Flexible pressure sensor unit and mounting structure and preparation method thereof

Abstract

The invention discloses a flexible pressure sensor unit which comprises a pressure sensing layer, a first substrate layer and a first electrode layer, the first substrate layer and the first electrode layer are arranged on one side of the pressure sensing layer, and a selectable second substrate layer and a selectable second electrode layer are arranged on the other side of the pressure sensing layer. According to the invention, by selecting the bonding layer material of which the mechanical property is between the mechanical property of the silica gel structure and the mechanical property of the sensor substrate layer and optimizing the thickness range of the bonding layer material, efficient bonding of the flexible pressure sensor and the silica gel structure is successfully realized. The bonding layer is used as a buffer medium, so that the problem of stress concentration caused by mechanical property difference between the silica gel and the sensor substrate layer is effectively solved, and the reliability of the sensor in long-term work and repeated deformation is ensured. The one-dimensional or two-dimensional array type sensor design is adopted, and sensing points are reasonably arranged, so that real-time monitoring of various mechanical effects applied when a user uses the male massage device is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flexible pressure sensors, and in particular to a flexible pressure sensor unit, its mounting structure and preparation method. BACKGROUND

[0002] Most of the existing male massage devices have simple structure and single function, mainly relying on physical structure simulation, lacking intelligent function. Although some products try to improve user experience by changing internal structure or material, they still cannot achieve accurate perception of user behavior and intelligent feedback. Therefore

[0003] Male massage devices based on flexible pressure sensors have emerged, which can bend and adhere to the surface of an object to achieve pressure sensing. However, flexible pressure sensors have difficulty meeting the application requirements of male massage devices in the following aspects:

[0004] Material compatibility: The material properties and design of existing flexible pressure sensors differ greatly from the mechanical properties of the soft silicone material widely used in male massage devices, making it difficult to achieve good adhesion and affecting the performance of the sensor and user experience.

[0005] Sensitivity and range: The sensitivity and range of existing sensors may not accurately measure the small deformation of silicone and the resulting stress changes during the operation of male massage devices.

[0006] Single sensing function: Existing sensors lack the ability to measure forces in multiple directions simultaneously, making it difficult to fully reflect the complex mechanical effects in human-related behaviors.

[0007] Integration difficulty: The thickness, hardness, and preparation process of existing sensors may make it difficult to integrate them into the silicone structure of existing male massage devices, affecting the appearance and comfort of the product.

[0008] Lack of intelligent feedback: Even if the pressure sensor is integrated, existing male massage devices lack intelligent feedback functions based on sensor data, such as sound simulation, image display, mechanical movement, etc.

[0009] To solve the above problems, WO2024216417A1 discloses a sexual ability monitoring system, which includes a dildo, a tensile and compressive force sensor, a control circuit board, a Bluetooth module, and a smart terminal device. The dildo has a latex layer inside, and the tensile and compressive force sensor is arranged at the bottom of the latex layer and electrically connected to the control circuit board. The control circuit board is electrically connected to the Bluetooth module, and the Bluetooth module is connected to the smart terminal device via Bluetooth.

[0010] The above technical solution still has the following problems:

[0011] The pressure sensor is only placed at the bottom of the latex layer, the collected signal is single, the complex feedback function cannot be realized, and the compatibility of the sensor and the silica gel material is not fully considered.

[0012] The existing flexible pressure sensor is difficult to be well combined with the silica gel material:

[0013] The material, design and sensing function of the existing flexible pressure sensor cannot well meet the demand of monitoring the strain of soft silica gel material in the existing male massage device, especially in terms of material compatibility, sensitivity, sensing function and integration difficulty.

[0014] The effective detection of multi-directional force cannot be realized: the existing sensor cannot realize effective detection of vertical force and shear force or mixed direction force.

[0015] Therefore, it is necessary to improve the above-mentioned prior art to overcome the above-mentioned defects. SUMMARY

[0016] The purpose of the present application is to provide a flexible pressure sensor unit, its mounting structure and preparation method, to solve the problems existing in the prior art.

[0017] The above technical purpose of the present application is realized by the following technical scheme:

[0018] A flexible pressure sensor unit, comprising a pressure sensing layer, and a first substrate layer and a first electrode layer arranged on one side of the pressure sensing layer, the first electrode layer being located between the first substrate layer and the pressure sensing layer, and forming a multilayer flexible structure with the first substrate layer and the pressure sensing layer.

[0019] Further, the other side of the pressure sensing layer is provided with a second substrate layer and a second electrode layer.

[0020] Further, the thickness of the pressure sensing layer ranges from 5 to 100 microns, which adopts a piezoresistive pressure sensing material, a capacitive pressure sensing material or a piezoelectric pressure sensing material;

[0021] The piezoresistive pressure sensing material is a composite material formed by uniformly dispersing conductive fillers in a polymer matrix;

[0022] The capacitive pressure sensing material is a composite material formed by dispersing high dielectric constant fillers, conductive fillers and hollow microspheres in a polymer matrix;

[0023] The piezoelectric pressure sensing material is prepared by piezoelectric polymer or piezoelectric ceramic;

[0024] The conductive filler is carbon black particles, carbon nanotubes, graphene, metal nanoparticles or conductive polymers; the hollow microspheres are silica or polymers;

[0025] The high dielectric constant material is barium titanate, barium strontium titanate or zirconium oxide;

[0026] The piezoelectric polymer is a homopolymer or copolymer of polyvinylidene fluoride, poly-L-lactic acid; the piezoelectric ceramic is lead zirconate titanate or lithium niobate;

[0027] The polymer matrix is an acrylic resin, a polyurethane resin, a silicone resin or a thermoplastic elastomer.

