Flexible dual-mode sensing array structure with variable detection depth and manufacturing method thereof

Abstract

The invention discloses a flexible dual-mode sensing array structure with variable detection depth and a manufacturing method thereof, and belongs to the technical field of sensors, the flexible dual-mode sensing array structure comprises an electrode layer, an upper alternating shielding layer, a lower alternating shielding layer and a flexible FPC circuit, and the electrode layer is divided into an excitation electrode layer and a grounding electrode layer; the upper alternating shielding layer and the lower alternating shielding layer are arranged on the circuit board corresponding to the corresponding FPC circuit; the excitation electrode layer and the grounding electrode layer are both provided with fractal electrodes, and the fractal electrodes are electrically connected with the flexible FPC circuit. Each of the upper alternating shielding layer and the lower alternating shielding layer comprises a sensing layer and a control layer, the sensing layer is provided with a flexible dual-mode electrode array, the control layer is used for independently driving connection or disconnection of a single electrode in the flexible dual-mode electrode array, and the flexible dual-mode electrode array is electrically connected with the fractal electrode. According to the flexible dual-mode sensing array structure with the variable detection depth, the problem that the resolution and the detection depth of a sensor of a conventional architecture are contradictory and cannot be compatible at the same time is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and particularly to a variable detection depth flexible dual-mode sensing array structure and a manufacturing method thereof. Background Art

[0002] With the development of new technologies such as computer technology, network technology, and flexible electronics technology, intelligent industries represented by robot technology have emerged vigorously. Electronic skin is an important way to help robots perceive the surrounding environment. By monitoring external information, robots can interact well with the outside world at any time, which is one of the most important sensing methods in the robot sensing system. To improve the sensing ability of robots to cope with increasingly complex application scenarios, proximity-contact dual-mode electronic skin sensing arrays have become a research hotspot. However, the improvement of its performance has long been restricted by the collaborative bottleneck of structural design and material properties. In traditional designs, the edge electric field effect of electrodes is not effectively utilized, and the contact sensitivity optimization mechanism is single, resulting in the inability to significantly improve the sensitivity. Only increasing the size of the sensor will bring problems such as cost and stacking compatibility. Currently, the traditional architecture design makes the resolution and detection depth contradictory, unable to be dynamically and adaptively adjusted, and there is also inter-electrode crosstalk, restricting the application scenarios. Summary of the Invention

[0003] In order to overcome the defects existing in the prior art, the present invention provides a variable detection depth flexible dual-mode sensing array structure and a manufacturing method thereof to solve the above problems.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a variable detection depth flexible dual-mode sensing array structure, including an electrode layer, an upper alternating shielding layer, a lower alternating shielding layer, and a flexible FPC circuit. The electrode layer is divided into an excitation electrode layer and a grounding electrode layer; the upper alternating shielding layer, the excitation electrode layer, the lower alternating shielding layer, and the grounding electrode layer are sequentially arranged from top to bottom. The upper alternating shielding layer and the lower alternating shielding layer are both arranged on the circuit board corresponding to the flexible FPC circuit corresponding to them; Both the excitation electrode layer and the grounding electrode layer are provided with fractal electrodes, and the fractal electrodes are electrically connected to the flexible FPC circuit; Both the upper alternating shielding layer and the lower alternating shielding layer include a sensing layer and a control layer. The sensing layer is provided with a flexible dual-mode electrode array. The control layer is used to independently drive the conduction or cutoff of a single electrode in the flexible dual-mode electrode array. The electrodes of the flexible dual-mode electrode array are electrically connected to the fractal electrodes to collect proximity and contact signals.

[0005] It should be noted that each electrode in the flexible dual-mode electrode array is electrically connected to the control layer through an independent wire.

[0006] Specifically, a strip-shaped constant shielding unit is provided in the middle of the sensing layer.

[0007] Optionally, the excitation electrode layer and the grounding electrode layer are mirror chiral symmetric.

[0008] It should be noted that both the excitation electrode layer and the grounding electrode layer include a conductive layer, a preformed layer, and a base layer, which are arranged in sequence from top to bottom.

[0009] Preferably, the fractal electrodes are all arranged on the conductive layer.

