A hierarchical temperature sensor based on non-covalent bond thermodynamic regulation and a preparation method and application thereof

Abstract

The application provides a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation and a preparation method and application thereof, and belongs to the technical field of temperature sensors. The hierarchical temperature sensor is obtained by clamping a composite material as a flexible sensitive layer between two layers of AgNWs / PDMS flexible electrodes and packaging; a hierarchical non-covalent bond network of hydrogen bonds, dynamic metal coordination bonds and pi-pi stacking is constructed in the composite material; the hydrogen bonds, the dynamic metal coordination bonds and the pi-pi stacking have different dissociation activation energies, so as to be sequentially dissociated in a temperature range of 25 DEG C to 80 DEG C, and have a stepwise response function of temperature signals. The sensitivity of the hierarchical temperature sensor is greater than or equal to 0.1 DEG C ‑1 , the response time and the recovery time are both less than or equal to 21s, the signal attenuation after 10000 seconds of thermal cycling is less than or equal to 10%, and the hierarchical temperature sensor has excellent sensitivity, rapid response capability and good thermal reversibility.

Description

Technical Field

[0001] This invention belongs to the field of temperature sensor technology, and in particular relates to a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation, its preparation method and application. Background Technology

[0002] Temperature sensors are among the most widely used and extensively applied sensor types, playing a crucial role in industrial production, healthcare, environmental monitoring, and consumer electronics. Traditional temperature sensors primarily include thermocouples, thermistors, and resistance temperature detectors (RTDs). Thermocouples operate based on the thermoelectric effect, offering advantages such as a wide temperature measurement range and no need for power supply, but their sensitivity is relatively low. Thermistors have high sensitivity but poor linearity and are mostly rigid structures, making them unsuitable for flexible wearable applications. RTDs offer good linearity and high accuracy, but have a slow response time and high cost.

[0003] With the rapid development of flexible electronics and wearable devices, new requirements have been placed on temperature sensors: high sensitivity to detect minute temperature changes, fast response to meet real-time monitoring needs, good flexibility to adapt to curved surfaces, and low power consumption to extend device battery life. However, existing temperature sensor technologies still have significant shortcomings in simultaneously meeting these requirements.

[0004] In recent years, capacitive temperature sensors based on ion-conducting materials have attracted widespread attention. These sensors utilize temperature changes to induce changes in ion mobility or dielectric constant, thereby altering the capacitance signal and achieving temperature sensing. However, the sensitivity of traditional ion-based temperature sensors is limited by the temperature dependence of ion thermal motion, resulting in a limited signal response per unit temperature change, making it difficult to achieve high-precision detection of minute temperature variations on the order of ±0.1℃. Simultaneously, their response speed is limited by ion kinetics, failing to meet the real-time monitoring requirements of rapid temperature changes. Therefore, there is an urgent need in this field for a novel temperature sensor that combines high sensitivity, fast response, and good flexibility. Summary of the Invention

[0005] In view of this, to address the technical bottleneck of existing temperature sensors that struggle to simultaneously achieve high sensitivity, rapid response, and flexible compatibility, this invention proposes a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation, along with its fabrication method and applications. This invention achieves temperature-induced stepwise dissociation of non-covalent bonds by constructing a hierarchical non-covalent bond network (hydrogen bonds-dynamic metal coordination bonds-π-π stacking) with different dissociation activation energies in a flexible composite material. This leads to the deconfinement and directional transport of ions, ultimately achieving efficient temperature-to-electrical signal conversion through double-layer capacitance reconstruction.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] The present invention provides a graded temperature sensor based on non-covalent thermodynamic regulation, wherein the graded temperature sensor is obtained by sandwiching a composite material as a flexible sensing layer between two AgNWs / PDMS flexible electrodes and then encapsulating it.

[0008] The composite material contains a hierarchical non-covalent bond network consisting of hydrogen bonds, dynamic metal coordination bonds, and π-π stacks. The hydrogen bonds, dynamic metal coordination bonds, and π-π stacks each have different dissociation activation energies, allowing them to dissociate sequentially within a temperature range of 25°C to 80°C, thereby achieving a stepwise response to the temperature signal.

[0009] In some preferred embodiments of the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation of the present invention, the composite material is composed of an ionic liquid mixture, a silica microstructure, a thermoplastic polyurethane elastic matrix, and a metal ion source organic solvent solution; the ionic liquid mixture is prepared by mixing [EMIM][TFSI] and [MMIM][TFSI]; the silica microstructure is formed by a sol-gel reaction of tetraethoxysilane, and its surface is modified with methyltrimethoxysilane to regulate the areal density and dissociation activation energy of the hydrogen bonds; the thermoplastic polyurethane serves as the elastic matrix, providing C=O groups as ligands for the dynamic metal coordination bonds; the metal ion source organic solvent solution is prepared by dissolving zinc acetate, zinc chloride, or zinc nitrate in an organic solvent;

[0010] In the hierarchical non-covalent network, the hydrogen bonds are formed by Si-OH on the surface of the silica microstructure and TFSI in the ionic liquid. - Hydrogen bonding between them forms; the dynamic metal coordination bond is formed by the metal ion Zn 2+ It is formed by coordination with the C=O groups of the thermoplastic polyurethane and the N atoms of the imidazole rings in the ionic liquid; the π-π stack is formed by face-to-face stacking between the imidazole rings in the ionic liquid.

[0011] In some preferred embodiments of the hierarchical temperature sensor based on non-covalent thermodynamic regulation of the present invention, the metal ion source organic solvent solution is prepared by dissolving zinc acetate in N,N-dimethylformamide.

[0012] Another aspect of the present invention provides a method for fabricating a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation, comprising the following steps:

[0013] S1. Tetraethoxysilane, deionized water, and methyltrimethoxysilane are mixed and stirred at 30-50°C. An ionic liquid mixture and an acid catalyst are added dropwise in sequence to obtain an ionic liquid-silica precursor gel. The volume ratio of tetraethoxysilane to deionized water is 1:0.3-0.8, the amount of methyltrimethoxysilane added is 0.5wt%-1.5wt% of the mass of tetraethoxysilane, and the volume ratio of acid catalyst to tetraethoxysilane is 0.5-2:10.

[0014] S2. Add thermoplastic polyurethane particles to an organic solvent at a mass ratio of TPU:organic solvent = 1:3~8, and stir at 70~90℃ until completely dissolved to obtain thermoplastic polyurethane gel; wherein, the mass ratio of TPU to tetraethoxysilane is 1:0.2~0.25, and the mass ratio of TPU to ionic liquid mixture is 4:1.

