Cellulose-based gesture control system and preparation method and application thereof
The construction of conductive cellulose fiber hand-propelled sheets and pressure sensors through cellulose substrate combined with carbon nanotubes and screen printing processes has solved the problem of wearing comfort and degradability of gesture control systems of existing smart wearable devices, and achieved efficient and accurate gesture recognition.
Patent Information
- Application Number
- CN202510513070.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2025-08-19
AI Technical Summary
The gesture control system of existing smart wearable devices has problems such as poor wearing comfort, insufficient flexibility, airtightness, high processing difficulty, high cost and non-degradable, making it difficult to achieve precise control of fine hand movements.
Using cellulose as the substrate, NaOH and urea swelling treatment combined with carbon nanotube grafting and screen printing technology, conductive cellulose fiber hand-written sheets and cellulose-based pressure sensors are constructed to form island-shaped microarrays, and reversible changes are achieved using the elasticity and stiffness of cellulose, and gesture control is achieved by combining a microcontroller and Bluetooth module.
It realizes a low-cost, degradable, good breathability and high flexibility in cellulose-based gesture control system, with a response time of less than 200ms and an identification accuracy of more than 95%, and is suitable for smart wearable devices.
Smart Images
Figure CN120508203A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of cellulose-based functional materials, and in particular to a cellulose-based gesture control system and a preparation method and application thereof. Background Art
[0002] In recent years, smart wearable devices that can convert mechanical stimuli into electrical signals have developed rapidly, especially smart wearable devices that can realize human-computer interaction under conditions such as virtual reality, which have attracted widespread attention from researchers.
[0003] Using smart wearable devices to obtain sensitive response signals and further enable gesture control of mechanical devices is a research hotspot in the field of human-computer interaction and holds enormous potential for application. Currently, gesture control systems often utilize metals and conductive polymers as the primary substrates for the sensing layer. These systems utilize complex reversible circuits to generate electrical signals influenced by parameters such as finger or palm motion and position, enabling gesture control. These systems suffer from poor wearing comfort, limited flexibility, and airtightness, making them difficult to achieve fine hand movements and unsuitable for long-term contact with human skin. In recent years, with the continuous refinement of design principles and optimization of response structures, gesture control systems have significantly improved in terms of wearing comfort, response speed, and accuracy. However, these performance improvements primarily rely on complex microfabrication processes (such as photolithography) and the microstructure of the sensing layer (such as aerogels), which are difficult and costly to manufacture, hindering widespread adoption. Furthermore, the extensive use of metals and conductive polymers in the sensing layer poses challenges such as non-degradability and non-renewability, making them unsuitable for sustainable development. A cellulose-based gesture control system, its preparation method, and its application address these issues. Summary of the Invention
[0004] (1) Technical problems solved In view of the deficiencies in the prior art, the present invention provides a cellulose-based gesture control system and a preparation method and application thereof, which solve the above-mentioned problems.
[0005] (2) Technical solution To achieve the above objectives, the present invention provides the following technical solution: a cellulose-based gesture control system, comprising a conductive cellulose fiber handsheet, a silk screen, a copper wire, a cellulose-based pressure sensor, gloves, a single-chip microcomputer, and a Bluetooth module, characterized in that: the conductive cellulose fiber handsheet comprises cellulose fibers, a mixed aqueous solution, and a carbon nanotube dispersion system, the mixed aqueous solution comprises NaOH, urea, and water, the carbon nanotube dispersion system comprises carbon nanotubes, a surfactant, and water, and the cellulose-based pressure sensor comprises a cellulose-based pressure sensor and a copper wire.
[0006] Preferably, the screen is in contact with the first surface of the conductive cellulose fiber handsheet, the copper wire is connected to the second surface of the conductive cellulose fiber handsheet, and the cellulose-based pressure sensor is attached to the finger joints of the glove.
[0007] Preferably, the ratio of NaOH, urea and water is 7:12:91, the ratio of carbon nanotubes, surfactant and water is 1:(2-8):100, and the cellulose-based pressure sensor is electrically connected to the single-chip microcomputer, Bluetooth module and power supply respectively.
