An integrated in-situ filtered array flexible sensor device and a method of manufacturing the same

Abstract

The application discloses an array flexible sensor device integrated with in-situ filtering and a preparation method thereof, and the device comprises a top packaging layer, a piezoelectric sensing functional layer, an insulating isolation layer, a capacitor layer and a bottom packaging layer. The piezoelectric sensing functional layer adopts a BTO nanoparticle doped P(VDF-TrFE) composite piezoelectric film, an entire surface ground silver paste electrode is arranged on the upper surface, and a 3*3 conductive electrode array is arranged on the lower surface, so that the accurate force-electricity conversion of mechanical deformation can be realized. The insulating isolation layer is provided with a 3*3 micropore array and filled with a conductive material, so that each sensing unit is coupled with a patterned carbon paste upper electrode of the capacitor layer one by one, and nine groups of independent parallel first-order RC low-pass filtering networks are formed. By adjusting the carbon black content of the carbon paste electrode and the thickness of the PVA solid dielectric layer, the controllable cut-off frequency, high impedance and adjustable intrinsic capacitance in the range of 10-30 Hz can be realized, and the preset range low-frequency pulse signal can be effectively reserved and the high-frequency motion noise can be inhibited.

Description

Technical Field

[0001] This invention relates to the fields of flexible wearable electronic devices and biomedical sensing technology, specifically to an array of flexible sensors with integrated in-situ filtering and its fabrication method. Background Technology

[0002] With the increasing demand for human health management, wearable health monitoring devices are gradually becoming an important means of disease prevention and early intervention because they can track human health status for a long time without affecting daily activities.

[0003] Traditional wearable sensors are mostly based on rigid substrate materials. Due to the significant mismatch between the Young's modulus of human skin and rigid sensors, prolonged wear can easily cause discomfort and even tissue damage. Furthermore, the low skin-to-skin fit of rigid structures limits the stability of signal acquisition. Flexible wearable devices, on the other hand, can conform to the skin surface and adapt to dynamic deformation, greatly mitigating the effects of Young's modulus mismatch. However, most flexible sensors still rely on external power supplies, limiting their application in long-term, non-intrusive monitoring scenarios.

[0004] Self-powered flexible wearable devices harvest energy from human movement using the piezoelectric effect, enabling continuous operation without an external power source. Polyvinylidene fluoride-trifluoroethylene copolymer (VDF-TrFE) organic piezoelectric materials are widely used in various fields due to their good flexibility and biocompatibility. However, the low intrinsic piezoelectric constant of the monomer VDF-TrFE limits its ability to sense weak physiological signals from the human body. Furthermore, low-frequency physiological signals generated by the human body are easily interfered with by high-frequency motion artifacts such as limb movement and clothing friction. Traditional methods rely on back-end digital signal processing algorithms for filtering; this non-in-situ processing not only increases system power consumption and signal delay but also further reduces the signal-to-noise ratio. Summary of the Invention

[0005] The present invention proposes an array flexible sensor device with integrated in-situ filtering and its fabrication method, which can at least solve one of the technical problems in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An array of flexible sensors with integrated in-situ filtering, comprising: a top encapsulation layer (1), a piezoelectric sensing functional layer (2), an insulating isolation layer (3), a capacitor layer (4), and a bottom encapsulation layer (5) stacked vertically from top to bottom; Among them, the piezoelectric sensing functional layer (2) is composed of a composite piezoelectric film (7) doped with barium titanate BTO nanoparticles and conductive silver paste electrodes (6) on its upper surface and conductive electrode array (8) on its lower surface. The piezoelectric sensing functional layer (2) is also provided with wires (9) formed by screen printing, which connect the conductive electrode array (8) to an external signal receiver; The insulating layer (3) has micropores (10) filled with conductive material. The capacitor layer (4) includes: a patterned array of carbon paste upper electrodes (11) as the uppermost layer of the capacitor layer (4), which is an intermittent pad structure, and its lower surface is in partial contact with the upper surface of the PVA solid dielectric layer (12); The lower surface of the PVA solid dielectric layer (12) is fully bonded to the carbon paste lower electrode (13).