[0015] S3. The ionic liquid-silica precursor gel prepared in S1 is dropped into the thermoplastic polyurethane gel prepared in S2, and a metal ion source organic solvent solution is added. The mixture is stirred at 70~90℃ to obtain a composite gel. The metal ion source in the metal ion source organic solvent solution accounts for 3.0~3.3% of the TPU mass.

[0016] S4. The composite gel prepared in S3 is poured into a mold to obtain a film;

[0017] S5. The thin film prepared in S4 is sandwiched between two AgNWs / PDMS flexible electrodes as a flexible sensing layer, so that the effective areas of the electrodes are completely aligned. Light pressure is applied to make the flexible sensing layer and AgNWs / PDMS flexible electrodes fit tightly. Encapsulating adhesive is applied to the edges, cured and encapsulated. After that, a flexible lead is connected to the end of the electrode with conductive paste to obtain the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation.

[0018] In some preferred embodiments of the preparation method of the graded temperature sensor based on non-covalent bond thermodynamic regulation of the present invention, in step S1, the stirring speed after mixing tetraethoxysilane, deionized water and methyltrimethoxysilane is 300~800 rpm and the stirring time is 5~20 min; after adding the ionic liquid mixture, stirring is continued for 10~30 min; after adding the acid catalyst, the stirring speed is controlled at 400~800 rpm and the stirring time is 10~40 min.

[0019] In step S2, the stirring speed is 300~600 rpm and the stirring time is 2~5 h;

[0020] In step S3, the stirring speed is 400~800 rpm and the stirring time is 1~4 h;

[0021] In step S4, specifically, the composite gel prepared in step S3 is poured into a mold, vacuum degassed for 10-60 minutes, heated from 30-50°C to 70-90°C at a heating rate of 5-15°C / h, and cured at a constant temperature for 48-96 hours. After natural cooling, the film is demolded to obtain a thin film.

[0022] In S5, the curing conditions are curing at 60~100℃ for 20~60 minutes.

[0023] In some preferred embodiments of the preparation method of the graded temperature sensor based on non-covalent bond thermodynamic regulation of the present invention, in step S1, [MMIM][TFSI] and [EMIM][TFSI] are mixed uniformly in a molar ratio of 2:3 to obtain the ionic liquid mixture; the amount of methyltrimethoxysilane added is 1.0 wt% of tetraethoxysilane; the volume ratio of acid catalyst to tetraethoxysilane is 1:10, and the acid catalyst is HCl with a concentration of 0.04-0.06 mol / L.

[0024] In some preferred embodiments of the method for preparing a graded temperature sensor based on non-covalent bond thermodynamic regulation according to the present invention, in step S2, the organic solvent is N,N-dimethylformamide; in step S3, zinc acetate is dissolved in N,N-dimethylformamide to obtain the metal ion source organic solvent solution, wherein the concentration of zinc acetate is 0.6-1.0 mmol / L.

[0025] In some preferred embodiments of the method for preparing a graded temperature sensor based on non-covalent bond thermodynamic regulation according to the present invention, in step S5, the preparation step of the AgNWs / PDMS flexible electrode is as follows: Polydimethylsiloxane adhesive and crosslinking agent are mixed at a mass ratio of 10:0.5-1, stirred for 5 min, vacuumed to remove air bubbles, poured into a patterned mold, cured at 80℃ for 2 h, and demolded to obtain a patterned PDMS substrate; 0.3-0.5 wt% silver nanowire dispersion is diluted with isopropanol to 0.20-0.25 mg / mL, ultrasonically dispersed for 1-2 h, and spray-coated onto the PDMS substrate using a spray coating machine on a 100℃ heating stage, annealed at 120℃ for 1-2 h to obtain the AgNWs / PDMS flexible electrode; the encapsulating adhesive is prepared by mixing PDMS base adhesive, crosslinking agent, and anhydrous ethanol at a mass ratio of 10:0.5-1:5.

[0026] In some preferred embodiments of the method for preparing a graded temperature sensor based on non-covalent bond thermodynamic regulation according to the present invention, the nozzle diameter of the spray coating machine is 0.02-0.05 mm, the spray pressure is 100-200 mbar, and the distance between the nozzle and the PDMS substrate is 10-15 cm.

[0027] Another aspect of the present invention provides an application of a graded temperature sensor based on non-covalent bond thermodynamic regulation in wearable electronic devices, human body temperature monitoring, temperature management of flexible electronic devices, and artificial electronic skin.

[0028] Compared with existing technologies, the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation, its preparation method, and its application described in this invention have the following advantages:

[0029] (1) In this invention, methyltrimethoxysilane is introduced into the composite material to modify the surface of the silica microstructure. By precisely shielding some of the -OH groups on the SiO2 surface, the areal density of the hydrogen bond donor is reduced, and the dissociation activation energy of the hydrogen bond is precisely controlled to 10~15 kJ·mol. -1 This allows hydrogen bonds to dissociate in a coordinated manner in the low-temperature range of 25–40 °C; simultaneously, the introduction of Zn... 2+ It coordinates with the C=O group of the TPU hard segment and the N atom of the imidazole ring of the ionic liquid to form a bond with an energy of 18~25 kJ·mol⁻¹. -1 The dynamic metal coordination bonds enable dissociation of the coordination bonds in the intermediate temperature range of 40–60 °C. Furthermore, by introducing [MMIM][TFSI] to regulate the π-π stacking order between imidazole rings, the activation energy for dissociation of π-π stacking is increased to 25–30 kJ·mol⁻¹. -1 This causes it to dissociate in the high-temperature range of 60-80℃. The three types of non-covalent bonds undergo stepwise dissociation in the three temperature ranges, and the dissociation of one type of bond lowers the dissociation energy barrier of another type, creating a cascade amplification effect. This results in the ion unconfining amount induced by a unit temperature change being more than 5 times that of the pure material, releasing a large amount of [EMIM]. + ][TFSI - Ion pairs diffuse directionally from the surface of the silica microstructure into the TPU elastic matrix and accumulate at the electrode interface, inducing a synergistic change in the double-layer thickness and the interfacial dielectric constant. This achieves signal amplification and conversion from minute temperature changes to strong capacitive responses, thereby endowing the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation with extremely high sensitivity—an average sensitivity ≥80.89%℃ across the entire temperature range of 25–80℃. -1 Sensitivity ≥ 5.69%℃ in the low temperature range of 25~40℃ -1 It can achieve high-precision detection of minute temperature changes of ±0.1℃.

