Ultrafast response self-powered liquid-solid interface temperature detection device based on hydro-thermal effect and preparation method of ultrafast response self-powered liquid-solid interface temperature detection device

Abstract

The invention belongs to the technical field of temperature detection, and relates to an ultrafast response self-powered liquid-solid interface temperature detection device based on a hydro-thermal effect and a preparation method of the ultrafast response self-powered liquid-solid interface temperature detection device. The device comprises a flexible water photovoltaic device patch, a voltage amplifier, a voltage and current detection and measurement module and an operation display module, the flexible water photovoltaic device patch is composed of a flexible PEN substrate, an ITO conductive film formed by magnetron sputtering, a PTFE functional layer formed by spin coating and a Pt electrode deposited by magnetron sputtering. According to the device, kinetic energy and sensible heat of recycled water flow in the cooling process are converted into electric energy by utilizing the friction electrification effect of liquid drops and the surface of a solid and the influence of temperature on the electricity generation performance, and real-time detection of the interface temperature is achieved through the corresponding relation between voltage / current and the temperature. The device is compact in structure, flexible, attachable, high in detection precision, free of external power supply, suitable for surface temperature monitoring in a humid environment, a non-power environment or an environment where wiring is difficult, and wide in application prospect.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology and self-powered energy utilization, specifically an ultrafast response self-powered liquid-solid interface temperature detection device based on the water voltaic effect and its preparation method; it can be widely used in scenarios where temperature monitoring is required, such as medical care, environmental monitoring, wearable devices and smart terminals. Background Technology

[0002] Currently, temperature detection technology, as a core means of environmental sensing and condition monitoring, has been widely applied in various fields such as industrial equipment operation monitoring, medical rehabilitation and surgical safety management, environmental climate monitoring, smart home control, and wearable electronic products. Existing temperature sensors are mainly divided into two categories: contact sensors and non-contact sensors. Contact sensors (such as thermocouples, thermistors, and resistance temperature detectors) measure temperature through direct contact with the object being measured, and have the advantages of simple structure and high sensitivity. Non-contact sensors (such as infrared thermometers and infrared thermal imagers) calculate temperature by detecting the infrared radiation on the surface of an object, enabling rapid and long-distance measurement, and are suitable for dynamic targets or occasions where direct contact is inconvenient.

[0003] However, traditional temperature detection solutions generally rely on batteries or external power supplies, which not only increases wiring complexity and maintenance costs but also faces power supply challenges in humid, high-temperature, enclosed, or remote environments. On the one hand, contact sensors such as thermocouples are easily affected by moisture and corrosive substances in humid environments, leading to signal drift and shortened lifespan. Furthermore, complex wiring is required to transmit signals to external processing equipment for centralized analysis and data aggregation, which increases installation and maintenance difficulty and raises system costs. On the other hand, while infrared sensors have a fast response speed, they are susceptible to factors such as the emissivity of the measured surface, environmental interference, and dust obstruction, resulting in unstable measurement accuracy. They are also bulky, consume more power, and are more expensive, making it difficult to achieve low-cost, large-scale applications.

[0004] For example, Chinese patent CN115790907A discloses an automatic testing method for high-precision temperature sensor chips, but it has certain requirements for the uniformity and stability of the temperature field, and also suffers from a slow response speed. Another Chinese patent, CN113328273A, discloses a wireless temperature measurement clamp that uses an electromagnetic induction power generation module for power supply, but it is only applicable to high-voltage transmission and distribution cables and does not cover other temperature measurement scenarios, thus having a narrow scope of application. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide an ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect and its preparation method. This solves the problems of existing temperature sensors relying on external power sources, complex wiring, and inability to detect in real time in humid or power-free areas. It can generate electricity using water in the cooling device, that is, by converting the kinetic and thermal energy released during the flow of hot water containing residual heat in the recovery pipe. Furthermore, the temperature of the heat-recovered water is tested by measuring the effect of heat on the hydrothermal power generation, thereby controlling the water flow rate and achieving energy and water conservation. It is particularly suitable for scenarios requiring self-powered operation and environmental adaptability.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions; The present invention first provides an ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect, comprising: a flexible hydrothermal device patch, a voltage amplifier, a current and voltage detection and measurement module, and a calculation and display module; Flexible water-voltaic device patches are used to generate electrical signals through friction and temperature gradient at the interface between droplets and solids. The flexible water-voltaic device patches can output voltage and current signals that are modulated with temperature changes when droplets fall or flow. The input terminal of the voltage amplifier is electrically connected to the flexible water-volt device patch to receive and amplify the voltage signal output by the flexible water-volt device patch. The output terminal of the voltage amplifier is connected to the current and voltage detection and measurement module to transmit the signal to the current and voltage detection and measurement module. The current and voltage detection and measurement module is used to record the electrical signal amplified by the voltage amplifier and convert it into temperature-related parameters; the current and voltage detection and measurement module is connected to the calculation and display module for subsequent data processing. The computing and display module includes a low-power computing microcontroller and an LED display screen. The input terminal of the computing and display module is connected to the output terminal of the current and voltage detection and measurement module. The low-power computing microcontroller performs calculations on the received signal according to a preset voltage or current-temperature fitting curve to obtain the real-time temperature value, and displays the detection result on the LED display screen.