[0008] Preferably, the cellulose substrate utilizes its elasticity and stiffness. When a finger moves, it causes a reversible change in the contact area of the island microarray of cellulose-based pressure sensors, which in turn changes resistance and generates a response signal. A single-chip microcontroller processes the signal and transmits it via a Bluetooth module, enabling gesture control.
[0009] Another technical problem to be solved by the present invention is to provide a method for preparing a cellulose-based gesture control system, comprising the following steps: 1) Preparation of conductive cellulose fiber handsheets: Cellulose fibers were placed in a mixed aqueous solution of NaOH and urea (7:12 by mass) and water (81 by mass), with a mass ratio of (10-15):1, at -12°C for 60-90 seconds. The fibers were then placed in a carbon nanotube dispersion consisting of carbon nanotubes, a surfactant (such as cetyltrimethylammonium bromide), and water (1:2-8:100 by mass), with a mass ratio of (5-8):1. The mixture was mechanically stirred at 30 rpm for 60 minutes to graft the carbon nanotubes onto the cellulose fiber surface. The conductive cellulose fiber handsheets were then vacuum filtered to obtain the result. 2) Construction of island microarrays: Screen printing was performed on the first surface of the conductive cellulose fiber handsheet using an 80-150 mesh screen. A pressure of 3-6 kPa was applied and the sheet was dried at 40°C for 12 hours to construct a uniform island microarray. 3) Fabrication of a cellulose-based pressure sensor: Two sets of screen-printed conductive cellulose fiber handsheets were placed in contact with each other on their first surfaces. Copper wires were then connected to the second surfaces of the two handsheets to fabricate a cellulose-based pressure sensor. 4) Assembling the Gesture Control System: Attach cellulose-based pressure sensors to the finger joints of the glove and connect them to a microcontroller, Bluetooth module, and power supply to complete the cellulose-based gesture control system. Also provided is the code for connecting the microcontroller to the cellulose-based pressure sensors to process the pressure sensing response signals, as well as a circuit diagram for connecting the sensors to the microcontroller, Bluetooth module, and power supply.
[0010] Preferably, the specific operation of the swelling treatment is: placing the cellulose fiber in a mixed aqueous solution of NaOH and urea for 60-90 s at -12°C for swelling; wherein the mass ratio of NaOH, urea, and water is 7:12:81, and the mass ratio of the mixed aqueous solution of NaOH and urea to the cellulose fiber is (10-15):1.
[0011] Preferably, the screen selected for the screen printing process is 80-150 mesh, the pressure applied to the screen surface is 3-6 kPa, and the drying temperature of the obtained island microarray is 40° C. and the drying time is 12 h.
[0012] Preferably, the carbon nanotube dispersion system is obtained by mixing carbon nanotubes, a surfactant and water; the mass ratio of the surfactant, carbon nanotubes and water is 1:(2-8):100; and the mass ratio of the cellulose fibers to the carbon nanotubes is (5-8):1.
[0013] Preferably, the carbon nanotubes are single-walled carbon nanotubes or multi-walled carbon nanotubes, and the surfactant is hexadecyltrimethylammonium bromide.
[0014] Preferably, the mechanical stirring speed is 30 r / min and the time is 60 min.
[0015] Preferably, the single chip microcomputer is connected to the cellulose-based pressure sensor, and gesture control is achieved by processing the pressure sensing response signal.
[0016] Another technical problem addressed by this invention is the application of a cellulose-based gesture control system, which can be used in the manufacture of smart wearable devices. Testing has shown that its response time to different gestures is less than 200ms, it can be reused more than 800 times, and its recognition accuracy exceeds 95%.