[0007] Furthermore, the insulating layer (3) of the present invention is made of polyurethane material, and its thickness is set to 10-30μm.

[0008] Furthermore, the insulating layer (3) of the present invention has 9 micropores (10) arranged in a 3×3 array, with a pore diameter of approximately 200 μm.

[0009] Furthermore, the micropores (10) of the present invention are formed by laser drilling, and the pores are filled with conductive silver paste.

[0010] Furthermore, the entire carbon paste lower electrode (13) of the capacitor layer (4) of the present invention is connected to the common ground terminal, and the upper electrode (6) of the piezoelectric sensing functional layer (2) is connected to the common ground terminal.

[0011] Furthermore, the conductive electrode array (8) of the piezoelectric sensing functional layer (2) of the present invention is electrically coupled one-to-one with the patterned array carbon paste electrodes (11) of the capacitor layer through the conductive silver paste in the micropores (10) of the insulating isolation layer (3), forming a parallel RC low-pass filter network.

[0012] On another front, a method for fabricating an array of flexible sensors with integrated in-situ filtering is provided, the method comprising: The patterned array carbon paste upper electrode (11) and the whole surface carbon paste lower electrode (13) are arranged opposite to each other, and a PVA solid precursor solution is injected between them to solidify and form a PVA solid dielectric layer (12). A polyurethane precursor solution is coated on the top of the electrode of the capacitor layer (4), and heated at 60-80°C to partially solidify it to form a semi-cured insulating layer (3). At this time, the degree of crosslinking is 40%-60%, the surface is viscous and does not undergo macroscopic flow; then, a micropore (10) array is formed on the insulating layer (3) by laser drilling. After aligning the conductive electrode array (8) on the lower surface of the piezoelectric sensing functional layer (2) with the micropore (10), apply a pressure of 50-100 kPa and then heat and cure it completely at 80-120°C, so that the polyurethane forms a strong physical interlocking interface with the adjacent piezoelectric film and carbon paste electrode. The piezoelectric sensing functional layer (2) is formed by dissolving BTO nanoparticles and vinylidene fluoride-trifluoroethylene copolymer powder in an organic mixed solvent, and then forming a piezoelectric film (7) by film formation or high voltage polarization; then, silver paste is screen-printed on the upper surface as an electrode (6), and a 3×3 array of silver paste is screen-printed on the lower surface as a conductive electrode array (8), and the signal output terminal (14) is formed by screen printing; the silver paste is cured by step heating and baking, that is, pre-baking at a lower temperature and then completely curing at a higher temperature.

[0013] Micropores (10) are filled with conductive silver paste to achieve electrical coupling between the conductive electrode array (8) and the patterned array carbon paste upper electrode (11); then the top encapsulation layer (1) and the bottom encapsulation layer (5) are covered, and the entire carbon paste lower electrode (13) is connected to the common ground terminal. The conductive electrode array (8) or the patterned array carbon paste upper electrode (11) is led out to the signal output terminal through wires (9). Complete the sensor fabrication; The PVA solid dielectric layer (12) is formed by curing pure polyvinyl alcohol aqueous solution. The film thickness is 5-20 μm, its intrinsic relative permittivity is stable between 5-15, and its volume resistivity is greater than 10. 10 Ω cm, ensuring minimal leakage current; A single patterned array of carbon paste upper electrode (11), together with the corresponding PVA solid dielectric layer (12) and the entire carbon paste lower electrode (13), constitutes a pure physical capacitor unit.

[0014] Furthermore, the heating time for coating the top of the electrode with polyurethane precursor solution on the capacitor layer (4) of the present invention is 5-15 minutes; the conductive electrode array (8) is aligned with the micropore (10) and then bonded together, and the heating curing time is 1-3 hours.

[0015] Furthermore, the specific capacitance per unit geometric area of ​​the pure physical capacitor unit of the present invention is 5-50 pF / mm², and the capacitance value change rate is less than 5% in the frequency range of 1-100 Hz.

