Integrated flexible pressure gait monitoring system and preparation packaging method

Abstract

The application discloses an integrated flexible pressure gait monitoring system and a preparation packaging method, relates to the technical fields of wearable flexible sensing and gait monitoring, and comprises a flexible array distributed pressure sensor, a miniaturized signal acquisition circuit module, a battery module and special shoes. The flexible array distributed pressure sensor comprises, from top to bottom, a pressure-sensitive layer, an adhesive layer and a flexible electrode which are laminated in sequence, the flexible array distributed pressure sensor is in the shape of an insole and is laid flat on the inner surface of the shoe sole of the special shoes, the miniaturized signal acquisition circuit module is electrically connected with the flexible electrode, and the battery module is electrically connected with the miniaturized signal acquisition circuit module. The application adopts the above-mentioned integrated flexible pressure gait monitoring system and preparation packaging method, improves product consistency and facilitates large-scale production; the interdigital electrode array greatly improves the plantar pressure resolution and can accurately capture local pressure abnormalities; the integrated microcircuit and the special shoes realize wireless transmission and convenient wearing.

Description

Technical Field

[0001] This invention relates to the fields of wearable flexible sensing and gait monitoring technology, and in particular to an integrated flexible pressure gait monitoring system and its preparation and packaging method. Background Technology

[0002] Gait recognition, as a biometric identification technology, has broad application prospects in fields such as sports biomechanics analysis, human-computer interaction, and identity recognition. The human foot contains complex skeletal, ligament, and neural structures, and the plantar pressure distribution can intuitively reflect key postures such as heel strike, full foot support, and toe lift-off during the gait cycle, making it a core indicator for assessing human health and motor function.

[0003] Existing gait monitoring technologies are mainly divided into image analysis methods and wearable sensing detection methods. Image analysis methods are easily affected by environmental factors such as lighting, clothing, and background, and have high requirements for scene deployment, making it impossible to achieve continuous and portable gait monitoring in daily life. Wearable sensors such as electromyography sensors and inertial measurement units have defects such as easy signal interference, large cumulative error, and poor individual adaptability, making it difficult to stably obtain accurate gait data. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated flexible pressure gait monitoring system and its fabrication and packaging method. The interdigital electrode array significantly improves the resolution of plantar pressure and can accurately capture local pressure anomalies. The row and column multiplexing wiring is easy to expand and the electrical connection is reliable.

[0005] This invention provides an integrated flexible pressure gait monitoring system and its fabrication and packaging method, including a flexible array distributed pressure sensor, a miniaturized signal acquisition circuit module, a battery module, and a special shoe. The flexible array distributed pressure sensor includes a pressure-sensitive layer, an adhesive layer, and a flexible electrode stacked sequentially from top to bottom. The flexible array distributed pressure sensor is shaped like an insole and is laid flat on the inner surface of the sole of the special shoe. The miniaturized signal acquisition circuit module is electrically connected to the flexible electrode, and the battery module is electrically connected to the miniaturized signal acquisition circuit module.

[0006] Preferably, the pressure-sensitive layer includes a first flexible substrate and a pressure-sensitive sensing unit disposed on the lower surface of the first flexible substrate, and the flexible electrode includes a second flexible substrate and an interdigitated electrode unit disposed on the upper surface of the second flexible substrate, with the interdigitated electrode unit and the pressure-sensitive sensing unit being disposed vertically and vertically respectively.

[0007] Preferably, the adhesive layer is located between the pressure-sensitive layer and the flexible electrode, and the adhesive layer has an array of through holes corresponding to the positions of the pressure-sensitive sensing unit and the interdigital electrode unit.

[0008] Preferably, the sole of the special footwear has a groove at the heel, and the miniaturized signal acquisition circuit module and battery module are both located inside the groove.

[0009] Preferably, a flexible buffer protective layer is provided in the groove, which covers the miniaturized signal acquisition circuit module and the battery module.

[0010] Preferably, the flexible electrode also includes a front lead of the flexible circuit, a back lead of the flexible circuit, and a gold finger interface, the gold finger interface being electrically connected to the miniaturized signal acquisition circuit module.

[0011] Preferably, both the pressure-sensitive sensing unit and the interdigital electrode unit are arranged in an 8-row × 8-column array.