[0028] Further, the material of the first substrate layer and the second substrate layer is a polyurethane film, a thermoplastic polyurethane, a silicone rubber, a polyimide or a parylene;

[0029] The Young's modulus of the first substrate layer and the second substrate layer ranges from 0.001 GPa to 2 Gpa, the bending modulus ranges from 0.001 GPa to 1.5 Gpa, the elongation at break ranges from 50% to 500%, the hardness ranges from Shore A 10 to Shore A 80, and the thickness ranges from 10 μm to 150 μm.

[0030] Further, the first electrode layer is a parallel interdigital electrode, the thickness of the electrode layer ranges from 5 nm to 500 nm, the width of the electrode strip ranges from 2 μm to 100 μm, and the electrode spacing ranges from 2 μm to 100 μm;

[0031] The material of the parallel interdigital electrode is a metal film, a conductive oxide, a conductive polymer, a nanomaterial or a composite material.

[0032] Further, the first electrode layer and the first electrode layer are respectively arranged on the upper and lower surfaces of the pressure sensing layer, and constitute an upper and lower electrode structure, and the thickness of the electrode layer ranges from 5 nm to 500 nm;

[0033] The material of the first electrode layer and the first electrode layer is a metal film, a conductive oxide, a conductive polymer, a nanomaterial or a composite material.

[0034] Further, the first substrate layer of the flexible pressure sensor unit is connected to the silicone structure through an adhesive layer, and a surface protection layer is provided on the outer surface of the flexible pressure sensor unit and the adhesive layer.

[0035] Further, the material of the adhesive layer is a silicone rubber, a polyurethane, a thermoplastic elastomer or an acrylic resin;

[0036] The Young's modulus of the adhesive layer ranges from 0.1 MPa to 50 MPa, the bending modulus ranges from 0.1 MPa to 5 MPa, the elongation at break ranges from more than 50%, the hardness ranges from Shore A 10 to A 50, and the thickness ranges from 3 μm to 50 μm.

[0037] Further, the flexible pressure sensor units are arranged in a one-dimensional array or a two-dimensional array on the surface of the silica gel structure.

[0038] The pitch of the flexible pressure sensor units is 2 mm to 10 mm.

[0039] Further, the preparation and installation method of the adhesive layer and the surface protection layer is as follows:

[0040] D1. Preparation of the adhesive layer

[0041] The liquid adhesive layer is uniformly coated on the surface of the silica gel structure, and the adhesive layer is formed by heat curing;

[0042] D2. Attaching the flexible pressure sensor units on the surface of the adhesive layer

[0043] The flexible pressure sensor units are attached in an array on the surface of the adhesive layer.

[0044] A roller is used to drive the bubbles from the center to the periphery to ensure that there is no gap.

[0045] After attachment, uniform pressure is applied and heat treatment is performed.

[0046] D3. Preparing the surface protection layer on the surface of the flexible pressure sensor units and the adhesive layer

[0047] The surface protection layer is a thermoplastic polyurethane film with a thickness of 10 um.

[0048] The thermoplastic polyurethane material is uniformly sprayed on the surface of the flexible pressure sensor units, and the protective film is formed by heat curing.

[0049] In summary, the present application has the following beneficial effects:

[0050] 1. Efficient attachment of flexible sensor and silica gel structure is achieved

[0051] By selecting an adhesive layer material with mechanical properties (such as Young's modulus, bending modulus and hardness) between the silica gel structure and the sensor substrate layer, and optimizing its thickness range, efficient attachment of the flexible pressure sensor and the silica gel structure is successfully achieved.

[0052] The adhesive layer acts as a buffer medium, effectively solving the stress concentration problem caused by the mechanical property difference between the silica gel and the sensor substrate layer, ensuring the reliability of the sensor in long-term operation and multiple deformations.

[0053] 2. Provides comprehensive monitoring of complex mechanical actions

[0054] Using one-dimensional or two-dimensional array sensor design, by reasonable layout of the sensing points, the real-time monitoring of various mechanical actions exerted by the user when using the male massage device is realized:

[0055] Vertical force: a single sensing point directly outputs a pressure signal perpendicular to the surface of the silica gel, which is used to accurately measure the size of the force in the vertical direction.

[0056] Mixed force: through the signal difference between multiple sensing points, combined with the interpolation algorithm to calculate the direction and amplitude of the mixed force, it can reflect the complex mechanical action with the vector direction between vertical and parallel.

[0057] Motion information: based on the data of the signal change of the sensing points at different positions in the array over time, the invention can calculate the moving speed, direction and trajectory of the user's organ in the massage device. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 is a schematic diagram of the flexible pressure sensor unit described in the invention.

[0059] Figure 2 is a schematic diagram of the installation of the flexible pressure sensor unit described in the invention.