[0010] Specifically, a manufacturing method for manufacturing a variable detection depth flexible dual-mode sensing array structure includes the following steps: Electrode layer manufacturing step: Use an Ecoflex film as the base layer in the electrode layer; prepare the conductive layer in the electrode layer by means of a mask screen printing template and an Ecoflex-MNCNTs conductive modified material, and form fractal electrodes on the conductive layer; wherein the fractal electrodes are composed of continuous wires distributed by the Gosper curve; Assembly step of the electrode layer and the alternating shielding layer: Attach the upper alternating shielding layer and the lower alternating shielding layer to the upper and lower sides of the excitation electrode layer respectively, and set Ecoflex substrates between the upper alternating shielding layer and the excitation electrode layer and between the lower alternating shielding layer and the excitation electrode layer to provide support.

[0011] It should be noted that in the electrode layer manufacturing step, for the base layer in the electrode layer, components A and B of Ecoflex-0030 are weighed at a mass ratio of 1:1 at room temperature, poured into a beaker, and stirred with a magnetic stirrer at a speed of 300 rpm for 8 min to form a mixed liquid. Then, the beaker is placed in a vacuum vessel, and a vacuum pump is connected to evacuate the vacuum vessel, so that the mixed liquid is maintained in an environment with a pressure less than -0.9 bar for 15 - 20 min to allow the bubbles in the mixed liquid to escape fully; Take out the beaker, pour the mixed liquid in the beaker into an aluminum alloy curing template, and then transfer the aluminum alloy curing template to a constant temperature drying oven. After heating at 65 °C for 20 min, take it out and cool it naturally to obtain an Ecoflex film.

[0012] Preferably, in the electrode layer manufacturing step, for the conductive layer in the electrode layer, a preformed layer with micro-circular grooves is introduced between the base layer and the mask screen printing template; Pour two samples of MWCNTs into two beakers containing anhydrous ethanol reagent respectively, and use an ultrasonic cleaner to disperse them ultrasonically for 30 minutes to obtain dispersion liquids. Then pour the dispersion liquids into containers containing Ecoflex component A and component B respectively. Insert an electric heating rod into the containers and use a magnetic stirrer to stir for 3 hours under the conditions of 50 °C and 500 rpm. Wait for the anhydrous ethanol in the liquids in the containers to volatilize, and after cooling to room temperature, two precursor liquids are obtained; among them, Ecoflex component A, anhydrous ethanol and MWCNTs are mixed in a mass fraction ratio of 12.5:10:1, and Ecoflex component B, anhydrous ethanol and MWCNTs are mixed in a mass fraction ratio of 12.5:10:1; Mix the two precursor liquids in a mass fraction ratio of 1:1, and stir in a magnetic stirrer under the condition of 300 rpm for 10 minutes to prepare a conductive Ecoflex-MWCNTs precursor; Dip a soft and fine nylon brush into the Ecoflex-MWCNTs precursor, and evenly brush it on the preformed layer. After completely covering the pattern of the template, use a metal scraper to scrape off the excess material on the surface, and let it stand for 10 minutes to make the Ecoflex-MWCNTs precursor fully fill the microgrooves on the surface of the preformed layer under the action of gravity and surface tension to form a micro-dome structure. Then, use the Ecoflex-MNCNTs conductive modification material to print the fractal electrode through a mask screen printing template, so that the fractal electrode is connected to the micro-dome structure.

[0013] It should be noted that in the step of fabricating the electrode layer, for the flexible FPC circuit, PI is used as the flexible FPC circuit substrate, and the conductive path components are Cu and Au; Attach the FPC flexible circuit board to the base layer of the electrode layer, and make the fractal electrode of the conductive layer have an interference fit within the conductive unit frame of the flexible FPC circuit.

[0014] The beneficial effect of the present invention is that in the variable detection depth flexible dual-mode sensing array structure, the alternating shielding architecture composed of the fractal electrode, the upper alternating shielding layer and the lower alternating shielding layer solves the contradiction problem between resolution and detection depth, can change the detection mode of the sensing array at any time, realizes the dynamic adjustment of the resolution and detection depth of the sensing array, and simultaneously reduces the interference of sensing signals between electrodes. Description of the Drawings