[0017] Compared with the prior art, the present invention provides a cellulose-based gesture control system and its preparation method and application, which has the following beneficial effects: 1. This cellulose-based gesture control system, its preparation method, and its application, involves first swelling a cellulose substrate with a mixed aqueous solution of NaOH and urea, thereby preserving the natural cellulose's crystal structure and mechanical strength while enhancing the bonding strength of carbon nanotubes to the cellulose fiber surface. This process is then vacuum-filtered to produce a conductive cellulose fiber handsheet. This is then screen-printed to form a uniform island microarray on the first surface of the conductive cellulose fiber handsheet. Furthermore, the two layers of island microarrays are brought into contact to form a conductive pathway, leveraging the elasticity and stiffness of the cellulose substrate to achieve reversible changes in the contact area of the island microarrays. The resulting cellulose-based pressure sensor is then connected to a single-chip microcomputer, a Bluetooth module, and a power supply to produce the gesture control system. The construction process primarily relies on screen printing, a mature process with simple operation and stable results, making it suitable for industrial production.
[0018] 2. The cellulose-based gesture control system, its preparation method, and its application, which uses cellulose as the substrate, has the advantages of low cost, biodegradability, good air permeability, high flexibility, and comfortable wearing. It is a beneficial raw material for the preparation of environmentally friendly smart wearable devices.
[0019] 3. The cellulose-based gesture control system, its preparation method, and application are provided. The application of the above-mentioned cellulose-based gesture control system in smart wearable devices is provided. By testing the response signals of the gesture control system under different gestures, it is proved that the device has a response time of less than 200ms to different gestures, can be recycled more than 800 times, and has a recognition accuracy rate higher than 95%. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 Schematic diagram of the structure of the cellulose-based pressure sensor prepared by the present invention; Figure 2 This is a schematic diagram of the working principle of the cellulose-based pressure sensor prepared in the present invention; Figure 3 1 and 2 are structural diagrams of the cellulose substrates of Example 1, Comparative Examples 1, 2, and 3; wherein (a) is a structural diagram of the cellulose fiber handsheet having a conductive island microarray of Example 1, (b) is a structural diagram of the cellulose substrate of Comparative Example 1, (c) is a structural diagram of the cellulose substrate of Comparative Example 2, and (d) is a structural diagram of the cellulose substrate of Comparative Example 3; Figure 4 is the response signal of the cellulose-based gesture control system prepared in Example 1 to the index finger bending process; Figure 5 is the response signal of the cellulose-based gesture control system prepared in Example 2 to the simultaneous bending of the index finger and the middle finger; Figure 6is the response signal of the cellulose-based gesture control system prepared in Example 3 to the simultaneous bending of the thumb and index finger; Figure 7 is the response signal of the cellulose-based gesture control system prepared in Example 4 to the simultaneous bending of the index finger, middle finger, ring finger, and little finger; Figure 8 This is a circuit diagram of the connection between the cellulose-based pressure sensor, the microcontroller, the Bluetooth module, and the power supply. DETAILED DESCRIPTION
[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0022] A method for preparing a cellulose-based gesture control system, the specific preparation process is as follows: (1) 0.5 g of hexadecyltrimethylammonium bromide, 1.0 g of single-walled carbon nanotubes (diameter 1-2 nm, length 4-30 μm) and 50 g of distilled water were mixed to prepare 50.8 g of carbon nanotube dispersion system; (2) 3.5 g of NaOH, 6 g of urea and 40.5 g of water were prepared to obtain a mixed aqueous solution of 50 g of NaOH and urea. After cooling to -12 °C, 5 g of cotton pulp was added thereto. After swelling treatment for 60 s, swollen cellulose was obtained. The swollen cellulose was then mixed with the obtained carbon nanotube dispersion system. After mechanical stirring at a speed of 30 r / min for 60 min, a conductive cellulose fiber hand sheet was obtained by vacuum filtration. (3) An 80-mesh screen was used to emboss the conductive cellulose handsheet, and the pressure applied to the screen surface was 3 kPa. After drying at 40 °C for 12 h, 8.9 g of cellulose fiber handsheet with conductive island microarrays was obtained. (4) Take two sets of conductive cellulose fiber handsheets II with island microarrays III from step (3) and make the island microarrays III of the two sets of conductive cellulose fiber handsheets II with island microarrays III contact each other; then connect copper wires with a diameter of 1 mm to the second surfaces of the two sets of conductive cellulose fiber handsheets II with island microarrays III, and then attach two sets of polydimethylsiloxane I (PDMS) elastic substrates to the second surfaces, respectively, to prepare cellulose-based pressure sensors.
