Analog-digital heterogeneous force bit decoupling sensor, decoupling method and preparation method

Abstract

The application discloses a kind of analog-digital heterogeneous force-position decoupling sensors, decoupling method and preparation method, belong to flexible tactile sensing technical field.Sensor includes the public electrode layer, continuous analog piezoresistance layer, insulating isolation layer and digital encoding track layer arranged in sequence.Digital encoding track layer includes multiple parallel conductive signal tracks, each track is partially covered with insulating mask according to Gray code logic, and continuous physical space is divided into multiple discrete sensing areas with unique binary level.Piezoresistive layer is pressed through isolation layer and track contact, respectively output discrete digital position quantity and continuous analog pressure amount.Dedoubling method uses time division multiplexing control: first, configure pin as digital input to read level combination to determine absolute coordinate, then switch to analog-digital conversion mode to read resistance value to solve pressure size.The application realizes the complete decoupling of force and position from the physical bottom layer, and fundamentally eliminates the position drift caused by flexible substrate deformation and the analog quantity aliasing of pressure and position signal.

Description

Technical Field

[0001] This invention relates to the fields of flexible electronics, tactile sensors, and human-computer interaction, specifically to a force-position dual decoupled sensor based on the heterogeneous integration of digital coded track and analog piezoresistive sensing, as well as a supporting time-division multiplexing decoupling method and fabrication method. Background Technology

[0002] In the fields of human-computer interaction, robotic electronic skin, and wearable devices, flexible tactile sensors need to simultaneously acquire information about the "position" and "pressure" of the object being contacted. Currently, to reduce the number of leads and simplify system wiring, single-channel or low-electrode force-position sensors have become a research hotspot. However, existing technologies still have insurmountable shortcomings in the physical-level decoupling of "force" and "position," specifically manifested as follows:

[0003] 1. Deformation Drift Problem Caused by "Continuous Analog Positioning": A paper published in the *Chemical Engineering Journal* (CEJ) in 2025 (DOI: 10.1016 / j.cej.2025.166454) proposed a two-electrode sensor array. The core of this technology is the "slide wire rheostat model." The approach in this paper (continuous analog positioning) is as follows: the bottom layer is a continuous resistance wire. When the top layer is pressed down, the farther the pressing point is from the electrode, the longer the resistance wire inserted into the circuit, and the greater the measured total resistance. Position is calculated by the "magnitude of the continuous resistance value."

[0004] Problem: In flexible wearable applications, sensors must conform to complex curved surfaces. Stretching or bending of the sensor substrate itself can physically elongate the underlying continuous resistance wire, causing drastic changes in the base resistance. In this situation, the system cannot distinguish whether the increase in resistance is due to a change in the pressing position or deformation of the device itself, leading to severe coordinate drift and signal crosstalk.

[0005] 2. Analog signal aliasing problem caused by "impedance network distribution": Compared with the 2022 patent application (publication number: CN115247998A), the approach of the patent application (series-parallel network) is to arrange multiple pressure sensing devices in series and parallel so that when any device is pressed, the entire circuit will present a "unique resistance and capacitance value" (for example, 1kΩ when pressing point A, 2kΩ when pressing point B, and 3kΩ when pressing point C). In essence, it is a large analog resistor network.

[0006] Problems: This method of determining location by measuring a single resistance and capacitance value is highly susceptible to "analog aliasing." Since the magnitude of the pressure applied changes the local contact resistance of the piezoresistive material, when the user applies heavy pressure to point A, causing a sharp drop in its local resistance, the total circuit resistance measured by the system may be exactly the same as the total resistance when "point B is lightly pressed." Simply relying on an analog impedance network makes it difficult to achieve orthogonal decoupling between pressure magnitude and spatial location.

[0007] In summary, existing technologies are all limited by the "analog era" and urgently need a completely new device structure design to completely eliminate position drift and force signal aliasing caused by flexible deformation from the physical level. Summary of the Invention

[0008] To address the technical problems of position drift caused by tensile deformation and aliasing of analog and analog resistance in existing technologies, this invention provides a heterogeneous analog-digital sensor logic and its decoupling method. Its core feature lies in pre-setting physical spatial coordinates as immutable "digital quantities" and mapping pressure magnitude as continuously changing "analog quantities," achieving complete decoupling at the physical level.

