of flexibility, dynamic measurement and strong anti-interference, rapid response, low cost and convenient signal output, and have high commercial value and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1This is a flow chart of a method for preparing a flexible stress angle sensor provided by an embodiment of the present invention;

[0030] Figure 2 This is an optical microscope image of the carbonized georgette obtained in Example 1 of the present invention;

[0031] Figure 3 This is the Raman image of the carbonized georgette obtained in Example 1 of the present invention;

[0032] Figure 4 This is a diagram showing the stress sensing magnitude of the flexible stress angle sensor obtained in Example 1 of the present invention;

[0033] Figure 5 This is a response time diagram of the flexible stress angle sensor obtained in Example 1 of the present invention;

[0034] Figure 6 is the stability of the flexible stress angle sensor obtained in Example 1 of the present invention;

[0035] Figure 7 This is a structural diagram of the flexible stress angle sensor obtained in Example 1 of the present invention;

[0036] Figure 8 This is a stress angle perception diagram of the flexible stress angle sensor Sensor1 obtained in Example 1 of the present invention;

[0037] Figure 9 This is a stress angle perception diagram of the flexible stress angle sensor Sensor2 obtained in Example 1 of the present invention;

[0038] Figure 10 This is a comprehensive stress angle perception diagram of the flexible stress angle sensor obtained in Example 1 of the present invention;

[0039] Figure 11 This is a structural diagram of the flexible stress angle sensor obtained in Example 2 of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] In order to enable those skilled in the art to fully understand how to implement the present invention, this section provides an explanatory embodiment that expands on the technical solutions of the claims.

[0042] like Figure 1 As shown, a method for preparing a flexible stress angle sensor provided by an embodiment of the present invention includes:

[0043] S101, ironing georgette fabric with high-temperature steam, then cutting it into strips using a laser cutting machine, and placing the strips of fabric in a tube furnace for heat treatment to remove moisture from the fabric.

[0044] S102 , the georgette fabric is further subjected to high-temperature heat treatment to remove small organic molecules from the fabric, resulting in a smooth, black, pre-carbonized fabric. The black fabric is then removed and carefully separated to prevent adhesion caused by volatilization of the organic matter. The heat treatment temperature is then increased to graphitize the protein in the fabric, resulting in a highly conductive material.

[0045] S103, cutting two pieces of carbonized georgette into suitable sizes, placing them on a polydimethylsiloxane base in a staggered stack at a certain angle, leading out conductors at both ends of the georgette, and finally coating them with polydimethylsiloxane.

[0046] The size of the georgette fabric in step S101 in the embodiment of the present invention is 250 mm*70 m.

[0047] In the embodiment of the present invention, the heat treatment temperature in step S101 is 300° C., and high-purity nitrogen is introduced into the tube furnace.

[0048] In step S102 of the embodiment of the present invention, the fabric is clamped between two quartz plates during the high temperature treatment.

[0049] In step S102 of the embodiment of the present invention, the heat treatment temperature is 600° C., and high-purity nitrogen is introduced into the tube furnace.

[0050] The size of the carbonized georgette in step S103 in the embodiment of the present invention is 50 mm*5 mm.

[0051] In the embodiment of the present invention, the misalignment angle in step S103 is 45°.

[0052] Example 1

[0053] (1) First, the georgette fabric was ironed with high-temperature steam and then cut into 250 mm*70 mm strips using a laser cutting machine. The strips were placed in a tubular furnace for heat treatment to remove moisture from the fabric. The heat treatment temperature was 300 °C, and high-purity nitrogen was introduced into the tubular furnace.

[0054] (2) The georgette fabric is then subjected to a high-temperature heat treatment. The fabric is clamped between two quartz plates to smooth the surface. The heat treatment temperature is 600°C, and high-purity nitrogen is introduced into the tube furnace to remove small organic molecules from the fabric, thereby obtaining a black, smooth, pre-carbonized fabric. The black fabric is then removed and carefully separated to prevent adhesion caused by the volatilization of organic matter. Increasing the heat treatment temperature causes the protein in the fabric to graphitize, resulting in a highly conductive material.

[0055] (3) Finally, two pieces of carbonized georgette were cut into 50 mm*5 mm pieces and placed on a polydimethylsiloxane substrate in a 45° offset stack. Wires were led out from both ends of the georgette and then coated with polydimethylsiloxane.

[0056] The structure of the obtained carbonized georgette is as follows Figure 2 As shown; the Raman spectrum of the obtained carbonized georgette is as shown Figure 3 As shown; the stress perception of the obtained flexible stress angle sensor is as follows Figure 4 As shown; the response time of the obtained flexible stress angle sensor is as follows Figure 5 As shown; the stability of the obtained flexible stress angle sensor is shown in Figure 6 As shown; the structure diagram of the obtained flexible stress angle sensor is shown in Figure 7 As shown; the stress angle perception diagram of the flexible stress angle sensor Sensor1 is as follows Figure 8 As shown; the stress angle perception diagram of the flexible stress angle sensor Sensor2 is as follows Figure 9 As shown; the comprehensive stress angle perception diagram of the flexible stress angle sensor is as follows Figure 10 shown.

[0057] In order to prove the creativity and technical value of the technical solution of the present invention, this section provides application examples of the claimed technical solution on specific products or related technologies.

[0058] The embodiment of the present invention provides a flexible stress angle sensor prepared by a method for preparing a stress angle sensor, which is used in the fields of soft robotics, human-computer interaction, and mechanical sensing. The present invention has the advantages of ingenious design, reasonable structure, simple process, abundant raw material sources, low cost, high stability, and easy industrial scale-up. It achieves the rapid preparation of a flexible stress angle sensor with high sensitivity, strong anti-interference and full-angle detection range, and has high commercial and practical value. The embodiment of the present invention has achieved some positive results in the process of research and development or use, and indeed has great advantages compared with the existing technology. The following content is described in conjunction with the data, icons, etc. of the experimental process.