[0023] (5) Five sets of cellulose-based pressure sensors obtained in step (4) were attached to the finger joints of the gloves, and then assembled with a single-chip microcomputer, a Bluetooth module, and a power supply to obtain a cellulose-based gesture control system. The code is as follows: #include "delay.h" #include "led.h" #include "AD.h" #include "function.h" #include "OLED.h" #include "Key.h" #include "SERIAL.h" uint16_t RxData0, RxData1, RxData2, RxData3; uint16_t AD0, AD1, AD2, AD3,AD4; uint8_t mode,flag; float dianliu,tempp; extern uint8_t Flag; INPUT Rec; int8_t ddd; uint8_t KeyNum; int8_t Speed; int i=0; int main(void) { OLED_Init(); Key_Init(); Serial_Init(); AD_Init(); delay_init(); LED_Init(); OLED_ShowString(1, 1, "AD0:"); OLED_ShowString(2, 1, "AD1:"); OLED_ShowString(3, 1, "AD2:"); OLED_ShowString(4, 1, "AD3:"); while(1) { KeyNum = Key_GetNum(); AD0 = AD_GetValue(ADC_Channel_0); AD1 = AD_GetValue(ADC_Channel_1); AD2 = AD_GetValue(ADC_Channel_2); AD3 = AD_GetValue(ADC_Channel_3); AD4 = AD_GetValue(ADC_Channel_4); OLED_ShowNum(1, 5, AD0, 4); OLED_ShowNum(2, 5, AD1, 4); OLED_ShowNum(3, 5, AD2, 4); OLED_ShowNum(4, 5, AD3, 4); OLED_ShowNum(1, 10, Serial_TxPacket[0], 2); OLED_ShowNum(2, 10, Serial_TxPacket[1], 2); OLED_ShowNum(3, 10, Serial_TxPacket[2], 2); OLED_ShowNum(4, 10, Serial_TxPacket[3], 2); OLED_ShowNum(4, 13, Serial_TxPacket[4], 2); delay_ms(100); if(AD0<2000) { Serial_TxPacket[0]=1; LED0_ON(); } else { Serial_TxPacket[0]=0; LED0_OFF(); } if(AD1 <1500) { Serial_TxPacket[1]=1; LED1_ON(); } else { Serial_TxPacket[1]=0; LED1_OFF(); } if(AD2<1500) { Serial_TxPacket[2]=1; LED2_ON(); } else { Serial_TxPacket[2]=0; LED2_OFF(); } if(AD3<2000) { Serial_TxPacket[3]=1; LED3_ON(); } else { Serial_TxPacket[3]=0; LED3_OFF(); } if(AD4 <2000) { Serial_TxPacket[4]=1; LED4_ON(); } else { Serial_TxPacket[4]=0; LED4_OFF(); } Serial_SendPacket(); } }.
[0024] Example 1 also provides a cellulose-based gesture control system, which is prepared using the above preparation method.
[0025] The working principle of the cellulose-based gesture control system of the present invention is as follows: The cellulose-based gesture control system described herein uses cellulose as a substrate. After carbon nanotube surface grafting and vacuum filtration, a conductive cellulose fiber handsheet is obtained. Using a screen printing process, a uniform island microarray III is formed on the surface of the conductive cellulose fiber handsheet II. Two groups of island microarrays III are brought into contact to form a conductive pathway. The elasticity and stiffness of the cellulose substrate are utilized to achieve reversible changes in the contact area of the island microarrays III, thereby causing a change in resistance response under different gesture conditions. When the external voltage is fixed, under the action of pressure 1, the contact area of the island microarrays III is reduced, resulting in a higher resistance of the cellulose-based gesture control system. When pressure 2 is applied to the cellulose-based gesture control system, the contact area of the island microarrays III increases, resulting in a decrease in the resistance of the cellulose-based gesture control system. Ultimately, the cellulose-based gesture control system obtains a current response signal related to the tester's gesture.