[0009] To achieve the above objectives, the present invention provides a modular heterogeneous force-position decoupling sensor, comprising, in sequence: a common electrode layer, a pressure-sensitive layer, an insulating isolation layer, and a digitally encoded track layer; the common electrode layer is used to connect to an external power supply positive electrode; the insulating isolation layer has an array of through holes; the digitally encoded track layer includes N parallel conductive signal tracks, which are divided into regions along the direction perpendicular to the length of the conductive signal tracks, and each region is pre-coded, and the conductive signal tracks in the region are covered with an insulating mask based on the region's code; in the working state, the pressure-sensitive layer deforms locally after being pressed, passes through the through holes of the insulating isolation layer, and through transient physical contact with the digitally encoded track layer, outputs discrete spatial digital switching quantities (for pressure position sensing) and continuous pressure analog ohmic quantities (for pressure magnitude sensing) at the same physical contact point.

[0010] The "position information" is encoded as a preset, pressure-independent spatial digital switch quantity (0 / 1), while the "pressure information" is retained as a continuously changing pressure analog ohm quantity (resistance value). Both output discrete spatial digital switch quantities and continuous pressure analog ohm quantities respectively at the same physical contact, but are physically independent of each other. When reading the position, only "which track is conducting" is detected, without regard to the resistance value. When reading the pressure, only "loop resistance value" is detected, without regard to which track is conducting.

[0011] Furthermore, the preset encoding logic is Gray code. This invention uses Gray code as the spatial encoding logic of the digital encoding track layer. By utilizing its characteristic that only one bit changes in adjacent regions, it eliminates the reading ambiguity and competition risk caused by simultaneous changes in multiple bits of the encoding, ensuring that the pressing point can still output a monotonous, unique, and stable absolute position code when moving at the boundaries of different regions. This enhances the robustness of the sensor to flexible deformation and noise interference from the encoding level.

[0012] Furthermore, the insulating isolation layer is an insulating thin film with an array of through-holes; or, the insulating isolation layer is an insulating mesh structure. This enables the pressure-sensitive layer and the digitally encoded track layer to achieve synergistic "physical isolation" and "force-induced conduction," resulting in high impedance and low power consumption under normal conditions; simultaneously, it achieves precise "force-induced positioning," preventing horizontal deformation interference.

[0013] Furthermore, the pressure-sensitive layer is made of an elastomer material doped with conductive nanoparticles.

[0014] Furthermore, the region is divided along a direction perpendicular to the length of the conductive signal track, resulting in 2... N -1 regions, each region is pre-coded, and the pre-coded code for each region is N bits. Each conductive signal track in the region corresponds to one bit (0 or 1) in the region code. An insulating mask is covered on the conductive signal track coded as "0" in each region, and the code of each region cannot be all "0" codes.

[0015] This invention also proposes a method for fabricating a modular heterogeneous force-potential decoupling sensor, comprising the following steps:

[0016] Step 1: Prepare the digitally encoded orbital layer

[0017] Multiple parallel conductive signal tracks are formed on a flexible substrate, and the area is divided along the direction perpendicular to the length of the conductive signal tracks.

[0018] Gray code is used to encode each region sequentially, with conductive regions encoded as "1" and insulating regions encoded as "0". An insulating mask is then placed over the conductive signal track encoded as "0" in each region.

[0019] Step 2: Prepare the insulating layer

[0020] An insulating film or insulating mesh with arrayed through holes is covered above the digital coding track layer as an insulating isolation layer;

[0021] Step 3: Prepare the pressure-sensitive layer

[0022] A flexible material film doped with conductive nanoparticles is attached or coated on top of the isolation layer as a pressure-sensitive layer;

[0023] Step 4: Fabrication of the common electrode layer

[0024] A conductive electrode layer is placed over the pressure-sensitive layer as a common electrode layer for connection to the positive terminal of an external power source.

[0025] Furthermore, the insulating mask described in step 1 is formed by screen printing using solder resist ink.

[0026] Furthermore, the conductive signal track is a copper foil track printed on a flexible substrate.

[0027] Furthermore, the pressure-sensitive layer is a flexible polydimethylsiloxane film doped with carbon nanotubes.

