A flexible trimodal pressure and light detection sensor array and method of making the same

Abstract

The application provides a flexible three-mode pressure and light detection sensor array and a preparation method thereof, and relates to the technical field of flexible electronics. The flexible three-mode pressure and light detection sensor array comprises a flexible TPU substrate, a resistance sensing unit arranged on the upper surface of the substrate, a capacitance sensing unit arranged on the upper surface of the resistance sensing unit, and a surface light detection unit arranged on the outermost upper surface of the capacitance sensing unit. The resistance sensing unit and the capacitance sensing unit are integrated in the same monitoring site in the vertical direction, and the array as a whole is in a matrix distribution and contains multiple independent monitoring sites. The resistance sensing unit is used for detecting the pressure change caused by the contact of an object and calibrating the capacitance signal, the capacitance sensing unit is used for detecting the approach and contact of a charged object, and the surface light detection unit is used for detecting X-rays and ultraviolet rays in the environment. The application integrates proximity sensing, pressure detection and harmful light detection, and has the advantages of strong curved surface adaptability, high detection precision and the like.

Description

Technical Field

[0001] This invention relates to the field of flexible electronics technology, and in particular to a flexible three-modal pressure and light detection sensor array and its fabrication method. Background Technology

[0002] With the rapid development of the Internet of Things and wearable devices, flexible pressure sensors are playing an important role in fields such as health monitoring, human-computer interaction, and electronic skin. However, most current flexible sensors are single-function and still have limitations.

[0003] In terms of sensing modes, traditional piezoresistive sensors, although highly sensitive, can only detect pressure changes after physical contact and cannot sense the approach of an object; while single capacitive sensors, although capable of proximity sensing, lack accurate correction for contact detection, making it difficult to achieve precise monitoring of the entire process from approach to contact.

[0004] In terms of environmental safety monitoring, existing electronic skin mainly focuses on acquiring mechanical signals, neglecting the real-time monitoring of potentially harmful radiation in the environment, such as excessive ultraviolet rays or invisible X-rays. Therefore, it cannot provide effective environmental safety early warning in operational scenarios such as medical examinations and industrial manufacturing.

[0005] Therefore, the technical problem to be solved by the present invention is: how to achieve accurate pressure measurement on various complex surfaces by designing a flexible substrate with a complex structure. Summary of the Invention

[0006] This invention provides a flexible trimodal pressure and light detection sensor array and its fabrication method. By placing a resistance sensing unit on the upper surface of a flexible TPU substrate, a capacitance sensing unit on the upper surface of the resistance sensing unit, and a surface light detection unit on the outermost upper surface of the capacitance sensing unit, the resistance and capacitance sensing units are integrated vertically at the same monitoring point. Simultaneously, the sensor array is arranged in a matrix distribution and includes multiple independent monitoring points. The resistance sensing unit detects pressure changes caused by contact with an object and calibrates the capacitance sensing signal. The capacitance sensing unit detects capacitance changes caused by the approach and contact of a charged object. This achieves coordinated monitoring from non-contact proximity sensing to contact pressure detection at the same monitoring point. Furthermore, the surface light detection unit enables real-time detection of X-rays and ultraviolet radiation in the environment, thus solving the problems of single sensing modes, lack of environmental monitoring capabilities, and difficulty in adapting to complex curved surface assembly in existing technologies.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a flexible trimodal pressure and light detection sensor array, characterized in that it comprises: Flexible TPU substrate; The resistance sensing unit disposed on the upper surface of the flexible TPU substrate is used to detect pressure changes caused by contact with an object and to calibrate the capacitance sensing signal. The capacitance sensing unit disposed on the upper surface of the resistance sensing unit is used to detect the capacitance change caused by the approach and contact of a charged object. The surface light detection unit, located on the outermost upper surface of the capacitive sensing unit, is used to detect X-rays and ultraviolet rays in the environment. The resistance sensing unit and the capacitance sensing unit are integrated at the same monitoring point in the vertical direction, and the sensor array is distributed in a matrix, containing multiple independent monitoring points.

[0008] Preferably, in the above-mentioned flexible trimodal pressure and light detection sensor array, the flexible TPU substrate has an arrayed mesh-like connection structure, which can be attached to complex curved surfaces by stretching and arranging.

[0009] Preferably, in the above-mentioned flexible trimodal pressure and light detection sensor array, the resistance sensing unit includes: A resistance-sensitive unit disposed on the upper surface of the flexible TPU substrate; A flexible TPU electrode plate is disposed on the upper surface of the resistance-sensitive unit; Conductive copper paste is disposed on the surface of the intermediate flexible TPU electrode plate; the intermediate flexible TPU electrode plate serves as both the upper electrode of the resistance sensing unit and the lower electrode of the capacitance sensing unit.

[0010] Preferably, in the above-mentioned flexible three-modal pressure and light detection sensor array, the resistance-sensitive unit is a porous piezoresistive composite cuboid, which is prepared by mixing conductive filler, flexible matrix material and thermally expandable microspheres; the thermally expandable microspheres expand in volume during the heat curing stage, extruding carbon nanotubes and silicone rubber matrix, and constructing a uniform porous conductive network inside the material; The conductive filler is selected from any one or more combinations of the following: Carbon-based conductive materials include one of the following: conductive carbon black, acetylene black, carbon microspheres, carbon dots, fullerenes, expanded graphite, carbon sponges, carbon aerogels, single-walled carbon nanotubes, double-walled carbon nanotubes, arrayed carbon nanotubes, carbon nanofibers, graphene, few-layer graphene, graphene oxide, reduced graphene oxide, and graphene nanoribbons. Metal-based conductive materials, including silver nanoparticles, gold nanoparticles, copper nanoparticles, silver flakes / silver microsheets, nickel powder, silver nanowires, copper nanowires, gold nanowires, gallium indium alloys, gallium indium tin alloys, liquid metal droplets, and liquid metal nanoparticles. Transition metal carbides / nitrides, including Ti3C2T xOne of V2C, Mo2C; Metallic transition metal dichalcogenides include one of 1T-MoS2, TaS2, and VS2; Intrinsically conductive polymers, including one of PEDOT:PSS, polyaniline, polypyrrole, and polythiophene; Composite / core-shell hybrid materials, including one of the following: silver-plated glass microspheres, silver-plated copper powder, gold-plated silica nanospheres, carbon nanotube-graphene hybrid materials, carbon black-carbon nanotube hybrid materials, and silver nanowire-carbon nanotube hybrid materials; The flexible matrix material is selected from any one or more combinations of the following: Polysiloxane elastomers, including one of polydimethylsiloxane, platinum-catalyzed silicone rubber, room temperature vulcanizing silicone rubber, liquid silicone rubber, and fluorosilicone rubber; Polyurethane elastomers include one of thermoplastic polyurethane elastomers (TPU), polyurethane foam, polyurethane sponge, polyurethane foam, polyether polyurethane, polyester polyurethane, and polycarbonate polyurethane; Styrene-based and other thermoplastic elastomers, including one of thermoplastic elastomers, thermoplastic rubbers, SEBS, SBS, TPV, and POE; Traditional synthetic rubber and natural rubber, including one of the following: natural rubber, styrene-butadiene rubber, nitrile rubber, ethylene propylene diene monomer (EPDM) rubber, chloroprene rubber, butyl rubber, and fluororubber; Gel-based flexible matrices include one of the following: polyvinyl alcohol hydrogel, polyacrylamide hydrogel, alginate hydrogel, gelatin hydrogel, cellulose-based hydrogel, poly(N-isopropylacrylamide) hydrogel, and ionogel. Flexible plastic and resin films, including one of polyimide film, polyethylene terephthalate film, polyethylene naphthalate film, polytetrafluoroethylene, and vinylidene fluoride-trifluoroethylene copolymer film; Natural and bio-based flexible materials, including one of the following: silk fibroin film / sponge, bacterial cellulose, chitosan film, and nanocellulose paper.