[0060] Figure 3 is a schematic diagram of the sensor array described in the invention.

[0061] Figure 4 is a schematic diagram of the sensor array and silica gel structure described in the invention. DETAILED DESCRIPTION

[0062] In order to make the technical means, creative features, purposes and effects realized by the invention easy to understand, the invention is further described below in combination with the drawings and specific embodiments.

[0063] Embodiment 1

[0064] A flexible pressure sensor unit in this embodiment includes a pressure sensing layer, a first substrate layer and a first electrode layer arranged on one side of the pressure sensing layer, the first electrode layer is located between the first substrate layer and the pressure sensing layer, and forms a multilayer flexible structure with the first substrate layer and the pressure sensing layer.

[0065] Among them, the material and performance requirements of the first substrate layer are as follows:

[0066] Young's modulus range: 0.001 GPa (1 MPa) to 2 GPa.

[0067] Young's modulus is an indicator of material stiffness, the lower the softer. To match the softness of the silicone, the Young's modulus of the base layer should be as low as possible, but not less than 1 MPa to ensure a certain structural strength.

[0068] Bending modulus range: 0.001 GPa (1 MPa) to 1.5 GPa.

[0069] Bending modulus is an indicator of the ease of bending of the material, the lower the easier to bend. The bending modulus should be lower than the PET film to ensure that the base layer can better fit the silicone surface.

[0070] Breaking elongation range: 50% to 500%.

[0071] Breaking elongation is an indicator of the material's tensile deformation capacity, the higher the less likely to break. High breaking elongation can ensure that the base layer does not break when the silicone deforms.

[0072] Hardness range: Shore A 10 to Shore A 80.

[0073] Hardness is an indicator of the material's surface resistance to deformation. Shore A hardness is suitable for measuring soft materials, and this range can match the hardness of the silicone.

[0074] Material: The first base layer material is a polyurethane film with a Young's modulus of 0.5 GPa, a bending modulus of 0.4 GPa, a breaking elongation of 300%, and a Shore A hardness of 50. This material has good flexibility and chemical resistance, and can be well matched with the soft silicone of the silicone toy.

[0075] The first base layer material can also be selected from thermoplastic polyurethane, silicone rubber, polyimide or parylene. These materials have good flexibility and biocompatibility, and can meet the requirements of the invention.

[0076] Thickness range: 10 μm to 150 μm

[0077] Lower limit (10 μm): A too thin base layer may be difficult to handle during sensor preparation, prone to wrinkles, tears or permanent deformation, resulting in unstable performance. 10 μm is the lower limit to ensure operability and stability.

[0078] Upper limit (150 μm): A too thick base layer will reduce the flexibility and fit of the sensor, affecting the accurate measurement of silicone deformation, and even affecting the user experience. 150 μm is the upper limit to ensure flexibility and fit.

[0079] Preferred range: 20 μm to 100 μm. Within this range, flexibility, fit and operability can be better balanced.

[0080] The first electrode layer in this embodiment is a parallel interdigital electrode. The parallel interdigital electrode type pressure sensor only makes electrodes on one substrate. The electrode is a two interlaced comb pattern. The two patterns are not connected to each other, but there is a fixed distance between the patterns. When in operation, current flows between the two patterns. When external pressure is applied to the sensor, the dielectric constant or conductivity of the sensing material changes, causing changes in current or voltage between the electrodes, realizing pressure sensing function.

[0081] Interdigital electrode 1: Located on the first substrate layer, constituting one comb pattern of interdigital electrode.

[0082] Interdigital electrode 2: Located on the first substrate layer, constituting another comb pattern of interdigital electrode, interlaced with interdigital electrode 1.

[0083] Sensing material layer: Covering on the interdigital electrode, is the core material to realize pressure sensing function.

[0084] Pattern design: The pattern of interdigital electrode consists of two interlaced comb patterns. Each comb pattern is composed of multiple parallel electrode strips. The width, spacing and length of the electrode strips can be adjusted according to actual needs to optimize the performance of the sensor.

[0085] Material selection: The electrode material should have good conductivity, flexibility and stability. The selectable materials are the same as those of the upper and lower electrode type, including metal film, conductive oxide, conductive polymer, nanomaterial and composite material, etc.

[0086] Thickness range: The thickness of the electrode layer ranges from 5 nm to 500 nm, preferably from 10 nm to 200 nm.

[0087] Geometric parameters:

[0088] Electrode strip width (w): The range is 2 μm to 100 μm, preferably 5 μm to 50 μm.

[0089] Electrode spacing (g): The range is 2 μm to 100 μm, preferably 5 μm to 50 μm. The electrode width and spacing should be as equal as possible to obtain the best sensitivity.

[0090] Electrode length (L): Determined according to the size of the sensing area.

[0091] Number of electrode pairs (n): The more the number of electrode pairs, the higher the sensitivity, but it will also increase the capacitance value.

[0092] Preparation method: The preparation method of the electrode layer can be determined according to the selection of electrode material. Common preparation methods include magnetron sputtering, evaporation plating, chemical vapor deposition, spin coating, spraying, printing and photolithography, etc.