[0007] Preferably, the flexible water-voltaic device patch includes a flexible PEN substrate, an ITO film, a PTFE film, a Pt electrode, a patch positive terminal wire, and a patch negative terminal wire; Specifically, from bottom to top, the structure consists of a flexible PEN (polyethylene naphthalate) substrate, an ITO (indium tin oxide) film, a PTFE (polytetrafluoroethylene) film, and a Pt electrode; the positive terminal of the patch is connected to the Pt electrode, and the negative terminal of the patch is located at the junction of the ITO film and the PTFE film.

[0008] Preferably, the overall thickness of the flexible hydrophobic device patch is ≤500μm, the minimum bending radius is ≤5mm, and it has flexible application characteristics, which can stably adhere to the surface of skin, metal pipes, glass plates, and curved devices; suitable for applications such as medical wearables, industrial equipment thermal process monitoring, and environmental sensor arrays.

[0009] Preferably, the voltage amplifier is provided with a positive voltage input interface, a negative voltage input interface, an input ground interface, a positive voltage output interface, a negative voltage output interface, and an output ground interface at its ends; Specifically, the positive voltage input interface is connected to the positive terminal of the flexible hydrovoltaic device patch, and the negative voltage input interface is connected to the negative terminal of the patch, thereby amplifying the electrical signal.

[0010] Preferably, the voltage amplifier adopts a low-noise differential amplifier circuit with a gain range of 10 to 1000 times, an input bias current ≤1pA, and an input noise voltage density ≤5nV / Hz, which can effectively improve the detection sensitivity of weak electrical signals generated by the flexible water-voltaic device patch and ensure the calculation accuracy of the calculation and display module. Preferably, the current and voltage detection and measurement module is provided with a positive power supply interface, a negative power supply interface, and an output connection; the positive power supply interface is connected to the positive voltage output interface of the voltage amplifier, the negative power supply interface is connected to the negative voltage output interface of the voltage amplifier, and the output connection is connected to the low-power computing microcontroller of the computing and display module; the computing and display module does not require an external power supply. The low-power microcontroller calculates the temperature corresponding to the response voltage and current based on the given program and the voltage-current fitting curve with respect to temperature, and displays this temperature on the LED display screen.

[0011] Preferably, the flexible PEN substrate is a polyester polymer film material with a thickness of 25μm to 100μm, a tensile strength ≥150MPa (with strong physical and mechanical properties), an oxygen permeability ≤0.2cm³ / m²·24h·atm (excellent gas barrier performance), chemical stability (showing resistance to both acid and alkali solutions), a heat resistance temperature ≥180℃, and resistance to ultraviolet radiation and radiation, which can ensure that the device can maintain stable performance under harsh environments such as high temperature, strong light, and radiation. The ITO thin film is formed by magnetron sputtering, with a thickness of 50nm to 200nm, a surface sheet resistance of ≤20Ω, and a light transmittance of ≥85%. It has both good conductivity to ensure signal transmission efficiency and high transparency, which makes it easy to integrate with optical detection systems and match with flexible micro-energy systems. The PTFE film is formed by spin coating and has a thickness of 500 nm to 5 μm. Its surface roughness Ra ≤ 10 nm and contact angle ≥ 110° (excellent hydrophobicity). As a key interface layer for droplet tribothermal power generation, it can both inhibit water droplet adhesion and enhance the efficiency of triboelectric charge separation, thereby improving the accuracy and signal stability of temperature detection.

[0012] The Pt electrode is deposited using a magnetron sputtering process, with a thickness of 20nm to 100nm. The electrode coverage area is 30% to 70% of the total area of ​​the flexible water-voltaic device patch. Through an asymmetric distribution design, a temperature gradient region can be formed on the interface to enhance the sensitivity of the output signal to temperature changes.

[0013] Preferably, the flexible water-voltaic device patch, voltage amplifier, current and voltage detection and measurement module, and calculation and display module can be independently packaged or integrated through flexible printed circuit (FPC), supporting distributed deployment and modular expansion, and having good compatibility and scalability.

