A silicone composite functional material for intelligent applications and a preparation method thereof

Abstract

The application discloses a kind of organic silicon composite functional materials and its wireless monitoring system and method for intelligent application, the interface film includes by outer to inner sequentially stacked anti-fouling and wetting-resistant surface layer, hydrogen bond enhanced dynamic adaptive layer and inorganic filler modulus enhanced protective layer.Anti-fouling and wetting-resistant surface layer is composed of organic silicon elastomer composite material, hydrogen bond enhanced dynamic adaptive layer is introduced by blending in organic silicon matrix into the modified component containing urea group and the like can form hydrogen bond functional group, and inorganic filler modulus enhanced protective layer is introduced by inorganic filler such as barium titanate to improve modulus and compression resistance.The interface film is integrated with pressure sensor module, wireless communication module and host computer system, to form a complete wireless pressure monitoring system, realize real-time transmission of pressure signal, visual display, threshold alarm and data management.The application is suitable for wearable health monitoring, medical care, child companion guardianship and robot touch and the like fields.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronic materials and pressure sensing technology, specifically relating to an organosilicon composite functional material for smart applications and its preparation method. Background Technology

[0002] With the rapid development of wearable health monitoring, intelligent medical care, human-computer interaction, and robotic tactile perception, electronic skin has become one of the core research directions in flexible electronics technology. As a type of flexible sensor that simulates the tactile perception function of human skin, electronic skin typically consists of functional components such as a flexible substrate, a sensitive layer, and electrodes. It shows broad application prospects in areas such as human physiological signal monitoring, tactile feedback in intelligent prostheses, force feedback in surgical robots, and safe interaction with robots.

[0003] In practical applications, flexible pressure sensors typically need to be attached to human skin or the surface of the object being measured for continuous signal acquisition. The interface layer between the sensor's sensitive element and the object being measured plays a crucial mediating role in the pressure signal transmission process. The material properties of the interface layer directly determine the stability of the pressure transmission path, the accuracy and reliability of the signal output, and the long-term performance of the device in complex environments. An ideal electronic skin interface layer should simultaneously possess the following core properties: (a) softness and conformability to achieve close conformal contact with the curved surface of the object being measured; (b) resistance to wetting and contamination to resist interference from sweat, oils, and other bodily fluids and environmental pollutants; (c) mechanical cycle stability to withstand long-term repeated compression and bending without irreversible structural damage; and (d) long-term signal output reliability to ensure the accuracy and repeatability of the pressure signal.

[0004] However, existing pressure-sensing interface materials generally face the following technical bottlenecks in meeting the above requirements, which restrict the advancement of electronic skin technology from laboratory research to engineering applications:

[0005] First, interface wetting and contamination cause signal drift. In wearable applications, sweat (mainly NaCl aqueous solution, containing small amounts of lactic acid, urea, and other organic matter), sebum (mainly triglycerides, wax esters, and squalene), moisture, and external dust and other contaminants can easily adhere to, spread, or even form continuous liquid films or liquid bridges at the interface between the sensor and the skin. This uncontrolled change in interface wetting directly alters the effective contact area and contact stiffness for pressure transmission, leading to baseline drift, amplitude fluctuations, or even false triggering of the sensor output signal, severely affecting the accuracy and reliability of the monitoring data.

[0006] Second, traditional flexible matrix materials have limited resistance to damage and fatigue. Currently, commonly used flexible matrix materials in the field of electronic skin include polydimethylsiloxane, platinum-catalyzed addition-type silicone elastomers, thermoplastic polyurethanes, and various hydrogels. While these materials possess good flexibility and a certain degree of biocompatibility, their molecular network structure relies primarily on covalent cross-links to maintain structural integrity and shape stability. However, once these covalent bonds break under stress (homogeneous or heterogeneous cracking), the break sites cannot spontaneously reconnect under normal temperature and pressure. Therefore, under long-term repeated compression, bending, or localized scratching, microcracks in the covalent network, once formed, will gradually expand and accumulate, leading to irreversible structural relaxation, creep, and a decrease in elastic recovery rate. This cumulative degradation of the microstructure ultimately manifests as a decline in macroscopic mechanical properties and instability in pressure signal output. Several studies have reported the performance degradation of pure covalently cross-linked elastomers in cyclic mechanical testing.

[0007] Third, traditional packaging methods struggle to balance sensitivity, flexibility, and durability. The sensing elements and electrode leads of electronic skin devices typically require encapsulation layers for protection against external mechanical damage and environmental corrosion. However, existing packaging technologies have inherent contradictions: (a) rigid encapsulation (such as epoxy resin potting or glass encapsulation) significantly increases the overall stiffness and thickness of the device, reducing flexibility and pressure response sensitivity, making it unsuitable for application to soft, curved surfaces like human skin; (b) while thin-film flexible encapsulation maintains some flexibility, the film layer thickness is typically only 1–10 μm, limiting mechanical strength and failing to improve the material's dynamic deformation recovery and self-healing capabilities at the molecular network level; (c) the mismatch in thermal expansion coefficients between the encapsulation layer and the functional layer can easily lead to interfacial stress concentration and interlayer debonding under varying temperature conditions, resulting in encapsulation failure.

[0008] Fourth, there is a lack of systematic application integration capabilities. In practical applications such as clinical health monitoring, child safety monitoring, and robotic tactile interaction, pressure sensors not only need stable signal output, but also need to transmit pressure signals wirelessly to remote devices in real time for visualization, threshold warning, data recording, and analysis. However, most existing technical solutions remain at the stage of single-point acquisition and offline data analysis in the laboratory, lacking a complete systematic integration solution from "interface materials—sensor components—wireless transmission—host computer processing".

[0009] In summary, there is an urgent need for an electronic skin interface material that can simultaneously address the three issues of interface wetting and contamination interference, fatigue damage of covalent network structures, and system integration. This material should possess dynamic self-healing capabilities at the molecular network design level and form a complete system solution with wireless transmission and host computer processing. Summary of the Invention

[0010] The technical problems to be solved by this invention are: (1) pressure signal drift caused by interface wetting and contamination; (2) irreversible structural damage to the covalent cross-linked network under cyclic mechanical loading leading to a decrease in signal repeatability; (3) difficulty in simultaneously taking into account flexibility, sensitivity and mechanical protection by traditional encapsulation methods; and (4) insufficient system integration capability. This invention provides an organosilicon composite functional material for intelligent applications and its preparation method.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0012] In a first aspect, the present invention provides an organosilicon composite functional material for smart applications.

[0013] The organosilicon composite functional material has a three-layer stacked structure, consisting of, from the outside to the inside: an antifouling and antiwetting surface layer (Ⅰ), a hydrogen bond-reinforced dynamic adaptation layer (Ⅱ), and an inorganic filler-reinforced modulus protection layer (Ⅲ). The three layers have clearly defined functions and complement each other.

[0014] Regarding the antifouling and antiwetting surface layer (Ⅰ):

[0015] The antifouling and antiwetting surface layer is composed of an organosilicon elastomer composite material formed by cross-linking and curing hydrogen-containing silicone oil and vinyl silicone oil through platinum catalytic addition and compounding with inorganic fillers. The organosilicon material inherently possesses low surface free energy. Combined with the continuous, dense, and non-porous film structure formed after addition curing, the surface exhibits a high contact angle with water (static contact angle ≥100°), effectively inhibiting the adhesion, spread, and penetration of sweat, moisture, oil, and external pollutants at the interface.