[0028] Based on the analog-digital heterogeneous force-position decoupling sensor of the present invention, the present invention also proposes an analog-digital heterogeneous force-position decoupling method, comprising: connecting N signal tracks of the digital encoding track layer to N pins of the microcontroller respectively, configuring the N pins as digital input mode with pull-down resistors, reading the logic level of each signal track, obtaining the logic level combination, thereby obtaining the encoding of the pressing area;

[0029] After determining the encoding of the pressing area, the pins in the microcontroller connected to the high-level conductive signal track are reconfigured to analog-to-digital conversion mode. The equivalent resistance value is read and the vertical pressure is calculated. The equivalent resistance value read in analog-to-digital conversion mode corresponds to the resistance change of the pressure-sensitive layer caused by pressure variation. The vertical pressure is calculated using a preset pressure-resistance calibration curve.

[0030] Beneficial effects: This invention proposes a modular heterogeneous force potential decoupling sensor and its decoupling method, wherein the modular heterogeneous force potential decoupling sensor includes a common electrode layer, a pressure-sensitive layer, an insulating isolation layer and a digital coding track layer arranged sequentially;

[0031] The digitally encoded track layer comprises multiple parallel conductive signal tracks, which rely on the encoded pattern (0 and 1) of the surface insulating layer to lock the position. Regardless of the degree of stretching or bending deformation of the sensor substrate, the preset digital mask encoding does not drift, fundamentally eliminating deformation interference; thus, the sensor of this invention has complete physical-level decoupling and anti-drift capability, overturning the logic of existing technology that relies on analog resistance to calculate position.

[0032] Based on the heterogeneous integration of the pressure-sensitive layer and the digitally encoded track layer, and the time-division multiplexing decoupling method, force-position characteristic aliasing is eliminated, overcoming the analog signal aliasing easily generated by impedance networks in existing technologies. This invention physically separates pressure sensing from position sensing. The pressure-sensitive layer is only responsible for outputting analog ohmic quantities that change continuously with pressure, while the digitally encoded track layer does not provide resistance values, but only provides on / off signals (0 and 1), outputting only discrete digital switching quantities (position codes). Combined with the microcontroller's time-division multiplexing strategy (first reading the digital level for positioning, then reading the analog force measurement), changes in pressure magnitude do not affect position determination at all, completely avoiding interference from pressure magnitude on position judgment.

[0033] This invention uses N parallel tracks to form 2 through a surface insulating mask. N Each absolute coding region has a spatial resolution that increases exponentially with the number of orbits (2). N For example, only 8 leads are needed to divide 256 independent absolute physical sensing areas. Compared with traditional matrix scanning sensors, this greatly reduces the wiring complexity and size of the flexible electronic skin; the position information is uniquely determined by the combination of levels, without relying on the absolute value of analog resistance. Compared with the schemes in the prior art that locate the position by the unique resistance and capacitance values ​​of continuous resistance values ​​or series-parallel networks, the digital level signals of this invention have higher noise immunity and deformation immunity, and at the same time, high spatial resolution can be achieved with only a few leads, significantly reducing the wiring complexity of the flexible electronic skin.

[0034] This invention incorporates an insulating isolation layer with arrayed through-holes between the pressure-sensitive layer and the digitally encoded track layer. This layer is insensitive to horizontal tensile and bending stresses, only exhibiting localized conductivity under vertical pressure. This ensures complete electrical isolation between the digital track layer and the pressure-sensitive layer when not under pressure, preventing false triggering caused by bending or vibration of the flexible substrate, and further enhancing the system's reliability in complex curved surface attachment scenarios. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a three-dimensional structural diagram of the sensor of the present invention;

[0037] Figure 2 This is a schematic diagram of the planar structure of each functional layer of the sensor of the present invention;

[0038] Figure 3This is a schematic diagram with 3 conductive signal tracks as an example, and the physical contact output code is 011.

[0039] The structure consists of: 1. Common electrode layer; 2. Pressure-sensitive layer; 3. Insulating layer; 4. Digital coding track layer. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0041] Example 1

[0042] like Figure 1 and Figure 2 As shown, this embodiment provides a modular heterogeneous force-position decoupling sensor, including a common electrode layer, a pressure-sensitive layer, an insulating isolation layer, and a digitally encoded track layer arranged sequentially.