[0014] The current and voltage detection and measurement module uses a precision high-end current detection amplifier chip with integrated internal resistors. Its detection capability range is 0-3A, and the output terminal can provide a voltage signal proportional to the input current. It also has the characteristic of being directly powered by the detected signal without the need for an external power supply, which significantly reduces the system power consumption and size. The signal conversion delay of this module is ≤10μs, which can ensure a fast response.

[0015] The computational display module can output the liquid-solid interface temperature in real time based on a preset "voltage or current-temperature" response model, with a temperature measurement accuracy of ±0.5℃ and a detection response time of ≤0.5s. The self-powered liquid-solid interface temperature detection device provided by this invention is suitable for high-precision and rapid monitoring scenarios, meeting the needs of rapid temperature monitoring in dynamic environments. It is particularly suitable for applications requiring high response time, such as medical skin cooling and industrial thermal process monitoring. The preparation method of an ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect is as follows:

[0016] Step 1: Flexible substrate pretreatment Transparent, high-heat-resistant polyester material—PEN (polyethylene naphthalate) film—is selected as the flexible substrate material for the patch. First, the PEN film is cut to the required size, then ultrasonically cleaned sequentially with deionized water and anhydrous ethanol to remove surface dust, oil, and organic impurities. After cleaning, the PEN film is dried with nitrogen (to remove residual moisture and solvents), resulting in a clean and dry flexible PEN film, which serves as the flexible PEN substrate. Preferably, in step one, the PEN film is cut into square sheets of 20mm × 20mm, and the ultrasonic cleaning time is 10-15 minutes; the drying conditions are: drying at 60℃~80℃ for 10 minutes.

[0017] Step 2: Deposition of transparent conductive film The flexible PEN substrate obtained in step one is fixed on the sample stage of a magnetron sputtering instrument, and an ITO (indium tin oxide) thin film is deposited using a magnetron sputtering process. After deposition, it is placed in a tube furnace under nitrogen protection for annealing treatment (to improve the crystallinity and conductivity of the ITO film). Finally, an ITO thin film is uniformly covered on the surface of the flexible PEN substrate to form an ITO film / PEN substrate composite sheet. During sputtering, the working atmosphere is Ar, the working pressure is maintained at 0.5 Pa to 1.0 Pa, the target power is controlled at 100 W to 150 W, and the deposition time is 10 to 15 minutes, so that the film thickness is controlled at 150 nm to 200 nm; the annealing temperature is 250 °C to 300 °C, and the time is 30 to 40 minutes. Step 3: Fabrication of PTFE functional layer The ITO film / PEN substrate composite sheet obtained in step two is placed on a spin coater, and a concentrated polytetrafluoroethylene dispersion is uniformly coated onto the surface of the ITO film using a spin coating process. After spin coating, drying is performed (to remove residual solvent and cure into a film), thereby covering the surface of the ITO film with a uniform and dense PTFE film, which is the PTFE / ITO / PEN composite sheet. The PTFE layer is the key hydrophobic and triboelectric functional interface layer. The spin coating parameters are set as follows: spin speed 2000rpm~3000rpm, spin coating duration 30s, to control the PTFE film thickness within the range of 500nm~5μm; the solid content of the polytetrafluoroethylene concentrated dispersion is 60wt%; the drying is carried out in a constant temperature oven at 90~100℃ for 10~15 minutes.

[0018] Step 4: Pt electrode deposition The PTFE / ITO / PEN composite sheet obtained in step three is fixed on the sample stage of a magnetron sputtering instrument, and a noble metal Pt thin film is deposited as an electrode using a DC magnetron sputtering process. The deposition area of ​​the electrode is controlled by a masking process, covering 40% to 60% of the surface area of ​​the PTFE / ITO / PEN composite sheet, forming a local electric field difference and temperature gradient response region, and finally obtaining a Pt electrode / PTFE / ITO / PEN multilayer composite structure. In the DC magnetron sputtering process: the working gas is Ar, the working pressure is 0.3Pa~0.8Pa, the target power is 50W~100W, the deposition time is 5~10 minutes, and the thickness of the control electrode is 20nm~100nm; Step 5: Electrode Connection and Packaging The Pt electrode of the Pt electrode / PTFE / ITO / PEN multilayer composite structure obtained in step four is led out with wires at both ends as electrical signal output terminals. The connection between the wires and the electrode is silver spot welding or conductive adhesive bonding. After curing, the overall structure is flexibly encapsulated using encapsulation materials, including transparent silicone elastomer or polyurethane film, with an encapsulation thickness of 100μm to 300μm (to improve the mechanical strength, moisture resistance and corrosion resistance of the device). After encapsulation, a flexible water-based photovoltaic device patch is obtained. The curing condition is heating at 80℃ for 10 minutes (to enhance the bonding strength).