[0015] Figure 1 It is an exploded view of the variable detection depth flexible dual-mode sensing array structure in an embodiment of the present invention; Figure 2 It is a schematic diagram of the state conversion of the upper alternating shielding layer and the lower alternating shielding layer in an embodiment of the present invention; Figure 3Schematic diagram of the three - level architecture of the upper alternating shielding layer and the lower alternating shielding layer in an embodiment of the present invention; Figure 4 Schematic diagram of the three - level architecture of the upper alternating shielding layer and the lower alternating shielding layer in another embodiment of the present invention; Figure 5 Schematic diagram of the Gosper curve in an embodiment of the present invention; Figure 6 Distribution diagram of the fractal electrodes in the excitation electrode layer and the grounding electrode layer in an embodiment of the present invention; Figure 7 Schematic diagram of the relationship between the lower alternating shielding layer, the excitation electrode layer and the Ecoflex substrate in an embodiment of the present invention; Figure 8 Schematic process diagram of preparing the electrode layer in an embodiment of the present invention; Figure 9 Schematic structural diagram of the silk - screen template in an embodiment of the present invention; Figure 10 Schematic software architecture diagram in an embodiment of the present invention; Figure 11 Schematic diagram of the gesture acquisition method in an embodiment of the present invention; In the figure: 1 upper alternating shielding layer; 2 excitation electrode layer; 3 lower alternating shielding layer; 4 grounding electrode layer; 5 Ecoflex substrate. Detailed implementation manners

[0016] The following further explains the detailed implementation manners of the present invention with reference to the accompanying drawings. It should be noted here that the description of these implementation manners is used to help understand the present invention, but does not limit the present invention. In addition, the technical features involved in the various implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] As Figures 1-11 shown, a variable detection depth flexible dual - mode sensing array structure includes an electrode layer, an upper alternating shielding layer 1, a lower alternating shielding layer 3 and a flexible FPC circuit. The electrode layer is divided into an excitation electrode layer 2 and a grounding electrode layer 4; As Figure 1 shown, the upper alternating shielding layer 1, the excitation electrode layer 2, the lower alternating shielding layer 3 and the grounding electrode layer 4 are arranged in sequence from top to bottom. The upper alternating shielding layer 1 and the lower alternating shielding layer 3 are both arranged on the circuit board corresponding to their respective flexible FPC circuits; In this way, this circuit board serves as the carrier of the upper alternating shielding layer 1 or the lower alternating shielding layer 3; Both the excitation electrode layer 2 and the grounding electrode layer 4 are provided with fractal electrodes, and the fractal electrodes are electrically connected to the flexible FPC circuit; The upper alternating shielding layer 1 and the lower alternating shielding layer 3 both include a sensing layer and a control layer. The sensing layer is provided with a flexible dual-mode electrode array. The control layer is used to individually drive the conduction or cut-off of a single electrode in the flexible dual-mode electrode array. The electrodes of the flexible dual-mode electrode array are electrically connected to the fractal electrodes to collect proximity and tactile signals.

[0018] In the variable detection depth flexible dual-mode sensing array structure, the alternating shielding architecture composed of the fractal electrodes, the upper alternating shielding layer 1 and the lower alternating shielding layer 3 solves the contradiction between resolution and detection depth. It can change the detection mode of the sensing array at any time, realize the dynamic adjustment of the resolution and detection depth of the sensing array, and simultaneously reduce the interference of sensing signals between electrodes.

[0019] The sensor array structure has an alternating shielding layer structure. Through the dynamic spatio-temporal modulation of a single electrode in the flexible dual-mode electrode array, the adaptive control of resolution and detection depth is completed. At the same time, it has high sensitivity, linearity and good stability. The sensor array structure can monitor various external stimuli from approaching to leaving in all directions and from low voltage to high voltage ranges, and realize high-precision dual-mode perception.

[0020] The upper alternating shielding layer 1 and the lower alternating shielding layer 3 cover the upper and lower sides of the excitation electrode layer 2. Its function is to control the electric field opening state of the excitation electrode layer 2 by controlling the "shielding" (cut-off) and "non-shielding" (conduction) of each alternating shielding unit (a single electrode in the flexible dual-mode electrode array) at each moment. As Figure 2 shown in the state, at each moment, one alternating shielding unit is in a floating state (NC = not connect). At this time, the electrode electric field inside this alternating shielding unit is released into the space, while other alternating shielding units are connected to the active shielding signal to shield the electrode electric fields in other areas; the alternating shielding unit with the NC state is switched at the next moment. Therefore, the external capacitance sensed by the excitation electrode layer 2 at each moment represents the external capacitance of different geometric regions. By alternately changing the shielded regions within a cycle period, an array scan can be completed within one cycle. The advantage of this is that the size of the "open" electrode geometric region can be controlled at each moment (such as opening 2 or 4 electrode regions simultaneously), so as to realize the dynamic adjustment of resolution and detection distance (the detection distance is strongly related to the size of the exposed electrode area), so as to cover and adapt to a variety of complex application scenarios.