[0043] The common electrode layer is a conductive film used to connect to the external power supply positive electrode to realize signal conduction and transmission;

[0044] The pressure-sensitive layer is a continuous simulated piezoresistive layer with resistance change characteristics under pressure, and is made of a flexible material with wide-range piezoresistive characteristics (such as an elastomer doped with conductive nanoparticles). Under pressure, the pressure-sensitive layer undergoes local deformation downward, and as the pressure increases, the internal volume resistance and surface contact resistance of the pressure-sensitive layer decrease nonlinearly.

[0045] An insulating layer, possessing stress-bearing conductive properties, is located between the pressure-sensitive layer and the digital coding track layer. The insulating layer has an array of distributed through-holes or acts as an insulating mesh. Its function is to ensure that the pressure-sensitive layer and the digital coding track layer remain physically disconnected and electrically insulated when there is no vertical pressure; furthermore, the insulating layer is insensitive to horizontal tensile and bending stresses, preventing mis-conduction due to deformation.

[0046] The digital coding track layer, also known as the discrete digital electrode array layer, is set on a flexible substrate and contains N parallel conductive signal tracks. It is divided into regions along a direction perpendicular to the length of the conductive signal tracks, and can be divided into a maximum of 2... N-1 regions are defined, each with a pre-set Gray code. Based on this Gray code, the conductive signal tracks within that region are covered with an insulating mask. Conductive regions are encoded as "1", and insulating regions are encoded as "0", dividing the continuous physical space into multiple discrete sensing regions with unique binary level characteristics. Through the combination of on / off states of N signal tracks, a 2... N -1 digitally encoded pattern of absolute physical coordinates, where N is a positive integer.

[0047] This embodiment uses 3 conductive signal tracks, which can achieve a maximum of 2 N The detection of -1 region involves three conductive signal tracks, denoted as conductive signal track A, conductive signal track B, and conductive signal track C. Based on the preset Gray code for each region, an insulating mask is applied to the conductive signal tracks within that region. An example is provided below:

[0048] Let the region with Gray code 001 be region 1: In this region, the conductive signal track A corresponds to bit 0 → the surface of the conductive signal track A in this region is covered with insulation; In this region, the conductive signal track B corresponds to bit 0 → the surface of the conductive signal track B in this region is covered with insulation; In this region, the conductive signal track C corresponds to bit 1 → the surface of the conductive signal track C in this region is not covered with insulation.

[0049] Let the region with Gray code 011 be the second region: In this region, the conductive signal track A corresponds to bit 0 → the surface of the conductive signal track A in this region is covered with insulation; In this region, the conductive signal track B corresponds to bit 1 → the surface of the conductive signal track B in this region is not covered with insulation; In this region, the conductive signal track C corresponds to bit 1 → the surface of the conductive signal track C in this region is not covered with insulation.

[0050] Let the region with Gray code 010 be region 3: In this region, the conductive signal track A corresponds to bit 0 → covered and insulated; the conductive signal track B in this region corresponds to bit 1 → not covered; the conductive signal track C in this region corresponds to bit 0 → covered and insulated.

[0051] Similarly, for regions 4 (Gray code 110), 5 (Gray code 111), 6 (Gray code 101), and 7 (Gray code 100), insulation is covered on the conductive signal track coded as "0" in each region.

[0052] Based on the modular heterogeneous force-potential decoupling sensor of the present invention, the present invention also proposes a modular heterogeneous force-potential decoupling method, as follows:

[0053] The N signal tracks of the digital encoding track layer are connected to the N pins of the microcontroller. In this specific embodiment, the microcontroller is an STM32. In this embodiment, N=3. Therefore, conductive signal track A is connected to the PA1 pin of the STM32, conductive signal track B is connected to the PA2 pin of the STM32, and conductive signal track C is connected to the PA3 pin of the STM32. All pins are grounded by default through pull-down resistors.