[0019] Step Six: Finally, connect and assemble the flexible water-voltaic device patch with the voltage amplifier, current and voltage detection and measurement module, and calculation and display module to obtain an ultrafast response self-powered liquid-solid interface temperature detection device based on the water-voltaic thermal effect; wherein, the flexible water-voltaic device patch is attached to the object to be measured with high-temperature tape, and the voltage amplifier, current and voltage detection and measurement module and calculation and display module are packaged separately, with the voltage amplifier and current and voltage detection and measurement module both packaged below the calculation and display module; The high-temperature tape includes PET high-temperature tape.

[0020] During operation: When droplets (such as cooling water or heat recovery liquid) fall or flow through the flexible water-based photovoltaic device patch of this invention, contact / sliding friction occurs between the PTFE film and the droplets, stimulating surface charge transfer (typically electron transfer). Simultaneously, due to the temperature gradient at the interface, the band structures of the liquid and solid are disturbed under thermal excitation, inducing electrons to migrate from the liquid to the solid electrode or redistribute along the solid interface, thereby forming a temperature-enhanced triboelectric effect. The flexible water-voltaic device patch is based on the water-driven triboelectric-thermal-excited coupled charge transfer effect. Its working principle is as follows: under the multi-physics field coupling of friction, electric field, and temperature difference, charge separation and migration occur between the droplet and the solid surface, thereby forming a measurable electrical signal. This signal has a linear or quasi-linear correspondence with the temperature change at the liquid-solid interface, allowing the establishment of a "voltage / current-temperature" mapping model to achieve highly sensitive temperature estimation under self-powered conditions. The conductive layer between the flexible PEN substrate and the Pt electrode forms a local electric field difference. Combined with the temperature gradient and the kinetic energy carried by the liquid movement, this further promotes the directional separation and accumulation of interfacial charges, ultimately forming a measurable voltage and current output between the positive and negative electrodes of the patch. The beneficial effects of this invention are:

[0021] This invention requires no external power source and is self-powered. It utilizes the thermal effect of a water droplet triboelectric generator to achieve energy harvesting and signal conversion, avoiding the dependence of traditional temperature sensors on batteries or external power sources, fundamentally solving the problem of limited power supply. This characteristic makes it particularly suitable for remote, humid, high-temperature, or enclosed environments where wiring and battery replacement are inconvenient, reducing maintenance frequency and costs, and improving system reliability and applicability.

[0022] This invention features a fast response time and strong real-time temperature detection capability. The device directly reflects temperature changes through the thermal excitation effect of charge migration at the liquid-solid interface. Voltage and current signals can respond quickly and calculate temperature in real time, significantly reducing detection delay. Compared to traditional thermocouples or infrared temperature measurement devices, this invention offers higher response speed and real-time performance, meeting the needs of rapid temperature monitoring in dynamic environments. It is suitable for applications requiring high response time, such as medical skin cooling and industrial thermal process monitoring.

[0023] This invention features a flexible structure that can be applied to various surfaces. The composite design, employing a flexible PEN-ITO substrate, a PTFE functional coating, and a magnetron sputtering electrode, gives the device excellent mechanical flexibility and conformability, allowing direct attachment to flat, curved, and even irregular surfaces to achieve stable temperature sensing. This feature not only enhances the device's adaptability to wearable devices, smart home devices, and medical devices but also expands its application prospects in temperature detection on the surfaces of complex structures. Attached Figure Description

[0024] Figure 1 The temperature measurement path of an ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect is shown. Figure 2 A schematic diagram of the structure of an ultrafast response self-powered liquid-solid interface temperature detection device based on the water-voltaic thermal effect is shown, including a combination structure of a flexible water-voltaic device patch, a voltage amplifier, a voltage and current detection and measurement module (13) and a calculation and display module; Figure 3 The structure and wiring method of the flexible water-based photovoltaic device patch are shown; Figure 4 The power generation performance of the flexible hydrovoltaic device at different temperatures is shown, where (a) voltage changes with temperature and (b) current changes with temperature. Reference numerals: 1-Flexible water-based photovoltaic device patch, 2-High-temperature tape, 3-Positive voltage input interface, 4-Negative voltage input interface, 5-Input grounding interface, 6-Positive voltage output interface, 7-Negative voltage output interface, 8-Output grounding interface, 9-Voltage amplifier, 10-Positive power supply interface, 11-Negative power supply interface, 12-Output wiring, 13-Current and voltage detection and measurement module, 14-Arithmetic display module, 15-Current detection amplifier chip, 16-Low-power microcontroller, 17-Flexible PEN substrate, 18-ITO film, 19-PTFE film, 20-Pt electrode, 21-Patch positive wiring, 22-Patch negative wiring, 23-LED display screen. Detailed Implementation

[0025] The present invention will be further described below with reference to specific accompanying drawings and embodiments. Example 1:

[0026] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the embodiments of this invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described are merely preferred examples of this invention and are not intended to limit the scope of protection of this invention.