[0012] A method for fabricating and packaging an integrated flexible pressure gait monitoring system includes the following steps: Step S1: Preparation of conductive paste; A pressure-sensitive conductive paste is prepared using few-layer graphene as the conductive filler, epoxy resin E-51 as the matrix material, polyetheramine D400 as the curing agent, and terpineol as the diluent; wherein, the mass ratio of epoxy resin to graphene is 1:4, the mass ratio of epoxy resin to polyetheramine is 2:1, and 0.3g of terpineol is added to adjust the viscosity; first, the bottom of the beaker is wetted with terpineol, then epoxy resin, graphene, and polyetheramine are added in sequence, and the mixture is manually stirred for 15 minutes until the graphene is uniformly dispersed to obtain the conductive paste; Step S2: Preparation of pressure-sensitive functional layer; The conductive paste is transferred to the lower surface of the first flexible substrate with a thickness of 75μm by screen printing process, and then cured by heating at 110℃ for 60 minutes to form a pressure-sensitive sensing unit array, thus obtaining the pressure-sensitive layer; Step S3: Fabrication of flexible electrode layer; The interdigitated electrode unit and the gold finger interface are fabricated using a PI copper-clad laminate through photolithography and etching processes. The non-electrode area is covered with an insulating protective layer to obtain a flexible electrode. Step S4: Preparation of adhesive layer; 3M 300LSE high-adhesion acrylic double-sided tape is selected as adhesive layer, and through-hole array matching interdigital electrode unit is laser cut out; Step S5: Sensor packaging; The pressure-sensitive layer, adhesive layer, and flexible electrode are sequentially aligned and bonded together to form a flexible array distributed pressure sensor through integrated packaging. Step S6, System Integration: Lay the flexible array distributed pressure sensor flat on the inner surface of the sole of the special footwear, connect it to the miniaturized signal acquisition circuit module through the gold finger interface, install the miniaturized signal acquisition circuit module and battery module into the groove and cover them with a flexible buffer protective layer to complete the system integration.

[0013] Therefore, the present invention adopts the above-mentioned integrated flexible pressure gait monitoring system and preparation and packaging method. The interdigital electrode array greatly improves the resolution of plantar pressure and can accurately capture local pressure anomalies; the row and column multiplexing wiring is easy to expand and the electrical connection is reliable.

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0015] Figure 1 This is an exploded view of the overall structure of an integrated flexible pressure gait monitoring system according to the present invention; Figure 2 This is a schematic diagram of the structure of a flexible array distributed pressure sensor in an integrated flexible pressure gait monitoring system according to the present invention. Figure 3 This is a schematic diagram of the array distribution of flexible array distributed pressure sensor electrodes in an integrated flexible pressure gait monitoring system of the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of a single sensing unit area in a flexible array distributed pressure sensor in an integrated flexible pressure gait monitoring system of the present invention when it is not under stress. Figure 5 This is a schematic diagram of the cross-sectional structure of a single sensing unit region in a flexible array distributed pressure sensor of an integrated flexible pressure gait monitoring system of the present invention when subjected to force. Figure 6 This is a schematic diagram of the structure of the interdigitated electrode in a single region of a flexible array distributed pressure sensing unit in an integrated flexible pressure gait monitoring system of the present invention. Figure 7 This is a front view schematic diagram of the special footwear in the integrated flexible pressure gait monitoring system of the present invention; Figure 8 This is a top view schematic diagram of the special footwear in the integrated flexible pressure gait monitoring system of the present invention; Figure 9 This is a circuit block diagram of the miniaturized signal acquisition circuit module in the integrated flexible pressure gait monitoring system and its fabrication and packaging method of the present invention. Figure 10 This is a schematic diagram of the overall process for the fabrication and packaging method of an integrated flexible pressure gait monitoring system according to the present invention.

[0016] Figure Labels 1. Pressure-sensitive layer; 2. Adhesive layer; 3. Flexible electrode; 4. Miniaturized signal acquisition circuit module; 5. Battery module; 6. Special footwear; 11. Pressure-sensitive sensing unit; 12. First flexible substrate; 31. Interdigitated electrode unit; 32. Second flexible substrate; 33. Front lead of flexible circuit; 34. Back lead of flexible circuit; 35. Gold finger interface; 61. Groove; 62. Flexible buffer protective layer. Detailed Implementation

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0019] The terms "first," "second," and similar words used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example 1 like Figures 1-10 As shown, the present invention discloses an integrated flexible pressure gait monitoring system and its fabrication and packaging method, comprising a flexible array distributed pressure sensor, a miniaturized signal acquisition circuit module 4, a battery module 5, and a special shoe 6; the flexible array distributed pressure sensor comprises a pressure-sensitive layer 1, an adhesive layer 2, and a flexible electrode 3 stacked sequentially from top to bottom, the flexible array distributed pressure sensor being in the shape of an insole and laid flat on the inner surface of the sole of the special shoe 6, the miniaturized signal acquisition circuit module 4 being electrically connected to the flexible electrode 3, and the battery module 5 being electrically connected to the miniaturized signal acquisition circuit module 4.