[0093] Example 2

[0094] The flexible pressure sensor unit in this embodiment includes a pressure sensing layer, and a first substrate layer and a first electrode layer arranged on one side of the pressure sensing layer, and a second substrate layer and a second electrode layer arranged on the other side of the pressure sensing layer.

[0095] The first substrate layer and the second substrate layer in this embodiment are the same as the first substrate layer in Example 1, and thus are not described in detail here.

[0096] The first electrode layer and the second electrode layer in this embodiment are upper and lower electrodes, which adopt two layers of electrodes respectively located on the upper and lower sides of the sensing material, forming a structure similar to a parallel plate capacitor. The patterns of the upper and lower electrodes are the same, and are aligned and overlapped on the upper and lower sides. The sensing material (such as piezoresistive material, piezoelectric material or dielectric elastomer) is sandwiched between the upper and lower electrodes. In operation, current flows between the upper and lower electrodes. When external pressure is applied to the sensor, the resistance, capacitance or piezoelectric properties of the sensing material change, thereby causing changes in the current or voltage between the electrodes, realizing the pressure sensing function.

[0097] Lower electrode layer: located above the first substrate layer, serving as the lower electrode of the sensor.

[0098] Upper electrode layer: located above the sensing material layer, corresponding to the lower electrode layer on the upper and lower sides, serving as the upper electrode of the sensor.

[0099] Sensing material layer: located between the upper and lower electrodes, is the core material for realizing the pressure sensing function.

[0100] Pattern design: the patterns of the upper and lower electrodes can be designed in various geometric shapes, including but not limited to circular, square, rectangular, oval, polygonal, etc. Preferably, the patterns of the upper and lower electrodes are the same, and are aligned and overlapped on the upper and lower sides. The size and shape of the electrode pattern can be adjusted according to actual needs, for example, designed according to the shape and size of the silicone structure of the male massage device.

[0101] Material selection: the electrode material should have good electrical conductivity, flexibility and stability. The selectable materials include:

[0102] Metal thin film: gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), etc. The metal thin film can be prepared by magnetron sputtering, evaporation coating and other methods.

[0103] Conductive oxide: indium tin oxide (ITO), zinc oxide (ZnO), etc. The conductive oxide can be prepared by chemical vapor deposition, sol-gel method, etc.

[0104] Conductive polymer: Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), Polyaniline (PANI), Polypyrrole (PPy), etc. Conductive polymer can be prepared by spin coating, spray coating, printing, etc.

[0105] Nanomaterial: Carbon nanotube (CNT), Graphene, Metal nanowire (AgNW, CuNW), etc. Nanomaterial can be prepared by solution method, chemical vapor deposition, etc.

[0106] Composite material: Disperse conductive filler (such as carbon black, carbon nanotube, graphene, etc.) in polymer material (such as polyurethane, silicone rubber, polyimide, etc.) to form conductive composite material. Conductive composite material can be prepared by mixing, coating, etc.

[0107] Thickness range: The thickness of the electrode layer ranges from 5 nm to 500 nm, preferably from 10 nm to 200 nm. Too thin electrode layer may result in insufficient conductivity, and too thick electrode layer may affect the flexibility of the sensor.

[0108] Preparation method: The preparation method of the electrode layer can be determined according to the selection of electrode material. Common preparation methods include:

[0109] Magnetron sputtering: Sputter metal target in vacuum environment onto substrate layer to form metal thin film.

[0110] Evaporation plating: Heat and evaporate metal material in vacuum environment to deposit onto substrate layer to form metal thin film.

[0111] Chemical vapor deposition: Decompose gaseous precursor at high temperature to deposit onto substrate layer to form thin film.

[0112] Spin coating: Spin liquid material onto substrate layer to form thin film.

[0113] Spray coating: Spray liquid material onto substrate layer to form thin film.

[0114] Printing: Print liquid material onto substrate layer to form pattern.

[0115] Lithography: Use photoresist and etchant to etch thin film into specific pattern.

[0116] Example 3

[0117] The pressure sensing layer in this embodiment can use

[0118] The piezoresistive pressure sensing material can be a composite material of a polymer material and a conductive filler. Specifically, the conductive filler is uniformly dispersed in the polymer material. The conductive filler can be carbon black particles, carbon nanotubes, graphene, etc. The polymer material can be an acrylic resin, a polyurethane resin, a silicone resin, etc. The composite material changes in capacitance under pressure. Specifically, the resistance decreases with the increase of pressure, thereby realizing the pressure sensing function.

[0119] The piezoresistive pressure sensing material can be a composite material of a polymer material and a conductive filler. Specifically, the conductive filler is uniformly dispersed in the polymer material. The conductive filler can be carbon black particles, carbon nanotubes, graphene, etc. The polymer material can be an acrylic resin, a polyurethane resin, a silicone resin, etc. The composite material changes in capacitance under pressure. Specifically, the resistance decreases with the increase of pressure, thereby realizing the pressure sensing function.

[0120] The piezoresistive pressure sensing material can be a composite material of a polymer material and a conductive filler. Specifically, the conductive filler is uniformly dispersed in the polymer material. The conductive filler can be carbon black particles, carbon nanotubes, graphene, etc. The polymer material can be an acrylic resin, a polyurethane resin, a silicone resin, etc. The composite material changes in capacitance under pressure. Specifically, the resistance decreases with the increase of pressure, thereby realizing the pressure sensing function.