[0021] Based on the functional requirements of the capacitive flexible dual-mode sensing array, the hardware systems of the upper alternating shielding layer 1 and the lower alternating shielding layer 3 adopt a three-level architecture design of sensing layer - control layer - communication layer. Therefore, the upper alternating shielding layer 1 and the lower alternating shielding layer 3 both further include a communication layer. As Figure 3 and 4As shown, the sensing layer is composed of a flexible dual-mode electrode array. The detection area is dynamically regulated by an alternating shielding layer to achieve synchronous acquisition of proximity and tactile signals. The control layer takes a microcontroller MCU as the core and integrates a high-precision capacitance digital converter and a multiplexing module. The timing switching of the shielding unit is controlled by an embedded program to ensure accurate switching of the scanning mode and accurate acquisition of capacitance digital signals. The communication layer uses a USRAT serial port to implement the transmission link of control instructions and data feedback, and transmits the sensing data processed by the MCU to the host computer, i.e., the PC terminal, in real time. At the same time, it has a local caching function, supporting offline acquisition and resume from breakpoint. Through the collaborative optimization of software and hardware, this architecture endows the electronic skin with the capabilities of dynamic detection range adjustment, multi-modal signal decoupling, and environmental adaptive perception, providing highly reliable sensing input for robot environmental perception and human-machine interaction.

[0022] It should be noted that each electrode in the flexible dual-mode electrode array is electrically connected to the control layer through an independent wire.

[0023] To minimize the impact of the upper alternating shielding layer 1 or the lower alternating shielding layer 3 on the flexibility of the overall sensor, the electrodes in the flexible dual-mode electrode array are made of a mesh copper layer. Each electrode is connected to the hardware circuit part by an independent wire, and through circuit connection design, it is ensured that the electrodes above and below the same electrode position are electrically connected to each other, and the electrodes at different electrode positions are not electrically connected to each other. Thus, independent control of each electrode can be achieved. Each electrode controls the electric field intensity at the edge of the electrode network in this geometric area. By circuit control, the electrodes at different positions are connected to the active shield (ACsheild) of the AD7747 chip or in a floating state (NC), and alternate at different times to achieve shielding of different positions of the electrode layer at different times, and realize the function of one scan within one cycle. The maximum outer dimensions of the upper alternating shielding layer 1 and the lower alternating shielding layer 3 are 160 mm × 60 mm, and the size of a single electrode in the flexible dual-mode electrode array is 25 mm × 25 mm, slightly larger than the fractal electrode to obtain the best shielding characteristics.

[0024] The alternating shielding logic controls the connection of each shielding unit to the active shield or floating state (NC) independently, and alternately activates the electric field shielding in different regions in the time domain. Its electrode layer is a whole conductive network formed by the actual electrical connection of each fractal electrode. Therefore, the electric field in different geometric regions can be opened at different time steps within a cycle, thus completing a high-resolution scan, but with a low detection depth. If all the electrodes in the sex-dual-mode electrode array are connected to the NC state, the electric field formed by the full-size electrode conductive network can be completely opened, thus completing a scan with a high detection depth, but the resolution is 1. The advantages of this architecture are as follows: The upper alternating shielding layer 1 and the lower alternating shielding layer 3 can prevent the parasitic capacitance between adjacent electrodes from entering the open area, thus generating signal crosstalk. At the same time, the alternating shielding mechanism can construct a real large-size open electric field through alternating logic while keeping the physical electrode unit miniaturized, increasing the detection depth by several times. The time and space modulation logic of the alternating shielding layer allows any combination of activated electrode regions to achieve a resolution-detection depth dynamically adjustable adaptive detection mode.

[0025] Optionally, a strip-shaped constant shielding unit is provided in the middle of the sensing layer. The maximum size of the outer shape of the sensing layer of the alternating shielding layer is 160 mm × 60 mm, and the size of a single shielding unit is 25 mm × 25 mm, slightly larger than the fractal electrode to obtain the best shielding characteristics. A constant shielding unit with a size of 130 mm × 5 mm is also provided at the middle position of the shielding layer to isolate the capacitive crosstalk in the middle part of the sensor.

[0026] Preferably, the excitation electrode layer 2 and the grounding electrode layer 4 are mirror chiral symmetric to arrange the microstructures inwardly relative to each other and obtain a good packaging operation space. The conductive path of the electrode layer is formed by connecting each fractal electrode with a flexible FPC circuit (mainly composed of Cu and Au), which has the characteristics of low resistance and can be bent arbitrarily. The flexible FPC circuit ensures that each fractal electrode is electrically connected to form a whole conductive grid, and ensures that the voltage loss at the connection part between the fractal electrodes can be ignored, ensuring the consistency of the edge field strength of each fractal electrode, and at the same time endowing the electrode layer with the flexible and bendable characteristics.