[0016] The working principle of the antifouling and antiwetting surface layer is as follows: When the sensor is attached to human skin, the antifouling and antiwetting surface layer is located between the skin and the intermediate functional layer. Its low surface energy characteristics cause liquids such as sweat to form high contact angle droplets at the interface rather than spreading into a continuous liquid film. This maintains the effective contact state for pressure transmission without being affected by liquid spreading, reducing the probability of signal drift and false triggering. Unlike traditional fluorosilane surface-modified hydrophobic coatings, the antifouling surface layer of this invention is integrally coated and cured from the same organosilicon matrix material as the intermediate functional layer. The interlayer interface is a molecular diffusion interface rather than a physical coating interface. Therefore, the interlayer bonding force is significantly better than that of coating-type hydrophobic coatings, and it is less prone to interface debonding or coating peeling during long-term use.

[0017] Regarding the hydrogen bond-enhanced dynamic adaptation layer (II):

[0018] The hydrogen bond-enhanced dynamic adaptation layer is constructed by blending modified components containing functional groups capable of forming hydrogen bonds into an organosilicon elastomer matrix formed by platinum-catalyzed addition crosslinking and curing of hydrogen-containing silicone oil and vinyl silicone oil and composite inorganic fillers. This layer is the core functional layer of the present invention, and its molecular network has the dual network characteristics of "covalent crosslinking network + dynamic hydrogen bond physical network".

[0019] Specifically, the modified components form multi-point reversible hydrogen bonds in the organosilicon matrix through the following two pathways, jointly constructing a dynamic reversible hydrogen bond physical network superimposed on the covalent crosslinking network:

[0020] Approach 1: Self-complementary hydrogen bonding between modified component molecules. Taking urea-containing modified components as an example, two adjacent urea groups (-NH-CO-NH-) form a dimer or chain-like supramolecular structure through double NH···O=C hydrogen bonds.

[0021] Approach 2: Weak hydrogen bond interactions between the hydrogen-bonded functional groups of the modified component and the oxygen-containing groups in the organosilicon segments. The NH group of the urea group can form a weak hydrogen bond (NH···O-Si) with the lone pair electrons of the oxygen atom in the siloxane backbone (Si-O-Si). Although the strength of a single weak hydrogen bond is low (about 3–8 kJ / mol), the synergistic effect of a large number of weak hydrogen bonds can "anchor" the modified component to the organosilicon network at the molecular level, improving the dispersion uniformity and network connectivity of the modified component in the matrix.

[0022] The aforementioned dual-network structure endows the hydrogen-bonded enhanced dynamic adaptation layer with a unique dynamic response mechanism, the process of which can be divided into three stages:

[0023] Phase 1 (Initial State): When no external force is applied, both the covalent cross-linked network and the hydrogen bond physical network are in an intact state, and the material has a stable elastic modulus and mechanical transmission path.

[0024] Phase Two (Pressure Loading State): When external force is applied to the interfacial film, the stress is initially borne by both the covalent network and the hydrogen bond network. Since the bond energy of hydrogen bonds is much lower than that of covalent bonds, some hydrogen bonds in the hydrogen bond network undergo reversible breakage first (i.e., the "sacrificial bond mechanism"). The breakage process absorbs and dissipates stress energy, effectively buffering local stress concentration and protecting the integrity of the covalent crosslinked network.

[0025] Stage 3 (Pressure Unloading State): After the external force is removed, the broken hydrogen bond donor and acceptor sites spontaneously re-pair and reorganize the network structure due to their strong directional complementary affinity, restoring the material's mechanical properties and structural integrity. This reorganization process can be completed spontaneously at room temperature within a timescale of milliseconds to seconds, without the need for external heating or catalysis.

[0026] Through a dynamic cyclic mechanism of "loading → hydrogen bond breaking → stress dissipation and unloading → hydrogen bond recombination → structural recovery", the hydrogen bond-enhanced dynamic adaptation layer can maintain stable mechanical properties and pressure transmission path under repeated compression, bending or local micro-damage conditions, and significantly suppress signal attenuation and repeatability reduction caused by irreversible damage accumulation in the covalent network.

[0027] Regarding the inorganic filler-reinforced modulus protective layer (Ⅲ):

[0028] The inorganic filler-reinforced modulus protective layer is composed of an organosilicon elastomer composite material formed by cross-linking and curing hydrogen-containing silicone oil and vinyl silicone oil through platinum catalytic addition and incorporating inorganic fillers. The introduction of inorganic fillers (such as barium titanate particles) in this layer significantly improves the elastic modulus, dimensional stability, and resistance to compressive deformation through the following mechanisms: (a) the filler particles, as rigid phases, are dispersed in a flexible matrix, increasing the equivalent elastic modulus of the composite material through the stress transfer effect at the particle-matrix interface; (b) the presence of filler particles restricts the molecular chain slippage and rearrangement of organosilicon segments under pressure, reducing the creep tendency of the material.

[0029] This layer is located on the innermost side of the three-layer structure (facing the pressure sensor module) and serves a dual function: (a) as a mechanical protection layer, protecting the internal pressure sensing element, electrode lead-out structure and wireless monitoring connection area from direct damage caused by external mechanical stress; (b) as a mechanical transmission support layer, providing a stable rigid support backplate for the dynamic deformation of the intermediate layer during pressure loading, so that the deformation of the intermediate layer is controlled within an appropriate range, and preventing the mechanical transmission path from becoming unstable due to excessive deformation.

[0030] Regarding the electrode lead-out structure:

[0031] The surface of the hydrogen bond-reinforced dynamic adaptation layer (II) is provided with an electrode lead-out structure, which is encapsulated between the hydrogen bond-reinforced dynamic adaptation layer and the inorganic filler-reinforced modulus protective layer. This "interlayer encapsulation" design provides mechanical protection for the electrode lead-out structure by the inorganic filler-reinforced modulus protective layer, preventing the electrode from shifting, debonding, or breaking under external forces, and ensuring the long-term stability of the electrical connection.

[0032] Regarding the three-tier collaborative working mechanism:

[0033] In use, the organosilicon composite functional material is disposed between the pressure sensor module and the object being measured (such as human skin). The anti-fouling and anti-wetting surface layer (Ⅰ) is disposed facing the object being measured, and the inorganic filler-reinforced modulus protective layer (Ⅲ) is disposed facing the pressure sensor module. When the object being measured applies pressure to the sensor, the pressure signal is transmitted sequentially through the three layers to the pressure sensor module. The functional division of the three layers is as follows:

[0034] Layer I (Anti-fouling and anti-wetting surface layer) – Interface environmental isolation function: Inhibits the interference of body fluids such as sweat and oil and external pollutants on the interface, maintaining a clean and stable pressure contact interface.

[0035] Layer II (Hydrogen Bond Enhanced Dynamic Adaptation Layer) – Dynamic Deformation Adaptation and Stress Dissipation Function: Stress buffering and structural self-recovery are achieved through the reversible breakage and recombination of the dynamic hydrogen bond network, maintaining the stability of mechanical properties and signal output during cyclic use.

[0036] Layer III (Inorganic Filler Reinforced Modulus Protective Layer) – Mechanical Protection and Support Function: Provides mechanical protection for internal components through a high elastic modulus, while providing a stable rigid reference surface for the dynamic deformation of the intermediate layer.

[0037] The three layers are mutually exclusive, complementary in their gradients, and synergistic in their effects, achieving a comprehensive performance combination that a single homogeneous layer cannot simultaneously achieve.