[0011] Preferably, in the above-mentioned flexible trimodal pressure and light detection sensor array, the capacitive sensing unit includes: A resin dielectric layer disposed on the upper surface of the intermediate flexible TPU electrode plate; The upper flexible TPU electrode plate is disposed on the upper surface of the resin dielectric layer.

[0012] Preferably, in the above-mentioned flexible trimodal pressure and light detection sensor array, the resin dielectric layer is prepared by photosensitive resin through photocuring 3D printing technology; the resin dielectric layer has a macroscopic elliptical frustum geometry, with a three-dimensional interconnected porous structure inside, and micro dome structures are arrayed on the upper surface.

[0013] Preferably, in the above-mentioned flexible trimodal pressure and light detection sensor array, the surface light detection unit includes a UV-excited luminescent material film and an X-ray excited luminescent material film arranged in sections; the UV-excited luminescent material film emits first visible light under UV excitation, and the X-ray excited luminescent material film emits second visible light under X-ray excitation.

[0014] Secondly, the present invention also provides a method for fabricating the flexible trimodal pressure and light detection sensor array as described above, comprising the following steps: A flexible TPU substrate, an intermediate flexible TPU electrode plate, and an upper flexible TPU electrode plate are prepared, and conductive copper paste is applied to the surface of the intermediate flexible TPU electrode plate. Fabrication of porous piezoresistive composite resistive sensing units; An elliptical frustum-shaped resin dielectric layer with three-dimensional interconnected pores and a surface micro-dome structure was prepared. A resistance sensing unit, an intermediate flexible TPU electrode plate, a resin dielectric layer, and an upper flexible TPU electrode plate are sequentially stacked on the flexible TPU substrate to form a vertically integrated structure of a resistance sensing unit and a capacitance sensing unit. Prepare photoluminescent thin films containing ultraviolet-excited luminescent materials and X-ray-excited luminescent materials; The photoluminescent film is attached to the upper surface of the upper flexible TPU electrode plate to complete the encapsulation of the sensor array.

[0015] Preferably, in the above preparation method, the preparation of the porous piezoresistive composite material resistive sensing unit specifically includes: Ecoflex component A and conductive filler were mixed at a mass ratio of 50:(5~7) to obtain the first mixed solution; Ecoflex component B was mechanically mixed with thermally expanded microspheres at a mass ratio of 50:(4~6), and heated on a heating stage at 110℃~130℃ for 6~10 minutes to allow the thermally expanded microspheres to expand initially, thus obtaining a second mixed solution. After the first mixture and the second mixture are mixed evenly, the mixture is applied to the mold and cured by heating on a heating table at 110℃~130℃. The cured material is cut into cuboids with a length of 3.5~4.5mm, a width of 3.5~4.5mm, and a height of 2.5~3.5mm to obtain the resistance-sensitive unit.

[0016] Preferably, in the above preparation method, the ultraviolet-excited luminescent material is selected from any one or more combinations of the following: Inorganic sulfide and sulfur oxide materials, including one of zinc sulfide, alkaline earth metal sulfides, and rare earth sulfur oxides; Inorganic aluminates, silicates and oxides, including one of strontium aluminate, barium magnesium aluminate, yttrium aluminum garnet, alkaline earth metal silicates, yttrium oxide, zinc oxide, calcium tungstate and lead molybdate; Halogenated and phosphate materials, including one of calcium halophosphate, orthophosphate, pyrophosphate, and fluoride matrix; Nitride and oxide luminescent materials, including one of the CaAlSiN3:Eu, Sr2Si5N8:Eu, and SiAlON series; Quantum dot and nanocrystalline luminescent materials, including one of CdS, CdSe, CdTe, PbS, InP, CuInS2, AgInS2, CsPbX3 (X=Cl / Br / I), carbon quantum dots, graphene quantum dots, gold nanoclusters, and silver nanoclusters; Organic fluorescent materials and their complexes, including one of the following: rhodamine derivatives, coumarin derivatives, fluorescein derivatives, cyanine derivatives, tetraphenylethylene and its derivatives, europium / terbium β-diketone complexes, polyphenylene oxide, polyfluorene, and stilbene fluorescent whitening agents; The X-ray excitation luminescent material is selected from any one or more combinations of the following: Alkali metal and alkaline earth metal halides, including one of calcium fluoride, barium fluoride, sodium iodide, cesium iodide, barium fluoride bromide, lanthanum bromide, lanthanum chloride, and strontium iodide; Tungstates and germanates, including one of calcium tungstate, cadmium tungstate, lead tungstate, and bismuth germanate; Rare earth sulfur oxides and oxides, including one of gadolinium sulfide, yttrium sulfide, lanthanum sulfide, yttrium oxide, and lutetium oxide; Silicates and aluminates, including one of lutetium silicate, lutetium yttrium silicate, yttrium aluminum garnet, lutetium aluminum garnet, and gadolinium silicate; Perovskites and low-dimensional metal halides, including one of CsPbBr3, CsPbI3, MAPbI3, MAPbBr3, Cs2AgBiBr6, Cs3Cu2I5, and CsCu2I3; Organic scintillation plastics and polymer composites, including one of polystyrene-based scintillation plastics, polyvinyl toluene-based scintillation plastics, and heavy metal-doped composite plastics.

[0017] The flexible trimodal pressure and light detection sensor array and its fabrication method provided by the present invention have at least the following beneficial effects: (1) The present invention adopts a flexible TPU substrate with an arrayed grid-like connection structure, which breaks through the planar limitation of traditional sensors. It can be flexibly attached to various complex curved surfaces by stretching and arranging, ensuring close contact between the sensor and the measured surface, effectively avoiding poor contact and deformation problems when assembling on non-flat surfaces, and ensuring stable detection function in complex curved surface environments.