[0030] (2) This invention controls the dissociation and recombination characteristic times of the three types of non-covalent bonds to within 21 s by regulating the dissociation-recombination kinetics of the three types of non-covalent bonds; at the same time, Zn 2+ The coordination-decoordination reaction between TPU-C=O and the imidazole ring N exhibits a rapid kinetic exchange rate (the coordination bond exchange rate constant can reach 10). 3 ~104 s -1 When the temperature decreases, the thermal kinetic energy decreases, and the dissociated non-covalent bonds rapidly recombine through intermolecular interactions. The ions are re-confined to the surface of the silica microstructure, and the electric double layer quickly recovers to its initial state. This process does not require the relaxation process of long-range ion migration, thus shortening the kinetic path of response and recovery from the root. This gives the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation an extremely fast response speed—both response time and recovery time are ≤21s, meeting the real-time monitoring requirements of wearable devices for temperature changes.

[0031] (3) In the hierarchical non-covalent network of the present invention, all three types of bonds are weak interactions (bond energy 10~30kJ·mol). -1 After the temperature decreases, the molecules can spontaneously recombine through intermolecular interactions. The recombination process of hydrogen bonds, coordination bonds, and π-π stacking is highly reversible, avoiding the irreversible bond breakage problem common in covalent systems. At the same time, the TPU elastic matrix provides a flexible confinement environment for ion confinement, the silica microstructure acts as a confinement template to ensure the spatial consistency of ion repositioning, and the flexible interface of the AgNWs / PDMS electrode ensures the mechanical stability of the electrode-sensitive layer interface. The three together ensure the structural integrity and signal recoverability of the sensor during long-term thermal cycling, thus endowing the hierarchical temperature sensor based on non-covalent thermodynamic regulation with excellent thermal reversibility and cycling stability. After 10,000 s of thermal cycling at 25~80℃, the capacitance signal attenuation rate is ≤10%, and the change rate of response time and recovery time is ≤20%, meeting the reliability requirements for long-term use.

[0032] (4) This invention constructs a hierarchical network in composite materials where three types of non-covalent bonds coexist: hydrogen bonds, dynamic metal coordination bonds, and π-π stacking. The dissociation temperature range of the three types of bonds continuously covers 25~80℃. Through the step-dissociation design, it effectively avoids the signal nonlinear response problem caused by the broadening of bond energy distribution in a single non-covalent bond system. Only the corresponding type of bond dissociates in each temperature range. The concentration of dissociation products changes nearly linearly with temperature, and the cascade amplification effect has a uniform enhancement effect on each range. This endows the hierarchical temperature sensor based on non-covalent bond thermodynamic control with excellent temperature response linearity—the coefficient of determination R of the ΔC / C0-T curve. 2With a value ≥0.98, the temperature calibration process is simplified, and the measurement accuracy is improved. At the same time, the TPU elastic matrix gives the sensitive layer excellent flexibility, and the spray coating process of the AgNWs / PDMS electrode ensures a strong bond between the conductive layer and the flexible substrate. Moreover, the interface between the sensitive layer and the electrode is physically bonded, and no interface slippage or delamination occurs during bending. The overall structure of the sensor can maintain a stable output of the capacitance signal under repeated bending (bending radius ≤5mm), thus giving the graded temperature sensor based on non-covalent bond thermodynamic regulation good flexibility and wearability, making it suitable for applications such as skin adhesion and integration of flexible electronic devices. Attached Figure Description

[0033] Figure 1 A schematic diagram of the structure of the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1;

[0034] Figure 2 This is a schematic diagram of the microstructure of the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1;

[0035] Figure 3 middle, Figure 3 A shows the electron microscope image and EDS elemental distribution diagram of the TPU-SiO2 film prepared in Comparative Example 1. Figure 3 B shows the electron microscope image and EDS elemental distribution diagram of the TPU-SiO2-IL film prepared in Comparative Example 2; Figure 3 C represents the electron microscope image and EDS elemental distribution diagram of the TPU-SiO2-IL-Zn thin film prepared in Example 1; Figure 3 D is a schematic diagram of the flexibility of the TPU-SiO2-IL-Zn film prepared in Example 1;

[0036] Figure 4 middle, Figure 4 A is the sensitivity curve of the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1; Figure 4 B represents the step test of the graded temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1; Figure 4 C is a comparison of the sensitivity curves of the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1 and the sensors prepared in Comparative Examples 1 and 2. Figure 4 D represents the response time of the sensor prepared in Comparative Example 3; Figure 4 E represents the response time of the hierarchical temperature sensor based on non-covalent thermodynamic regulation prepared in Example 1; Figure 4 F represents the response time of the sensor prepared in Comparative Example 4; Figure 4 G represents a sensitivity comparison between the graded temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1 and the sensors prepared in Comparative Examples 3 and 4. Figure 4 H represents the stability test of the graded temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1;

[0037] Figure 5 middle, Figure 5 A is a physical image of a 4×4 dot matrix temperature sensor array; Figure 5 B is a static partition / global temperature imaging test, proving that the array can resolve the spatial distribution of temperature in a plane; Figure 5 C represents a time-series imaging of a glass rod sliding at 45°C, demonstrating that the array can track the motion trajectory of moving temperature stimuli in real time.

[0038] Figure Labels

[0039] 1-Upper encapsulation layer, 2-Upper electrode layer, 3-Flexible sensitive layer, 4-Lower electrode layer, 5-Lower encapsulation layer. Detailed Implementation

[0040] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0041] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0042] Example 1

[0043] Fabrication of a hierarchical temperature sensor based on non-covalent thermodynamic control

[0044] S1. Preparation of ionic liquid-silica precursor gel: Add 0.5 mL of tetraethyl orthosilicate (TEOS) and 0.25 mL of deionized water to a 25 mL three-necked flask, add methyltrimethoxysilane (MTMS, 1.0 wt% of TEOS mass), and stir at 40 °C and 500 rpm for 10 minutes to hydrolyze the MTMS. Add dropwise the ionic liquid mixture IL (IL to TPU mass ratio 1:4, i.e., IL accounts for 20% of the total mass of IL+TPU; wherein the molar ratio of [MMIM][TFSI] to [EMIM][TFSI] in IL is 2:3), and stir at 40 °C and 500 rpm for 15 minutes. Add dropwise 0.05 mL of 0.06 M HCl, and stir at 40 °C and 600 rpm for 20 minutes until the solution is clear, thus obtaining the IL-SiO2 precursor gel.

[0045] S2. Preparation of thermoplastic polyurethane gel: TPU particles (KA-480, hard segment content 35%, number average molecular weight 80000) were added to N,N-dimethylformamide (DMF) at a mass ratio of TPU:DMF=1:5. The mixture was stirred at 80℃ and 400rpm for 3 hours until completely dissolved to obtain TPU gel, wherein the mass ratio of TPU to tetraethoxysilane was 1:0.25.