[0027] like Figure 2-3 As shown, the present invention provides a self-powered liquid-solid interface temperature detection device based on the hydrothermal effect, comprising: a flexible hydrothermal device patch 1, a voltage amplifier 9, a voltage and current detection and measurement module 13, and a calculation and display module 14. The flexible water-based photovoltaic (VPS) patch 1 constitutes the core energy harvesting and signal generation unit of this device. The flexible VPS patch 1 includes a flexible PEN substrate 17, an ITO film 18, a PTFE film 19, a Pt electrode 20, a positive electrode connection 21, and a negative electrode connection 22; as shown... Figure 3 As shown, the patch is composed of multiple layers of functional materials arranged sequentially from bottom to top: a flexible PEN substrate 17, an ITO film 18, a PTFE film 19, and a Pt electrode 20. The positive terminal 21 of the patch connects to the Pt electrode 20, and the negative terminal 22 is located at the junction of the ITO film and the PTFE film 19. The flexible hydrovoltaic device patch 1 has an overall thickness ≤500μm and a minimum bending radius ≤5mm, enabling flexible application. It can stably adhere to various surfaces such as skin, metal pipes, glass plates, and curved devices, making it suitable for applications such as medical wearables, industrial equipment thermal process monitoring, and environmental sensor arrays, achieving non-invasive temperature monitoring and status sensing.

[0028] The flexible PEN substrate 17 is a polyester polymer film material, preferably with a thickness of 25μm to 100μm. It possesses strong physical and mechanical properties (tensile strength ≥150MPa), excellent gas barrier properties (oxygen permeability ≤0.2cm³ / m²·24h·atm), chemical stability (resistance to both acid and alkali solutions), and good heat resistance (heat resistance temperature ≥180℃), UV resistance, and radiation resistance, ensuring that the device maintains stable performance even under harsh environments such as high temperature, strong light, and radiation. In this embodiment, the thickness is specifically controlled at 100μm. The ITO thin film 18 is formed by magnetron sputtering, and its thickness is preferably 50nm to 200nm, with a surface sheet resistance ≤20Ω and a light transmittance ≥85%. It has both good conductivity to ensure signal transmission efficiency and high transparency, which is convenient for integration with optical detection systems and flexible micro-energy systems. In this embodiment, the thickness is specifically controlled to be 180nm. The PTFE film 19 is formed by spin coating, with a preferred thickness of 500 nm to 5 μm and a surface roughness Ra ≤ 10 nm, providing excellent hydrophobicity (contact angle ≥ 110°). As a key interface layer for droplet triboelectric-thermal synergistic power generation, it can both suppress water droplet adhesion and enhance triboelectric charge separation efficiency, thereby improving the accuracy and signal stability of temperature detection. In this embodiment, the thickness is specifically controlled to be 1 μm. The Pt electrode 20 is deposited using a magnetron sputtering process, with a preferred thickness of 20 nm to 100 nm. The electrode coverage area is 30% to 70% of the total area of ​​the flexible water-voltaic device patch 1. Through an asymmetric distribution design, a temperature gradient region can be formed on the interface to enhance the sensitivity of the output signal to temperature changes. In this embodiment, the thickness is specifically controlled to be 100 nm. The electrode coverage area is 50% of the total area of ​​the flexible water-voltaic device patch 1 and is located at the axis of symmetry of the flexible water-voltaic device patch 1. The voltage amplifier 9 is provided with a positive voltage input interface 3, a negative voltage input interface 4, an input ground interface 5, a positive voltage output interface 6, a negative voltage output interface 7, and an output ground interface 8 at its end; the positive voltage input interface 3 is connected to the positive terminal wiring 21 of the flexible water-voltaic device patch, and the negative voltage input interface 4 is connected to the negative terminal wiring 22 of the patch, thereby amplifying the electrical signal; Among them, the voltage amplifier 9 adopts a low-noise differential amplifier circuit with a gain range of 10 to 1000 times, an input bias current ≤1pA, and an input noise voltage density ≤5nV / Hz, which can effectively improve the detection sensitivity of the weak electrical signals generated by the flexible water-volt device patch 1 and ensure the calculation accuracy of the calculation and display module. The current and voltage detection and measurement module 13 is provided with a positive power interface 10, a negative power interface 11, and an output connection 12. The positive power interface 10 is connected to the positive voltage output interface 6 of the voltage amplifier 9, the negative power interface 11 is connected to the negative voltage output interface 7 of the voltage amplifier 9, and the output connection 12 is connected to the low-power computing microcontroller 16 of the computing and display module 14. The computing and display module 14 does not require an external power supply. The current and voltage detection and measurement module 13 adopts a precision high-end current detection amplifier chip 15, which integrates internal resistors and has a detection capability range of 0-3A. The output terminal can provide a voltage signal proportional to the input current and has the characteristic of being directly powered by the detected signal without an external power supply, which significantly reduces the system power consumption and size. The signal conversion delay of this module is ≤10μs, which can ensure fast response. The low-power computing microcontroller 16 calculates the temperature corresponding to the response voltage and current based on the given program and the fitting curve of voltage and current with respect to temperature, and displays this temperature on the LED display screen 23. The computing and display module 14 includes the low-power computing microcontroller 16 and the LED display screen 23, and can output the liquid-solid interface temperature in real time based on the preset "voltage or current-temperature" response model. The temperature measurement accuracy can reach ±0.5℃, and the detection response time is ≤0.5s, which is suitable for high-precision and fast monitoring scenarios. The preparation method of an ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect is as follows:

[0029] Step 1: Flexible substrate pretreatment Commercially available polyethylene naphthalate (PEN) film (100 μm thickness, ≥90% transparency, ≥200℃ heat resistance) was selected and cut into 20 mm × 20 mm square pieces. The cut PEN films were then ultrasonically cleaned for 5 minutes each in deionized water and anhydrous ethanol to remove surface impurities. After cleaning, the films were dried with high-purity nitrogen and immediately placed in a constant temperature drying oven at 70℃ for 10 minutes to remove residual moisture and solvents. This resulted in a clean, smooth, and uncontaminated flexible PEN film, which is the flexible PEN substrate 17.

[0030] Step 2: ITO thin film deposition The flexible PEN substrate 17 prepared in step one was fixed onto a magnetron sputtering target holder. The target material was In₂O₃:SnO₂ (90:10, 99.99% purity). A vacuum of 5 × 10⁻⁶ was applied to the vacuum chamber. -4Below Pa, high-purity argon gas (99.999%) was introduced as the sputtering gas, with the pressure controlled at 0.5 Pa. A DC magnetron sputtering process was used, with a sputtering power of 150 W and a deposition time of 10 min, resulting in an ITO film 18 with a thickness of approximately 180 nm. After deposition, the sample was placed in an annealing furnace and annealed at 280 °C for 30 min in air to improve the crystallinity and conductivity of the ITO film. After cooling to room temperature, the ITO film 18 was obtained and tightly adhered to the flexible PEN substrate 17. Finally, the ITO film was uniformly covered on the surface of the flexible PEN substrate 17, forming an ITO film / PEN substrate composite sheet. Step 3: Preparation of PTFE film 19 A commercially available concentrated polytetrafluoroethylene dispersion (60 wt% solids content) was used as the coating precursor. The PEN / ITO substrate obtained in step two was placed on a spin coater table and coated using a spin coating process. Spin coating parameters: 2000 rpm acceleration for 2 seconds, followed by 3000 rpm rotation for 30 seconds. Coating result: A uniform and continuous PTFE film 19 with a thickness of 1 μm was formed on the surface of the ITO film 18. After coating, the sample was placed in a constant temperature oven and heated at 100°C for 10 minutes to remove the solvent and promote PTFE film formation. After cooling to room temperature, a three-layer PEN / ITO / PTFE film structure was obtained.

[0031] Step 4: Pt electrode deposition The PEN / ITO / PTFE three-layer thin film obtained in step three was fixed in a magnetron sputtering system. The target material was high-purity Pt (platinum metal, 99.99%). A vacuum of 5 × 10⁻⁶ was applied. -4 Below Pa, high-purity argon gas was introduced, with a working pressure of 0.3 Pa. Sputtering conditions: RF power 100 W, sputtering time 3 min, resulting in a Pt electrode 20 with a thickness of approximately 80 nm. The mask position was controlled so that the Pt electrode 20 covered only 50% of the total patch area, forming a local electric field difference and temperature response region, ultimately obtaining a Pt electrode / PTFE / ITO / PEN multilayer composite structure.

[0032] Step 5: Electrode leads and wire connections The Pt electrode obtained in step four, consisting of a multilayer composite structure of Pt electrode / PTFE / ITO / PEN, is led out at both ends with wires as electrical signal output terminals. 0.2mm diameter tin-plated copper wires are used as external leads, and silver paste (room temperature resistivity ≤1×10⁻⁶) is applied to the edge of the Pt electrode 20. -4 The positive electrode connection 21 of the patch (Ω·cm) is bonded. The negative electrode connection 22 of the patch is bonded to the exposed edge of the ITO film 18 using the same method. The bonded sample is placed in an oven and cured at 80°C for 10 minutes to enhance the strength and conductivity of the electrode connection. At this point, the main structure of the flexible water-voltaic device patch 1 is complete.