[0021] The pressure-sensitive layer 1 includes a first flexible substrate 12 and a pressure-sensitive sensing unit 11 disposed on the lower surface of the first flexible substrate 12. The first flexible substrate 12 is made of a 75μm thick polyimide (PI) film, which has both good flexibility and mechanical strength. The pressure-sensitive sensing unit 11 is formed by curing a mixture of few-layer graphene and epoxy resin at a mass ratio of 1:4. The surface of the pressure-sensitive sensing unit 11 has a regularized microgrid structure, and the effective pressure-sensing area is 4.4mm × 6.8mm.

[0022] The flexible electrode 3 includes a second flexible substrate 32 and interdigital electrode units 31 disposed on the upper surface of the second flexible substrate 32. The interdigital electrode units 31 are arranged vertically and vertically corresponding to the pressure-sensitive sensing unit 11. Both the pressure-sensitive sensing unit 11 and the interdigital electrode units 31 are arranged in an 8-row × 8-column array, totaling 64 units. The second flexible substrate 32 is made of 0.13mm thick PI copper-clad laminate; the interdigital electrode units 31 are made of copper. They are fabricated using photolithography etching, with an electrode linewidth of 0.254mm. The 64 interdigital electrode units 31 are arranged regionally according to the physiological structure of the human foot: 32 interdigital electrode units 31 are arranged in the forefoot area, 16 interdigital electrode units 31 are arranged in the arch area, and 16 interdigital electrode units 31 are arranged in the heel area, fully covering the main pressure areas of the sole of the foot.

[0023] The flexible electrode 3 also includes a flexible circuit front lead 33, a flexible circuit back lead 34, and a gold finger interface 35, which is electrically connected to the miniaturized signal acquisition circuit module 4. The 64 arrayed interdigital electrode units 31 are electrically connected via the flexible circuit front lead 33 and flexible circuit back lead 34 through metallized vias on the polyimide substrate, and are uniformly connected to the gold finger interface 35, thereby achieving a reliable electrical connection with the miniaturized signal acquisition circuit module 4.

[0024] Adhesive layer 2 is located between pressure-sensitive layer 1 and flexible electrode 3. Adhesive layer 2 uses 0.15mm thick 3M 300LSE high-adhesion acrylic double-sided tape to achieve precise positioning and firm adhesion between pressure-sensitive layer 1 and flexible electrode layer 3. An array of through holes is formed on adhesive layer 2, corresponding to the positions of pressure-sensitive sensing unit 11 and interdigital electrode unit 31. The size of the through holes matches that of pressure-sensitive sensing unit 11 to ensure gapless electrical contact between pressure-sensitive sensing unit 11 and the underlying interdigital electrode unit 31.

[0025] The pressure sensing principle is based on the contact resistance change mechanism: In the unstressed state, a gap formed by the thickness of the adhesive layer 2 exists between the pressure-sensitive sensing unit 11 and the interdigital electrode unit 31. The two finger-shaped electrodes of the interdigital electrode unit 31 are in an open circuit state, resulting in a relatively high overall resistance. In the stressed state, the pressure-sensitive sensing unit 11 undergoes elastic deformation and passes through the through-hole of the adhesive layer 2, making close contact with the surface of the interdigital electrode unit 31. The conductive graphene filler forms a conductive path between the interdigital electrodes; and the contact area increases with increasing pressure, causing the resistance value between the interdigital electrode units 31 to decrease systematically. By detecting the change in resistance, the magnitude of the pressure can be quantitatively sensed.

[0026] The special-purpose shoe 6 has a groove 61 at the heel of the sole. The miniaturized signal acquisition circuit module 4 and battery module 5 are both housed inside the groove 61. A flexible cushioning protective layer 62 is provided within the groove 61, covering the miniaturized signal acquisition circuit module 4 and battery module 5. The special-purpose shoe 6 adopts an ergonomic design, with a 7cm × 3cm × 1cm recess 61 at the heel to accommodate the miniaturized signal acquisition circuit module 4 and power module 5. The groove 61 is filled with a flexible silicone cushioning protective layer 62, the thickness of which is configured so that its upper surface is flush with or slightly higher than the edge of the groove 61 opening. This provides cushioning protection for the internal circuit modules while ensuring flatness of the foot support and wearing comfort.