[0038] Further, the hydrogen-containing silicone oil is one or more hydrogen-containing polysiloxanes with a hydrogen content of 0.01%–2.5% (mass fraction) and a viscosity range of 20–1000 mPa·s. The vinyl silicone oil is one or more vinyl polysiloxanes with a vinyl content of 0.01%–2.5% (mass fraction) and a viscosity range of 50–2000 mPa·s. The mass ratio of the hydrogen-containing silicone oil to the vinyl silicone oil is 0.6:1–1.7:1. The Si-H bonds in the hydrogen-containing silicone oil and the vinyl groups (Si-CH=CH2) in the vinyl silicone oil undergo a hydrosilylation reaction under the action of a platinum catalyst (such as a Karstedt catalyst) to form Si-CH2-CH2-Si covalent crosslinks, constructing a three-dimensional elastic covalent crosslinked network.

[0039] Further, the inorganic filler is selected from one or more of barium titanate (BaTiO3), fumed silica (SiO2), precipitated silica (SiO2), alumina (Al2O3), calcium carbonate (CaCO3), and boron nitride (BN). The particle size of the inorganic filler is 50 nm–50 μm. The amount of the inorganic filler added to the total organosilicon composite matrix is ​​1.0 wt%–10.0 wt% of the organosilicon matrix mass.

[0040] Preferably, the inorganic filler is nano-sized barium titanate particles with a particle size of 100–500 nm.

[0041] Furthermore, the modifying component containing hydrogen-bonding functional groups is selected from one or more organic compounds containing urea (-NH-CO-NH-), amide (-CO-NH-), urethane (-NH-CO-O-), hydroxyl (-OH), carboxyl (-COOH), amidine (-C(=NH)-NH2), urethane (-NH-CO-O-), or multiple hydrogen-bonding units. The amount of the modifying component added is 1.0 wt%–25.0 wt% of the organosilicon matrix. When the amount added is less than 1.0 wt%, the hydrogen bond network density is too low, and the dynamic dissipation and self-recovery effects are not obvious; when the amount added exceeds 25.0 wt%, the excessive polar component may cause phase separation or significantly weaken the hydrophobicity and flexibility of the organosilicon matrix.

[0042] Preferably, the modifying component is a urea-containing organic modifier. The urea-containing organic modifier is selected from: (a) small molecule urea compounds, such as 1,3-dimethylurea; (b) diurea or polyurea compounds, such as 4,4'-methylenebis(phenylurea); and (c) polyurea-siloxane oligomers, such as polyurea-siloxane copolymers formed by reacting 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane with isocyanates (such as toluene diisocyanate TDI, hexamethylene diisocyanate HDI, etc.). Among these, polyurea-siloxane oligomers exhibit the best compatibility with the organosilicon matrix because they simultaneously contain organosilicon segments and urea hydrogen-bonded functional groups.

[0043] Furthermore, the electrode lead-out structure is selected from one or more of the following: copper foil (thickness 20–100 μm), copper tape (including a conductive voltage-sensitive adhesive layer, total thickness 40–80 μm), silver paste wires (prepared by screen printing or dot coating, film thickness 5–30 μm), or flexible printed circuit (FPC) conductive sheets. The electrode lead-out structure is disposed in the edge region or a preset electrode region of the surface of the hydrogen bond-enhanced dynamic adaptation layer. The electrode can be embedded during the curing process (i.e., the electrode is attached to the surface of the intermediate layer when it is semi-cured or not fully cured, and then integrated and encapsulated by the subsequent curing process of the protective layer) or attached after curing (i.e., the electrode is attached to the surface of the intermediate layer using conductive adhesive after the intermediate layer is fully cured).

[0044] Furthermore, the cured film thickness of the antifouling and antiwetting surface layer (Ⅰ) is 30–200 μm; the cured film thickness of the hydrogen bond-reinforced dynamic adaptation layer (Ⅱ) is 80–400 μm; and the cured film thickness of the inorganic filler-reinforced modulus protective layer (Ⅲ) is 150–600 μm. The total thickness of the three layers is 260–1200 μm, preferably 400–800 μm. Within the above thickness range, the film exhibits good overall flexibility (bending radius can reach 3–10 mm without interlayer debonding), while also possessing sufficient mechanical strength and protective capability.

[0045] Secondly, the present invention provides a method for preparing the above-mentioned organosilicon composite functional material for smart applications.

[0046] The preparation method is based on a process strategy of "differentiated raw materials from the same batch + functional modification of intermediate layers + layer-by-layer coating and curing". Its core design idea is that the three-layer organosilicon matrix is ​​derived from the same batch of raw materials, ensuring a high degree of consistency in chemical composition and thermal expansion coefficient between layers, reducing interlayer interface stress and debonding risk; functional stratification is achieved by introducing a small amount of hydrogen bond modification components in the intermediate layer, making the process simple and easy to control.

[0047] The preparation method includes the following steps (all parts of raw materials used below are by weight):

[0048] Step 1: Preparation of the total material of the organosilicon composite matrix.

[0049] Mix 1.5–2.5 parts of hydrogen-containing silicone oil (component A) with 1.5–2.5 parts of vinyl silicone oil (component B), add 0.05–0.30 parts of inorganic filler (preferably nano-sized barium titanate particles), and simultaneously add a platinum catalyst (such as Karstedt catalyst) and an appropriate amount of inhibitor. Stir and mix under vacuum for 5–15 min to ensure that the inorganic filler particles are uniformly dispersed in the organosilicon system and that air bubbles are fully removed, resulting in a uniform organosilicon composite matrix without visible air bubbles. The mixing operation is carried out at an ambient temperature of 10–30°C to avoid premature curing of the system.

[0050] The total material is a shared matrix material with a three-layer structure. Subsequent layers achieve functional stratification by "using different masses of the same total material + introducing hydrogen-bonding modified components only in the middle layer". This "homogeneous extraction" process design ensures a high degree of consistency in the chemical composition, crosslinking density, and coefficient of thermal expansion of the three-layer matrix, which is conducive to good chemical bonding and mechanical matching between layers and reduces the risk of interlayer debonding.

[0051] Step 2, preparation of antifouling and antiwetting surface layer (Ⅰ).

[0052] Take 0.5–1.0 parts of the total material obtained in step one and apply it evenly to the surface of a clean substrate or release substrate (such as a glass substrate treated with fluorosilane, PET release film or PTFE film, etc.) by scraping, blade coating or dot coating followed by scraping, etc., and control the wet film thickness to 50–250 μm to obtain the first wet film.

[0053] The substrate coated with the wet film is placed horizontally in a forced-air drying oven and cured at 100–130 °C (preferably 110 °C) for 5–15 min (preferably 10 min). At this temperature, the inhibitor desorbs from the surface of the platinum catalyst, the catalytic system is activated, and the Si-H bonds in the hydrogen-containing silicone oil and the vinyl groups in the vinyl silicone oil undergo a hydrosilylation crosslinking reaction under the action of the platinum catalyst to form a dense and continuous organosilicon elastomer film, i.e., an antifouling and antiwetting surface layer.

[0054] The resulting antifouling and antiwetting surface layer is a transparent to semi-transparent flexible elastic film with a cured thickness of approximately 40–200 μm. The surface is smooth, dense, and free of pinholes. This surface layer utilizes the synergistic effect of the intrinsically low surface energy characteristics of silicone materials (approximately 20–25 mJ / m²) and the dense, continuous film structure to achieve highly efficient antiwetting and anti-adhesion functions against sweat, moisture, and oil.

[0055] Step 3: Preparation of hydrogen bond-enhanced dynamic adaptation layer (II).