[0121] Other types of pressure sensing materials that realize the function of converting pressure changes into electrical, magnetic, optical, etc. signals.

[0122] The thickness of the pressure sensing layer is between 5-100 microns, preferably between 10-50 microns. The benefits of this thickness: thin enough to effectively deform with the deformation of the silicone structure of the male massage device, thereby effectively monitoring the pressure amplitude and changes during work, while not too thin to cause poor consistency of pressure sensing.

[0123] The pressure sensing layer is the core functional layer of the flexible pressure sensor of the present application, and its material and structure directly determine the sensitivity, linearity, hysteresis and response speed of the sensor. The present application provides multiple types of pressure sensing materials to meet the needs of different application scenarios.

[0124] Piezoresistive pressure sensing material

[0125] The piezoresistive pressure sensing material is a material whose resistance value changes under pressure. It is usually a composite material formed by uniformly dispersing a conductive filler in a polymer matrix. When pressure is applied to the composite material, the distance between the conductive fillers decreases, and the conductive path increases, thereby causing the resistance value to decrease.

[0126] Composition:

[0127] Polymer matrix: Provides flexibility and elasticity of the material. Alternative materials include:

[0128] Acrylic resin: Has good transparency, weather resistance and chemical corrosion resistance.

[0129] Polyurethane resin: Has good flexibility, wear resistance and chemical corrosion resistance.

[0130] Silicone resin: Has excellent flexibility, temperature resistance and biocompatibility, especially suitable for integration with silicone toys.

[0131] Thermoplastic elastomer: Has the elasticity of rubber and the processability of plastic.

[0132] Conductive filler: Provides electrical conductivity of the material. Alternative materials include:

[0133] Carbon black particles: Low cost, easy to disperse, but relatively poor electrical conductivity.

[0134] Carbon nanotubes: Have excellent electrical conductivity and mechanical properties, but are more expensive and less dispersed.

[0135] Graphene: Has excellent electrical conductivity, mechanical properties and specific surface area, but is more expensive and prone to aggregation.

[0136] Metal nanoparticles: Gold (Au), silver (Ag), copper (Cu) and other metal nanoparticles have good electrical conductivity, but are more expensive and prone to oxidation.

[0137] Conductive polymer: Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), polyaniline (PANI), polypyrrole (PPy) and others.

[0138] Composite ratio: The mass percentage concentration of conductive filler in the polymer matrix is usually 0.1% to 30%, preferably 1% to 10%. Too low filler concentration may result in insufficient electrical conductivity, and too high filler concentration may affect the flexibility and mechanical properties of the material. The composite ratio needs to be optimized according to the performance of the selected materials.

[0139] Preparation method: The preparation method of piezoresistive pressure sensing material usually includes the following steps:

[0140] 1. Disperse the conductive filler in the solvent to form a uniform suspension. Ultrasonic, stirring and other methods can be used to promote dispersion.

[0141] 2. Dissolve the polymer matrix in the solvent to form a uniform solution.

[0142] 3. Mix the conductive filler suspension and polymer matrix solution and stir evenly.

[0143] 4. Apply the mixture onto a substrate layer, for example by spin coating, blade coating, printing, etc.

[0144] 5. Dry the coated substrate layer to remove the solvent, obtaining a piezoresistive pressure sensing film.

[0145] Capacitive pressure sensing material

[0146] Capacitive pressure sensing material is a material whose dielectric constant or thickness changes under pressure. It is usually formed by dispersing high dielectric constant fillers or conductive fillers in a polymer matrix to form a composite material. When pressure is applied to the composite material, the dielectric constant or thickness of the material changes, resulting in a change in capacitance.

[0147] Composition:

[0148] Polymer matrix: provides flexibility and elasticity of the material, the same as piezoresistive.

[0149] Filler: high dielectric constant material: barium titanate (BaTiO3), barium strontium titanate ((Ba, Sr) TiO3), zirconium oxide (ZrO2), etc. High dielectric constant materials can increase the dielectric constant of the composite material, thereby improving the sensitivity of the sensor.

[0150] Conductive filler: the same as piezoresistive, used to form a conductive path.

[0151] Hollow microspheres: used to improve the sensitivity of the sensor, as the hollow structure is more likely to deform. The material can be silica, polymer, etc.

[0152] Composite ratio: the volume percentage concentration of fillers in the polymer matrix is usually 10% to 70%, preferably 30% to 50%. Too low filler concentration may result in insufficient dielectric constant or conductivity, and too high filler concentration may affect the flexibility and mechanical properties of the material. The composite ratio needs to be optimized according to the performance of the selected material.

[0153] Preparation method: the preparation method of capacitive pressure sensing material is similar to piezoresistive, but attention should be paid to the dispersion and uniformity of the fillers.

[0154] Piezoelectric pressure sensing material

[0155] Piezoelectric pressure sensing material is a material that generates electric charge under pressure. The materials that can be selected include:

[0156] Piezoelectric polymer: homopolymer or copolymer of polyvinylidene fluoride (PVDF), poly-L-lactic acid (PLLA), etc. Piezoelectric polymers have good flexibility and easy processing.

[0157] Piezoelectric ceramics: lead zirconate titanate (PZT), lithium niobate (LiNbO3), etc.