[0027] Specifically, both the excitation electrode layer 2 and the grounding electrode layer 4 include a conductive layer, a preformed layer, and a base layer, which are arranged in sequence from top to bottom.

[0028] It should be noted that the fractal electrodes are all arranged on the conductive layer.

[0029] The maximum outer dimensions of both the excitation electrode layer 2 and the ground electrode layer 4 are 160 mm × 60 mm. The size of a single fractal electrode is 22.5 mm × 22.5 mm. The width of the fractal structure feature in the fractal electrode is 1.5 mm. A total of 10 fractal electrodes are arranged in an array in the form of 2 rows and 5 columns.

[0030] Specifically, a manufacturing method for manufacturing a variable detection depth flexible dual-mode sensing array structure includes the following steps: Electrode layer manufacturing step: Use an Ecoflex film as the base layer in the electrode layer to provide flexibility characteristics; prepare the conductive layer in the electrode layer through a mask screen printing template and use an Ecoflex-MNCNTs conductive modified material, and form a fractal electrode in the conductive layer to improve the contact sensitivity by increasing the surface roughness; among them, the fractal electrode is composed of continuous wires distributed by the Gosper curve to obtain a stronger edge effect and improve the proximity sensitivity; in this embodiment, the Ecoflex-MNCNTs conductive modified material is an Ecoflex material doped with 8 wt% of MWCNTs. In this embodiment, as Figure 5 and 6 shown, the fractal electrode realizes an efficient increase in the side length and the number of corners through self-similarity and recursive iteration; the principle is that starting from an initial simple shape, each iteration subdivides the local area according to specific rules; each iteration generates new broken lines on the original line segment, and the newly added line segments bring more side lengths, and a large number of corners are formed at the turning points of the line segments, accumulating in a geometric progression, so as to efficiently increase the quantity of both; this characteristic can greatly increase the number of edges and corners of the capacitive sensor. Coupled with the phenomenon that charges tend to accumulate at the edges of the electrode plates, the edge effect of the electrode increases geometrically. Assembly step of the electrode layer and the alternating shielding layer: Attach the upper alternating shielding layer 1 and the lower alternating shielding layer 3 to the upper and lower sides of the excitation electrode layer 2 respectively, and set an Ecoflex substrate 5 between the upper alternating shielding layer 1 and the excitation electrode layer 2 and between the lower alternating shielding layer 3 and the excitation electrode layer 2 to provide support. The Ecoflex substrate 5 is used for encapsulation between layers. As Figure 7 shown, after each layer is manufactured, an uncured Ecoflex precursor is applied, pressed and heated for curing, and a complete sensor array can be obtained after taking it out.

[0031] It should be noted that in the electrode layer manufacturing step, as Figure 8As shown in the figure, for the base layer in the electrode layer, component A and component B of Ecoflex-0030 are weighed at a mass ratio of 1:1 at room temperature and poured into a beaker. A magnetic stirrer is used to stir the mixture at a speed of 300 rpm for 8 minutes to form a mixed liquid. Then, the beaker is placed in a vacuum vessel, and a vacuum pump is connected to evacuate the vacuum vessel, so that the mixed liquid is kept under an environment with a pressure less than -0.9 bar for 15 - 20 minutes to allow the bubbles in the mixed liquid to escape fully; Take out the beaker, pour the mixed liquid in the beaker into an aluminum alloy curing template, and then transfer the aluminum alloy curing template to a constant temperature drying oven. After heating at 65 °C for 20 minutes, take it out and cool it naturally to obtain an Ecoflex film.

[0032] Since the thickness of the Ecoflex film is small, if it is directly peeled off, affected by surface tension, the Ecoflex film will shrink and wrinkle naturally, affecting subsequent operations. Therefore, it is not necessary to peel the cured Ecoflex film from the template, and processing will be directly carried out on the surface of the Ecoflex film in the aluminum alloy curing template in subsequent operations.