[0016] As can be seen from the above technical solution, this invention performs differentiated optimization design on the thickness of each functional layer, limiting the thickness of the insulating isolation layer (10-30μm) to be smaller than that of the upper and lower encapsulation layers, and ensuring that the thickness of the top and bottom encapsulation layers is equal. This ensures that the neutral layer is precisely located at the geometric center when the device is dynamically bent, effectively reducing interlayer shear stress and avoiding the problems of multilayer structure peeling and cracking. At the same time, the deformation stress is concentrated in the upper and lower encapsulation layers, which have better mechanical properties, significantly reducing the risk of breakage and detachment of the conductive silver paste in the micropores of the insulating isolation layer. This solves the defects of traditional multilayer flexible sensors that fail to conduct and suffer structural damage after repeated bending. Attached Figure Description

[0017] Figure 1 This is a three-dimensional schematic diagram of the vertically stacked multiple layers of sensors according to an embodiment of this application; Figure 2 This is a schematic diagram of the longitudinal cross-sectional structure of the sensor according to an embodiment of this application; Figure 3 This is an equivalent circuit diagram of the RC low-pass filter for a single pixel unit in an embodiment of this application; Figure 4 This is a schematic diagram of the signal output wiring principle according to an embodiment of this application; Figure 5 This is a three-dimensional top view of the piezoelectric sensing functional layer array according to an embodiment of this application; Figure 6 This is a planar layout of the piezoelectric sensing functional layer electrode array according to an embodiment of this application; Figure 7 This is a side cross-sectional view of the piezoelectric sensing functional layer electrode in an embodiment of this application. Figure 8 This is a three-dimensional top view of the micropores in the insulating layer according to an embodiment of this application; Figure 9 This is a top plan view of the micropores in the insulating layer according to an embodiment of this application; Figure 10 This is a planar layout of the patterned array carbon paste on-electrode according to an embodiment of this application; Figure 11 This is a side cross-sectional view of the patterned array carbon paste top electrode according to an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0019] like Figure 1 As shown, the integrated in-situ filtering array flexible sensor device described in this embodiment has a multi-layer vertical stacked structure, consisting of a top encapsulation layer 1, a piezoelectric sensing functional layer 2, an insulating isolation layer 3, a capacitor layer 4, and a bottom encapsulation layer 5 from top to bottom. like Figure 2 As shown, the piezoelectric sensing functional layer 2 of the array flexible sensor device is composed of a piezoelectric thin film 7 of polyvinylidene fluoride-trifluoroethylene copolymer P(VDF-TrFE) doped with barium titanate BTO nanoparticles, a full-surface conductive silver paste electrode 6 on its upper surface, and a conductive electrode array 8 on its lower surface. The piezoelectric sensing functional layer 2 is also provided with wires 9 formed by screen printing, which are used to connect the conductive electrode array 8 to an external signal receiver; The insulating layer 3 has micropores 10 filled with conductive material. The capacitor layer 4 includes: a patterned array of carbon paste upper electrode 11, a PVA solid dielectric layer 12, and a full-surface carbon paste lower electrode 13; The patterned array carbon paste top electrode 11 serves as the top layer of the capacitor layer 4 and has an intermittent pad structure. Its lower surface is in partial contact with the upper surface of the PVA solid dielectric layer 12 (the pads are in close contact, and there are gaps between the pads). The lower surface of the PVA solid dielectric layer 12 is fully bonded to the carbon paste lower electrode 13.

[0020] The conductive electrode array 8 of the piezoelectric sensing functional layer 2 is electrically coupled to the patterned array carbon paste electrodes 11 of the capacitor layer 4 through the conductive material in the micropores 10 of the insulating isolation layer, forming an independent parallel RC low-pass filter network. The lower electrode 13 of the full-surface carbon paste of the capacitor layer 4 is connected to the common ground terminal (GND), and the upper electrode 6 of the piezoelectric sensing functional layer 2 is connected to the common ground terminal (GND).

[0021] The thickness of the PVA solid dielectric layer 12 is 5-20 μm; The thickness of the carbon paste under electrode 13 is 5-50 μm; The thickness of the insulating isolation layer 3 is 10-30 μm; wherein, the thickness of the insulating isolation layer 3 is less than the thickness of the top encapsulation layer 1 and the bottom encapsulation layer 5, so as to ensure that the deformation is concentrated in the encapsulation layer during dynamic bending and reduce the risk of breakage of the conductive material in the micropore 10.