[0033] Step Six: Flexible Packaging Process PDMS (Sylgard 184, prepolymer:curing agent = 10:1) was used as the flexible encapsulation material. Leads were left exposed, and a layer of PDMS was uniformly drop-coated onto the surface, with a thickness controlled at approximately 150 μm, covering the entire patch surface. Curing was performed at 80°C for 10 minutes to obtain the flexible encapsulation structure. This encapsulation layer possesses good flexibility and transparency, effectively preventing moisture and corrosion, ensuring long-term stable operation of the device. Thus, the complete flexible water-based photovoltaic device patch 1 was obtained.

[0034] Finally, the flexible water-voltaic device patch 1 is sequentially connected and assembled with the voltage amplifier 9, the current and voltage detection and measurement module 13, and the calculation and display module 14 according to their electrical connections. Specifically, the positive and negative terminals 22 of the flexible water-voltaic device patch 1 are connected to the positive voltage input interface 3 and the negative voltage input interface 4 of the voltage amplifier 9, respectively, to ensure that the initial electrical signal output can be effectively received and amplified. The positive voltage output interface 6 and the negative voltage output interface 7 of the voltage amplifier 9 are connected to the positive power supply interface 10 and the negative power supply interface 11 of the current and voltage detection and measurement module 13, respectively, to stably transmit the amplified signal to the current and voltage detection and measurement module 13. The output terminal 12 of the current and voltage detection and measurement module 13 is then connected to the input terminal of the calculation and display module 14 to achieve further processing of the electrical signal and conversion of the temperature signal.

[0035] After the above assembly is completed, a closed information and energy transfer link is formed between the modules: the flexible water-voltaic device patch 1 outputs a voltage / current signal that changes with temperature under the action of the droplet, which is amplified by the voltage amplifier 9, and then converted into quantifiable temperature parameters by the current and voltage detection and measurement module 13. Finally, the calculation and visualization output is performed by the calculation and display module 14. The entire system does not require an external power source and can operate by relying on the electrical signal generated by the friction-thermal coupling effect of the liquid-solid interface. It has the advantages of fast response speed, high detection sensitivity, flexible structure that can be applied, and adaptability to complex curved surface environments. In the end, an ultrafast response self-powered liquid-solid interface temperature detection device based on the water-voltaic thermal effect is obtained.

[0036] This device is the first to organically couple the triboelectric and thermoelectric effects. The kinetic energy generated by droplet motion and the temperature difference jointly drive charge separation, forming a high potential difference. This improves energy utilization and signal strength, enabling the system to generate a stable and measurable signal even under minute temperature differences. Furthermore, its compact structure, mature manufacturing process, and excellent flexibility and scalability make it suitable for temperature monitoring on fixed surfaces as well as for attaching to curved surfaces, making it applicable to various temperature control scenarios. The device generates its own power, eliminating the need for an external power supply system, making it particularly suitable for temperature detection tasks in humid, power-free, remote, or dynamic environments.

[0037] Figure 1 The temperature measurement path of an ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect is shown. During operation, when cooling water droplets or recycled hot water flow on the patch surface, the droplets come into frictional contact with the PTFE film 19 surface. Simultaneously, the interface temperature difference induces heat generation, triggering charge separation and transport, thus forming a stable tribothermal coupling power generation effect at the liquid-solid interface. Especially when the temperature rises, the droplet kinetic energy increases, the charge excitation capability improves, and the generated voltage and current signals correspondingly increase, forming the basis for the temperature sensing response.

[0038] Specifically, the micro-signal output from the flexible hydrovoltaic device patch 1 is input to the positive voltage input interface 3 through the patch positive terminal connection 21 and to the negative voltage input interface 4 through the patch negative terminal connection 22. Finally, a weak electrical signal is output to the voltage amplifier 9. The amplified signal from the voltage amplifier 9 is transmitted to the current and voltage detection and measurement module 13 via the positive voltage output interface 6 and the negative voltage output interface 7. This module uses a high-sensitivity current detection amplifier chip 15, enabling high-precision acquisition and storage of voltage and current. The output signal is transmitted to the back-end calculation and display module 14 via the output connection 12.

[0039] The computation and display module 14 houses a low-power microcontroller 16 control unit, which has a preset "voltage / current-temperature" response model based on experimental data fitting. In actual operation, the acquired electrical signals are input to the computation module, and after model matching and algorithm processing, the current interface temperature can be calculated in real time and displayed intuitively on the LED display screen 23. Figure 4 As shown, the voltage output at different temperatures ( Figure 4 a) and current output ( Figure 4 b) It shows a significant linear or fitting function upward trend, reflecting good temperature response sensitivity and signal stability.