[0026] Example 2 A method for preparing a cellulose-based gesture control system, the specific preparation process is as follows: (1) 0.4 g of hexadecyltrimethylammonium bromide, 1.6 g of multi-walled carbon nanotubes (diameter 30-50 nm, length 10-20 μm) and 40 g of distilled water were mixed to prepare 40.5 g of carbon nanotube dispersion system; (2) 7.4 g of NaOH, 12.7 g of urea and 85.5 g of water were prepared to obtain a mixed aqueous solution of 105.6 g of NaOH and urea. After cooling to -12 °C, 9.6 g of larch pulp was added thereto. After swelling treatment for 70 s, swollen cellulose was obtained. The swollen cellulose was then mixed with the obtained carbon nanotube dispersion system. After mechanical stirring at a speed of 30 r / min for 60 min, a conductive cellulose fiber hand sheet was obtained by vacuum filtration. (3) A 100-mesh screen was used to emboss the conductive cellulose handsheet, and a pressure of 4 kPa was applied to the screen surface. After drying at 40 °C for 12 h, 13.5 g of a cellulose fiber handsheet with a conductive island microarray was obtained. (4) Take two sets of conductive cellulose fiber handsheets II with island microarrays III from step (3) and make the island microarrays III of the two sets of conductive cellulose fiber handsheets II with island microarrays III contact each other; then connect copper wires with a diameter of 1 mm to the second surfaces of the two sets of conductive cellulose fiber handsheets II with island microarrays III, and then attach two sets of polydimethylsiloxane I (PDMS) elastic substrates to the second surfaces, respectively, to prepare cellulose-based pressure sensors.
[0027] (5) Five groups of cellulose-based pressure sensors obtained in step (4) are attached to the finger joints of the gloves, and then assembled with a single-chip microcomputer, a Bluetooth module, and a power supply to obtain a cellulose-based gesture control system.
[0028] Example 2 also provides a cellulose-based gesture control system, which is prepared using the above preparation method.
[0029] Example 3 A method for preparing a cellulose-based gesture control system, the specific preparation process is as follows: (1) 0.3 g of hexadecyltrimethylammonium bromide, 1.8 g of single-walled carbon nanotubes (diameter 1-2 nm, length 4-30 μm) and 30 g of distilled water were mixed to prepare 31.1 g of carbon nanotube dispersion system; (2) 10.6 g of NaOH, 18.1 g of urea and 122.5 g of water were prepared to obtain a mixed aqueous solution of 151.2 g of NaOH and urea. After cooling to -12 °C, 12.6 g of hemp pulp was added thereto. After swelling treatment for 80 s, swollen cellulose was obtained. The swollen cellulose was then mixed with the obtained carbon nanotube dispersion system. After mechanical stirring at a speed of 30 r / min for 60 min, a conductive cellulose fiber hand sheet was obtained by vacuum filtration. (3) A 120-mesh screen was used to emboss the conductive cellulose handsheet, and a pressure of 5 kPa was applied to the screen surface. After drying at 40 °C for 12 h, 15.9 g of cellulose fiber handsheet with conductive island microarrays was obtained. (4) Take two sets of conductive cellulose fiber handsheets II with island microarrays III from step (3) and make the island microarrays III of the two sets of conductive cellulose fiber handsheets II with island microarrays III contact each other; then connect copper wires with a diameter of 1 mm to the second surfaces of the two sets of conductive cellulose fiber handsheets II with island microarrays III, and then attach two sets of polydimethylsiloxane I (PDMS) elastic substrates to the second surfaces, respectively, to prepare cellulose-based pressure sensors.
[0030] (5) Five groups of cellulose-based pressure sensors obtained in step (4) are attached to the finger joints of the gloves, and then assembled with a single-chip microcomputer, a Bluetooth module, and a power supply to obtain a cellulose-based gesture control system.