[0018] (2) This invention integrates a resistance sensing unit and a capacitance sensing unit in the vertical direction at the same monitoring point, and integrates a surface light detection unit on the outermost upper surface of the capacitance sensing unit, realizing multimodal integration of non-contact proximity detection, contact pressure detection, and detection of harmful environmental light. The resistance sensing unit detects the pressure change caused by contact with an object, and the capacitance sensing unit detects the capacitance change caused by the approach and contact of a charged object. The two work together to achieve full-process monitoring from approach to contact. The detection signal of the resistance sensing unit calibrates the pressure sensing of the capacitance sensing unit, significantly improving the detection accuracy of the sensor.

[0019] (3) The resistivity-sensitive unit of the present invention adopts a porous piezoresistive composite material prepared by mixing conductive filler, flexible matrix material and thermally expandable microspheres. The thermally expandable microspheres expand in volume during the heat curing stage, squeezing carbon nanotubes and silicone rubber matrix to build a uniform porous conductive network inside the material. The resin dielectric layer of the capacitance-sensitive unit is prepared by photosensitive resin through photocuring 3D printing technology. It has a macroscopic elliptical frustum geometry, with a three-dimensional interconnected pore structure inside, and an array of micro dome structures on the upper surface. The above structural design enables the sensor system to have a wide linear detection range, high sensing accuracy and high sensitivity. The surface light detection unit includes a partitioned ultraviolet-excited luminescent material film and an X-ray-excited luminescent material film, which can simultaneously detect ultraviolet and X-rays in the environment, providing a safe, accurate and portable environmental sensing solution for industrial manufacturing and medical examination. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] Figure 1 This is a structural diagram of a flexible three-modal pressure and light detection sensor array provided in an embodiment of the present invention; Figure 2 A cross-sectional micrograph of a flexible trimodal pressure and light detection sensor array provided in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the fabrication method of a flexible three-modal pressure and light detection sensor array provided in an embodiment of the present invention. Figure 4 A flowchart illustrating a method for fabricating a flexible three-modal pressure and light detection sensor array according to an embodiment of the present invention; Figure 5The capacitance and resistance changes of the flexible trimodal pressure and light detection sensor array provided in this embodiment of the invention under different pressures; wherein, (A) the capacitance change of the sensor system under 0-1N pressure, (B) the capacitance change of the sensor system under 0-16N pressure, (C) the resistance change of the sensor system under 0-1N pressure, and (D) the resistance change of the sensor system under 0-16N pressure. Figure 6 The graph shows the capacitance change of the sensor provided in this embodiment after 2000 pressurization-release cycle tests. Figure 7 The graph shows the resistance change of the sensor provided in this embodiment of the invention after 2000 pressurization-release cycle tests.

[0022] Figure label: 1. Flexible TPU substrate; 2. Resistance sensing unit; 3. Capacitance sensing unit; 4. Surface light detection unit; 21. Resistance sensing unit; 22. Middle flexible TPU electrode plate; 23. Conductive copper paste; 31. Resin dielectric layer; 32. Upper flexible TPU electrode plate.

[0023] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0024] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] Example 1: This invention provides a flexible trimodal pressure and light detection sensor array, such as... Figure 1 and Figure 2As shown, the flexible trimodal pressure and light detection sensor array includes a flexible TPU substrate 1, a resistance sensing unit 2, a capacitance sensing unit 3, and a surface light detection unit 4. The resistance sensing unit 2 is disposed on the upper surface of the flexible TPU substrate 1 and is used to detect pressure changes caused by contact with an object and to calibrate the capacitance sensing signal. The capacitance sensing unit 3 is disposed on the upper surface of the resistance sensing unit 2 and is used to detect capacitance changes caused by the approach and contact of a charged object. The surface light detection unit 4 is disposed on the outermost upper surface of the capacitance sensing unit 3 and is used to detect X-rays and ultraviolet rays in the environment. The resistance sensing unit 2 and the capacitance sensing unit 3 are integrated at the same monitoring point in the vertical direction, and the sensor array is distributed in a matrix, containing multiple independent monitoring points.

[0026] In practical implementation, when a charged object approaches the sensor array, the capacitive sensing unit 3 detects a change in capacitance; when the object further contacts and applies pressure, the resistive sensing unit 2 detects a change in pressure and generates a resistance signal. There is a definite correspondence between this resistance signal and the contact pressure, while the capacitance output value of the capacitive sensing unit 3 under the same contact state is easily affected by environmental interference or material hysteresis. By using the pressure value corresponding to the resistance signal as a reference, the theoretical capacitance value of the capacitive sensing unit 3 under that pressure is calculated. Then, the theoretical capacitance value is compared with the actual capacitance output value to obtain a calibration coefficient, which is used to correct the capacitance measurement value in the subsequent proximity detection stage, thereby achieving real-time calibration of the capacitance sensing signal of the capacitive sensing unit 3. Through this method, full-process monitoring and signal calibration from proximity to contact are achieved. Simultaneously, the surface light detection unit 4, located on the outermost upper surface of the capacitive sensing unit 3, detects X-rays and ultraviolet rays in the environment in real time. By integrating the resistive sensing unit 2 and the capacitive sensing unit 3 in the vertical direction at the same monitoring point, and making the sensor array as a whole matrix, multiple independent monitoring points can work collaboratively to complete multimodal environmental sensing.

[0027] As an example only, the sensor array is arranged in a 4×4 matrix, containing 16 independent monitoring points. Each monitoring point has geometric dimensions of 4mm in length, 4mm in width, and 3mm in height. This allows for simultaneous detection of object proximity and contact at multiple points, as well as detection of ultraviolet and X-rays in the environment.

[0028] It should be noted that the specific parameters of the above-mentioned sensor array, which is distributed in a 4×4 matrix, contains 16 independent monitoring points, and each monitoring point has geometric dimensions of 4mm in length, 4mm in width, and 3mm in height, are merely an exemplary implementation of the present invention and not a necessary limitation thereof. In specific applications, those skilled in the art can flexibly adjust the number, arrangement, and geometric dimensions of individual monitoring points according to actual detection needs, the shape and area of ​​the attached surface, the precision of the manufacturing process, and the signal acquisition and processing capabilities. For example, the monitoring points can be distributed in a 2×2, 3×3, 4×6, or other arbitrary M×N matrix, or a customized non-matrix layout can be used; the size of a single monitoring point can also be reasonably varied in the range of micrometers to centimeters according to the requirements of sensitivity and spatial resolution. Therefore, any equivalent substitutions, improvements, or changes made to the number, arrangement, and geometric dimensions of the monitoring points under the core concept of the present invention should fall within the protection scope of the present invention.

[0029] In some embodiments, the flexible TPU substrate 1 has an arrayed mesh-like connection structure that can be stretched and attached to complex curved surfaces.

[0030] In this embodiment, the flexible TPU substrate 1 is made of thermoplastic polyurethane material, and its internal arrayed mesh-like connection structure gives the substrate good tensile strength and flexibility. In use, the flexible TPU substrate 1 is stretched and attached to a complex three-dimensional curved surface, which allows the substrate to form a tight contact with the surface being measured, thereby reducing the contact problems and deformation problems that are prone to occur when traditional rigid sensors are assembled on non-flat surfaces.