[0056] Take 0.8–1.2 parts of the total material obtained in step one, and add 0.01–0.30 parts of the modified component containing functional groups that can form hydrogen bonds (the amount of modified component added is 1.0 wt%–25.0 wt% based on the total mass of the organosilicon matrix). Stir and mix evenly at an ambient temperature of 10–30 ℃ to uniformly disperse the modified component in the organosilicon matrix by blending, and obtain the hydrogen bond modified composite slurry.

[0057] The obtained hydrogen bond-modified composite slurry was uniformly coated onto the cured film surface of the antifouling and antiwetting surface layer obtained in step two, and the wet film thickness was controlled to be 100–500 μm to obtain a hydrogen bond-reinforced dynamic adaptation layer wet film. The sample coated with the wet film was placed horizontally in a forced-air drying oven and cured at 100–130 ℃ for 5–15 min.

[0058] It should be noted that the surface of the antifouling and antiwetting surface layer obtained in step two still retains a certain degree of surface activity during the coating process in step three (a small amount of unreacted Si-H and vinyl groups exist on the surface of the cured silicone film). When the intermediate wet film is coated and then heated and cured, the interface area between the two layers can form covalent chemical bonds through the cross-linking reaction of residual reactive groups, thereby achieving a strong interlayer bond.

[0059] Step four: Setting up the electrode lead-out structure.

[0060] During or after the curing process in step three, an electrode lead-out structure is set at a preset position on the surface of the hydrogen bond-enhanced dynamic adaptation layer.

[0061] Step 5, Preparation of the third inorganic filler-enhanced modulus protective layer: Take 1.2–2.0 parts by weight of the total material obtained in Step 4 and uniformly coat it on the surface of the second hydrogen bond-enhanced dynamic adaptation layer obtained in Step 3 and the electrode lead-out structure set in Step 4 to form a third wet film; heat and cure the third wet film at 100–130℃ for 5–15 min to obtain the third inorganic filler-enhanced modulus protective layer, thus completing the preparation of the three-layer electronic skin interface film.

[0062] Furthermore, the vacuum conditions described in step S1 are a vacuum degree ≤ -0.08 MPa and a mixing time of 5–30 min.

[0063] Furthermore, the curing described in steps S2 to S5 is an addition-type platinum-catalyzed hydrosilylation crosslinking curing process, wherein the total organic silicon composite matrix contains a platinum catalyst and an inhibitor.

[0064] Furthermore, the hydrogen bond modifying component in step S3 is a urea-containing organic modifier, and the amount of the urea-containing organic modifier added is 1%–30% of the total weight of the material obtained in step S1.

[0065] Furthermore, the mixing operations in each step are carried out under ambient temperature conditions of 10–35°C and relative humidity of 30%–70%.

[0066] A third aspect of this invention provides a wireless pressure monitoring system for organosilicon composite functional materials for smart applications, the system comprising:

[0067] The aforementioned organosilicon composite functional material for intelligent applications is placed between the pressure sensor module and the object being measured.

[0068] The pressure sensor module is electrically connected to the second hydrogen bond-enhanced dynamic adaptation layer of the electronic skin interface film through the electrode lead-out structure, and is used to convert interface pressure changes into electrical signals.

[0069] A wireless communication module, electrically connected to the pressure sensor module, is used to wirelessly transmit the electrical signal output by the pressure sensor module; the wireless communication module adopts one of Bluetooth Low Energy (BLE), ZigBee, Wi-Fi or LoRa communication protocols.

[0070] The host computer software system is used to receive pressure signal data sent by the wireless communication module and perform one or more of the following functions: real-time display of pressure value, visual plotting of pressure curve, setting and alarm of pressure threshold, baseline calibration and signal filtering, and data export and saving.

[0071] Furthermore, the pressure sensor module is one of a capacitive pressure sensor, a piezoresistive pressure sensor, or a piezoelectric pressure sensor.

[0072] Furthermore, the system also includes a power supply module, which is a rechargeable lithium battery or a button battery.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] (1) The present invention provides an anti-fouling and anti-wetting surface layer on the side of the electronic skin interface film facing the test object. By utilizing the intrinsic low surface energy characteristics of organosilicon material and the continuous and dense solidified film structure, the spread, retention and penetration of sweat, moisture, oil and external pollutants at the interface are effectively reduced, thereby reducing the interference of environmental factors on the pressure transmission path and signal stability, and solving the signal drift problem caused by interface wetting and pollution in the prior art.

[0075] (2) This invention constructs a superimposed dynamic reversible hydrogen bond network in a covalently crosslinked organosilicon network by introducing modified components containing urea groups or other components capable of forming reversible hydrogen bonds into the organosilicon elastomer matrix. During pressure loading, this dynamic hydrogen bond network can dissipate energy through the preferential dissociation of hydrogen bonds, alleviating local stress concentration; after pressure release, the dissociated hydrogen bonds spontaneously reconstruct under thermodynamic drive, restoring the continuity and integrity of the network structure. This dual-network synergistic mechanism of "covalent network conformal preservation and hydrogen bond network dissipation" enables the electronic skin interface film to maintain stable pressure response performance under repeated compression, bending or local damage conditions, significantly improving the material's cycle stability and signal repeatability.

[0076] (3) By setting an inorganic filler-enhanced modulus protection layer as the third layer, the present invention improves the modulus and compressive stability of the overall structure of the electronic skin interface film, effectively protecting the internal pressure sensing elements, electrode lead-out structures and wireless monitoring connection areas, and avoiding signal instability and structural failure caused by excessive deformation under continuous pressure loading or local stress conditions.

[0077] (4) This invention integrates a three-layer electronic skin interface film with a pressure sensor module, a wireless communication module and a host computer software system to build a complete pressure monitoring technology chain from the material interface layer to the signal acquisition layer, and then to the data processing and visualization layer. It realizes systematic application functions such as real-time transmission of pressure signals, visualization display, threshold control, data export and storage, and overcomes the limitations of existing technologies that are mostly limited to single-point acquisition in the laboratory.

[0078] (5) The three-layer structure design of the present invention realizes the functional layered synergy of "anti-fouling and anti-wetting - dynamic deformation adaptation - enhanced modulus protection". The three layers adopt the same organosilicon composite matrix system, which ensures the interlayer bonding force and interface compatibility. At the same time, each layer achieves functional division of labor through the differentiation of specific functional components, taking into account the multi-objective coordinated optimization of sensitivity, flexibility, stability and protection. Attached Figure Description

[0079] Figure 1 This is a schematic diagram of an organosilicon composite functional material for smart applications; where Ⅰ represents the antifouling and antiwetting surface layer;

[0080] II represents the hydrogen bond-reinforced dynamic adaptation layer; III represents the inorganic filler-reinforced modulus protection layer; IV represents the pressure sensor module.

[0081] Figure 2 This is a stress diagram of an organosilicon composite functional material for intelligent applications; where I is the initial state; II is the pressure loading state; III is the pressure unloading state; and IV is the structural recovery state. Detailed Implementation

[0082] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and should not be considered as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art within the scope of the inventive concept should fall within the protection scope of the claims of the present invention.

[0083] Example 1

[0084] Step 1: Preparation of the total material of the organosilicon composite matrix

[0085] Weigh 2.0 g of hydrogen-containing silicone oil (component A, hydrogen content approximately 0.15%) and 2.0 g of vinyl silicone oil (component B, vinyl content approximately 0.25%), place them in a clean mixing container, add 0.1513 g of micron-sized barium titanate (BaTiO3, average particle size approximately 2 μm), 0.02 g of platinum catalyst, and 0.005 g of inhibitor. Mix and stir for 15 min using a planetary mixer under a vacuum of ≤-0.09 MPa at room temperature (25±5 ℃) and relative humidity of 59%±5% to remove air bubbles, obtaining a homogeneous organosilicon composite matrix. The mass fraction of barium titanate in the total material is approximately 3.6%.