[0031] Example 3 also provides a cellulose-based gesture control system, which is prepared using the above preparation method.
[0032] Example 4 A method for preparing a cellulose-based gesture control system, the specific preparation process is as follows: (1) 0.2 g of hexadecyltrimethylammonium bromide, 1.6 g of multi-walled carbon nanotubes (diameter 30-50 nm, length 10-20 μm) and 20 g of distilled water were mixed to obtain 20.9 g of carbon nanotube dispersion. (2) 192 g of a mixed aqueous solution of NaOH and urea was prepared by taking 13.4 g of NaOH, 23.1 g of urea and 155.5 g of water. After cooling to -12 °C, 12.8 g of straw pulp was added thereto. After swelling treatment for 90 s, swollen cellulose was obtained. The swollen cellulose was then mixed with the obtained carbon nanotube dispersion system. After mechanical stirring at a speed of 30 r / min for 60 min, a conductive cellulose fiber hand sheet was obtained by vacuum filtration. (3) A 150-mesh screen was used to emboss the conductive cellulose handsheet, and a pressure of 6 kPa was applied to the screen surface. After drying at 40 °C for 12 h, 16.5 g of cellulose fiber handsheet with conductive island microarrays was obtained. (4) Take two sets of conductive cellulose fiber handsheets II with island microarrays III from step (3) and make the island microarrays III of the two sets of conductive cellulose fiber handsheets II with island microarrays III contact each other; then connect copper wires with a diameter of 1 mm to the second surfaces of the two sets of conductive cellulose fiber handsheets II with island microarrays III, and then attach two sets of polydimethylsiloxane I (PDMS) elastic substrates to the second surfaces, respectively, to prepare cellulose-based pressure sensors.
[0033] (5) Five groups of cellulose-based pressure sensors obtained in step (4) are attached to the finger joints of the gloves, and then assembled with a single-chip microcomputer, a Bluetooth module, and a power supply to obtain a cellulose-based gesture control system.
[0034] Example 4 also provides a cellulose-based gesture control system, which is prepared using the above preparation method.
[0035] In order to demonstrate the response performance of the cellulose-based gesture control system prepared by the present invention, the present invention also conducted experiments of Comparative Examples 1 to 3.
[0036] Comparative Example 1 Comparative Example 1 provides a cellulose substrate which has been subjected to a swelling treatment but has not been subjected to a carbon nanotube grafting process or a screen printing process.
[0037] Comparative Example 2 Comparative Example 2 provides a cellulose substrate, which is subjected to swelling treatment and screen printing process, but is not grafted with carbon nanotubes.
[0038] Comparative Example 3 Comparative Example 3 provides a cellulose substrate which has been subjected to a swelling treatment and grafted with carbon nanotubes but has not been subjected to a screen printing process.
[0039] Test Example 1 The structures of the cellulose fiber handsheet with conductive island microarray prepared in Example 1 and the three cellulose substrates of Comparative Examples 1-3 were observed using an optical microscope. Figure 3 As shown, (a), (b), (c), and (d) correspond to the cellulose-based structural diagrams of Example 1 and Comparative Examples 1-3, respectively.
[0040] observe Figure 3 (a) It can be seen that the surface of the cellulose fiber handsheet with conductive island microarray in Example 1 is grafted with uniform and continuous carbon nanotubes. After the screen printing process, a uniform conductive island microarray is formed on the surface, which can be used to prepare a pressure sensor. Figure 3 As can be seen in (b), the cellulose substrate of Comparative Example 1 has been subjected to swelling treatment, with loose fiber arrangement and improved transparency. It has not been subjected to carbon nanotube grafting or screen printing treatment, so the cellulose substrate obtained in Comparative Example 1 is not conductive. Figure 3 As can be seen in (c), the cellulose substrate of Comparative Example 2 is loosely arranged after swelling treatment, and its transparency is improved. After the screen printing process, it is not grafted with carbon nanotubes. Therefore, a uniform island microarray can be observed on the surface of the cellulose substrate obtained in Comparative Example 2, but it is not conductive. Figure 3 (d) The cellulose substrate of Comparative Example 3 was subjected to swelling treatment and carbon nanotube grafting but not to screen printing. The cellulose substrate of Comparative Example 3 did not have an island microarray and therefore could not be used to prepare a cellulose-based gesture control system.