[0031] In some embodiments, such as Figure 1 As shown, the resistance sensing unit 2 includes a resistance sensing unit 21, an intermediate flexible TPU electrode plate 22, and a conductive copper paste 23; wherein, the resistance sensing unit 21 is disposed on the upper surface of the flexible TPU substrate 1; the intermediate flexible TPU electrode plate 22 is disposed on the upper surface of the resistance sensing unit 21; the conductive copper paste 23 is disposed on the surface of the intermediate flexible TPU electrode plate 22; the intermediate flexible TPU electrode plate 22 serves as both the upper electrode of the resistance sensing unit 2 and the lower electrode of the capacitance sensing unit 3.

[0032] When an object comes into contact with and presses against the sensor array, the resistance-sensitive unit 21 undergoes compression deformation due to vertical pressure. The porous conductive network inside it densifies, increasing the conductive pathways and causing a decrease in resistance. This change in resistance is monotonically correlated with the magnitude of the applied pressure. The intermediate flexible TPU electrode plate 22 stably leads out the resistance signal through the conductive copper adhesive 23. Since the intermediate flexible TPU electrode plate 22 also serves as the lower electrode of the capacitance-sensing unit 3, the resistance signal output by the resistance-sensing unit 2 and the capacitance signal of the capacitance-sensing unit 3 can be synchronously acquired and compared at the same monitoring point. This allows for real-time calibration of the capacitance signal using the resistance signal, eliminating measurement deviations caused by environmental interference or material hysteresis, and ensuring the sensor array maintains high-precision pressure detection capabilities throughout the entire process from approach to contact.

[0033] In some embodiments, the resistance-sensitive unit 21 is a porous piezoresistive composite cuboid, which is prepared by mixing conductive filler, flexible matrix material and thermally expandable microspheres; the thermally expandable microspheres expand in volume during the heat curing stage, squeezing the conductive filler and silicone rubber matrix to build a uniform porous conductive network inside the material.

[0034] In this embodiment, the core material of the 21-element resistance sensing unit is formed by mechanically mixing conductive fillers, flexible matrix materials, and thermally expandable microspheres in a specific mass ratio, and then heating and curing at 120°C. During the curing stage, the thermally expandable microspheres expand in volume and compress the carbon nanotubes and silicone rubber matrix, constructing a porous conductive network within the material. When the sensor is subjected to external pressure and deforms, this porous structure becomes compacted, generating more carbon nanotube conductive pathways within the sensing unit, thereby changing the resistance value. This design endows the sensor with excellent sensitivity, a wide linear detection range, and stable performance under repeated cycles.

[0035] The conductive filler may be selected from any one or more combinations of the following: Carbon-based conductive materials, such as conductive carbon black, acetylene black, carbon microspheres, carbon dots, fullerenes (C60), expanded graphite, carbon sponges, carbon aerogels, single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), arrayed carbon nanotubes, carbon nanofibers (CNFs), graphene, few-layer graphene, graphene oxide (GO), reduced graphene oxide (rGO), and graphene nanoribbons; Metal-based conductive materials, such as silver nanoparticles (AgNPs), gold nanoparticles, copper nanoparticles, silver flakes / silver microsheets, nickel powder, silver nanowires (AgNWs), copper nanowires (CuNWs), gold nanowires (AuNWs), gallium indium alloy (EGaIn), gallium indium tin alloy (Galinstan), liquid metal droplets, and liquid metal nanoparticles. Transition metal carbide / nitride (MXenes materials, such as Ti3C2T)x (V2C, Mo2C); metallic transition metal dichalcogenides (such as 1T-MoS2, TaS2, VS2); Intrinsically conductive polymers, such as PEDOT:PSS, polyaniline (PANI), polypyrrole (PPy), and polythiophene (PT). And composite / core-shell and hybrid materials, such as silver-plated glass microspheres, silver-plated copper powder, gold-plated silica nanospheres, carbon nanotube-graphene hybrid materials, carbon black-carbon nanotube hybrid materials, and silver nanowire-carbon nanotube hybrid materials.

[0036] The flexible matrix material may be selected from any one or more combinations of the following: Polysiloxane elastomers, such as polydimethylsiloxane (PDMS, such as Sylgard 184), platinum-catalyzed silicone rubber (such as Ecoflex, Dragon Skin series), room temperature vulcanizing silicone rubber (RTV), liquid silicone rubber (LSR), and fluorosilicone rubber; Polyurethane elastomers, such as thermoplastic polyurethane elastomer (TPU), polyurethane (PU) sponge, polyurethane foam, polyether polyurethane, polyester polyurethane, and polycarbonate polyurethane; Styrene-based and other thermoplastic elastomers, such as thermoplastic elastomers (TPE), thermoplastic rubber (TPR), SEBS, SBS, TPV, and POE; Traditional synthetic rubbers and natural rubbers, such as natural rubber (NR), styrene-butadiene rubber (SBR), nitrile rubber (NBR), ethylene propylene diene monomer (EPDM), chloroprene rubber (CR), butyl rubber (IIR), and fluororubber (FKM). Gel-based flexible matrices, such as polyvinyl alcohol (PVA) hydrogel, polyacrylamide (PAM) hydrogel, alginate hydrogel, gelatin hydrogel, cellulose-based hydrogel, poly(N-isopropylacrylamide) (PNIPAM) hydrogel, and ionogels. Flexible plastic and resin films, such as polyimide (PI) film, polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polytetrafluoroethylene (PTFE) film, and vinylidene fluoride-trifluoroethylene copolymer (P(VDF-TrFE)) film; And natural and bio-based flexible materials, such as silk fibroin films / sponges, bacterial cellulose, chitosan films, and nanocellulose paper.

[0037] It should be noted that multi-walled carbon nanotubes refer to tubular carbon materials composed of multiple coaxial carbon atom layers, with an outer diameter typically of 10-20 nm and a length ranging from several μm to tens of μm. They possess excellent electrical conductivity and mechanical strength and are used as conductive fillers in this invention. Ecoflex silicone rubber is a commercially available platinum-catalyzed two-component addition-type silicone rubber, which is cured at room temperature after mixing component A and component B in a 1:1 mass ratio. It exhibits high elasticity, low Young's modulus, and good biocompatibility and is used as a flexible matrix material in this invention. Component A mainly contains vinyl-terminated polysiloxane, and component B mainly contains hydrogen-containing silicone oil and a platinum catalyst. After mixing, they undergo a hydrogenation silylation crosslinking reaction under heating conditions to form an elastomer. Thermally expandable microspheres are polymer microspheres with a core-shell structure. The outer shell is a thermoplastic polymer, and the core encapsulates a low-boiling-point alkane liquid. When heated above the glass transition temperature of the outer shell, the alkane in the core vaporizes, generating internal pressure, causing the microsphere volume to expand to 2-5 times its original diameter. During the 120℃ curing process, the thermally expanded microspheres expand in volume, compressing the surrounding multi-walled carbon nanotubes and the not-yet-fully-cured Ecoflex silicone rubber matrix. This forces the carbon nanotubes to rearrange within the matrix, forming a uniform porous conductive network with the expanded microspheres as pores and the carbon nanotubes as the conductive framework. This network is characterized by: a polydisperse distribution of pore sizes, ranging from several micrometers to tens of micrometers; and conductive pathways primarily distributed on the walls between the pores, forming three-dimensional interconnected conductive channels. When the resistance-sensitive unit 21 is compressed, the pores are compressed, increasing the contact area between the walls and significantly increasing the number of conductive pathways, resulting in a decrease in resistance and achieving the conversion of pressure into a resistance signal.