[0022] like Figure 3 As shown, the equivalent circuit principle of the RC low-pass filter for a single pixel unit is as follows: The sensor area contains a piezoelectric current source. This voltage source is used to characterize the charge signal generated by a single conductive electrode array unit under mechanical deformation, and its equivalent model can be regarded as a piezoelectric current source. With capacitor The signal enters the in-situ RC low-pass filter region, which is composed of a supercapacitor network, specifically including the equivalent series resistance (ESR) and capacitance. A series structure. High-frequency motion noise signals typically have a frequency higher than 20Hz, and are contained in this RC network. The capacitor is bypassed to the common ground terminal GND, while the low-frequency pulse signal of 1-3Hz is preserved and... End output. Nine such pixel units work in parallel to form a complete 3×3 array filter output.

[0023] The cutoff frequency of the RC low-pass filter satisfies The cutoff frequency The cutoff frequency is tuned to the 10–30 Hz range by adjusting the mass fraction of conductive carbon black in the patterned array carbon paste electrode 11 or the thickness of the PVA solid dielectric layer 12. It is tuned to the 10–30Hz range; wherein, the equivalent series resistance R is adjusted by controlling the carbon black mass fraction of the patterned array carbon paste electrode 11 to achieve a high impedance matching of 10–150MΩ; the filter capacitor C is adjusted by controlling the thickness of the PVA solid dielectric layer 12 to achieve an intrinsic physical capacitance of 50–800pF, so that the RC product is in the range of 5.3–15.9ms.

[0024] like Figure 4 As shown, the electrical coupling relationship of the array flexible sensor device is as follows: The conductive electrode array 8 of the piezoelectric sensing functional layer 2 is electrically coupled one-to-one with the patterned array carbon paste upper electrode 11 of the capacitor layer through the conductive silver paste in the micropores 10 of the insulating isolation layer 3, forming a parallel RC low-pass filter network. Specifically, each piezoelectric electrode unit, its corresponding carbon paste upper electrode unit, and the PVA solid electrolyte and carbon paste lower electrode between them together form an independent first-order RC filter. The nine filters operate independently in parallel without crosstalk.

[0025] like Figure 5 , Figure 6 , Figure 7 As shown, the piezoelectric sensing functional layer 2 consists of a P(VDF-TrFE) composite piezoelectric film 7 doped with barium titanate BTO nanoparticles, a full-surface conductive silver paste electrode 6 on its upper surface, and a 3×3 conductive electrode array 8 on its lower surface.

[0026] The composite piezoelectric film 7 is prepared as follows: Barium titanate (BTO) nanoparticles with an average particle size of 100-200 nm and P(VDF-TrFE) powder are dissolved in a mixed solvent of DMF and acetone at a mass ratio of 1:4, and then ultrasonically dispersed and magnetically stirred to form a uniform precursor slurry. The slurry is then formed by electrospinning or blade coating and dried at a preset temperature, with the film thickness controlled within the range of 20-50 μm.

[0027] The conductive electrode array 8 consists of a 3×3 array of silver paste electrodes, with each electrode measuring 3mm×3mm and an array spacing of 2.5mm. The upper surface electrode is entirely covered in silver paste. All silver paste electrodes are formed by screen printing: using a 300-mesh polyester screen, a photosensitive film thickness of 15μm, and a squeegee angle of 45°, the electrodes are cured by a stepped temperature increase baking process, first pre-baking at 80℃ for 15 minutes, and then fully curing at 120℃ for 30 minutes. Simultaneously, conductive lines are formed on the lower surface edge of the piezoelectric film via screen printing, connecting the nine electrode units to the signal output terminals of the pad areas.