[0086] Step 2: Preparation of the first antifouling and antiwetting surface layer

[0087] Take 0.7 g of the total silicone composite matrix obtained in step one and uniformly coat it onto the clean surface of a polytetrafluoroethylene (PTFE) release substrate using a doctor blade coating method, controlling the wet film thickness to be approximately 100–200 μm. Then, place the substrate coated with the wet film in a forced-air drying oven and heat-cur it at 110 ℃ for 10 min. Remove it and allow it to cool naturally to room temperature to obtain the first layer of antifouling and antiwetting surface cured film. The obtained first layer of cured film has a smooth and dense surface, and the water contact angle is measured to be 108.3°, indicating that it has good hydrophobic and antifouling properties.

[0088] Step 3: Preparation of the second hydrogen-bonded dynamic adaptation layer

[0089] Take 0.9994 g of the total organic silicone composite matrix obtained in step one, and add 0.0203 g of a urea-containing hydrogen bond modifying component (1,3-dimethylurea) (approximately 2.0% of the total weight). Mix the mixture with a glass rod for 10 min at room temperature (25±5 ℃) and relative humidity (59%±5%) until homogeneous to obtain a urea-based hydrogen bond modified organic silicone composite slurry. Coat the obtained modified composite slurry onto the surface of the first antifouling and antiwetting surface layer obtained in step S2, controlling the wet film thickness to approximately 150–300 μm. Heat and cure at 110℃ for 10 min to obtain the second hydrogen bond-reinforced dynamic adaptation layer cured film.

[0090] The urea group (–NH–CO–NH–) in the hydrogen bond modified component contains two N–H hydrogen bond donors and one C=O hydrogen bond acceptor, which can form urea group-urea group multiple hydrogen bonds (N–H···O=C) between the modified component molecules. At the same time, the N–H group of the urea group can also form hydrogen bond interactions with oxygen atoms in residual Si–OH and Si–O–Si in the organosilicon chain segment, thereby constructing a superimposed dynamic reversible hydrogen bond network in the organosilicon covalent crosslinking network.

[0091] Step 4: Setting up the electrode lead-out structure

[0092] Two sections of copper tape (approximately 5 mm wide and 15 mm long) are taken. After the second hydrogen bond-reinforced dynamic adaptation layer obtained in step three has cured, the conductive surface of the copper tape is flatly attached to the edge area of ​​the surface of the hydrogen bond-reinforced dynamic adaptation layer, with a spacing of approximately 10 mm between the two sections of copper tape, forming an electrode lead-out structure. The tail end of the electrode lead-out structure extends beyond the edge of the film for subsequent external connection with the pressure sensor module.

[0093] Step 5: Preparation of the third inorganic filler-reinforced modulus protective layer

[0094] Take 1.62g of the total material obtained in step one and coat it evenly on the surface of the hydrogen bond-enhanced dynamic adaptation layer cured film obtained in step three and the copper tape electrode lead-out structure set in step four. Use a coating doctor blade with a gap of 400μm to control the wet film thickness to about 300–450μm, so that the copper tape electrode lead-out structure is completely covered by the organosilicon composite slurry, leaving only the electrode lead-out terminals extending beyond the edge of the film exposed, to obtain the third wet film.

[0095] The sample coated with the third wet film was placed horizontally in a forced-air drying oven and cured at 110°C for 10 minutes. During the curing process, the silicone matrix also underwent a platinum-catalyzed hydrosilylation crosslinking reaction to form a dense covalent elastic network. Due to the uniform dispersion of barium titanate nanoparticles in this layer, the cured silicone elastomer film exhibits a higher elastic modulus (estimated to be about 15%–40% higher, depending on filler content and particle size), better dimensional stability, and stronger resistance to compressive deformation compared to pure silicone elastomers.

[0096] This layer, as an inorganic filler-enhanced modulus protective layer, is located on the innermost side of the three-layer structure (i.e., the side facing the pressure sensor module) and plays the following synergistic roles: (a) It provides mechanical fixation and protection for the embedded copper tape electrode lead-out structure, preventing displacement, warping, or detachment of the electrodes during repeated stress, and maintaining the stability of the electrical connection; (b) It provides a uniform mechanical transmission interface for the internal pressure sensing element, applying the pressure signal transmitted through the first two layers to the pressure sensor sensitive surface in a more uniform stress distribution state, reducing signal distortion caused by stress concentration; (c) As a physical protective layer, it prevents external sharp objects or excessive pressure from directly damaging the internal sensor components.

[0097] This completes the entire preparation process of the three-layer structured organosilicon composite functional material for smart applications. The cured organosilicon composite functional material is carefully peeled off from the glass slide substrate to obtain an independent, self-supporting organosilicon composite functional material.

[0098] The total thickness of the resulting three-layer organosilicon composite functional material is approximately 380–550 μm (of which the antifouling and antiwetting surface layer is approximately 60–100 μm, the hydrogen bond-reinforced dynamic adaptation layer is approximately 120–200 μm, and the inorganic filler-reinforced modulus protective layer is approximately 200–350 μm). It appears as a milky white, semi-transparent, flexible film that can be freely bent to a curvature radius ≤5 mm without visible cracks or permanent deformation, and has good flexible adhesion capabilities.

[0099] Step Six: Assembly and Wireless Monitoring Testing

[0100] The obtained three-layer silicone composite functional material was placed between a commercial thin-film pressure sensor module and the object being measured (the skin of the fingertip). During installation, the anti-fouling and anti-wetting surface layer (first layer) faced the finger skin, and the inorganic filler-enhanced modulus protective layer (third layer) faced the sensitive surface of the pressure sensor. The signal from the hydrogen bond-enhanced dynamic adaptation layer was led out through copper tape electrode leads and connected to the input terminal of the signal conditioning circuit board using soldering.

[0101] The signal conditioning circuit board converts the analog resistance signal output by the pressure sensor into a voltage signal. After sampling by the ADC, the signal is wirelessly transmitted to the host computer system in real time via the Bluetooth Low Energy (BLE 5.0) wireless communication module.

[0102] The host computer system is a self-developed data acquisition and display software (developed based on the Python + PyQt5 framework) running on a Windows 10 tablet, which implements the following functions:

[0103] (a) Real-time digital display of pressure value: The current pressure value is updated digitally in real time (update frequency ≥ 10Hz, display resolution 0.1g).

[0104] (b) Pressure curve time domain waveform visualization: The pressure change curve over time is displayed in real time as a scrolling time domain waveform graph, and user-defined settings for the X-axis time window and Y-axis range are supported;

[0105] (c) Pressure threshold setting and over-threshold alarm: Users can set the upper and lower pressure thresholds in the software interface. When the real-time pressure value exceeds the set threshold, the software will automatically trigger an audible and visual alarm (the screen flashes a red warning box and emits a buzzer sound).

[0106] (d) Baseline zero-point calibration and digital filtering: Supports one-click zero-point calibration (sets the sensor output value under the current no-load state to the zero baseline) and low-pass digital filtering (using Butterworth low-pass filter, the cutoff frequency can be adjusted by the user in the range of 0.5–50Hz) to suppress high-frequency electromagnetic interference noise and environmental vibration noise;

[0107] (e) Data export and file saving: Supports one-click export and saving of all collected time-stress data to local files in CSV or Excel (.xlsx) format, which is convenient for subsequent offline analysis and report generation.