[0038] In some embodiments, such as Figure 1 As shown, the capacitive sensing unit 3 includes a resin dielectric layer 31 and an upper flexible TPU electrode plate 32. The resin dielectric layer 31 is disposed on the upper surface of the intermediate flexible TPU electrode plate 22; the upper flexible TPU electrode plate 32 is disposed on the upper surface of the resin dielectric layer 31.

[0039] When a charged object approaches the sensor array, the spatial electric field above the resin dielectric layer 31 changes, causing a change in the capacitance between the upper flexible TPU electrode plate 32 and the middle flexible TPU electrode plate 22. The capacitance sensing unit 3 converts this capacitance change into a detectable electrical signal. As the charged object moves closer to or even contacts the surface of the upper flexible TPU electrode plate 32, the resin dielectric layer 31 undergoes compressive deformation under vertical pressure. The resin dielectric layer 31 has a macroscopic elliptical frustum geometry with a three-dimensional interconnected porous structure inside and an array of micro-dome structures on its upper surface. These structural features allow the dielectric layer to undergo significant local deformation under slight pressure, resulting in a decrease in thickness and a change in dielectric constant distribution, thus causing a significant change in capacitance. By monitoring the capacitance change trend in real time, it is possible to determine whether an object is approaching and whether contact has occurred. When the object contacts and pressure is continuously applied, the capacitance changes monotonically with increasing pressure, enabling continuous detection of the entire process from approach to contact.

[0040] In some embodiments, the resin dielectric layer 31 is prepared by photosensitive resin through photocuring 3D printing technology; the resin dielectric layer 31 has a macroscopic elliptical frustum geometry, a three-dimensional interconnected porous structure inside, and an array of micro dome structures on its upper surface.

[0041] In this embodiment, the resin dielectric layer 31 is precisely prepared from photosensitive resin using photopolymerization 3D printing technology. Its microstructure is unique: macroscopically it exhibits an elliptical frustum geometry with a three-dimensional interconnected porous structure inside, and an array of micro-dome structures on its upper surface. When a charged object (such as a human finger or robotic arm) approaches the sensor but before contact, the sensor's capacitance changes due to the altered spatial electric field, achieving proximity sensing. When the object further contacts and presses against the sensor surface, the dielectric layer can detect even smaller elastic deformations due to its three-dimensional pores and micro-dome structure, achieving seamless and precise monitoring throughout the entire process from approach to contact.

[0042] It should be noted that the micro-dome structure refers to multiple micron-sized protrusions arrayed on the upper surface of the resin dielectric layer 31. Each protrusion is hemispherical or nearly hemispherical, with a base diameter between 10 μm and 100 μm and a height of 0.3 to 0.5 times the base diameter. The center-to-center distance between adjacent micro-dome structures is 1.2 to 1.5 times the base diameter. This micro-dome structure is integrally formed by photopolymerization 3D printing and connected to the dielectric layer body. When the upper flexible TPU electrode plate 32 is subjected to vertical pressure, the micro-dome structure preferentially undergoes elastic compression deformation, allowing the dielectric layer to produce a significant local dielectric constant distribution change even with minimal overall compression, thereby improving the response sensitivity of the capacitive sensing unit 3 to weak pressure. Simultaneously, the gaps between the micro-dome structures provide buffer space for the dielectric layer's deformation under pressure, preventing premature large-area contact on the upper surface that could lead to signal saturation, thus broadening the sensor's linear detection range.

[0043] In some embodiments, the surface light detection unit 4 includes a UV-excited luminescent material film and an X-ray excited luminescent material film arranged in sections; the UV-excited luminescent material film emits first visible light under UV excitation, and the X-ray excited luminescent material film emits second visible light under X-ray excitation.

[0044] In this embodiment, the photodetector unit, located on the outermost upper electrode plate of the capacitive sensing unit, is used for real-time and intuitive early warning of harmful radiation protection in the working environment. The surface photodetector unit 4 integrates partitioned ultraviolet-excited luminescent materials and X-ray-excited luminescent materials (including but not limited to CuZnS, CaF2, and other luminescent material films). When there is excessive ultraviolet or invisible X-ray pollution in the industrial, medical, or other working environments where the sensor is located, the luminescent material film absorbs radiation energy and emits first visible light under ultraviolet excitation and second visible light under X-ray excitation, thereby producing specific fluorescence effects that are visible to the naked eye and do not interfere with each other in different functional areas on the sensor surface.

[0045] The ultraviolet-excited luminescent material may be selected from any one or more combinations of the following: Inorganic sulfide and sulfur oxide materials, such as zinc sulfide series (ZnS:Cu, ZnS:Ag, ZnS:Mn), alkaline earth metal sulfides (CaS, SrS, BaS and their rare earth dopants), and rare earth sulfur oxides (Y2O2S, Gd2O2S, La2O2S and their dopants). Inorganic aluminates, silicates, and oxide materials, such as strontium aluminate (SrAl2O4:Eu,Dy), barium magnesium aluminate (BAM), yttrium aluminum garnet (YAG), alkaline earth metal silicates (orthosilicates M2SiO4, metasilicates, etc.), yttrium oxide (Y2O3:Eu), zinc oxide (ZnO), calcium tungstate, and lead molybdate; Halogen and phosphate materials, such as calcium halophosphate, orthophosphate, pyrophosphate, and fluoride matrix (such as NaYF4 and its rare earth-doped up / down conversion materials). Nitride and oxide luminescent materials, such as CaAlSiN3:Eu, Sr2Si5N8:Eu, and SiAlON series; Quantum dot and nanocrystalline luminescent materials, such as CdS, CdSe, CdTe, PbS, InP, CuInS2, AgInS2, CsPbX3 (X=Cl / Br / I), carbon quantum dots (CQDs), graphene quantum dots (GQDs), gold nanoclusters (Au NCs), and silver nanoclusters (Ag NCs); Organic fluorescent materials and complexes, such as rhodamine derivatives, coumarin derivatives, fluorescein derivatives, cyanine derivatives, tetraphenylethylene (TPE) and its derivatives, europium / terbium β-diketone complexes, polyphenylenevinyl chloride (PPV), polyfluorene (PF), and stilbene fluorescent whitening agents.