[0158] Preparation method: The preparation method of piezoelectric pressure sensing materials is determined by the selection of materials.

[0159] Piezoelectric polymers: thin films can be prepared by spin coating, casting, etc. In order to improve the piezoelectric performance, the polymer usually needs to be polarized.

[0160] Piezoelectric ceramics: can be prepared by sintering, thin film deposition, etc.

[0161] Other types of pressure sensing materials

[0162] In addition to the above three types of pressure sensing materials, other types of materials can also be used to realize the function of pressure sensing, such as:

[0163] Optical materials: realize pressure sensing by using the change of refractive index caused by pressure.

[0164] Magnetic materials: realize pressure sensing by using the change of magnetic permeability caused by pressure.

[0165] Thickness range: 5 μm to 100 μm. Preferred range: 10 μm to 50 μm.

[0166] Lower limit (5 μm): thickness less than 5 μm may result in poor continuity of the material, affecting the sensing performance, and it is difficult to prepare.

[0167] Upper limit (100 μm): thickness greater than 100 μm will reduce the flexibility and conformability of the sensor, affecting the accurate measurement of the deformation of the silicone structure, and even affecting the user experience.

[0168] Benefits: within this thickness range, the sensing material can effectively deform with the deformation of the silicone structure of the male massage device, effectively monitoring the pressure amplitude and changes during work, and not too thin resulting in poor consistency of pressure sensing.

[0169] Example 4

[0170] The sensor of the present application adopts an array design, which can be arranged in one dimension or two dimensions according to the application requirements.

[0171] One-dimensional array: preferably single column and multiple rows of sensing points, for example, 1 column and 8 rows of structure.

[0172] Two-dimensional array: can be arranged in multiple columns and multiple rows of sensing points, for example, 2 columns and 8 rows of structure.

[0173] The array design can cover the entire length direction of the sensor, adapt to the deformation distribution of the silicone structure in the male massage device, and ensure the comprehensive collection of mechanical information at different positions.

[0174] Sensor point spacing:

[0175] In one-dimensional or two-dimensional arrays, the spacing between sensor points can be adjusted according to actual needs. The preferred range is 2mm to 10mm.

[0176] Reasonable spacing design can ensure sufficient spatial resolution and avoid excessive density leading to signal interference or increased manufacturing difficulty.

[0177] Sensor point function:

[0178] Each sensor point can independently collect vertical force signals, and through the combination of signals from multiple sensor points in the array, the direction and amplitude of the mixed force can be further calculated.

[0179] Function implementation

[0180] Mechanical information collection:

[0181] The array sensor can monitor the various types of forces exerted by the user on the silicone structure when using the male massage device in real time, including:

[0182] Vertical force: force perpendicular to the surface of the silicone.

[0183] Mixed force: force containing both vertical and parallel components, with a vector direction between vertical and parallel.

[0184] A single sensor point directly outputs the vertical force size, and through algorithm analysis of the signal differences between multiple sensor points, the direction and amplitude of the mixed force can be further calculated.

[0185] Motion information calculation:

[0186] The time-varying signals of different position sensor points in the array can be used to calculate the moving speed, direction and trajectory of the user's organ in the massage device.

[0187] Speed calculation: based on the change of signal intensity of sensor points in time series, combined with interpolation algorithm to calculate the moving speed of user's organ.

[0188] Trajectory reconstruction: according to the signal change of multiple sensor points, the motion trajectory of user's organ in the silicone structure is reconstructed.

[0189] Sensor installation method on silicone structure

[0190] Step 1: Prepare the bonding layer on the surface of the silicone

[0191] Bonding layer material and performance

[0192] Mechanical properties:

[0193] Young's modulus:

[0194] Range: 0.1 MPa to 50 MPa

[0195] Preferred Range: 0.5 MPa to 5 MPa

[0196] Explanation: The Young's modulus of silicone is typically between 0.1 MPa and 1 MPa, while the Young's modulus of the sensor substrate layer is usually higher than 50 MPa. The Young's modulus of the bonding layer needs to be between the two to ensure effective deformation signal transmission without being too rigid or too soft.

[0197] Flexural Modulus:

[0198] Range: 0.1 MPa to 5 MPa

[0199] Preferred Range: 0.5 MPa to 2 MPa

[0200] Explanation: Flexural modulus reflects the rigidity of a material when bent. The bonding layer needs to have a certain flexibility to adapt to the dynamic deformation of the silicone surface while avoiding interface failure due to excessive rigidity.

[0201] Elongation at Break:

[0202] Range: Greater than 50%, preferably 100% to 500%

[0203] Explanation: High elongation at break ensures that the bonding layer does not easily break during repeated deformation, maintaining good adhesion with the silicone structure and the sensor substrate layer.

[0204] Hardness:

[0205] Range: Shore A 10 to A 50

[0206] Preferred Range: A 20 to A 40

[0207] Explanation: Too low hardness may cause the bonding layer to lose support, while too high hardness may affect flexibility and fit.

[0208] Material:

[0209] Silicone Rubber: Good chemical compatibility with silicone structure, excellent flexibility. Formulation can be adjusted to meet different hardness requirements. Example material: Dow Corning Sylgard 184.