[0028] Among them, the top encapsulation layer 1 and the bottom encapsulation layer 5 are made of biocompatible polymer materials, such as PDMS (polydimethylsiloxane), but not limited to this. Their thickness is within 20-30μm, and they are kept equal in thickness so that the neutral layer is located at the geometric center of the device. The composite piezoelectric film 7 has a thickness of 20-50 μm, and the electrode 6 on the upper surface is a full-surface conductive silver paste with a thickness of 5-15 μm; The conductive electrode array 8 is a 3×3 array of silver paste electrodes, with a single electrode size of 3mm×3mm, an array spacing of 2.5mm, and a thickness of 5-10μm.

[0029] The patterned array carbon paste on-electrode 11 in capacitor layer 4 is a 3×3 array, with a single size of 4mm×4mm and a thickness of 5-50μm. Its size is larger than the single electrode size of conductive electrode array 8, so as to ensure that after the conductive material is filled through micropores, there is sufficient alignment tolerance between the piezoelectric electrode and the carbon paste on-electrode, reducing the alignment accuracy requirements in photolithography or screen printing processes and facilitating mass production. like Figure 8 , Figure 9 As shown, the insulating layer is made of polyurethane material, with a thickness set at 10-30 μm, specifically 15 μm in this embodiment. Polyurethane has a moderate elastic modulus and good adhesion, and can achieve a strong bond with other layers through a semi-curing process.

[0030] Nine micropores 10 are formed on the insulating layer 3 in a 3×3 array, with a pore diameter of approximately 200 μm. The micropores are formed by laser drilling and filled with conductive silver paste. The positions of the micropores are strictly aligned with the conductive electrode array of the piezoelectric sensing functional layer and the patterned array of carbon paste electrodes in the capacitor layer.

[0031] The thickness of the insulating layer is less than that of the top and bottom encapsulation layers, and the thicknesses of the top and bottom encapsulation layers are equal. This design ensures that the neutral layer is located at the geometric center of the device when the sensor is dynamically bent, thereby reducing interlayer shear stress.

[0032] like Figure 10 , Figure 11 As shown, the individual size of the carbon paste electrode 11, 4mm × 4mm, is larger than the individual electrode size of the conductive electrode array 8, 3mm × 3mm. This size difference provides sufficient alignment tolerance during vertical stacking bonding, reducing the alignment accuracy requirements for screen printing or laser drilling, and facilitating mass production. Simultaneously, the gap between adjacent carbon paste electrodes 11 is greater than 1.5mm, far exceeding the typical length of fiber burrs on the carbon paste surface. Combined with the physical barrier of the insulating layer, this effectively prevents electrical short circuits.

[0033] Preparation methods include: The capacitor layer 4 has a patterned array of carbon paste upper electrode 11 and a full-surface carbon paste lower electrode 13 positioned opposite each other, with a PVA solid precursor solution injected between them, and solidified to form a PVA solid dielectric layer 12.

[0034] The top of the electrodes on the capacitor layer 4 is coated with a polyurethane precursor solution and heated at 60-80°C for 5-15 minutes to partially cure it into a semi-cured insulating layer 3. At this time, the degree of crosslinking is 40%-60%, the surface is viscous and does not undergo macroscopic flow. Then, a micropore array 10 is formed on the insulating layer 3 by laser drilling. The conductive electrode array 8 on the lower surface of the piezoelectric sensing functional layer 2 is aligned with the micropores 10 and then attached. A pressure of 50-100 kPa is applied, and then it is completely heated and cured at 80-120°C for 1-3 hours to form a strong physical interlocking interface between the polyurethane and the adjacent piezoelectric film and carbon paste electrode.

[0035] The piezoelectric sensing functional layer 2 is formed by dissolving BTO nanoparticles and P(VDF-TrFE) powder in an organic mixed solvent, and then forming a piezoelectric thin film 7 by film formation or high-voltage polarization. Then, silver paste is screen-printed on the upper surface as an electrode 6, and a 3×3 array of silver paste is screen-printed on the lower surface as a conductive electrode array 8. At the same time, the signal output terminal 14 is formed by screen printing. The silver paste is cured by step heating and baking, that is, pre-baking at a lower temperature and then fully curing at a higher temperature.