[0046] S3. Preparation of composite gel: The IL-SiO2 precursor gel obtained in S1 was slowly added dropwise to the TPU gel obtained in S2, and stirred at 80℃ and 500rpm for 20 hours. Zinc acetate (Zn(CH3COO)2·2H2O) was dissolved in 1mL DMF (to make the Zn concentration in the system equal to the concentration in the DMF). 2+ Add the Zn concentrate (to a final concentration of 0.3 mmol / L) to the above mixture and continue stirring at 80°C and 600 rpm for 2 hours to allow the Zn to reach a final concentration of 0.3 mmol / L. 2+ A composite gel was prepared by fully coordinating the components.

[0047] S4. Preparation of TPU-SiO2-IL-Zn film: The composite gel obtained in S3 was cast into a PTFE mold, vacuum degassed for 30 minutes, heated from 40℃ to 80℃ at a heating rate of 10℃ / h, and cured at a constant temperature for 72 hours. After natural cooling and demolding, TPU-SiO2-IL-Zn film was obtained.

[0048] S5. Preparation of AgNWs / PDMS flexible electrode: (a) PDMS base adhesive and crosslinking agent were mixed at a ratio of 10:1 (mass ratio), stirred for 5 minutes, vacuumed for 30 minutes to remove bubbles, poured into a patterned mold (electrode pattern is 2cm×2cm square, spacing 0.1cm), cured at 80℃ for 2 hours, and demolded to obtain patterned PDMS substrate; (b) 0.5wt% AgNWs dispersion was diluted with isopropanol to 0.25mg / mL, and ultrasonically dispersed for 1 hour; the PDMS substrate was spray coated on a 100℃ heating stage using a spray coating machine (nozzle diameter 0.05mm, spray pressure 200mbar, nozzle-substrate distance 15cm), and annealed at 120℃ for 1 hour to obtain AgNWs / PDMS flexible electrode with a sheet resistance of about 100Ω / sq;

[0049] S6. Fabrication of a hierarchical temperature sensor based on non-covalent thermodynamic regulation: The TPU-SiO2-IL-Zn film prepared in S4 is cut into 2.2cm×2.2cm squares to obtain a flexible sensitive layer. The flexible sensitive layer is sandwiched between two AgNWs / PDMS flexible electrodes prepared in S5. The interface is pressed tightly to ensure close adhesion. Uncured PDMS dilute adhesive (base adhesive: crosslinking agent: anhydrous ethanol = 10:1:5, mass ratio) is applied to the edges. The electrode is cured at 80℃ for 30 minutes and then encapsulated. Copper flexible leads are connected to the electrode ends with conductive silver paste to obtain the hierarchical temperature sensor based on non-covalent thermodynamic regulation, denoted as Sensor-Optimal.

[0050] like Figure 1 As shown, the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation includes a flexible sensing layer 3 in the middle, an upper electrode layer 2 (AgNWs / PDMS flexible electrode) on top of the flexible sensing layer 3, a lower electrode layer 4 (AgNWs / PDMS flexible electrode) on the bottom of the flexible sensing layer 3, an upper encapsulation layer 1 (PDMS encapsulation layer) on top of the upper electrode layer 2, and a lower encapsulation layer 5 (PDMS encapsulation layer) on the bottom of the lower electrode layer 4.

[0051] like Figure 2 As shown in the schematic diagram, this microstructure includes TPU, SiO2, ([EMIM][TFSI](1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide), Zn 2+ It clearly demonstrates the TPU chains, SiO2 surface, IL ions, and Zn. 2+ A complex collaborative network exists between the centers. As temperature increases, the three types of bonds undergo a stepwise dissociation: the hydrogen bonds, with the lowest activation energy, break first in the low-temperature region, triggering partial ion release; subsequently, the Zn bonds with moderate activation energy... 2+ The coordination bonds dissociate in the intermediate temperature region, triggering a large release of ions; finally, the π–π stack with the highest activation energy further dissociates in the high temperature region, achieving complete decongestion of ions.

[0052] Comparative Example 1

[0053] S1. Preparation of SiO2 precursor gel: Add 0.5 mL of tetraethyl orthosilicate (TEOS) and 0.25 mL of deionized water to a 25 mL three-necked flask and stir at 40 °C and 500 rpm for 10 minutes. Then add 0.05 mL of 0.06 M hydrochloric acid (HCl) dropwise and stir at 40 °C and 600 rpm for 20 minutes until the solution is clear to obtain SiO2 precursor gel;

[0054] S2. Preparation of thermoplastic polyurethane gel: Same as step S2 in Example 1;

[0055] S3. Preparation of composite gel: The SiO2 precursor gel obtained in S1 is slowly dripped into the TPU gel obtained in S2, and stirred at 80℃ and 500rpm for 20 hours to obtain the composite gel.

[0056] S4. Preparation of TPU-SiO2 film: The composite gel was cast into a PTFE mold, vacuum degassed for 30 minutes, heated from 40℃ to 80℃ at a heating rate of 10℃ / h, and cured at a constant temperature for 72 hours. The film was then naturally cooled and demolded to obtain TPU-SiO2 film.

[0057] S5. Preparation of AgNWs / PDMS flexible electrode: Same as step S5 in Example 1;

[0058] S6. Preparation of the control sensor: The TPU-SiO2 film prepared in S4 was cut into 2.2cm × 2.2cm squares and sandwiched between two AgNWs / PDMS electrodes prepared in S5. Light pressure was applied to ensure tight adhesion of the interface. Uncured PDMS adhesive (base adhesive: crosslinking agent: anhydrous ethanol = 10:1:5, mass ratio) was applied to the edges, and the mixture was cured at 80℃ for 30 minutes and encapsulated. Copper flexible leads were connected to the electrode ends using conductive silver paste to obtain the control sensor, denoted as Sensor-TS.

[0059] Comparative Example 2

[0060] S1. Preparation of IL-SiO2 precursor gel: Add 0.5 mL of tetraethyl orthosilicate (TEOS) and 0.25 mL of deionized water to a 25 mL three-necked flask and stir at 40 °C and 500 rpm for 10 minutes. Add dropwise the ionic liquid mixture IL (the mass ratio of IL to TPU is 1:4, that is, IL accounts for 20% of the total mass of IL+TPU; wherein, the molar ratio of [MMIM][TFSI] to [EMIM][TFSI] in IL is 2:3). Stir at 40 °C and 500 rpm for 15 minutes, then add dropwise 0.05 mL of 0.06 M HCl and stir at 40 °C and 600 rpm for 20 minutes until the solution is clear to obtain IL-SiO2 precursor gel.