[0027] The miniaturized signal acquisition circuit module 4 consists of a main control chip, an array scanning and signal conditioning unit, a high-precision ADC chip, and a Bluetooth module, realizing time-division scanning, signal conditioning, analog-to-digital conversion, and wireless transmission of 64 pressure signals. The miniaturized signal acquisition circuit module 4 adopts a row-column multiplexing architecture, reducing the signal leads of 64 sensing units to 16, greatly simplifying the wiring complexity.

[0028] The main control chip uses an STM32F401CBU6 microcontroller as the system control core, based on an ARM Cortex-M4 core with a main frequency of 84MHz. It features abundant SPI, USART interfaces, and general-purpose I / O ports. Its functions include: generating array scan timing sequences; controlling channel selection of multiple analog switches; configuring the sampling parameters of the ADC chip and reading the converted digital signal; and driving the Bluetooth module to complete wireless data transmission. The main control chip is powered by a 3.3V digital power supply from the power module.

[0029] The array scanning and signal conditioning unit includes a multiplexer analog switch and an operational amplifier. The multiplexer analog switch uses a TMUX4051PWR chip, with its eight input channels connected to the eight rows of the flexible array distributed pressure sensor, and its common output connected to the operational amplifier array. The multiplexer analog switch is controlled by the GPIO port of the main control chip, sequentially selecting the sensing units in rows 1 to 8 according to a preset timing sequence to achieve time-division multiplexing of 64 signals.

[0030] The operational amplifiers utilize four TP5594-TR quad operational amplifiers to form an eight-channel independent inverting amplifier circuit. When each row is selected, the outputs of the eight sensing units in that row are connected to the negative input of the corresponding operational amplifier. Each operational amplifier, along with a 1kΩ precision reference resistor Rf, forms a signal conditioning circuit that converts the resistance changes of the sensing units into measurable voltage changes, which are then amplified. The operational amplifiers are powered by a ±2.5V high-precision symmetrical analog power supply from the power module to ensure the linearity and accuracy of the signal conditioning.

[0031] The high-precision ADC chip uses the ADS1258IRTCT16-channel 16-bit high-precision ADC chip. Eight channels are connected to the output voltage VC of eight operational amplifiers, and the other eight channels are connected to the reference voltage VA at the sensor input. These 16 voltage signals are simultaneously acquired at a sampling rate of 200kSPS. The converted digital signals are transmitted to the main control unit via the SPI interface. The main control chip calculates the real-time resistance value of each sensing unit according to the formula R=Rf×(VA-VC) / VC, and further converts it into the corresponding pressure value. The high-precision ADC chip is powered by a 3.3V digital power supply provided by the battery module.

[0032] The Bluetooth module uses the MX22-A low-power Bluetooth module, based on the TICC2541 chip, supporting the BLE4.0 protocol. Its idle standby power consumption is approximately 2.8mA, and its sleep mode power consumption is as low as 0.34μA. This module connects to the main control unit via a USART interface, wirelessly transmitting processed pressure data to a host computer terminal, enabling remote real-time monitoring and storage of the data.

[0033] Battery module 5 provides a stable multi-channel power output for the entire system. Its core component is a rechargeable lithium battery with a rated voltage of 3.7V and a maximum operating current of 1.5A. The power conversion process is as follows: The lithium battery output voltage is boosted to 5V by the MT3608 boost converter; the boosted 5V voltage is divided into two paths: one path is converted into a stable 3.3V digital power supply by the ME6209A33 low dropout linear regulator to power the main control chip, high-precision ADC chip and Bluetooth module; the other path is converted into a ±2.5V high-precision symmetrical analog power supply by the TPS7A3901 low dropout linear regulator to power the operational amplifier array.

[0034] A method for fabricating and packaging an integrated flexible pressure gait monitoring system includes the following steps: Step S1: Preparation of conductive paste; A pressure-sensitive conductive paste is prepared using few-layer graphene as the conductive filler, epoxy resin E-51 as the matrix material, polyetheramine D400 as the curing agent, and terpineol as the diluent; wherein, the mass ratio of graphene to epoxy resin is 1:4, the mass ratio of epoxy resin to polyetheramine is 2:1, and 0.3g of terpineol is added to adjust the viscosity; to meet the requirements of the screen printing process, the bottom of the beaker is first soaked with terpineol, and then epoxy resin, graphene and polyetheramine are added in sequence, and manually stirred for 15 minutes until the graphene is evenly dispersed to obtain the conductive paste.