[0036] The micropores 10 are filled with conductive silver paste to achieve electrical coupling between the conductive electrode array 8 and the patterned array carbon paste upper electrode 11; then the top encapsulation layer 1 and the bottom encapsulation layer 5 are covered, and the entire carbon paste lower electrode 13 is connected to the common ground terminal (GND). The conductive electrode array 8 or the patterned array carbon paste upper electrode 11 is led out to the signal output terminal through the wires 9 respectively. ), and complete the sensor fabrication.

[0037] In the capacitor layer 4, both the patterned array carbon paste upper electrode 11 and the full-surface carbon paste lower electrode 13 are multi-screen printed carbon-based composite films with a thickness of 5-50 μm. They are constructed from conductive carbon black and polymer binders to form a percolation conductive network, and their sheet resistance is controlled at 10 Ω·cm. 7 -10 8 Within the Ω range, to provide the high equivalent series resistance (ESR) required for in-situ filtering; The PVA solid dielectric layer 12 is formed by curing pure polyvinyl alcohol aqueous solution, with a film thickness of 5-20 μm, an intrinsic relative permittivity stable between 5-15, and a volume resistivity greater than 10⁻⁶. 10 Ω cm, ensuring minimal leakage current; A single patterned array of carbon paste upper electrode 11, together with the corresponding PVA solid dielectric layer 12 and the entire carbon paste lower electrode 13, constitutes a pure physical capacitor unit. Its specific capacitance per unit geometric area is 5-50pF / mm², and the capacitance value change rate is less than 5% in the frequency range of 1-100Hz.

[0038] In summary, this invention employs differentiated optimization design for the thickness of each functional layer, limiting the thickness of the insulating isolation layer (10-30μm) to be smaller than that of the upper and lower encapsulation layers, and ensuring that the thickness of the top and bottom encapsulation layers is equal. This ensures that the neutral layer is precisely located at the geometric center during dynamic bending of the device, effectively reducing interlayer shear stress and avoiding the problems of multilayer structure peeling and cracking. Simultaneously, the deformation stress is concentrated in the upper and lower encapsulation layers, which have superior mechanical properties, significantly reducing the risk of breakage and detachment of the conductive silver paste within the micropores of the insulating isolation layer. This solves the defects of traditional multilayer flexible sensors, such as conduction failure and structural damage after repeated bending.

[0039] The piezoelectric sensing unit and RC low-pass filter unit are integrated into one unit, eliminating the need for external filter circuits and utilizing the sensor's own structure to construct an in-situ filter network. A high equivalent series resistance of 10-150MΩ is achieved by precisely controlling the carbon black mass fraction on the carbon paste electrode, and an intrinsic physical capacitance of 50-800pF is achieved by adjusting the thickness of the PVA solid dielectric layer. The RC filter cutoff frequency is precisely tuned to the optimal range of 10–30Hz. This effectively filters out high-frequency noise above 20Hz caused by human movement while fully preserving the core effective low-frequency pulse signal of 1-3Hz.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0041] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0042] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible array sensor device integrating in-situ filtering, characterized in that, The sensor device includes a vertically stacked structure from top to bottom of a top encapsulation layer (1), a piezoelectric sensing functional layer (2), an insulating isolation layer (3), a capacitor layer (4), and a bottom encapsulation layer (5); Among them, the piezoelectric sensing functional layer (2) is composed of a composite piezoelectric film (7) doped with barium titanate BTO nanoparticles and conductive silver paste electrodes (6) on its upper surface and conductive electrode array (8) on its lower surface. The piezoelectric sensing functional layer (2) is also provided with wires (9) formed by screen printing, which connect the conductive electrode array (8) to an external signal receiver; The insulating layer (3) has micropores (10) filled with conductive material. The capacitor layer (4) includes: a patterned array of carbon paste upper electrodes (11) as the uppermost layer of the capacitor layer (4), which is an intermittent pad structure, and its lower surface is in partial contact with the upper surface of the PVA solid dielectric layer (12); The lower surface of the PVA solid dielectric layer (12) is fully bonded to the carbon paste lower electrode (13).

2. The array flexible sensor device with integrated in-situ filtering according to claim 1, characterized in that, The insulating layer (3) is made of polyurethane material, and its thickness is set to 10-30μm.