[0210] Polyurethane: Good flexibility, wear resistance, and chemical corrosion resistance. Mechanical properties can be adjusted by adjusting cross-linking density. Example material: BASF Elastollan series.

[0211] Thermoplastic Elastomer: Combines rubber elasticity and plastic processability. Easy to prepare in film form. Example material: Kraton series TPE.

[0212] Acrylic resin: provides high strength bonding while maintaining good transparency and weather resistance. Example material: Loctite series acrylic adhesives.

[0213] Bonding layer thickness range: 3-50 μm Preferred range: 10-30 μm.

[0214] Benefits: moderate thickness ensures sufficient cushioning without significantly increasing overall sensor thickness, maintaining flexibility and conformability.

[0215] Thin layer design helps reduce interfacial stress concentration, improving long-term reliability.

[0216] Preparation method of bonding layer

[0217] Uniformly coat or spray liquid bonding material onto the surface of the silica gel, and form a uniform thin film through thermal curing or UV curing.

[0218] Use a pre-made independent film to adhere between the sensor base layer and the silica gel surface, and firmly bond through heat pressing or other methods.

[0219] Step 2: Adhere sensor to bonding layer surface

[0220] Ensure that there are no air bubbles at the interface between the sensor and the silica gel structure to ensure that the deformation can be effectively transmitted to the inside of the sensor.

[0221] Details of the lamination process:

[0222] 1. Clean the surface of the silica gel to remove dust, grease and other impurities.

[0223] 2. Apply appropriate pressure to the bonding layer using rollers or other tools to drive out air bubbles from the center to the periphery, ensuring a smooth interface without gaps.

[0224] 3. If using heat-cured or UV-cured bonding materials, set appropriate temperature and time for curing treatment according to material properties.

[0225] Step 3: Prepare surface protection layer on sensor surface and adjacent silica gel structure

[0226] The surface protection layer is the outermost structure of the flexible pressure sensor of the present application, and its main function is to protect the internal electrode layer and sensing material layer, improve the water resistance, corrosion resistance, wear resistance, biocompatibility of the sensor, and the durability and reliability of long-term work.

[0227] Description: The surface protective layer covers the sensor surface, forming a dense protective film that prevents water, moisture, chemicals, and other substances from entering, thereby protecting the internal structure from damage. At the same time, the surface protective layer should also have good mechanical properties, able to withstand certain pressure, bending and stretching, ensuring the reliable work of the sensor in complex environments.

[0228] Composition: The surface protective layer can be composed of a single material or a combination of multiple materials. Commonly used materials include:

[0229] Polymer film:

[0230] Poly-p-xylylene: excellent chemical stability and biocompatibility, can form a dense, uniform film, effectively blocking the entry of water vapor and chemicals.

[0231] Polyurethane: good flexibility, wear resistance and chemical corrosion resistance, can be prepared by spin coating, spraying and other methods.

[0232] Thermoplastic polyurethane: higher strength and wear resistance, good processing performance.

[0233] Silicone rubber: excellent flexibility, temperature resistance and biocompatibility, especially suitable for integration with silicone toys.

[0234] Polyimide: excellent temperature resistance and chemical stability, good mechanical properties.

[0235] Acrylic resin: good transparency, weather resistance and chemical corrosion resistance.

[0236] Composite material:

[0237] Disperse inorganic nanoparticles (such as silicon dioxide, aluminum oxide, etc.) in the polymer matrix to form a composite material. The composite material can combine the flexibility of the polymer material and the wear resistance of the inorganic material.

[0238] Mix hydrophobic materials (such as fluorinated polymers) with polymer materials to improve the water resistance of the surface protective layer.

[0239] Performance indicators:

[0240] Mechanical properties:

[0241] Young's modulus: The surface protective layer has a certain flexibility, which can coordinate with the deformation of other layers of the sensor. The Young's modulus should be less than 5GPa, preferably less than 2GPa.

[0242] Elongation at break: The elongation at break should be greater than 10%, preferably greater than 50%, to ensure that the surface protective layer does not easily break when bending and stretching.

[0243] Hardness: The hardness of the surface protective layer should be moderate, too hard may affect the flexibility of the sensor, too soft has poor wear resistance. Shore A or D.

[0244] Chemical properties:

[0245] Water resistance: The surface protective layer should have good water resistance, can be soaked in water for a long time without swelling, dissolving or performance degradation.

[0246] Corrosion resistance: The surface protective layer should be able to resist corrosion of common cleaning agents, lubricants and human body secretions, etc.

[0247] Biocompatibility: The surface protective layer should be non-toxic, non-irritating and harmless to the human body.

[0248] Thickness: The thickness of the surface protective layer ranges from 1 μm to 20 μm, preferably 2 μm to 10 μm. Too thin protective layer may not provide adequate protection, too thick protective layer may affect the flexibility and sensitivity of the sensor

[0249] Preparation process

[0250] Coating or spraying: Uniformly coat or spray the liquid protective material on the surface of the sensor, and form a dense film by thermal curing or UV curing.

[0251] Film lamination: Use a pre-made independent film to cover the surface of the sensor, and firmly bond it by heat pressing or other methods.

[0252] In this paper, the terms "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of expressing the clarity and description of the technical scheme, therefore cannot be understood as a limitation on the present application.