[0059] The flexible stress angle sensor prepared in Example 1 is applied to the field of flexible electronics. The structure of the carbonized georgette as its sensing material is as follows: Figure 2 As shown in the figure, the rate of change of resistance of this twisted plain weave structure under tension after carbonization is extremely large, so that the sensor prepared from it has high sensitivity and strong perception of tiny deformation. Figure 3 This is the Raman spectrum of carbonized georgette at 1590 cm -1 1348cm -1 The G peak and D peak appear at the sp 2The vibration of the crystalline carbon formed by bonding proves that the ginseng georgette has been completely converted into conductive graphite. Figure 4-6 The strain sensing performance of a sensor made of carbonized georgette was investigated. It was found that the sensor was extremely sensitive in the 0.5% to 5% range, with a fast response speed of 0.18 seconds. However, the sensor's recovery speed was relatively slow, at 0.5 seconds. This is primarily due to the base material, polydimethylsiloxane, which, as a polymer elastomer, exhibits a certain creep effect. The graph shows that this sensor exhibits good cyclic stability, maintaining good detection stability even after 100 cycles. Figure 7 The figure shows the structure of the flexible stress angle sensor. The present invention cuts two pieces of carbonized georgette into appropriate sizes, stacks them at a 45° angle, and places them on a polydimethylsiloxane base. Wires are drawn from both ends of the georgette, and finally coated with polydimethylsiloxane. During the stress process, under the same stretching angle conditions, the two sensors will exhibit different sensing performance. Figure 8 As can be seen in the figure, the resistance change rate of Sensor 1 shows a monotonically decreasing characteristic in the range of 0° to 90°, which makes it easy to identify the angle of stress. However, the resistance change rate from 90° to 180° is mirrored to the resistance change rate from 0° to 90°, making it impossible to identify the range of stress. Figure 9 The figure shows the resistance change rate of Sensor 2 as the stress angle changes. It can be seen that when the stress angle is in the range of 0° to 90°, the resistance change rate is negative. This is because in this range, Sensor 2 is actually in a compressed state, resulting in a decrease in resistance. When the stress angle is in the range of 90° to 180°, the resistance change rate is positive. This is because in this stress angle range, Sensor 2 is in a stretched state and the resistance value increases. Figure 10 The above angle detection information can be clearly observed in the figure. Through the characteristics of this composite flexible stress angle sensor, the angle and magnitude of stress can be accurately and stably tested.

[0060] The preferred embodiments of the present invention have been described in detail above. It should be understood that numerous modifications and variations based on the concepts of the present invention can be made by one of ordinary skill in the art without inventive effort. Therefore, any technical solution that can be derived by one of ordinary skill in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

[0061] Example 2

[0062] Cut two pieces of carbonized georgette into 50mm*5mm and place them on a polydimethylsiloxane base in a 45° offset stack, labeled as Sensor 1 and Sensor 2. Cut another 25mm*5mm piece of carbonized georgette as the third set of sensors, Sensor 3. One end of the sensor is placed at the intersection of Sensor 1 and Sensor 2, perpendicular to Sensor 1 as a whole, and at an angle of 45° to Sensor 2. Wires are led out from both ends of each conductive carbonized georgette, and finally coated with polydimethylsiloxane. Its structure is shown in the figure below. Figure 11 As shown, in the stress direction detection of a single stress point, the sensor can not only identify within the range of 0-180°, but also, through Sensor 3, it can determine whether the stress direction is 0-180° or 180°-360°.

Claims

1. A method for preparing a flexible stress angle sensor, characterized in that: The following steps are involved: Step 1: iron the georgette fabric with high-temperature steam, cut it into strips using a laser cutting machine, and place the strips in a tubular furnace for heat treatment to remove moisture from the fabric. In step 2, the georgette fabric is further heat-treated at high temperatures to remove small organic molecules from the fabric, resulting in a smooth, black, pre-carbonized fabric. The black fabric is then removed and carefully separated to prevent adhesion caused by the volatilization of organic matter. Increasing the heat treatment temperature graphitizes the protein in the fabric, resulting in a highly conductive material. Step 3: Cut two pieces of carbonized georgette into appropriate sizes, place them on a polydimethylsiloxane base in a staggered stack at a certain angle, lead wires to both ends of the georgette, and finally coat them with polydimethylsiloxane.

2. The medium georgette fabric as claimed in claim 1 has a size of 250 mm*70 mm.

3. The heat treatment temperature as claimed in claim 1 is 300° C., and high-purity nitrogen is introduced into the tubular furnace.

4. The fabric is clamped between two quartz plates during the high temperature treatment as claimed in claim 1.

5. The heat treatment temperature as claimed in claim 1 is 600°C, and high-purity nitrogen is introduced into the tubular furnace.

6. The carbonized georgette according to claim 1 has a size of 50 mm*5 mm.

7. The misalignment angle as claimed in claim 1 is 45°.

8. A flexible stress angle sensor, characterized in that: The flexible stress angle sensor is prepared by using the preparation method of the flexible stress angle sensor according to any one of claims 1 to 7.

9. A stress direction identification sensor, the sensor being prepared using the flexible stress angle sensor according to claim 8.

10. A human-computer interactive flexible electronic device, characterized in that: The flexible electronic device is prepared using the flexible stress angle sensor according to claim 8.

11. A soft robot perception system, wherein the perception system is prepared using the flexible stress angle sensor according to claim 8.

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