[0108] Performance testing methods and conditions:

[0109] The pressure sensing performance of the three-layer organosilicon composite functional material prepared in Example 1 was tested. Test environment conditions: room temperature 25±2℃, relative humidity 50±10%. Test equipment: electronic universal testing machine (model: Instron 5944 or equivalent) with a custom-made flat-head cylindrical indenter (10mm diameter, stainless steel).

[0110] Test Method: The assembled silicone composite functional material-pressure sensor assembly was fixed to the base of the testing machine, and pressure was applied vertically from above using a flat-head indenter. A displacement control mode was used, and a loading-unloading cycle test was performed at a rate of 0.5 mm / min. The loading force range was 0–500 g (corresponding to 0–4.9 N), with each cycle consisting of two phases: loading (0→500 g) and unloading (500 g→0). 100 cycles were performed continuously, and the pressure sensor output signal was recorded synchronously during each cycle.

[0111] The performance evaluation metrics are defined as follows:

[0112] (a) Pressure Resolution: The smallest pressure change that can be reliably distinguished by the sensor system within a low pressure range of 5–50 g. The criterion is the smallest pressure increment in which the change in output signal is greater than 3 times the standard deviation of signal noise in 5 consecutive repeated measurements;

[0113] (b) Signal Noise Amplitude: The percentage of peak-to-peak fluctuation of the sensor output signal relative to the full-range output signal under constant pressure (250g) for 30 seconds;

[0114] (c) Repeatability Error: The ratio of the standard deviation to the mean of the output signal for each cycle under the same pressure loading value (250g) in 100 cycles, expressed as a percentage.

[0115] The test results are shown in Table 1.

[0116] Table 1. Test results of pressure sensing performance in Example 1

[0117]

[0118] The above results indicate that the dynamic reversible hydrogen bond network formed by the urea-containing hydrogen bond modified component in the hydrogen bond-enhanced dynamic adaptation layer can effectively buffer local stress concentration during pressure loading and maintain the continuity and integrity of the interface structure through the dynamic cycle of reversible hydrogen bond breakage and recombination, thereby achieving a high pressure resolution of ±5g, a low signal noise amplitude of ±3.2%, and good signal repeatability of 4.1%.

[0119] Example 2

[0120] The preparation method of Example 2 is basically the same as that of Example 1, except for the following three adjustments: (a) the amount of barium titanate added is increased from 0.1513g to 0.1800g (accounting for 4.5wt% of the mass of the organosilicon matrix) to further improve the coating rheology and increase the modulus of the composite material; (b) the amount of the first antifouling and antiwetting surface layer is increased from 0.70g to 0.80g, and the curing time is extended from 10min to 12min to obtain a denser antifouling surface layer; (c) the amount of hydrogen bond modification component added is increased from 0.0203g to 0.0230g (accounting for 2.5wt% of the mass of the organosilicon matrix, higher than 2.03wt% in Example 1) to moderately increase the dynamic hydrogen bond network density.

[0121] Step 1: Preparation of the total material of the organosilicon composite matrix

[0122] Weigh out 2.0 g of hydrogen-containing silicone oil (component A), 2.0 g of vinyl silicone oil (component B), and 0.1800 g of barium titanate (BaTiO3, nano-sized, particle size 100–500 nm). Mix the above raw materials under vacuum conditions (vacuum degree ≤ -0.08 MPa) using a planetary mixer for 5 min at an ambient temperature of approximately 25°C and a relative humidity of approximately 59% to obtain the total organic silicone composite matrix.

[0123] Step 2: Preparation of the first antifouling and antiwetting surface layer

[0124] Take 0.80g of the total material and apply it evenly to the surface of a clean glass slide using a doctor blade. Heat and cure at 110℃ for 12 minutes to form an antifouling and anti-wetting surface layer. The cured film thickness is approximately 80–120μm. Appropriately increasing the amount of material and extending the curing time helps to form a denser and more uniform antifouling film, further improving the anti-wetting effect.

[0125] Step 3: Preparation of the second hydrogen-bonded dynamic adaptation layer

[0126] Take 0.92g of the total material and add 0.0230g of a urea-containing hydrogen-bonding modifier (1,3-dimethylurea). The amount of modifier added is approximately 2.5wt% of the organosilicon matrix. Mix thoroughly under ambient temperature of approximately 25℃ and relative humidity of approximately 59% to obtain a urea-based hydrogen-bonding modified composite slurry. Coat the slurry onto the surface of the first cured film and heat-cur at 110℃ for 10 min to form a hydrogen-bonded enhanced dynamic adaptation layer. The cured film thickness is approximately 130–210 μm.

[0127] Compared to Example 1, this example increases the amount of hydrogen bond modifying component added from 2.03 wt% to 2.5 wt%. Appropriately increasing the content of the modifying component can increase the density of dynamic hydrogen bond interaction points in the organosilicon covalent network, making the hydrogen bond physical network more uniform and dense, thereby further improving the energy dissipation efficiency and structural recovery speed of the material during repeated stress processes. However, the amount of modifying component added should not be too high (generally not exceeding 25 wt%) to avoid phase separation of the modifying component in the organosilicon matrix or excessive dilution of the covalent crosslinking density of the matrix.

[0128] Step 4: Setting up the electrode lead-out structure

[0129] The setup method is the same as in Example 1. Two sections of copper tape (3mm wide, 20mm long, and approximately 60μm thick, including a conductive voltage-sensitive adhesive layer) are attached to the edge areas on both sides of the surface of the hydrogen bond-enhanced dynamic adaptation layer cured film to serve as electrode lead-out structures.

[0130] Step 5: Preparation of the third inorganic filler-reinforced modulus protective layer

[0131] Take 1.75g ​​of the total material and coat it onto the surface of the hydrogen-bonded enhanced dynamic adaptation layer cured film and the copper tape electrode lead-out structure, ensuring complete coverage of the electrode lead-out structure. Heat and cure at 110℃ for 12 minutes to form an inorganic filler-enhanced modulus protective layer. The cured film thickness is approximately 220–380μm. In this embodiment, the amount of material used for the third layer (1.75g ​​vs 1.62g) and the curing time (12min vs 10min) were appropriately increased to obtain a protective layer with higher modulus, further improving the mechanical protection of the internal sensing elements and electrodes.

[0132] This completes the preparation of the three-layer organosilicon composite functional material of Example 2. The total thickness is approximately 430–710 μm.

[0133] Step Six: Assembly and Wireless Monitoring Testing

[0134] The assembly and testing methods, conditions, and evaluation indicators were exactly the same as in Example 1. The test results are shown in Table 2.

[0135] Table 2. Pressure sensing performance test results of Example 2

[0136]

[0137] The test results of Example 2 show that, after appropriately increasing the content of the hydrogen bond modification component (from 2.03 wt% to 2.5 wt%) and increasing the amount of the first / third layer, the pressure resolution of the three-layer organosilicon composite functional material was further improved to ±4 g, the signal noise amplitude was reduced to ±2.8%, and the repeatability error was reduced to 3.5%. The reasons for the above performance improvement are: (a) the higher density dynamic hydrogen bond network provides more sufficient stress dissipation and faster structural recovery; (b) the thicker and denser antifouling surface layer enhances the interface anti-wetting effect; and (c) the higher modulus protective layer provides more stable mechanical support for the sensing element.