[0035] Step S2: Preparation of the pressure-sensitive functional layer; The conductive paste is transferred to the lower surface of the first flexible substrate 12 with a thickness of 75μm using a screen printing process. The first flexible substrate 12 with a thickness of 75μm is flattened and fixed on the screen printing table. A screen with a preset arrangement pattern of 64 units (200 mesh, each unit size 4.4mm×6.8mm, and the position corresponds one-to-one with the subsequent interdigital electrode units 31) is installed. The prepared conductive paste is poured onto one end of the screen and scraped with a squeegee at a 45° angle. The pressure of the squeegee is used to make the conductive paste transfer accurately through the screen holes to the surface of the first flexible substrate 12.

[0036] The first flexible substrate 12, printed with conductive paste, is removed and cured at 110°C for 60 minutes to allow the epoxy resin and polyetheramine to fully crosslink and react, while terpineol completely evaporates. After curing, an array of pressure-sensitive sensing units 11 is formed, thus obtaining the pressure-sensitive layer 1.

[0037] Step S3: Fabrication of the flexible electrode layer; Interdigitated electrode units 31 and gold finger interfaces 35 are fabricated using a PI copper-clad laminate via photolithography and etching processes. Photoresist is spin-coated onto the surface of the PI copper-clad laminate (PI substrate 0.13 mm, copper layer 35 μm), and after exposure and development, the interdigitated electrode and wire patterns are formed. Copper chloride etchant is used to etch away the copper layer not protected by the photoresist, and then the residual photoresist is removed to obtain the copper interdigitated electrodes 31 and wires.

[0038] A double-sided wiring method is adopted: 8 row lines are laid on the front side and 8 column lines are laid on the back side, and electrical connections are achieved through metallized vias on the PI substrate; the conductor line width is set to 100μm to balance wiring density and process yield.

[0039] The non-electrode area is covered with an insulating protective layer to obtain the flexible electrode 3; the surface of the wires, except for the interdigital electrode area and the gold finger interface 35 area, is covered with a PI insulating protective layer, and all the leads eventually converge to the gold finger interface 35 at the bottom of the sensor.

[0040] Step S4: Adhesive Layer Preparation; 3M 300LSE high-adhesion acrylic double-sided tape is selected as adhesive layer 2, and a through-hole array matching the interdigital electrode units 31 is laser-cut. Using a laser cutter according to the preset CAD drawings, an array of through holes (the through-hole size is slightly larger than the interdigital electrode units 31) that perfectly matches the position and shape of the 64 interdigital electrode units 31 on the flexible electrode layer 3 is cut from the 3M 300LSE high-adhesion acrylic double-sided tape. After cutting, the waste material in the through holes and the release paper on the surface of the tape are removed.

[0041] Step S5: Sensor Encapsulation; The pressure-sensitive layer 1, adhesive layer 2, and flexible electrode 3 are sequentially aligned and bonded together to form a flexible array distributed pressure sensor. A three-layer structure encapsulation is completed using an alignment bonding process. The pre-cut intermediate adhesive layer 2 is smoothly bonded to the upper surface of the flexible electrode layer 3. Positioning marks are used to ensure precise alignment of each through-hole with the underlying interdigitated electrode unit 31. A roller is used to evenly press and remove air bubbles. The first flexible substrate 12, on which the pressure-sensitive sensing unit 11 is printed and cured, is inverted onto the intermediate adhesive layer 2. Positioning marks are used again to precisely align each pressure-sensitive sensing unit 11 with its corresponding through-hole and interdigitated electrode unit 31. Even pressure is applied to bond the three layers together into a single unit, completing the integrated encapsulation of the distributed pressure sensor.

[0042] Step S6, System Integration: The flexible array distributed pressure sensor is laid flat on the inner surface of the sole of the special shoe 6, and connected to the miniaturized signal acquisition circuit module 4 through the gold finger interface 35. The miniaturized signal acquisition circuit module 4 and the battery module 5 are installed in the groove 61 and covered with the flexible buffer protective layer 62 to complete the system integration.