[0046] The X-ray excitation luminescent material may be selected from any one or more combinations of the following: Alkali metal and alkaline earth metal halides, such as calcium fluoride (CaF2:Eu), barium fluoride (BaF2), sodium iodide (NaI:Tl), cesium iodide (CsI:Tl, CsI:Na), and barium fluoride bromide (BaFBr:Eu). 2+ Lanthanum bromide (LaBr3:Ce), lanthanum chloride (LaCl3:Ce), strontium iodide (SrI2:Eu); tungstates and germanates, such as calcium tungstate (CaWO4), cadmium tungstate (CdWO4), lead tungstate (PbWO4), and bismuth germanate (Bi4Ge3O4). 12 Rare earth sulfur oxides and oxides, such as gadolinium sulfide (Gd2O2S:Tb, Gd2O2S:Pr, GOS), yttrium sulfide (Y2O2S:Tb), lanthanum sulfide (La2O2S:Tb), yttrium oxide (Y2O3:Eu), and lutetium oxide (Lu2O3:Eu); silicates and aluminates, such as lutetium silicate (Lu2SiO5:Ce, LSO), lutetium yttrium silicate (LYSO:Ce), yttrium aluminum garnet (YAG:Ce), and lutetium aluminum garnet (LuAG:Ce). e) Gadolinium silicate (Gd2SiO5:Ce, GSO); perovskites and low-dimensional metal halides, such as CsPbBr3, CsPbI3, MAPbI3, MAPbBr3, Cs2AgBiBr6, Cs3Cu2I5, CsCu2I3; organic scintillation plastics and polymer composites, such as polystyrene (PS) based scintillation plastics (doped with PPO, POPOP), polyvinyl toluene (PVT) based scintillation plastics, and heavy metal doped composite plastics (doped with organic lead, organic bismuth).

[0047] Example 2: This invention provides a method for fabricating a flexible trimodal pressure and light detection sensor array, such as... Figure 3 The diagram shown illustrates the principle of this preparation method. First, the functional material for the resistance-sensitive unit is prepared. Resin solution A (Ecoflex A) and carbon nanotubes are mixed at room temperature, while resin solution B (Ecoflex B) and thermally expanded microspheres are simultaneously mixed and heated thoroughly at 120°C. After homogenization, the mixture is cured at 120°C and cut into appropriate sizes. Simultaneously, a TPU flexible substrate is prepared using a fused deposition modeling (FDM) 3D printer, and a dielectric layer is prepared using a photopolymerization (PRC) 3D printer. The cut resistance-sensitive material is assembled with the TPU flexible substrate to form a resistance-sensing unit, and the dielectric layer is assembled with the TPU flexible substrate to form a capacitance-sensing unit. A photoluminescent material is prepared separately. Finally, the photoluminescent material, resistance-sensing unit, and capacitance-sensing unit are integrated and packaged to form a complete flexible trimodal pressure and light detection sensor system (i.e., a flexible trimodal pressure and light detection sensor array).

[0048] For more details, please refer to the following: Figure 4 As shown, the fabrication method of this flexible trimodal pressure and light detection sensor array includes the following steps S1~S6: S1: Prepare a flexible TPU substrate 1, an intermediate flexible TPU electrode plate 22 and an upper flexible TPU electrode plate 32, and apply conductive copper paste 23 to the surface of the intermediate flexible TPU electrode plate 22.

[0049] This embodiment utilizes technologies including, but not limited to, direct-write 3D printing, photopolymerization 3D printing, molding, and laser cutting to fabricate a TPU flexible substrate and electrode plate. Specifically, a unique arrayed connection structure is constructed during the fabrication process, enabling the substrate to be stretched and adhered to complex curved surfaces. After fabrication, conductive copper paste is attached to designated locations on the substrate as the lower electrode.

[0050] S2: Prepare porous piezoresistive composite material resistive sensing unit 21.

[0051] This embodiment uses Ecoflex silicone rubber as the flexible matrix material and multi-walled carbon nanotubes as the conductive filler as an example. However, it should be understood that the flexible matrix material and the conductive filler can be replaced by any one or more combinations listed above. Ecoflex component A is mixed with multi-walled carbon nanotubes at a mass ratio of 50:6, and Ecoflex component B is mechanically mixed with thermally expanded microspheres at a mass ratio of 50:5. The mixture is then heated on a 120°C heating stage for 8 minutes to allow the microspheres to initially expand. After the two solutions are thoroughly mixed, they are coated into a mold and cured on a 120°C heating stage. During this process, the thermally expanded microspheres further expand and compress the conductive network, forming a porous structure. After curing, the microspheres are cut into uniform cuboids with a length of 4 mm, a width of 4 mm, and a height of 3 mm.

[0052] S3: Prepare an elliptical frustum-shaped resin dielectric layer 31 with three-dimensional interconnected pores and a surface micro-dome structure.

[0053] This embodiment utilizes technologies including, but not limited to, direct-write 3D printing, photopolymerization 3D printing, casting, and laser cutting to prepare a resin dielectric layer. This dielectric layer is designed with an elliptical pore structure and micro-dome surfaces to enhance the sensitivity of capacitive sensing.

[0054] S4: The resistance sensing unit 21, the intermediate flexible TPU electrode plate 22, the resin dielectric layer 31 and the upper flexible TPU electrode plate 32 are sequentially stacked on the flexible TPU substrate 1 to form a vertically integrated structure of the resistance sensing unit 2 and the capacitance sensing unit 3.

[0055] In this embodiment, a lower electrode is arranged on a flexible TPU substrate 1, and the resistance sensing unit 21 prepared in step S2 is placed on the flexible TPU substrate 1; then an intermediate flexible TPU electrode plate 22 (as an intermediate common electrode) is covered; a resin dielectric layer 31 is placed on the intermediate flexible TPU electrode plate 22; finally, an upper flexible TPU electrode plate 32 is covered to complete the vertical integration of the resistance sensing unit 2 and the capacitance sensing unit 3.

[0056] S5: Prepare a photoluminescent thin film containing ultraviolet-excited luminescent materials and X-ray-excited luminescent materials.

[0057] This embodiment uses CuZnS as the ultraviolet-excited luminescent material and CaF2 as the X-ray-excited luminescent material as examples for illustration. However, it should be understood that the ultraviolet-excited luminescent material and the X-ray-excited luminescent material can be replaced by any one or more combinations listed above. Photoluminescent films containing ultraviolet-excited luminescent materials and photoluminescent films containing X-ray-excited luminescent materials are prepared separately. On the outermost layer of the sensor array, these two films are attached in a predetermined distribution pattern: specifically, the ultraviolet-excited luminescent material film is attached to the upper surface of a portion of the monitoring sites, and the X-ray-excited luminescent material film is attached to the upper surface of another portion of the monitoring sites, so that different monitoring sites respond to ultraviolet light and X-rays respectively; or, the upper surface of the same monitoring site is divided into two sub-regions, and the two films are attached to each sub-region, so that a single monitoring site has the ability to detect both types of radiation simultaneously.