3. The array flexible sensor device with integrated in-situ filtering according to claim 2, characterized in that, The insulating layer (3) has 9 micropores (10) arranged in a 3×3 array with a pore diameter of about 200 μm.

4. The array flexible sensor device with integrated in-situ filtering according to claim 1, characterized in that, The micropores (10) are formed by laser drilling and filled with conductive silver paste.

5. The array flexible sensor device with integrated in-situ filtering according to claim 1, characterized in that, The lower electrode (13) of the entire carbon paste layer (4) is connected to the common ground terminal, and the upper electrode (6) of the piezoelectric sensing functional layer (2) is connected to the common ground terminal.

6. The array flexible sensor device with integrated in-situ filtering according to claim 1, characterized in that, The conductive electrode array (8) is electrically coupled one-to-one with the patterned array carbon paste electrodes (11) of the capacitor layer through the conductive silver paste in the micropores (10), forming a parallel RC low-pass filter network.

7. A method for fabricating an array flexible sensor device with integrated in-situ filtering, used to manufacture the array flexible sensor device according to any one of claims 1-6, characterized in that, The method includes: The patterned array carbon paste upper electrode (11) and the whole surface carbon paste lower electrode (13) are arranged opposite to each other, and a PVA solid precursor solution is injected between them to solidify and form a PVA solid dielectric layer (12). A polyurethane precursor solution is coated on the top of the electrode of the capacitor layer (4), and heated at 60-80°C to partially solidify it to form a semi-cured insulating layer (3). At this time, the degree of crosslinking is 40%-60%, the surface is viscous and does not undergo macroscopic flow; then, a micropore (10) array is formed on the insulating layer (3) by laser drilling. After aligning the conductive electrode array (8) on the lower surface of the piezoelectric sensing functional layer (2) with the micropore (10), apply a pressure of 50-100 kPa and then heat and cure it completely at 80-120°C, so that the polyurethane forms a strong physical interlocking interface with the adjacent piezoelectric film and carbon paste electrode. The piezoelectric sensing functional layer (2) is formed by dissolving BTO nanoparticles and vinylidene fluoride-trifluoroethylene copolymer powder in an organic mixed solvent, and then forming a piezoelectric film (7) by film formation or high voltage polarization; then, silver paste is screen-printed on the upper surface as an electrode (6), and a 3×3 array of silver paste is screen-printed on the lower surface as a conductive electrode array (8), and the signal output terminal (14) is formed by screen printing; the silver paste is cured by step heating and baking, that is, pre-baking at a lower temperature and then completely curing at a higher temperature; Micropores (10) are filled with conductive silver paste to achieve electrical coupling between the conductive electrode array (8) and the patterned array carbon paste upper electrode (11); then the top encapsulation layer (1) and the bottom encapsulation layer (5) are covered, and the entire carbon paste lower electrode (13) is connected to the common ground terminal. The conductive electrode array (8) or the patterned array carbon paste upper electrode (11) is led out to the signal output terminal through wires (9). Complete the sensor fabrication; The PVA solid dielectric layer (12) is formed by curing pure polyvinyl alcohol aqueous solution. The film thickness is 5-20 μm, its intrinsic relative permittivity is stable between 5-15, and its volume resistivity is greater than 10. 10 Ω cm, ensuring minimal leakage current; A single patterned array of carbon paste upper electrode (11), together with the corresponding PVA solid dielectric layer (12) and the entire carbon paste lower electrode (13), constitutes a pure physical capacitor unit.

8. The method for fabricating an array flexible sensor device with integrated in-situ filtering according to claim 7, characterized in that, The top of the electrode on the capacitor layer (4) is coated with a polyurethane precursor solution and heated for 5-15 minutes; the conductive electrode array (8) is aligned with the micropores (10) and then bonded together, and the heating and curing time is 1-3 hours.

9. The method for fabricating an array flexible sensor device with integrated in-situ filtering according to claim 8, characterized in that, The specific capacitance per unit geometric area of ​​the pure physical capacitor unit is 5-50pF / mm², and the capacitance value changes by less than 5% in the frequency range of 1-100Hz.

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