[0033] Preferably, in the manufacturing step of the electrode layer, for the conductive layer in the electrode layer, a preformed layer with micro-circular grooves is first introduced between the base layer and the mask screen printing template; Pour two samples of MWCNTs into two beakers filled with anhydrous ethanol reagent respectively, and use an ultrasonic cleaner to disperse them ultrasonically for 30 minutes to obtain dispersions. Pour the dispersions into containers filled with Ecoflex component A and component B respectively, insert an electric heating rod into the containers, and use a magnetic stirrer to stir at 50 °C and 500 rpm for 3 hours. Wait for the anhydrous ethanol in the liquid in the containers to volatilize, and after cooling to room temperature, two precursor solutions are obtained; among them, Ecoflex component A, anhydrous ethanol, and MWCNTs are mixed in a mass fraction ratio of 12.5:10:1, and Ecoflex component B, anhydrous ethanol, and MWCNTs are mixed in a mass fraction ratio of 12.5:10:1; Mix the two precursor solutions in a mass fraction ratio of 1:1 and stir them in a magnetic stirrer at a condition of 300 rpm for 10 minutes to prepare a conductive Ecoflex-MWCNTs precursor; Use a clean, soft nylon brush to dip into the Ecoflex-MWCNTs precursor and evenly brush it on the preformed layer. After completely covering the pattern of the template, use a metal squeegee to scrape off the excess material on the surface and let it stand for 10 minutes. Under the action of gravity and surface tension, the Ecoflex-MWCNTs precursor fully fills the microgrooves on the surface of the preformed layer to form a microdome structure. Then, use the Ecoflex-MNCNTs conductive modification material to print the fractal electrode through a mask screen printing template, so that the fractal electrode is connected to the microdome structure. In this embodiment, setting the microdome structure on the fractal electrode can further improve the contact sensitivity of the fractal electrode.

[0034] The preparation of the electrode layer requires the production of a preformed layer, which refers to a pre-cured elastic sealing layer introduced between the mask screen printing template and the base layer. The preformed layer is made of the same Ecoflex silicone rubber material as the base layer and is formed by brushing a thin layer of Ecoflex solution and curing. Its cured body is closely attached to the base layer and completely fills the micron-sized gap between the aluminum alloy curing template and the base layer, forming a seamless interface closed structure. In addition, grooving on the surface of the base layer can provide a preformed solution for the microdome structure of the conductive layer.

[0035] Specifically, as Figure 3 shown, the mask screen printing template has the following characteristics: the size is 140mm×60mm×0.5mm, made of 304 stainless steel, and the hollowed-out pattern is completely complementary to the pattern of the electrode layer to facilitate the formation of the preformed layer; among them, the printed pattern of the ground electrode layer 4 and the printed pattern of the excitation electrode layer 2 are also complementary.

[0036] Specifically, in the electrode layer manufacturing step, for the flexible FPC circuit, PI is used as the base of the flexible FPC circuit, and the conductive path components are Cu and Au to have good electrical conductivity and bendable characteristics; Attach the FPC flexible circuit board to the base layer of the electrode layer, and make the fractal electrode of the conductive layer have an interference fit within the conductive unit frame of the flexible FPC circuit.

[0037] To ensure a stable and reliable electrical connection between the fractal electrode and the exposed copper area of the FPC flexible circuit, 6wt% mass fraction Ecoflex-MWCNTs conductive silicone rubber with better mechanical properties is selected as the preferred material for dot coating connection; Component A of Ecoflex, absolute ethanol, and MWCNTs are mixed in a mass ratio of 16:12.5:1, and Component B of Ecoflex, absolute ethanol, and MWCNTs are mixed in a mass ratio of 16:12.5:1; After preparation, a syringe with a needle diameter of 0.8 mm is used to inject and dot coat the uniformly mixed conductive silicone rubber, and the dot coating range needs to cover the edge of the fractal electrode and the exposed copper area where the FPC flexible circuit conducts electricity to ensure sufficient contact and effective connection. Finally, the dot coating area is cured to further improve the stability and reliability of the connection and meet the usage requirements of flexible electronic devices under complex working conditions.

[0038] In this solution, as Figure 10 shown, the software application is built based on the Python language and uses the PySide6 library. The overall architecture follows the MVC pattern, aiming to achieve efficient interaction with hardware devices such as the dual-mode electronic skin system and accurate processing and presentation of data.

[0039] In the presentation layer (View), a series of key controls such as "Start", "Save", "DAP", "Link", "Move" are laid out in the UI layer (Ui_MainWindow) built with PySide6. These controls serve as the direct entry for users to interact with the software. After the user clicks, the respective operation instruction functions they are connected to are executed. At the same time, a visualization graphic control based on QGraphicsView is set up for data display, presenting the processed data to the user in the form of intuitive graphs and charts. When the user performs an operation, the UI layer quickly captures this interaction information and accurately transmits it to the control layer in a timely manner, thus initiating the subsequent processing flow.