[0058] S6: Attach the photoluminescent film to the upper surface of the upper flexible TPU electrode plate 32 to complete the encapsulation of the sensor array.

[0059] The final sensor obtained in this embodiment has geometric dimensions of 4mm in length, 4mm in width, and 3mm in height for each monitoring point.

[0060] Example 3: This embodiment performs performance testing and application verification based on the flexible trimodal pressure and light detection sensor array prepared in Example 2. For example... Figures 5 to 7 As shown, when an object comes into contact with and applies pressure, the porous structure of the resistance sensing unit deforms under pressure. The porous conductive network inside, constructed from multi-walled carbon nanotubes, Ecoflex silicone rubber, and thermally expanded microspheres, becomes denser, significantly increasing the conductive pathway and thus changing the resistance value. This unique "capacitance + resistance" dual-mode mechanism enables the system to monitor the entire process from non-contact "approach" to contact "pressure," and also allows for real-time calibration and compensation of the pressure sensing data from the capacitive sensing unit using the resistance signal. Simultaneously, by designing a flexible substrate with a special structure, the sensor can be tightly attached to various complex surfaces thanks to its stretchable and deformable characteristics, eliminating the effects of deformation and compression. This collaborative calibration mechanism effectively avoids potential interference, further ensuring measurement accuracy in curved surface environments. Figure 5 The values ​​(A)-(D) quantitatively reflect the changing trends of the capacitance and resistance of the sensor under pressures of 0-1N and 0-16N.

[0061] like Figure 6 , Figure 7As shown, after undergoing 2000 high-frequency pressurization-release cycle tests, the response curves of the capacitance and resistance signals of the sensor still maintained a high degree of consistency. This is mainly due to two factors: first, the excellent elastic recovery performance of the Ecoflex silicone rubber matrix in the resistance sensing unit, and the stable porous framework constructed by thermally expanded microspheres; second, the resin dielectric layer of the capacitance sensing unit adopts a special microstructure design, whose macroscopic elliptical frustum shape combined with the internal three-dimensional interconnected porous structure, along with the arrayed micro-dome on the upper surface, gives it excellent structural fatigue resistance and elastic recovery force under repeated pressure. The test results fully demonstrate that this sensor system still possesses excellent long-term operational stability and durability under complex mechanical environments.

[0062] In summary, this invention, by designing a flexible TPU substrate with an arrayed mesh-like connection structure, enables the sensor array to adhere tightly to various complex curved surfaces. This effectively solves the problem of inaccurate pressure detection caused by poor contact in traditional rigid or planar sensors on uneven surfaces, achieving accurate pressure measurement in complex curved surface environments. Building upon this, the invention utilizes the synergistic advantages of 3D printing technology (FDM and photopolymerization) to construct a flexible trimodal sensor system integrating proximity sensing, high-sensitivity tactile sensing, and harmful light detection. By integrating a resistive sensing unit based on carbon nanotube / thermally expanded microsphere composite material and a capacitive sensing unit with a three-dimensional porous and micro-dome structure in the vertical direction, the system achieves accurate monitoring of the entire process from non-contact proximity to contact pressure, and effectively calibrates the capacitive signal using the resistive signal, improving detection accuracy in complex curved surface environments. Furthermore, the photoluminescent thin film integrated on the surface endows the sensor with intuitive early warning capabilities for ultraviolet and X-ray rays in the environment. With its excellent adaptability to curved surfaces, high sensitivity, and superior cyclic stability (2000 cycles), this system provides a low-cost, portable, and highly integrated sensing platform for industrial manufacturing safety protection, medical environment monitoring, and robotic electronic skin.

[0063] 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible trimodal pressure and light detection sensor array, characterized in that, include: Flexible TPU substrate (1); The resistance sensing unit (2) disposed on the upper surface of the flexible TPU substrate (1) is used to detect the pressure change caused by the contact of the object and to calibrate the capacitance sensing signal. The capacitance sensing unit (3) disposed on the upper surface of the resistance sensing unit (2) is used to detect the capacitance change caused by the approach and contact of a charged object. The surface light detection unit (4) is located on the outermost upper surface of the capacitive sensing unit (3) and is used to detect X-rays and ultraviolet rays in the environment. The resistance sensing unit (2) and the capacitance sensing unit (3) are integrated at the same monitoring point in the vertical direction. The sensor array is distributed in a matrix and contains multiple independent monitoring points.

2. The flexible trimodal pressure and light detection sensor array according to claim 1, characterized in that, The flexible TPU substrate (1) has an arrayed grid-like connection structure, which can be stretched and attached to complex curved surfaces.

3. The flexible trimodal pressure and light detection sensor array according to claim 1, characterized in that, The resistance sensing unit (2) includes: A resistance-sensitive unit (21) is disposed on the upper surface of the flexible TPU substrate (1). The intermediate flexible TPU electrode plate (22) is disposed on the upper surface of the resistance-sensitive unit (21). Conductive copper paste (23) is disposed on the surface of the intermediate flexible TPU electrode plate (22); the intermediate flexible TPU electrode plate (22) serves as both the upper electrode of the resistance sensing unit (2) and the lower electrode of the capacitance sensing unit (3).

4. The flexible trimodal pressure and light detection sensor array according to claim 3, characterized in that, The resistance-sensitive unit (21) is a porous piezoresistive composite cuboid, which is prepared by mixing conductive filler, flexible matrix material and thermally expandable microspheres; the thermally expandable microspheres expand in volume during the heat curing stage, squeezing carbon nanotubes and silicone rubber matrix to build a uniform porous conductive network inside the material. The conductive filler is selected from any one or more combinations of the following: Carbon-based conductive materials include one of the following: conductive carbon black, acetylene black, carbon microspheres, carbon dots, fullerenes, expanded graphite, carbon sponges, carbon aerogels, single-walled carbon nanotubes, double-walled carbon nanotubes, arrayed carbon nanotubes, carbon nanofibers, graphene, few-layer graphene, graphene oxide, reduced graphene oxide, and graphene nanoribbons. Metal-based conductive materials, including silver nanoparticles, gold nanoparticles, copper nanoparticles, silver flakes / silver microsheets, nickel powder, silver nanowires, copper nanowires, gold nanowires, gallium indium alloys, gallium indium tin alloys, liquid metal droplets, and liquid metal nanoparticles. Transition metal carbides / nitrides, including Ti3C2T x One of V2C, Mo2C; Metallic transition metal dichalcogenides include one of 1T-MoS2, TaS2, and VS2; Intrinsically conductive polymers, including one of PEDOT:PSS, polyaniline, polypyrrole, and polythiophene; Composite / core-shell hybrid materials, including one of the following: silver-plated glass microspheres, silver-plated copper powder, gold-plated silica nanospheres, carbon nanotube-graphene hybrid materials, carbon black-carbon nanotube hybrid materials, and silver nanowire-carbon nanotube hybrid materials; The flexible matrix material is selected from any one or more combinations of the following: Polysiloxane elastomers, including one of polydimethylsiloxane, platinum-catalyzed silicone rubber, room temperature vulcanizing silicone rubber, liquid silicone rubber, and fluorosilicone rubber; Polyurethane elastomers include one of the following: thermoplastic polyurethane elastomers, polyurethane foam, polyurethane sponge, polyurethane foam, polyether polyurethane, polyester polyurethane, and polycarbonate polyurethane; Styrene-based and other thermoplastic elastomers, including one of thermoplastic elastomers, thermoplastic rubbers, SEBS, SBS, TPV, and POE; Traditional synthetic rubber and natural rubber, including one of the following: natural rubber, styrene-butadiene rubber, nitrile rubber, ethylene propylene diene monomer (EPDM) rubber, chloroprene rubber, butyl rubber, and fluororubber; Gel-based flexible matrices include one of the following: polyvinyl alcohol hydrogel, polyacrylamide hydrogel, alginate hydrogel, gelatin hydrogel, cellulose-based hydrogel, poly(N-isopropylacrylamide) hydrogel, and ionogel. Flexible plastic and resin films, including one of polyimide film, polyethylene terephthalate film, polyethylene naphthalate film, polytetrafluoroethylene, and vinylidene fluoride-trifluoroethylene copolymer film; Natural and bio-based flexible materials, including one of the following: silk fibroin film / sponge, bacterial cellulose, chitosan film, and nanocellulose paper.