[0061] S2. Preparation of thermoplastic polyurethane gel: Same as step S2 in Example 1;

[0062] S3. Preparation of composite gel: The IL-SiO2 precursor gel obtained in S1 is slowly dripped into the TPU gel obtained in S2, and stirred at 80℃ and 500rpm for 20 hours to obtain the composite gel.

[0063] S4. Preparation of TPU-SiO2-IL film: The composite gel was cast into a PTFE mold, vacuum degassed for 30 minutes, heated from 40℃ to 80℃ at a heating rate of 10℃ / h, and cured at a constant temperature for 72 hours. The film was then naturally cooled and demolded to obtain the TPU-SiO2-IL film.

[0064] S5. Preparation of AgNWs / PDMS flexible electrode: Same as step S5 in Example 1;

[0065] S6. Preparation of the control sensor: The TPU-SiO2-IL film prepared in S4 was cut into 2.2cm × 2.2cm squares and sandwiched between two AgNWs / PDMS electrodes prepared in S5. Light pressure was applied to ensure tight adhesion of the interface. Uncured PDMS adhesive (base adhesive: crosslinking agent: anhydrous ethanol = 10:1:5, mass ratio) was applied to the edges, and the mixture was cured at 80℃ for 30 minutes and encapsulated. Copper flexible leads were connected to the electrode ends using conductive silver paste to obtain the control sensor, denoted as Sensor-TS-IL.

[0066] Comparative Example 3

[0067] S1. Preparation of IL-SiO2 (IL-10%) precursor gel: Add 0.5 mL of tetraethyl orthosilicate (TEOS) and 0.25 mL of deionized water to a 25 mL three-necked flask, add methyltrimethoxysilane (MTMS, 1.0 wt% of TEOS mass), and stir at 40 °C and 500 rpm for 10 minutes to hydrolyze MTMS. Add dropwise the ionic liquid mixture IL (i.e., IL accounts for 10% of the total mass of IL+TPU; wherein the molar ratio of [MMIM][TFSI] to [EMIM][TFSI] in IL is 2:3), and stir at 40 °C and 500 rpm for 15 minutes. Add dropwise 0.05 mL of 0.06 M HCl, and stir at 40 °C and 600 rpm for 20 minutes until the solution is clear, thus obtaining the IL-SiO2 (IL-10%) precursor gel.

[0068] S2. Preparation of thermoplastic polyurethane gel: Same as step S2 in Example 1, except that the amount of TPU used is 2.0 g;

[0069] S3. Preparation of composite gel: The IL-SiO2 (IL-10%) precursor gel obtained in S1 was slowly added dropwise to the TPU gel obtained in S2, and stirred at 80℃ and 500rpm for 20 hours. Zinc acetate (Zn(CH3COO)2·2H2O) was dissolved in 1mL DMF (to make the Zn concentration in the system...). 2+ Add the Zn concentrate (to a final concentration of 0.3 mmol / L) to the above mixture and continue stirring at 80°C and 600 rpm for 2 hours to allow the Zn to reach a final concentration of 0.3 mmol / L. 2+ A composite gel (IL-10%) was prepared by fully coordinating the components.

[0070] S4. Preparation of TPU-SiO2-IL-Zn film (IL-10%): The composite gel (IL-10%) obtained in S3 was cast into a PTFE mold, vacuum degassed for 30 minutes, heated from 40℃ to 80℃ at a heating rate of 10℃ / h, and cured at a constant temperature for 72 hours. After natural cooling, the TPU-SiO2-IL-Zn film (IL-10%) was obtained.

[0071] S5. Preparation of AgNWs / PDMS flexible electrode: Same as step S5 in Example 1;

[0072] S6. Preparation of control sensor: The TPU-SiO2-IL-Zn film (IL-10%) prepared in S4 was cut into 2.2cm×2.2cm squares and sandwiched between two AgNWs / PDMS flexible electrodes prepared in S5. The interface was pressed tightly to ensure close contact. The edges were coated with uncured PDMS dilute adhesive (base adhesive: crosslinking agent: anhydrous ethanol = 10:1:5, mass ratio), cured at 80℃ for 30 minutes and encapsulated. Copper flexible leads were connected to the electrode ends with conductive silver paste to obtain the temperature sensor, denoted as Sensor-IL-10%.

[0073] Comparative Example 4

[0074] S1. Preparation of IL-SiO2 (IL-30%) precursor gel: Add 0.5 mL of tetraethyl orthosilicate (TEOS) and 0.25 mL of deionized water to a 25 mL three-necked flask, add methyltrimethoxysilane (MTMS, 1.0 wt% of TEOS mass), and stir at 40 °C and 500 rpm for 10 minutes to hydrolyze MTMS. Add dropwise an ionic liquid mixture (i.e., IL accounts for 30% of the total mass of IL + TPU; wherein the molar ratio of [MMIM][TFSI] to [EMIM][TFSI] in IL is 2:3), and stir at 40 °C and 500 rpm for 15 minutes. Add dropwise 0.05 mL of 0.06 M HCl, and stir at 40 °C and 600 rpm for 20 minutes until the solution is clear, thus obtaining the IL-SiO2 (IL-10%) precursor gel.

[0075] S2. Preparation of thermoplastic polyurethane gel: Same as step S2 in Example 1, except that the amount of TPU used is 2.0 g;

[0076] S3. Preparation of composite gel: The IL-SiO2 (IL-30%) precursor gel obtained in S1 was slowly added dropwise to the TPU gel obtained in S2, and stirred at 80℃ and 500rpm for 20 hours. Zinc acetate (Zn(CH3COO)2·2H2O) was dissolved in 1mL DMF (to make the Zn concentration in the system...). 2+Add the Zn concentrate (to a final concentration of 0.3 mmol / L) to the above mixture and continue stirring at 80°C and 600 rpm for 2 hours to allow the Zn to reach a final concentration of 0.3 mmol / L. 2+ A composite gel (IL-30%) was prepared by fully coordinating the components.

[0077] S4. Preparation of TPU-SiO2-IL-Zn film (IL-30%): The composite gel (IL-30%) obtained in S3 was cast into a PTFE mold, vacuum degassed for 30 minutes, heated from 40℃ to 80℃ at a heating rate of 10℃ / h, and cured at a constant temperature for 72 hours. After natural cooling and demolding, TPU-SiO2-IL-Zn film (IL-30%) was obtained.