[0054] Step 1, Digital Addressing Stage, Location Decoupling

[0055] Initialize STM32 pins PA1, PA2, and PA3 to digital input mode. For example, when region 2 is compressed, the top pressure-sensitive layer deforms under pressure, passing through the via in the insulating layer to contact the conductive signal track. Because conductive signal track A in region 2 is covered by the insulating layer, conductive signal tracks B and C are connected, and voltage is introduced into the STM32 pins through conductive signal tracks B and C. The microcontroller instantly reads the pin level as 011, which means it has read the Gray code corresponding to this region. By consulting the encoding dictionary in memory, which records the correspondence between Gray code and region location, the microcontroller immediately locks the physical contact to "region 2". No resistance measurement is performed during this process, so even if the sensor is stretched, the encoded output remains 011.

[0056] Step 2, Force Measurement Simulation Stage, Pressure Decoupling

[0057] Within 10 microseconds of the locked position, the microcontroller, through register operations, reconfigures the pins connected to the high-level conductive signal track in the microcontroller to analog-to-digital conversion mode. In this embodiment, the pressure is in region 2, and pins PA2 and PA3 are at a high level. Therefore, the high-level PA2 and PA3 pins are dynamically reconfigured as ADC (Analog-to-Digital Converter) analog input pins. At this time, the microcontroller reads the analog voltage / current flowing into pins PA2 and PA3. As the conductive network inside the pressure-sensitive film is further compressed with increasing applied pressure, its bulk resistance decreases, and the analog quantity measured by the ADC changes continuously. The microcontroller substitutes this analog quantity into a preset pressure-resistance calibration curve to calculate the corresponding absolute pressure value.

[0058] Through the combination of the two embodiments described above, this invention perfectly realizes a generational decoupling scheme that outputs discrete digital position signals and continuous analog pressure signals using a single physical contact. The number N of conductive signal tracks can be expanded according to the actual required spatial resolution without departing from the scope of protection of this invention.

[0059] Example 2

[0060] Based on the modular heterogeneous force-potential decoupling sensor in Example 1, the present invention also provides a method for fabricating a modular heterogeneous force-potential decoupling sensor, comprising the following steps:

[0061] Step 1, Prepare the digitally encoded orbital layer

[0062] Polyimide (PI) is used as the flexible substrate. N parallel conductive copper foil tracks are etched onto the PI substrate using a printed circuit board (FPC) process to serve as conductive signal tracks. The length of each conductive signal track is uniformly divided into no more than 2... N -1 independent sensing area, each area is encoded using Gray code, and then solder resist ink is used for screen printing on the surface of the conductive signal track. An insulating mask layer is formed on the conductive signal track encoded as "0" in each area. The printed pattern follows N-bit Gray code logic.

[0063] For example, in this embodiment, N=3 is used, and there are three conductive signal tracks, namely conductive signal track A, conductive signal track B, and conductive signal track C, which are evenly divided into 2 sections along the length of the conductive signal tracks. 3 -1=7 independent sensing regions. Each region is encoded sequentially using Gray code. The Gray code for the second region is 011. An insulating mask layer is formed on the conductive signal track encoded as "0" in the region. That is, the surface of conductive signal track A in the second region is covered with insulating ink, the surface of conductive signal track B is not covered with insulating ink and the conductive surface is exposed (defined as logic 1), and the surface of conductive signal track C is not covered with insulating ink and the conductive surface is exposed (defined as logic 1).

[0064] Step 2, Prepare the insulating layer

[0065] A 50-micrometer-thick polyethylene terephthalate (PET) insulating film with an array of circular holes is placed over the digital coding track layer as an insulating layer.

[0066] Preparation 3: Preparation of pressure-sensitive layer

[0067] A flexible polydimethylsiloxane (PDMS) pressure-sensitive film doped with carbon nanotubes is bonded on top of the insulating layer as a pressure-sensitive layer.

[0068] Step 4, Prepare the common electrode layer

[0069] A copper foil conductive electrode is covered on top of the varistor layer, and the entire copper foil conductive electrode is connected to the positive power supply terminal.