5. The flexible trimodal pressure and light detection sensor array according to claim 3, characterized in that, The capacitance sensing unit (3) includes: A resin dielectric layer (31) is disposed on the upper surface of the intermediate flexible TPU electrode plate (22). Upper flexible TPU electrode plate (32) disposed on the upper surface of the resin dielectric layer (31).

6. The flexible trimodal pressure and light detection sensor array according to claim 5, characterized in that, The resin dielectric layer (31) is prepared by photosensitive resin through photocuring 3D printing technology; the resin dielectric layer (31) has a macroscopic elliptical frustum geometry, with a three-dimensional interconnected porous structure inside, and an array of micro dome structures on the upper surface.

7. The flexible trimodal pressure and light detection sensor array according to claim 1, characterized in that, The surface light detection unit (4) includes a UV-excited luminescent material film and an X-ray excited luminescent material film arranged in sections; the UV-excited luminescent material film emits first visible light under UV excitation, and the X-ray excited luminescent material film emits second visible light under X-ray excitation.

8. A method for fabricating a flexible trimodal pressure and light detection sensor array as described in any one of claims 1-7, characterized in that, Includes the following steps: A flexible TPU substrate (1), an intermediate flexible TPU electrode plate (22) and an upper flexible TPU electrode plate (32) are prepared, and conductive copper paste (23) is provided inside the intermediate flexible TPU electrode plate (22) and on its upper and lower surfaces. Prepare a porous piezoresistive composite resistive sensing unit (21); An elliptical frustum-shaped resin dielectric layer with three-dimensional interconnected pores and surface micro-dome structure was prepared (31). A resistance sensing unit (21), an intermediate flexible TPU electrode plate (22), a resin dielectric layer (31) and an upper flexible TPU electrode plate (32) are sequentially stacked on the flexible TPU substrate (1) to form a vertically integrated structure of a resistance sensing unit (2) and a capacitance sensing unit (3). Prepare photoluminescent thin films containing ultraviolet-excited luminescent materials and X-ray-excited luminescent materials; The photoluminescent film is attached to the upper surface of the upper flexible TPU electrode plate (32) to complete the encapsulation of the sensor array.

9. The preparation method according to claim 8, characterized in that, The preparation of the porous piezoresistive composite material resistive sensing unit (21) specifically includes: The flexible matrix material component A and the conductive filler are mixed at a mass ratio of 50:(5~7) to obtain the first mixed solution; The flexible matrix material B component and the thermally expanded microspheres were mechanically mixed at a mass ratio of 50:(4~6), and heated on a heating stage at 110℃~130℃ for 6~10 minutes to allow the thermally expanded microspheres to expand initially, thus obtaining a second mixed solution. After the first mixture and the second mixture are mixed evenly, the mixture is applied to the mold and cured by heating on a heating table at 110℃~130℃. The cured material was cut into cuboids with a length of 3.5~4.5mm, a width of 3.5~4.5mm, and a height of 2.5~3.5mm to obtain the resistance-sensitive unit (21).

10. The preparation method according to claim 8, characterized in that, The ultraviolet-excited luminescent material is selected from any one or more combinations of the following: Inorganic sulfide and sulfur oxide materials, including one of zinc sulfide, alkaline earth metal sulfides, and rare earth sulfur oxides; Inorganic aluminates, silicates and oxides, including one of strontium aluminate, barium magnesium aluminate, yttrium aluminum garnet, alkaline earth metal silicates, yttrium oxide, zinc oxide, calcium tungstate and lead molybdate; Halogenated and phosphate materials, including one of calcium halophosphate, orthophosphate, pyrophosphate, and fluoride matrix; Nitride and oxide luminescent materials, including one of the CaAlSiN3:Eu, Sr2Si5N8:Eu, and SiAlON series; Quantum dot and nanocrystalline luminescent materials, including one of CdS, CdSe, CdTe, PbS, InP, CuInS2, AgInS2, CsPbX3 (X=Cl / Br / I), carbon quantum dots, graphene quantum dots, gold nanoclusters, and silver nanoclusters; Organic fluorescent materials and their complexes, including one of the following: rhodamine derivatives, coumarin derivatives, fluorescein derivatives, cyanine derivatives, tetraphenylethylene and its derivatives, europium / terbium β-diketone complexes, polyphenylene oxide, polyfluorene, and stilbene fluorescent whitening agents; The X-ray excitation luminescent material is selected from any one or more combinations of the following: Alkali metal and alkaline earth metal halides, including one of calcium fluoride, barium fluoride, sodium iodide, cesium iodide, barium fluoride bromide, lanthanum bromide, lanthanum chloride, and strontium iodide; Tungstates and germanates, including one of calcium tungstate, cadmium tungstate, lead tungstate, and bismuth germanate; Rare earth sulfur oxides and oxides, including one of gadolinium sulfide, yttrium sulfide, lanthanum sulfide, yttrium oxide, and lutetium oxide; Silicates and aluminates, including one of lutetium silicate, lutetium yttrium silicate, yttrium aluminum garnet, lutetium aluminum garnet, and gadolinium silicate; Perovskites and low-dimensional metal halides, including one of CsPbBr3, CsPbI3, MAPbI3, MAPbBr3, Cs2AgBiBr6, Cs3Cu2I5, and CsCu2I3; Organic scintillation plastics and polymer composites, including one of polystyrene-based scintillation plastics, polyvinyl toluene-based scintillation plastics, and heavy metal-doped composite plastics.

Images