[0138] Comparative Example 1 (intermediate layer without hydrogen bond modification)

[0139] This comparative example is used to verify the key contribution of the hydrogen bond modification component to the performance of the intermediate layer. By directly comparing it with Example 1, it demonstrates the necessity of the dynamic reversible hydrogen bond network in improving the stability and repeatability of the pressure sensing signal.

[0140] The preparation method of this comparative example is basically the same as that of Example 1, except that in step (3), 1.0g of the total material is directly coated onto the surface of the first layer to form an intermediate layer, without adding any modified components containing functional groups that can form hydrogen bonds. Therefore, the intermediate layer is only an organosilicon elastomer composite material layer formed by the addition crosslinking and curing of hydrogen-containing silicone oil and vinyl silicone oil and the composite of barium titanate. Its molecular network is only composed of covalent crosslinks and does not form any dynamic reversible hydrogen bond physical network.

[0141] The remaining steps, including the preparation of the total material (containing 2.0 g of hydrogen silicone oil, 2.0 g of vinyl silicone oil, and 0.1513 g of barium titanate), the preparation of the first antifouling and antiwetting surface layer (total material 0.7 g, 110 °C / 10 min), the setting of the electrode lead-out structure (copper tape), and the preparation of the third inorganic filler-enhanced modulus protective layer (total material 1.62 g, 110 °C / 10 min), are exactly the same as in Example 1.

[0142] The assembly and testing methods, conditions, and evaluation indicators were exactly the same as in Example 1. The test results are shown in Table 3.

[0143] Table 3. Test results of pressure sensing performance in Comparative Example 1

[0144]

[0145] A point-by-point comparative analysis will be conducted between Comparative Example 1 and Example 1:

[0146] (a) The pressure resolution deteriorated from ±5g to ±30g, a decrease of approximately 6 times. This means that in the low pressure range, the pressure signal transmitted by the unmodified intermediate layer fluctuates too much, and the sensor system cannot reliably distinguish small pressure changes, resulting in a significant decrease in sensitivity.

[0147] (b) The signal noise amplitude increased from ±3.2% to ±11.2%, an increase of approximately 3.5 times. Under constant pressure, the unmodified intermediate layer, lacking the stress buffer and structural stabilization mechanism of the dynamic hydrogen bond network, experienced slow creep and relaxation of the interface microstructure under constant load, resulting in significant drift and random fluctuations in the output signal.

[0148] (c) Repeatability error increased from 4.1% to 14.6%, an increase of approximately 3.6 times. During 100 cycles of testing, the covalent cross-linked network of the unmodified intermediate layer gradually accumulated micro-damage, and the microcracks at local stress concentration sites continued to expand but could not repair themselves, resulting in a gradual decline in the mechanical properties of the material and a progressive change in the pressure transmission path. Ultimately, this manifested as a significant decrease in the consistency of the output signal between cycles.

[0149] The significant differences in the aforementioned performance indicators fully demonstrate that the introduction of hydrogen-bonded modified components and the dynamic reversible hydrogen bond network formed in the intermediate layer are key factors in achieving high-sensitivity, low-noise, and high-repeatability pressure signal output. In the absence of a dynamic hydrogen bond network, the intermediate layer can only rely on the covalent cross-linked network to withstand stress, and cannot achieve effective energy dissipation and structural self-recovery through reversible intermolecular interactions, resulting in a significant overall decline in pressure sensing performance.

[0150] Comparative Example 2 (without a third layer of inorganic filler to enhance modulus protection)

[0151] This comparative example is used to verify the irreplaceable role of the third inorganic filler-reinforced modulus protective layer in the three-layer synergistic structure. Through direct comparison with Example 1, it demonstrates the protective layer's contribution to the stability of the internal sensing elements, electrode lead-out structures, and mechanical transmission paths.

[0152] The preparation method of this comparative example is basically the same as that of Example 1, except that step (5) is omitted, that is, the third inorganic filler-reinforced modulus protective layer is not prepared. The final product is a two-layer organosilicon composite functional material containing only an antifouling and antiwetting surface layer and a hydrogen bond-reinforced dynamic adaptation layer.

[0153] The specific steps are as follows:

[0154] (a) Preparation of total material: 2.0 g of hydrogen-containing silicone oil, 2.0 g of vinyl silicone oil, and 0.1513 g of barium titanate were mixed under vacuum to obtain the total material. This was exactly the same as in Example 1.

[0155] (b) Preparation of the first antifouling and antiwetting surface layer: Take 0.7g of the total material, coat it on the substrate surface, and cure at 110°C for 10min. This is exactly the same as in Example 1.

[0156] (c) Preparation of hydrogen bond-enhanced dynamic adaptation layer: Take 0.9994g of total material, add 0.0203g of urea-containing modified component (the same type and amount as in Example 1), mix evenly, and coat it onto the surface of the first layer. Cure at 110℃ for 10min. Completely the same as in Example 1.

[0157] (d) Electrode lead-out structure setup: Two sections of copper tape are attached to the edge areas on both sides of the surface of the hydrogen bond-enhanced dynamic adaptation layer cured film. This is identical to Example 1.

[0158] (e) No third layer is applied or cured. Therefore, the hydrogen bond-enhanced dynamic adaptation layer and the copper tape electrode lead-out structure are directly exposed to the external environment without being covered or encapsulated by a protective layer.

[0159] The obtained two-layer organosilicon composite functional material was placed between the pressure sensor module and the object under test for testing. The test methods, conditions, and evaluation indicators were exactly the same as in Example 1. The test results are shown in Table 4.

[0160] Table 4. Test results of pressure sensing performance in Comparative Example 2

[0161]

[0162] Comparative analysis (Comparative Example 2 vs. Example 1):

[0163] (a) The pressure resolution deteriorated from ±5g to ±18.5g, a decrease of approximately 3.7 times. Although the intermediate layer contains hydrogen bond-modified components (the same as in Example 1), due to the lack of mechanical support from the third protective layer, the overall deformation of the hydrogen bond-enhanced dynamic adaptation layer is too large during pressure loading, and the pressure transmission path is significantly deviated, making it impossible to stably transmit the pressure signal to the sensitive surface of the pressure sensor.

[0164] (b) The signal noise amplitude was ±11.2%, which was the same as Comparative Example 1, but much higher than Example 1 (±3.2%). This indicates that in the absence of a protective layer, even if the intermediate layer has a dynamic hydrogen bond network, the exposed hydrogen bond-enhanced dynamic adaptation layer directly bears all the external mechanical stress and lacks rigid support. As a result, the material still undergoes significant creep under constant pressure, which leads to the inability to effectively suppress signal noise.

[0165] (c) The repeatability error was as high as 21.3%, which is not only much higher than that of Example 1 (4.1%), but also significantly higher than that of Comparative Example 1 (14.6%). The reason for this anomaly is that the copper tape electrode lead-out structure in Comparative Example 2 was not fixed and covered by a protective layer. During repeated pressure loading, the contact state between the copper tape and the hydrogen bond-enhanced dynamic adaptation layer changed continuously (local warping, slippage, or contact resistance fluctuations occurred), which severely damaged the stability of the electrical signal transmission path. In addition, the exposed intermediate layer had an excessively large overall deformation without rigid constraints, which exceeded the range that the dynamic hydrogen bond network could effectively buffer and recover from, resulting in an accelerated accumulation rate of irreversible structural damage.