[0041] Test Example 2 The cellulose-based gesture control system prepared in Example 1 was analyzed.
[0042] Test Example 3 The response signals of the cellulose-based gesture control systems prepared in Examples 1-4 were detected.
[0043] Figure 4 This is the response signal of the cellulose-based gesture control system prepared in Example 1 to the index finger bending process. As can be seen from the figure, the response time of the cellulose-based gesture control system prepared in Example 1 to the index finger bending process is 180 ms, the number of cycles is greater than 1000, and the recognition accuracy is 97%.
[0044] Figure 5This is the response signal of the cellulose-based gesture control system prepared in Example 2 to the simultaneous bending of the index finger and middle finger. As can be seen from the figure, the response time of the cellulose-based gesture control system prepared in Example 2 to the simultaneous bending of the index finger and middle finger is 150 ms, the number of cycles is greater than 1100, and the recognition accuracy is 98%.
[0045] Figure 6 This is the response signal of the cellulose-based gesture control system prepared in Example 3 to the simultaneous bending of the thumb and index finger. As can be seen from the figure, the response time of the cellulose-based gesture control system prepared in Example 3 to the simultaneous bending of the thumb and index finger is 140 ms, the number of cycles is greater than 800, and the recognition accuracy is 96%.
[0046] Figure 7 This is the response signal of the cellulose-based gesture control system prepared in Example 4 to the simultaneous bending of the index finger, middle finger, ring finger, and little finger. As can be seen from the figure, the response time of the cellulose-based gesture control system prepared in Example 4 to the simultaneous bending of the index finger, middle finger, ring finger, and little finger is 110 ms, the number of cycles is greater than 1200, and the recognition accuracy is 99%.
[0047] The beneficial effects of the present invention are as follows: the cellulose-based gesture control system and its preparation method and application, which use cellulose as a substrate, have the advantages of low cost, biodegradability, good air permeability, high flexibility, and comfortable wearing. It is a beneficial raw material for preparing environmentally friendly smart wearable devices. The application of the above-mentioned cellulose-based gesture control system in smart wearable devices is provided. By detecting the response signals of the gesture control system under different gestures, it is proved that the response time of the device to different gestures is less than 200ms, the number of recycling times is greater than 800 times, and the recognition accuracy rate is higher than 95%.
[0048] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A cellulose-based gesture control system comprising a conductive cellulose fiber handsheet, a silk screen, a copper conductor, a cellulose-based pressure sensor, gloves, a single-chip microcomputer, and a Bluetooth module, characterized in that: The conductive cellulose fiber handsheet includes cellulose fibers, a mixed aqueous solution and a carbon nanotube dispersion system, the mixed aqueous solution includes NaOH, urea and water, the carbon nanotube dispersion system includes carbon nanotubes, a surfactant and water, and the cellulose-based pressure sensor is composed of a cellulose-based pressure sensor and a copper wire.
2. The cellulose-based gesture control system according to claim 1, characterized in that: The silk screen is in contact with the first surface of the conductive cellulose fiber handsheet, the copper wire is connected to the second surface of the conductive cellulose fiber handsheet, and the cellulose-based pressure sensor is attached to the finger joints of the glove.
3. The cellulose-based gesture control system according to claim 1, characterized in that: The ratio of NaOH, urea, and water is 7:12:81, and the ratio of carbon nanotubes, surfactant, and water is 1:(2 - 8):
100. The cellulose-based pressure sensor is electrically connected to the microcontroller, Bluetooth module, and power supply, respectively.