[0078] S5. Preparation of AgNWs / PDMS flexible electrode: Same as step S5 in Example 1;

[0079] S6. Preparation of control sensor: The TPU-SiO2-IL-Zn film (IL-30%) prepared in S4 was cut into 2.2cm×2.2cm squares and sandwiched between two AgNWs / PDMS flexible electrodes prepared in S5. The interface was pressed tightly by light pressure. The edges were coated with uncured PDMS dilute adhesive (base adhesive: crosslinking agent: anhydrous ethanol = 10:1:5, mass ratio), cured at 80℃ for 30 minutes and encapsulated. Copper flexible leads were connected to the electrode ends with conductive silver paste to obtain the temperature sensor, denoted as Sensor-IL-30%.

[0080] Test Example 1: Microstructure Characterization

[0081] Test methods: The TPU-SiO2-IL-Zn film prepared in Example 1, the TPU-SiO2 film prepared in Comparative Example 1, and the TPU-SiO2-IL film prepared in Comparative Example 2 were characterized by SEM and EDS. The results are as follows: Figure 3 As shown.

[0082] Figure 3 A (excluding ionic liquids and Zn) 2+ The image on the left shows a scanning electron microscope (SEM) image, revealing uniformly dispersed SiO2 microspheres (approximately 200–500 nm in diameter) within the TPU elastic matrix. The surface is smooth and shows no obvious aggregation. The image on the right shows an EDS elemental distribution map, clearly demonstrating the uniform distribution of Si and O elements within the TPU matrix, proving the successful embedding of the SiO2 microstructure into the TPU matrix. However, no ionic liquid-related elements (such as F and S) or Zn are present. 2+ The signal;

[0083] Figure 3 B (Introducing ionic liquid, Zn-free) 2+In the SEM image, a blurred coating layer appears on the surface of the SiO2 microspheres, indicating that ionic liquids ([EMIM][TFSI] and [MMIM][TFSI]) are adsorbed on the SiO2 surface and the TPU interface. In the EDS elemental distribution map, in addition to Si and O, the uniform distribution of F and S elements (derived from TFSI) is also observed. - (Anions), confirming that the ionic liquid was successfully introduced and dispersed in the composite material, but no Zn element signal was found;

[0084] Figure 3 C (Complete system, containing ionic liquid and Zn) 2+ In the image, SEM images show a denser coating on the SiO2 microspheres, and nanoscale bright spots are visible in the TPU matrix, corresponding to Zn. 2+ Coordination region. In the EDS elemental distribution map, in addition to Si, O, F, and S, the uniform distribution of Zn proves that Zn... 2+ Successful coordination with the C=O group and the N atom of the imidazole ring of TPU to form dynamic metal coordination bonds, without aggregation, indicates that the coordination network is uniformly constructed at the molecular scale;

[0085] Figure 3 The D-image shows actual photos of the TPU-SiO2-IL-Zn film under twisting, bending (bending radius ≤ 5 mm) and stretching conditions. The film maintains structural integrity without cracks or delamination, which intuitively proves that the sensitive layer has excellent flexibility and mechanical deformation resistance, and can be adapted to skin adhesion or flexible electronic device integration scenarios.

[0086] In conclusion, Figure 3 The hierarchical non-covalent network (hydrogen bonds, Zn) was systematically verified through SEM morphology, EDS elemental distribution, and flexibility demonstration. 2+ The successful construction of coordinate bonds (π-π stacking) in the TPU-SiO2-IL-Zn system and its microscopic uniformity also demonstrate that the material has good flexibility, providing a structural basis for the high sensitivity, fast response and wearable applications of sensors.

[0087] Test Example 2 Sensitivity Test

[0088] Test method: The sensitivity curves of the graded temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1 and the sensors prepared in Comparative Examples 1-4 were tested by heating them to different temperature points on a constant temperature heating stage. The results are shown in Table 1. Figure 4 A, Figure 4 C Figure 4 G.

[0089] Table 1

[0090]

[0091] From Table 1 and Figure 4 A, Figure 4 C Figure 4 As can be seen from G, the graded temperature sensor prepared in Example 1 has superior sensitivity performance compared with the sensors prepared in Comparative Examples 1-4, and the sensitivity is best when the amount of ionic liquid mixture added is 20%.

[0092] Through comparison, the optimal addition amount of ionic liquid IL was determined to be 20% of the total mass of IL + TPU; wherein, the molar ratio of [MMIM][TFSI] to [EMIM][TFSI] in IL was 2:3. On the other hand, the sensitivity of Example 1 (TPU-SiO2-IL-Zn) was significantly better than that of Comparative Example 1 (TPU-SiO2) and Comparative Example 2 (TPU-SiO2-IL). Figure 4 C) indicates that methyltrimethoxysilane was introduced into the sensitive layer composite material to modify the surface of the silica microstructure and to introduce Zn. 2+ By constructing dynamic metal coordination bonds and introducing [MMIM][TFSI] to regulate the π-π stacking order, a hierarchical non-covalent network of hydrogen bonds, dynamic metal coordination bonds, and π-π stacking was synergistically built. The three types of non-covalent bonds each have different dissociation activation energies—hydrogen bonds have energies of 10–15 kJ·mol⁻¹. -1 (25~40℃), dynamic metal coordination bond is 18~25kJ·mol -1 (40~60℃), π-π stacking has a value of 25~30kJ·mol. -1 (60~80℃), during the heating process, a stepwise dissociation occurs sequentially, and the dissociation of one type of bond lowers the dissociation energy barrier of another type of bond, forming a cascade amplification effect. This results in the amount of ions unconfined by a unit temperature change being more than 5 times that of Comparative Example 2 (containing only a single hydrogen bond network). When the temperature changes slightly, the non-covalent bonds in the corresponding range undergo cooperative dissociation, breaking the confinement state of ions on the surface of the silica microstructure and releasing a large amount of [EMIM] + ][TFSI -Ion pairs diffuse directionally from the silica surface into the TPU elastic matrix. The ion diffusion coefficient increases exponentially with increasing temperature. Even a small change in temperature can trigger a significant increase in ion transport, achieving mesoscopic amplification of the ion signal. The diffused ions rapidly accumulate at the interface between the sensitive layer and the AgNWs / PDMS electrode, causing a synergistic change in the double layer thickness and the interface dielectric constant. According to the Gouy-Chapman-Stern double layer theory, the EDL capacitance C_EDL=εε0A / d. Changes in ion concentration directly lead to significant changes in d and ε, ultimately manifesting as a significant change in the overall capacitance of the sensor. Comparative Example 1, lacking ionic liquids and non-covalent networks, derives its capacitance signal solely from the intrinsic dielectric response of TPU and SiO2, exhibiting almost no change with temperature (least sensitivity), demonstrating that the non-covalent network is the core source of the temperature response. Comparative Example 2, containing only a single hydrogen bond network, has a narrow hydrogen bond dissociation temperature range (mainly concentrated between 25 and 45°C), with ion release tending to saturate above 45°C, failing to achieve a linear response over a wide temperature range. Furthermore, it lacks a cascade amplification effect, has limited ion deconfinement, and exhibits small capacitance signal variation (moderate sensitivity). In contrast, Example 1, through continuous coverage of three types of non-covalent temperature ranges (25–80°C) and cascaded synergistic dissociation, achieves a complete signal conversion chain: small temperature change → stepwise non-covalent dissociation → ion deconfinement and directional transport → double-layer reconstruction → strong capacitance response. This endows the graded temperature sensor based on non-covalent thermodynamic regulation with extremely high sensitivity—an average sensitivity ≥80.89°C across the entire temperature range of 25–80°C. -1 Sensitivity ≥ 5.69℃ in the low temperature range of 25~40℃. -1 It can achieve high-precision detection of minute temperature changes of ±0.1℃.