[0043] Therefore, the present invention adopts the above-mentioned integrated flexible pressure gait monitoring system and preparation and packaging method to improve product consistency and facilitate mass production; the interdigital electrode array greatly improves the resolution of plantar pressure and can accurately capture local pressure anomalies; the row and column multiplexing wiring is easy to expand and the electrical connection is reliable; the integration of microcircuits and special footwear enables wireless transmission and convenient wear.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention; and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An integrated flexible pressure gait monitoring system, characterized in that, It includes a flexible array distributed pressure sensor, a miniaturized signal acquisition circuit module, a battery module, and a special shoe. The flexible array distributed pressure sensor includes a pressure-sensitive layer, an adhesive layer, and a flexible electrode stacked from top to bottom. The flexible array distributed pressure sensor is shaped like an insole and is laid flat on the inner surface of the sole of the special shoe. The miniaturized signal acquisition circuit module is electrically connected to the flexible electrode, and the battery module is electrically connected to the miniaturized signal acquisition circuit module.

2. The integrated flexible pressure gait monitoring system according to claim 1, characterized in that, The pressure-sensitive layer includes a first flexible substrate and a pressure-sensitive sensing unit disposed on the lower surface of the first flexible substrate. The flexible electrode includes a second flexible substrate and an interdigitated electrode unit disposed on the upper surface of the second flexible substrate. The interdigitated electrode unit and the pressure-sensitive sensing unit are arranged vertically and vertically respectively.

3. The integrated flexible pressure gait monitoring system according to claim 2, characterized in that, An adhesive layer is located between the pressure-sensitive layer and the flexible electrode, and an array of through holes is formed on the adhesive layer corresponding to the positions of the pressure-sensitive sensing unit and the interdigital electrode unit.

4. The integrated flexible pressure gait monitoring system according to claim 3, characterized in that, The sole of the special footwear has a groove at the heel, and the miniaturized signal acquisition circuit module and battery module are both located inside the groove.

5. The integrated flexible pressure gait monitoring system according to claim 4, characterized in that, A flexible buffer protective layer is provided inside the groove, which covers the miniaturized signal acquisition circuit module and the battery module.

6. The integrated flexible pressure gait monitoring system according to claim 5, characterized in that, The flexible electrode also includes a front lead of the flexible circuit, a back lead of the flexible circuit, and a gold finger interface, which is electrically connected to the miniaturized signal acquisition circuit module.

7. The integrated flexible pressure gait monitoring system according to claim 6, characterized in that, Both the pressure-sensitive sensing unit and the interdigital electrode unit are arranged in an 8-row × 8-column array.

8. The fabrication and packaging method of the integrated flexible pressure gait monitoring system according to claim 7, characterized in that, Includes the following steps: Step S1: Preparation of conductive paste; A pressure-sensitive conductive paste is prepared using few-layer graphene as the conductive filler, epoxy resin E-51 as the matrix material, polyetheramine D400 as the curing agent, and terpineol as the diluent; wherein, the mass ratio of epoxy resin to graphene is 1:4, the mass ratio of epoxy resin to polyetheramine is 2:1, and 0.3g of terpineol is added to adjust the viscosity; first, the bottom of the beaker is wetted with terpineol, then epoxy resin, graphene, and polyetheramine are added in sequence, and the mixture is manually stirred for 15 minutes until the graphene is uniformly dispersed to obtain the conductive paste; Step S2: Preparation of pressure-sensitive functional layer; The conductive paste is transferred to the lower surface of the first flexible substrate with a thickness of 75μm by screen printing process, and then cured by heating at 110℃ for 60 minutes to form a pressure-sensitive sensing unit array, thus obtaining the pressure-sensitive layer; Step S3: Fabrication of flexible electrode layer; The interdigitated electrode unit and the gold finger interface are fabricated using a PI copper-clad laminate through photolithography and etching processes. The non-electrode area is covered with an insulating protective layer to obtain a flexible electrode. Step S4: Preparation of adhesive layer; 3M 300LSE high-adhesion acrylic double-sided tape is selected as adhesive layer, and through-hole array matching interdigital electrode unit is laser cut out; Step S5: Sensor packaging; The pressure-sensitive layer, adhesive layer, and flexible electrode are sequentially aligned and bonded together to form a flexible array distributed pressure sensor through integrated packaging. Step S6, System Integration: Lay the flexible array distributed pressure sensor flat on the inner surface of the sole of the special footwear, connect it to the miniaturized signal acquisition circuit module through the gold finger interface, install the miniaturized signal acquisition circuit module and battery module into the groove and cover them with a flexible buffer protective layer to complete the system integration.

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