[0040] The core of the Control layer is the main program class MainWindow. On the one hand, it precisely responds to operation events such as button clicks from the Presentation layer through the buttonClick() method, and calls the corresponding processing logic according to different instruction types. On the other hand, methods such as update_scene() and update_data() ensure the synchronous update of data and interface display, ensuring that users can obtain the latest information in real time. In addition, with the help of the timer mechanism, the software can execute timed loop tasks, and put time-consuming operations in the Model layer into sub-thread implementation. The serial communication class SerialReader undertakes the key task of data communication with the hardware device (dual-mode electronic skin system) through USART in the Control layer. It reads the hexadecimal data packets transmitted from the hardware system in real time, and performs preliminary screening and processing through methods such as filter(), extracts and classifies the content of the data packets into different sensor data sequences, providing a data basis for subsequent data processing in the Model layer.

[0041] The Model layer is dominated by the APP function class APPFunction, covering multiple key functional modules. The data processing and visualization module converts the original data array into a color matrix according to the corresponding rules through methods such as paintPicData() and update_color_array(), and transmits it to the main program for data visualization display, making complex data easy to understand. The interpretable neural network module provides strong support for data analysis and prediction, inputs the original data into the deep learning model, and outputs gesture recognition results, etc. The data cloud upload, local storage and call module packs the array variables into PKL files during each data transmission process, saves them to the local or cloud platform, ensuring the security and traceability of the data, and facilitating users to obtain and manage the data at any time.

[0042] Specifically, the software application includes the following features: It has the application function of gesture recognition. As Figure 11 shown, the gesture data collection method includes: The subject hovers the hand randomly above the sensor, performs five basic actions: right shift, left shift, two-finger zoom in, two-finger zoom out, and approach. Each action is repeated 300 times to cover different hand shape sizes, movement speeds, and spatial position variables. The necessity of gesture recognition technology stems from its value in the human-computer interaction scenario: The non-contact sensing ability of the electronic skin can replace traditional cameras or mechanical buttons, and achieve contactless control in privacy-sensitive scenarios or complex environments, such as in oil stains and low light.

[0043] Preferably, the gesture data classification results include the following features: the features of the fully connected layer are visualized by dimensionality reduction using t-SNE. Before model training, high-dimensional sensor signals are preprocessed by dimensionality reduction to observe the potential distribution patterns of the original data. After training, the deep features extracted by the neural network are dimensionally reduced to analyze the clustering characteristics of the feature space. Before classification, various gesture samples form tight clusters in the embedding space, interpenetrating each other without obvious distinction. However, as the model is continuously trained, an obvious separation trend occurs among the gesture data clusters during the intermediate training process. After the training ends, there is an obvious gap between different types of samples, proving that the model has good performance for the gesture classification task.

[0044] In this solution, the proposed variable detection depth flexible dual-mode sensing array structure can expand and enhance the perception ability of the robot. This dual-mode sensing array structure can be widely applied to the safety obstacle avoidance and precision assembly of industrial collaborative robots, the contact force monitoring and non-invasive interaction of medical rehabilitation robots, the dynamic environment perception and virtual tactile feedback in embodied intelligence applications, the in-vehicle interaction in cars, the gesture recognition and touch interaction of consumer electronics products, the proximity avoidance and collision analysis of home service robots, etc., to achieve environmental perception and intelligent response in multiple scenarios.

[0045] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A variable detection depth flexible dual-mode sensing array structure, characterized in that: It includes an electrode layer, an upper alternating shielding layer, a lower alternating shielding layer, and a flexible FPC circuit. The electrode layer is divided into an excitation electrode layer and a grounding electrode layer; the upper alternating shielding layer, the excitation electrode layer, the lower alternating shielding layer, and the grounding electrode layer are arranged in sequence from top to bottom. The upper alternating shielding layer and the lower alternating shielding layer are both disposed on the circuit board corresponding to the flexible FPC circuit corresponding to them. Both the excitation electrode layer and the grounding electrode layer are provided with fractal electrodes, and the fractal electrodes are electrically connected to the flexible FPC circuit. Both the upper alternating shielding layer and the lower alternating shielding layer include a sensing layer and a control layer. The sensing layer is provided with a flexible dual-mode electrode array. The control layer is used to individually drive the conduction or cutoff of a single electrode in the flexible dual-mode electrode array. The electrodes of the flexible dual-mode electrode array are electrically connected to the fractal electrodes to collect proximity and contact sensing signals.

2. The variable detection depth flexible dual-mode sensing array structure according to claim 1, characterized in that: Each electrode in the flexible dual-mode electrode array is electrically connected to the control layer through an independent wire.