[0253] In this paper, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, in addition to including the listed elements, but also including other elements not explicitly listed.

[0254] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above examples, the above examples and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A flexible pressure sensor unit, characterized in that: The pressure sensing layer comprises a pressure sensing layer, a first substrate layer and a first electrode layer arranged on one side of the pressure sensing layer. The first electrode layer is located between the first substrate layer and the pressure sensing layer and forms a multi-layer flexible structure with the first substrate layer and the pressure sensing layer.

2. The flexible pressure sensor unit according to claim 1, wherein: A second substrate layer and a second electrode layer are provided on the other side of the pressure sensing layer.

3. The flexible pressure sensor unit according to claim 1 or 2, characterized in that: The pressure sensing layer has a thickness ranging from 5 μm to 100 μm, and is made of piezoresistive pressure sensing material, capacitive pressure sensing material or piezoelectric pressure sensing material; The piezoresistive pressure sensing material is a composite material formed by uniformly dispersing conductive fillers in a polymer matrix; The capacitive pressure sensing material is a composite material formed by dispersing high dielectric constant fillers, conductive fillers and hollow microspheres in a polymer matrix; The piezoelectric pressure sensing material is prepared by piezoelectric polymer or piezoelectric ceramic; The conductive filler is carbon black particles, carbon nanotubes, graphene, metal nanoparticles or conductive polymers; the hollow microspheres are silica or polymers; The high dielectric constant material is barium titanate, barium strontium titanate or zirconium oxide; The piezoelectric polymer is a homopolymer or copolymer of polyvinylidene fluoride, or poly-L-lactic acid; the piezoelectric ceramic is lead zirconate titanate or lithium niobate; The polymer matrix is ​​acrylic resin, polyurethane resin, silicone resin or thermoplastic elastomer.

4. The flexible pressure sensor unit according to claim 2, wherein: The materials of the first base layer and the second base layer are polyurethane film, thermoplastic polyurethane, silicone rubber, polyimide or polyparaxylene; The Young's modulus of the first substrate layer and the second substrate layer ranges from 0.001 GPa to 2 GPa, the flexural modulus ranges from 0.001 GPa to 1.5 GPa, the elongation at break ranges from 50% to 500%, the hardness ranges from Shore A10 to Shore A80, and the thickness ranges from 10 μm to 150 μm.

5. The flexible pressure sensor unit according to claim 1, wherein: The first electrode layer is a parallel interdigitated electrode, the thickness of the electrode layer is in the range of 5 nm to 500 nm, the width of the electrode strip is in the range of 2 μm to 100 μm, and the electrode spacing is in the range of 2 μm to 100 μm; The material of the parallel interdigitated electrodes is a metal film, a conductive oxide, a conductive polymer, a nanomaterial or a composite material.

6. The flexible pressure sensor unit according to claim 2, characterized in that The first electrode layer and the second electrode layer are respectively arranged on the upper and lower sides of the pressure sensing layer to form an upper and lower electrode structure, and the thickness of the electrode layer ranges from 5nm to 500nm; The materials of the first electrode layer and the second electrode layer are metal thin films, conductive oxides, conductive polymers, nanomaterials or composite materials.

7. The flexible pressure sensor unit according to claim 1 or 2, characterized in that: The first base layer of the flexible pressure sensor unit is connected to the silicone structure through an adhesive layer, and a surface protection layer is provided on the outer surfaces of the flexible pressure sensor unit and the adhesive layer.

8. The flexible pressure sensor unit according to claim 7, characterized in that The material of the bonding layer is silicone rubber, polyurethane, thermoplastic elastomer or acrylic resin; The bonding layer has a Young's modulus ranging from 0.1 MPa to 50 MPa, a flexural modulus ranging from 0.1 MPa to 5 MPa, an elongation at break ranging from greater than 50%, a hardness ranging from Shore A10 to A50, and a thickness ranging from 3 μm to 50 μm.

9. The flexible pressure sensor unit according to claim 1 or 2, characterized in that: A plurality of the flexible pressure sensor units are distributed on the surface of the silicone structure in a one-dimensional array or a two-dimensional array; The spacing between the flexible pressure sensor units is 2 mm to 10 mm.

10. The flexible pressure sensor unit according to claim 9, characterized in that The preparation and installation method of the bonding layer and the surface protection layer are as follows: D1. Preparation of Adhesive Layer The liquid adhesive layer is evenly coated on the surface of the silicone structure and formed into an adhesive layer by thermal curing; Or use a prefabricated adhesive film, stick it to the silicone surface, and achieve a firm bond through hot pressing; D2. Laminating the flexible pressure sensor unit on the adhesive layer surface Laminating the flexible pressure sensor units in an array to the surface of the adhesive layer; Use a roller to remove air bubbles from the center to the surrounding areas to ensure there are no gaps; Apply uniform pressure after lamination and perform heat treatment; D3. Preparing a surface protective layer on the surface of the flexible pressure sensor unit and the adhesive layer; The surface protection layer is a thermoplastic polyurethane film with a thickness of 10 μm; Thermoplastic polyurethane material is evenly sprayed on the surface of the flexible pressure sensor unit and then cured by heating to form a protective film.

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