[0093] Test Example 3: Response Time Test

[0094] Test Method: The response time of the graded temperature sensor based on non-covalent bond thermodynamic regulation prepared in Example 1 and the sensors prepared in Comparative Examples 3 and 4 were tested using the temperature step method. The temperature was stepped from 25℃ to 45℃ (low temperature region), held at that temperature for 30 s, and then stepped back from 45℃ to 25℃. The capacitance change curve was recorded synchronously by a high-speed data acquisition instrument. The results are shown in Table 2. Figure 4 D、 Figure 4 E, Figure 4 F.

[0095] Table 2

[0096]

[0097] From Table 2 and Figure 4 D、 Figure 4 E, Figure 4As shown in F, the sensor's response time is optimal when the ionic liquid content is 20%. This is due to a balance of two key factors: when the IL content is low (e.g., 10%), there are insufficient freely migrating ion carriers in the system, resulting in limited ionic conductivity of the sensitive layer and weak interfacial polarization, leading to a small electrical signal response amplitude and low sensitivity. Simultaneously, insufficient IL content leads to inadequate improvement in the compatibility of the TPU and SiO2 interface, resulting in micro-phase separation, which is not conducive to rapid diffusion of gas molecules and a longer response time. When the IL content is too high (e.g., 30%), excessive IL dilutes the mechanical network of the TPU matrix, reducing the structural density of the film. Furthermore, the TFSI in the IL... - The presence of a large amount of anions will interact with Zn. 2+ Competition for coordination weakens Zn 2+ The intended coordination crosslinking between the IL and TPU carbonyl oxygen leads to a decrease in the specific recognition ability of the sensitive layer for target molecules. Furthermore, the plasticizing effect caused by excessive IL makes the film too soft, deteriorating the interfacial contact stability between the AgNWs / PDMS electrode and the sensitive layer, which is detrimental to rapid signal transmission. Therefore, a 20% IL addition amount precisely balances ionic conductivity, interfacial compatibility, and Zn... 2+ Coordination effectiveness and structural stability enable the highest sensitivity and fastest response speed.

[0098] Test Example 4: Temperature Response Linearity Test

[0099] Test method: The graded temperature sensor based on non-covalent bond thermodynamic control prepared in Example 1 was tested using a temperature ramp method, with the temperature increased uniformly from 25℃ to 80℃ at a rate of 0.5℃ / min. Capacitive signals were continuously acquired to avoid signal fluctuations caused by temperature abrupt changes. Results are as follows: Figure 4 As shown in Figure B, the sensor's capacitive response increases proportionally with the applied temperature.

[0100] Test Example 5: Thermal Reversibility and Cyclic Stability Test

[0101] Test method: For the graded temperature sensor based on non-covalent bond thermodynamic control prepared in Example 1, a temperature cyclic step method was used. The temperature was cyclically stepped between 25 and 45°C for 10000 s (heating → holding at 80°C for 5 s → cooling → holding at 25°C for 5 s constitutes one cycle). The ΔC / C0, response time t1, and recovery time t2 of each cycle were recorded. The results are as follows: Figure 4 As shown in Figure H, after 10,000 cyclic steps between 25 and 45°C, the sensor's capacitance response curve did not show significant performance degradation, demonstrating the sensor's stability and reliability.

[0102] Test Example 6: Application Testing

[0103] Test method: The TPU-SiO2-IL-Zn film prepared in Example 1 was used to prepare a 4×4 dot matrix temperature sensing array to collect temperature sensing signals.

[0104] Depend on Figure 5 As can be seen from A: the photo shows a flexible temperature sensing array consisting of 16 independent sensing units (4 rows × 4 columns), which can realize multi-point parallel signal reading and provide a hardware foundation for spatial temperature distribution imaging.

[0105] Depend on Figure 5 B indicates that the left side is a pseudo-color temperature distribution map, showing the array's spatial resolution of temperatures in different regions at a given moment. The image shows that the left half of the array (e.g., columns 1-2) is red / yellow (high temperature region, approximately 45-50℃), while the right half (columns 3-4) is blue / green (low temperature region, approximately 25-30℃), with clear boundaries. This demonstrates that the array can accurately resolve planar temperature spatial distribution, achieving visualized imaging of static temperature fields. The right side may correspond to temperature values ​​or contour maps, further quantifying the temperature value of each pixel and verifying the array's quantitative detection capability of regional temperature differences.

[0106] Figure 5 C indicates that a set of pseudo-color thermal images arranged in chronological order (e.g., t1, t2, t3, t4) simulates the temperature response of a 45°C glass rod sliding from left to right across the array surface. In each frame, the high-temperature region (red highlight) moves synchronously with the glass rod, exhibiting a continuous and clear trajectory. This demonstrates that the array can track the motion trajectory of moving temperature stimuli in real time, and its temporal resolution is sufficient to capture dynamic thermal events. This test shows that the sensor array not only possesses static spatial resolution capabilities but also dynamic temperature monitoring and heat source tracking functions, making it suitable for scenarios such as heat source localization, thermal diffusion analysis, or human-computer interaction in wearable electronics.