[0166] The above results fully demonstrate the indispensable mechanical support and protection role of the third inorganic filler-reinforced modulus protective layer in the three-layer synergistic structure. Although the dynamic hydrogen bond network of the hydrogen bond-reinforced dynamic adaptation layer endows the material with stress dissipation and structural recovery capabilities, these capabilities can only be effectively realized under appropriate mechanical constraints and protection conditions. Without the protective layer, the intermediate layer and electrode lead-out structure are directly exposed to external stress, and excessive deformation exceeds the recovery limit of the hydrogen bond network, leading to overall performance degradation. The synergistic design of the three-layer structure achieves functional complementarity of "anti-fouling isolation—dynamic adaptation—mechanical protection," which is a necessary condition for achieving excellent comprehensive performance.

[0167] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An organosilicon composite functional material for intelligent applications, characterized in that, The organosilicon composite functional material comprises, from the outside to the inside, a non-fouling and non-wetting surface layer (Ⅰ), a hydrogen bond-enhanced dynamic adaptation layer (Ⅱ), and an inorganic filler-enhanced modulus protection layer (Ⅲ). The antifouling and antiwetting surface layer (Ⅰ) is composed of an organosilicon elastomer composite material formed by cross-linking and curing of hydrogen-containing silicone oil and vinyl silicone oil through platinum catalytic addition and compounding with inorganic fillers; The hydrogen bond-enhanced dynamic adaptation layer (II) is composed of an organosilicon elastomer matrix formed by cross-linking and curing hydrogen-containing silicone oil and vinyl silicone oil through platinum catalytic addition and composite inorganic fillers, and modified components containing functional groups that can form hydrogen bonds are introduced in a blending manner. The inorganic filler-reinforced modulus protective layer (Ⅲ) is composed of an organosilicon elastomer composite material formed by cross-linking and curing hydrogen-containing silicone oil and vinyl silicone oil through platinum catalytic addition and compounding with inorganic fillers. Its elastic modulus is higher than that of the hydrogen bond-reinforced dynamic adaptation layer. The surface of the hydrogen bond-enhanced dynamic adaptation layer (II) is provided with an electrode lead-out structure, which is covered between the hydrogen bond-enhanced dynamic adaptation layer (II) and the inorganic filler-enhanced modulus protection layer (III).

2. The organosilicon composite functional material for intelligent applications according to claim 1, characterized in that, The antifouling and antiwetting surface layer (Ⅰ), the hydrogen bond-enhanced dynamic adaptation layer (Ⅱ), and the inorganic filler-enhanced modulus protection layer (Ⅲ) are all made from the same total organic silicon composite matrix material. The total organic silicon composite matrix material is obtained by uniformly mixing and degassing hydrogen-containing silicone oil, vinyl silicone oil, and inorganic filler under vacuum conditions.

3. The organosilicon composite functional material for intelligent applications according to claim 1 or 2, characterized in that: The hydrogen-containing silicone oil is one or more of hydrogen-containing polysiloxanes with a hydrogen content of 0.01%–2.5% (mass fraction) and a viscosity of 20–1000 mPa·s; The vinyl silicone oil is one or more vinyl polysiloxanes with a vinyl content of 0.01%–2.5% (mass fraction) and a viscosity of 50–2000 mPa·s; The mass ratio of the hydrogen-containing silicone oil to the vinyl silicone oil is 0.6:1–1.7:

1.

4. The organosilicon composite functional material for intelligent applications according to claim 1, characterized in that, The inorganic filler is selected from one or more of barium titanate, fumed silica, precipitated silica, alumina, calcium carbonate and boron nitride; the amount of inorganic filler added to the total organic silicon composite matrix is ​​1.0 wt%–10.0 wt% of the mass of the organic silicon matrix.

5. The organosilicon composite functional material for intelligent applications according to claim 4, characterized in that, The inorganic filler is nano-sized barium titanate particles with a particle size of 100–500 nm.

6. The organosilicon composite functional material for intelligent applications according to claim 1, characterized in that, The modified component containing a functional group capable of forming hydrogen bonds is selected from one or more organic compounds containing urea, amide, urethane, hydroxyl, carboxyl, amidine, urethane, or multiple hydrogen bond units; the amount of the modified component added is 1.0 wt%–25.0 wt% of the organosilicon matrix.

7. The organosilicon composite functional material for intelligent applications according to claim 6, characterized in that, The modifying component is a urea-containing organic modifier; the urea-containing organic modifier is selected from one or more of the following: 1,3-dimethylurea, 4,4'-methylenebis(phenylurea), and polyurea siloxane oligomers generated by reacting 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane with isocyanate.

8. The organosilicon composite functional material for intelligent applications according to claim 1, characterized in that, The electrode lead-out structure is selected from one or more of copper foil, copper tape, silver paste wires, or flexible printed circuit conductive sheets.

9. The method for preparing the organosilicon composite functional material for intelligent applications according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1, Preparation of total organosilicon composite matrix: Mix 1.5–2.5 parts by weight of hydrogen-containing silicone oil with 1.5–2.5 parts by weight of vinyl silicone oil, add 0.05–0.30 parts by weight of inorganic filler, and add platinum catalyst and inhibitor. Stir and mix evenly under vacuum degree ≤ -0.08 MPa and degas to obtain total organosilicon composite matrix. Step 2, Preparation of antifouling and antiwetting surface layer (Ⅰ): Take 0.5–1.0 parts by weight of the total material obtained in Step 1, coat it evenly on the surface of a clean substrate or release substrate, and heat and cure it at 100–130 ℃ for 5–15 min to obtain the antifouling and antiwetting surface layer. Step 3, preparation of hydrogen bond-enhanced dynamic adaptation layer (II): Take 0.8–1.2 parts by weight of the total material obtained in Step 1, add 0.01–0.30 parts by weight of the modified component containing functional groups that can form hydrogen bonds, and mix evenly to obtain hydrogen bond-modified composite slurry; coat the hydrogen bond-modified composite slurry onto the surface of the cured film of the antifouling and antiwetting surface layer obtained in Step 2, and heat and cure at 100–130℃ for 5–15 min to obtain hydrogen bond-enhanced dynamic adaptation layer; Step 4, setting of electrode lead-out structure: During or after the curing process in Step 3, set the electrode lead-out structure at a preset position on the surface of the hydrogen bond-enhanced dynamic adaptation layer; Step 5, Preparation of Inorganic Filler Enhanced Modulus Protective Layer (Ⅲ): Take 1.2–2.0 parts by weight of the total material obtained in Step 1, and uniformly coat it on the cured film of the hydrogen bond enhanced dynamic adaptation layer obtained in Step 3 and the surface of the electrode lead-out structure set in Step 4. Heat and cure at 100–130 ℃ for 5–15 min to obtain the inorganic filler enhanced modulus protective layer, thus completing the preparation of the three-layer structure organosilicon composite functional material.

10. A wireless pressure monitoring system utilizing organosilicon composite functional materials for smart applications, characterized in that, include: The organosilicon composite functional material for smart applications as described in any one of claims 1–9; The pressure sensor module is electrically connected to the electrode lead-out structure of the organosilicon composite functional material, and is used to collect the pressure signal transmitted through the organosilicon composite functional material and convert it into an electrical signal. A wireless communication module, electrically connected to the pressure sensor module, is used to wirelessly transmit the electrical signal to a host computer system; and The host computer system is used to receive, process, and display the electrical signals; The organosilicon composite functional material is disposed between the pressure sensor module and the object being tested. The anti-fouling and anti-wetting surface layer (Ⅰ) is disposed on the side facing the object being tested, and the inorganic filler-reinforced modulus protective layer (Ⅲ) is disposed on the side facing the pressure sensor module.

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