4. The cellulose-based gesture control system according to claim 1, characterized in that: Using cellulose as the base material and utilizing the elasticity and stiffness of cellulose, when the finger moves, it causes reversible changes in the contact area of the island microarray of the cellulose-based pressure sensor, which in turn causes a change in resistance and generates a response signal. The microcontroller processes the signal and transmits it through the Bluetooth module to achieve gesture control.
5. A method for preparing a cellulose-based gesture control system, characterized in that: Steps: Prepare conductive cellulose fiber handsheets, construct island microarrays, cellulose-based pressure sensors, and assemble a gesture control system; 1) Preparation of conductive cellulose fiber handsheets: Cellulose fibers were placed in a mixed aqueous solution of NaOH and urea at a mass ratio of 7:12 and water at a mass ratio of 81 at -12°C, with the mixed aqueous solution and cellulose fiber mass ratio being (10-15):1, and allowed to swell for 60-90 seconds. The fibers were then placed in a carbon nanotube dispersion system consisting of carbon nanotubes, a surfactant (such as hexadecyltrimethylammonium bromide), and water at a mass ratio of 1:(2-8):100, with the cellulose fiber and carbon nanotube mass ratio being (5-8):
1. The mixture was mechanically stirred at a speed of 30 r / min for 60 minutes to graft the carbon nanotubes onto the cellulose fiber surface. The conductive cellulose fiber handsheets were then vacuum filtered to obtain the mechanically stirred mixture. The mechanical stirring speed was 30 r / min for 60 minutes. 2) Construction of island microarrays: Screen printing was performed on the first surface of the conductive cellulose fiber handsheet using an 80-150 mesh screen. A pressure of 3-6 kPa was applied and the sheet was dried at 40°C for 12 hours to construct a uniform island microarray. 3) Fabrication of a cellulose-based pressure sensor: Two sets of screen-printed conductive cellulose fiber handsheets were placed in contact with each other on their first surfaces. Copper wires were then connected to the second surfaces of the two handsheets to fabricate a cellulose-based pressure sensor. 4) Assembling the gesture control system: Attach the cellulose-based pressure sensors to the finger joints of the glove and then connect them to the microcontroller, Bluetooth module, and power supply to complete the preparation of the cellulose-based gesture control system. At the same time, the code for connecting the microcontroller to the cellulose-based pressure sensor to process the pressure sensing response signal is provided, as well as a circuit diagram for connecting the sensor to the microcontroller, Bluetooth module, and power supply. The microcontroller is connected to the cellulose-based pressure sensor and gesture control is achieved by processing the pressure sensing response signal.
6. The method for preparing a cellulose-based gesture control system according to claim 5, characterized in that: The specific operation of the swelling treatment is: placing the cellulose fiber in a mixed aqueous solution of NaOH and urea for 60-90 seconds at -12°C for swelling; wherein the mass ratio of NaOH, urea, and water is 7:12:81, and the mass ratio of the mixed aqueous solution of NaOH and urea to the cellulose fiber is (10-15):
1.
7. The method for preparing a cellulose-based gesture control system according to claim 5, characterized in that: The screen selected for the screen printing process is 80-150 mesh, the pressure applied to the screen surface is 3-6 kPa, and the drying temperature of the obtained island microarray is 40° C. and the drying time is 12 h.
8. The method for preparing a cellulose-based gesture control system according to claim 5, characterized in that: The carbon nanotube dispersion system is obtained by mixing carbon nanotubes, a surfactant, and water; the mass ratio of the surfactant, carbon nanotubes, and water is 1:(2-8):100; and the mass ratio of the cellulose fibers to the carbon nanotubes is (5-8):
1.
9. The method for preparing a cellulose-based gesture control system according to claim 5, characterized in that: The carbon nanotubes are single-walled carbon nanotubes or multi-walled carbon nanotubes, and the surfactant is cetyltrimethylammonium bromide.
10. The application of the cellulose-based gesture control system according to claim 1, characterized in that: This cellulose-based gesture control system can be used in the manufacture of smart wearable devices. Testing has shown that its response time to different gestures is less than 200ms, it can be reused more than 800 times, and its recognition accuracy is higher than 95%.