[0107] The above description is only 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. A hierarchical temperature sensor based on non-covalent bond thermodynamic control, characterized in that: The graded temperature sensor is obtained by sandwiching a composite material as a flexible sensing layer between two AgNWs / PDMS flexible electrodes and then encapsulating it. The composite material contains a hierarchical non-covalent bond network consisting of hydrogen bonds, dynamic metal coordination bonds, and π-π stacks. The hydrogen bonds, dynamic metal coordination bonds, and π-π stacks each have different dissociation activation energies, allowing them to dissociate sequentially within a temperature range of 25°C to 80°C, thus exhibiting a step-like response to temperature signals.

2. The hierarchical temperature sensor based on non-covalent bond thermodynamic control according to claim 1, characterized in that: The composite material is composed of an ionic liquid mixture, a silica microstructure, a thermoplastic polyurethane elastic matrix, and a metal ion source organic solvent solution; the ionic liquid mixture is prepared by mixing [EMIM][TFSI] and [MMIM][TFSI]; the silica microstructure is formed by a sol-gel reaction of tetraethoxysilane, and its surface is modified with methyltrimethoxysilane; the metal ion source organic solvent solution is prepared by dissolving zinc acetate, zinc chloride, or zinc nitrate in an organic solvent; In the hierarchical non-covalent network, the hydrogen bonds are formed by Si-OH on the surface of the silica microstructure and TFSI in the ionic liquid. - Hydrogen bonding between them forms; the dynamic metal coordination bond is formed by the metal ion Zn 2+ It is formed by coordination with the C=O groups of the thermoplastic polyurethane and the N atoms of the imidazole rings in the ionic liquid; the π-π stack is formed by face-to-face stacking between the imidazole rings in the ionic liquid.

3. The hierarchical temperature sensor based on non-covalent bond thermodynamic control according to claim 2, characterized in that: The metal ion source organic solvent solution is prepared by dissolving zinc acetate in N,N-dimethylformamide.

4. A method for fabricating a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation, characterized in that, Includes the following steps: S1. Tetraethoxysilane, deionized water, and methyltrimethoxysilane are mixed and stirred at 30-50°C. An ionic liquid mixture and an acid catalyst are added dropwise in sequence to obtain an ionic liquid-silica precursor gel. The volume ratio of tetraethoxysilane to deionized water is 1:0.3-0.8, the amount of methyltrimethoxysilane added is 0.5wt%-1.5wt% of the mass of tetraethoxysilane, and the volume ratio of acid catalyst to tetraethoxysilane is 0.1-2:

10. S2. Add thermoplastic polyurethane particles to an organic solvent at a mass ratio of TPU:organic solvent = 1:3~8, and stir at 70~90℃ until completely dissolved to obtain thermoplastic polyurethane gel; wherein, the mass ratio of TPU to tetraethoxysilane is 1:0.2~0.25, and the mass ratio of TPU to ionic liquid mixture is 4:

1. S3. The ionic liquid-silica precursor gel prepared in S1 is dropped into the thermoplastic polyurethane gel prepared in S2, and a metal ion source organic solvent solution is added. The mixture is stirred at 70~90℃ to obtain a composite gel. The metal ion source in the metal ion source organic solvent solution accounts for 3.0~3.3% of the TPU mass. S4. The composite gel prepared in S3 is poured into a mold to obtain a film; S5. The thin film prepared in S4 is sandwiched between two AgNWs / PDMS flexible electrodes as a flexible sensing layer. Encapsulating adhesive is applied to the edges, cured, and encapsulated. Flexible leads are then connected to the electrode ends with conductive paste to obtain the hierarchical temperature sensor based on non-covalent bond thermodynamic regulation.

5. The method for fabricating a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation according to claim 4, characterized in that: In step S1, the stirring speed of the mixture of tetraethoxysilane, deionized water and methyltrimethoxysilane is 300-800 rpm and the stirring time is 5-20 min; after the ionic liquid mixture is added dropwise, stirring is continued for 10-30 min; after the acid catalyst is added dropwise, the stirring speed is controlled at 400-800 rpm and the stirring time is 10-40 min. In step S2, the stirring speed is 300~600 rpm and the stirring time is 2~5 h; In step S3, the stirring speed is 400~800 rpm and the stirring time is 1~4 h; In step S4, specifically, the composite gel prepared in step S3 is poured into a mold, vacuum degassed for 10-60 minutes, heated from 30-50°C to 70-90°C at a heating rate of 5-15°C / h, and cured at a constant temperature for 48-96 hours. After natural cooling, the film is demolded to obtain a thin film. In S5, the curing conditions are curing at 60~100℃ for 20~60 minutes.

6. The method for fabricating a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation according to claim 4, characterized in that: In step S1, [MMIM][TFSI] and [EMIM][TFSI] are mixed evenly in a molar ratio of 2:3 to obtain the ionic liquid mixture; the amount of methyltrimethoxysilane added is 1.0 wt% of tetraethoxysilane; the volume ratio of acid catalyst to tetraethoxysilane is 1:10, and the acid catalyst is HCl with a concentration of 0.04-0.06 mol / L.

7. The method for fabricating a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation according to claim 4, characterized in that: In step S2, the organic solvent is N,N-dimethylformamide; in step S3, zinc acetate is dissolved in N,N-dimethylformamide to obtain the metal ion source organic solvent solution, wherein the concentration of zinc acetate is 0.6–1.0 mmol / L.

8. The method for fabricating a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation according to claim 4, characterized in that, In S5, the preparation steps of AgNWs / PDMS flexible electrode are as follows: polydimethylsiloxane adhesive and crosslinking agent are mixed at a mass ratio of 10:0.5~1, stirred, vacuumed to remove air bubbles, poured into a patterned mold, cured at 80℃, and demolded to obtain a patterned PDMS substrate; A 0.3–0.5 wt% silver nanowire dispersion was diluted with isopropanol to 0.20–0.25 mg / mL, and ultrasonically dispersed for 1–2 h. The dispersion was then applied to a PDMS substrate using a spray coating machine on a 100°C heating stage, followed by annealing at 120°C for 1–2 h to obtain an AgNWs / PDMS flexible electrode. The encapsulating adhesive was prepared by mixing PDMS base adhesive, crosslinking agent, and anhydrous ethanol in a mass ratio of 10:0.5–1:

5.

9. The method for fabricating a hierarchical temperature sensor based on non-covalent bond thermodynamic regulation according to claim 8, characterized in that: The nozzle diameter of the spray coating machine is 0.02-0.05 mm, the spray pressure is 100-200 mbar, and the distance between the nozzle and the PDMS substrate is 10-15 cm.

10. The use of the hierarchical temperature sensor based on non-covalent bond thermodynamic control as described in any one of claims 1 to 3, characterized in that: Applications in wearable electronic devices, human body temperature monitoring, temperature management of flexible electronic devices, and artificial electronic skin.

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