[0070] In summary, the analog-digital heterogeneous force-potential decoupling sensor, decoupling method, and fabrication method provided by this invention achieve complete decoupling of force and potential by setting up a heterogeneous integration of a digitally encoded track layer with a Gray code insulating mask pattern and a pressure-sensitive layer (continuous piezoresistive layer), combined with a time-division multiplexing signal readout strategy. When the sensor undergoes stretching, bending, or other deformations on a flexible substrate, its output position code remains absolutely stable, fundamentally overcoming the position drift problem caused by deformation in traditional analog sensors. Simultaneously, the pressure magnitude only affects the analog resistance value of the pressure-sensitive layer without interfering with the determination of the position code, eliminating force-potential signal aliasing. Furthermore, based on N tracks, no more than 2... N Encoding a single absolute position region enables an exponential increase in spatial resolution with the number of leads, significantly reducing the wiring complexity and signal processing difficulty of flexible tactile sensing systems. This invention can be widely applied in fields such as intelligent robot electronic skin, wearable health monitoring devices, and human-computer interaction interfaces.

Claims

1. A modular heterogeneous force-potential decoupling sensor, characterized in that, It includes, in sequence: a common electrode layer, a pressure-sensitive layer, an insulating isolation layer, and a digital coding track layer; The common electrode layer is used to connect to an external power source; The insulating layer has an array of through holes. The digital coding track layer includes N parallel conductive signal tracks, which are divided into regions along the direction perpendicular to the length of the conductive signal tracks. Each region is pre-coded, and an insulating mask is applied to the conductive signal tracks in that region based on the pre-coded region. When the pressure-sensitive layer is compressed, it deforms locally, passes through the through-hole of the insulating layer, and comes into contact with the digital coding track layer.

2. The modular heterogeneous force-potential decoupling sensor according to claim 1, characterized in that, The default encoding logic is Gray code.

3. The modular heterogeneous force-potential decoupling sensor according to claim 1, characterized in that, The insulating isolation layer is an insulating film, and an array of through holes is formed on the insulating film; Alternatively, the insulating isolation layer may be an insulating mesh structure.

4. The modular heterogeneous force-potential decoupling sensor according to claim 1, characterized in that, The pressure-sensitive layer is made of an elastomer material doped with conductive nanoparticles.

5. The modular heterogeneous force-potential decoupling sensor according to claim 1, characterized in that, The region is divided along a direction perpendicular to the length of the conductive signal track, dividing it into no more than 2... N -1 regions, each region is pre-coded, and based on the pre-coded regions, an insulating mask is covered on the conductive signal track coded as "0" in each region.

6. A method for fabricating a modular heterogeneous force-potential decoupling sensor, characterized in that, Includes the following steps: Step 1: Prepare the digitally encoded orbital layer Multiple parallel conductive signal tracks are formed on a flexible substrate, and the area is divided along the direction perpendicular to the length of the conductive signal tracks. Gray code is used to pre-encode each region sequentially, with conductive regions encoded as "1" and insulating regions encoded as "0". An insulating mask is then placed over the conductive signal track encoded as "0" in each region. Step 2: Prepare the insulating layer An insulating film or insulating mesh with arrayed through holes is covered above the digital coding track layer as an insulating isolation layer; Step 3: Prepare the pressure-sensitive layer A flexible material film doped with conductive nanoparticles is attached or coated on top of the isolation layer as a pressure-sensitive layer; Step 4: Fabrication of the common electrode layer A conductive electrode layer is placed over the pressure-sensitive layer as a common electrode layer for connection to the positive terminal of an external power source.

7. The preparation method according to claim 6, characterized in that, The insulating mask mentioned in step 1 is formed by screen printing with solder resist ink.

8. The preparation method according to claim 6, characterized in that, The conductive signal track is a copper foil track printed on a flexible substrate.

9. The preparation method according to claim 6, characterized in that, The pressure-sensitive layer is a flexible polydimethylsiloxane film doped with carbon nanotubes.

10. A method for decoupling modulus-to-digital heterogeneous force potential based on the sensor according to any one of claims 1 to 5, characterized in that, include: The N conductive signal tracks of the digital encoding track layer are connected to the N pins of the microcontroller, and the N pins are configured as digital input modes with pull-down resistors. The logic level of each conductive signal track is read to obtain the logic level combination, thereby obtaining the encoding of the pressing area. After determining the encoding of the pressing area, the pins in the microcontroller connected to the high-level conductive signal track are reconfigured to analog-to-digital conversion mode, the equivalent resistance value is read, and the vertical pressure magnitude is calculated.

Images