3. A variable detection depth flexible dual-mode sensing array structure according to claim 1, characterized in that: A strip-shaped constant shielding unit is provided in the middle of the sensing layer.

4. A variable detection depth flexible dual-mode sensing array structure according to claim 1, characterized in that: The excitation electrode layer and the grounding electrode layer are mirror chiral symmetric.

5. A variable detection depth flexible dual-mode sensing array structure according to claim 1, characterized in that: Both the excitation electrode layer and the grounding electrode layer include a conductive layer, a preformed layer, and a base layer, and the conductive layer, the preformed layer, and the base layer are arranged in sequence from top to bottom.

6. The variable detection depth flexible dual-mode sensing array structure according to claim 5, characterized in that: The fractal electrodes are all disposed on the conductive layer.

7. A manufacturing method for manufacturing a variable detection depth flexible dual-mode sensing array structure as described in claim 1, characterized in that, It includes the following steps: Electrode layer manufacturing step: Use Ecoflex film as the base layer in the electrode layer; prepare the conductive layer in the electrode layer by means of a mask screen printing template and using Ecoflex-MNCNTs conductive modified material, and form fractal electrodes on the conductive layer; among them, the fractal electrodes are composed of continuous wires distributed by Gosper curves. Assembly step of the electrode layer and the alternating shielding layer: Attach the upper alternating shielding layer and the lower alternating shielding layer to the upper and lower sides of the excitation electrode layer respectively, and set Ecoflex substrates between the upper alternating shielding layer and the excitation electrode layer and between the lower alternating shielding layer and the excitation electrode layer to provide support.

8. A manufacturing method according to claim 7, characterized in that: In the electrode layer manufacturing step, for the base layer in the electrode layer, weigh component A and component B of Ecoflex-0030 at a mass ratio of 1:1 at room temperature, pour them into a beaker, use a magnetic stirrer to stir at a speed of 300 rpm for 8 min to form a mixed liquid, then put the beaker into a vacuum vessel, connect a vacuum pump to evacuate the vacuum vessel, and keep the mixed liquid in an environment with a pressure less than -0.9 bar for 15 - 20 min to allow the bubbles in the mixed liquid to fully escape. Take out the beaker, pour the mixed liquid in the beaker into an aluminum alloy curing template, then transfer the aluminum alloy curing template to a constant temperature drying oven, heat it at 65 °C for 20 min and then take it out to cool naturally to obtain the Ecoflex film.

9. The manufacturing method according to claim 8, characterized in that: In the electrode layer manufacturing step, for the conductive layer in the electrode layer, first introduce a preformed layer with micro-circular grooves between the base layer and the mask screen printing template. Pour two samples of MWCNTs into two beakers containing anhydrous ethanol reagent respectively, and use an ultrasonic cleaner to disperse them ultrasonically for 30 min to obtain dispersions. Then pour the dispersions into containers containing Ecoflex component A and component B respectively. Insert an electric heating rod into the containers and stir with a magnetic stirrer at 50 °C and 500 rpm for 3 h. Wait for the anhydrous ethanol in the liquid in the containers to volatilize, and after cooling to room temperature, obtain two precursor solutions; Among them, Ecoflex component A, anhydrous ethanol and MWCNTs are mixed in a mass fraction ratio of 12.5:10:1, and Ecoflex component B, anhydrous ethanol and MWCNTs are mixed in a mass fraction ratio of 12.5:10:1; Mix the two precursor solutions in a mass fraction ratio of 1:1 and stir in a magnetic stirrer at 300 rpm for 10 min to prepare a conductive Ecoflex-MWCNTs precursor; Dip a soft nylon brush into the Ecoflex-MWCNTs precursor and evenly brush it on the preformed layer. After completely covering the pattern of the template, use a metal scraper to scrape off the excess material on the surface, and let it stand for 10 min to allow the Ecoflex-MWCNTs precursor to fully fill the micro-circular grooves on the surface of the preformed layer under the action of gravity and surface tension to form a micro-dome structure. Then, use the Ecoflex-MNCNTs conductive modification material to print the fractal electrode through a mask screen printing template to connect the fractal electrode with the micro-dome structure.

10. A manufacturing method according to claim 9, characterized in that: In the step of fabricating the electrode layer, for the flexible FPC circuit, PI is used as the flexible FPC circuit substrate, and the conductive path component is Cu and Au; Attach the FPC flexible circuit board to the base layer of the electrode layer, and make the fractal electrode of the conductive layer have an interference fit within the conductive unit frame of the flexible FPC circuit.

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