[0040] The examples described are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention are within the protection scope of the present invention.

Claims

1. An ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect, characterized in that, The device comprises a flexible hydrovoltaic device patch (1), a voltage amplifier (9), a current and voltage detection and measurement module (13), and a calculation and display module (14). The flexible water-voltaic device patch (1) is used to generate electrical signals through friction and temperature gradient between the droplet and the solid interface; the flexible water-voltaic device patch (1) can output voltage and current signals that are modulated by temperature changes when the droplet falls or flows. The input terminal of the voltage amplifier (9) is electrically connected to the flexible water-volt device patch (1) to receive and amplify the voltage signal output by the flexible water-volt device patch (1). The output terminal of the voltage amplifier (9) is connected to the current and voltage detection and measurement module (13) to transmit the signal to the current and voltage detection and measurement module (13). The current and voltage detection and measurement module (13) is used to record the electrical signal amplified by the voltage amplifier (9) and convert it into temperature-related parameters; the current and voltage detection and measurement module (13) is connected to the calculation and display module (14) for subsequent data processing; The computation and display module (14) includes a low-power computation microcontroller (16) and an LED display screen (23). The input terminal of the computation and display module (14) is connected to the output terminal of the current and voltage detection and measurement module (13). The low-power computation microcontroller (16) performs calculations on the received signal according to the preset voltage or current-temperature fitting curve to obtain the real-time temperature value, and displays the detection result through the LED display screen (23).

2. The ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect according to claim 1, characterized in that, The flexible hydrovoltaic device patch (1) includes a flexible PEN substrate (17), an ITO film (18), a PTFE film (19), a Pt electrode (20), a patch positive terminal wire (21), and a patch negative terminal wire (22). From bottom to top, the structure consists of a flexible PEN substrate (17), an ITO film (18), a PTFE film (19), and a Pt electrode (20). The positive terminal wire (21) of the patch is connected to the Pt electrode (20), and the negative terminal wire (22) of the patch is located at the connection between the ITO film (18) and the PTFE film (19). The overall thickness of the flexible water-cooled device patch (1) is ≤500μm, the minimum bending radius is ≤5mm, and it has flexible application characteristics, which can stably adhere to the surface of skin, metal pipes, glass plates, and curved devices.

3. The ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect according to claim 1, characterized in that, The voltage amplifier (9) is provided with a positive voltage input interface (3), a negative voltage input interface (4), an input ground interface (5), a positive voltage output interface (6), a negative voltage output interface (7), and an output ground interface (8) at its end. The positive voltage input interface (3) is connected to the positive terminal wiring (21) of the flexible water-volt device patch, and the negative voltage input interface (4) is connected to the negative terminal wiring (22) of the patch to realize the amplification of the electrical signal; The voltage amplifier (9) adopts a low-noise differential amplifier circuit with a gain range of 10 to 1000 times, an input bias current ≤1pA, and an input noise voltage density ≤5nV / Hz.

4. The ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect according to claim 1, characterized in that, The current and voltage detection and measurement module (13) is provided with a positive power interface (10), a negative power interface (11), and an output wiring (12); the positive power interface (10) is connected to the positive voltage output interface (6) of the voltage amplifier (9), the negative power interface (11) is connected to the negative voltage output interface (7) of the voltage amplifier (9), and the output wiring (12) is connected to the low-power computing microcontroller (16) of the computing and display module (14); the computing and display module (14) does not require an external power supply; The low-power microcontroller (16) calculates the temperature corresponding to the response voltage and current according to the given program and the fitting curve of voltage and current with respect to temperature, and displays this temperature on the LED display screen (23).

5. The ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect according to claim 1, characterized in that, The flexible PEN substrate (17) is a polyester polymer film material with a thickness of 25μm to 100μm, tensile strength ≥150MPa, oxygen permeability ≤0.2cm³ / m²·24h·atm, heat resistance temperature ≥180℃, and resistance to acid and alkali solutions, as well as UV resistance and radiation resistance. The ITO thin film (18) is formed by magnetron sputtering, with a thickness of 50nm to 200nm, a surface sheet resistance of ≤20Ω, and a light transmittance of ≥85%. The PTFE film (19) is formed by spin coating, with a thickness of 500 nm to 5 μm, a surface roughness Ra ≤ 10 nm, and a contact angle ≥ 110°. The Pt electrode (20) is deposited by magnetron sputtering and has a thickness of 20nm to 100nm. The electrode coverage area is 30% to 70% of the total area of ​​the flexible water-voltaic device patch (1).

6. The ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect according to claim 1, characterized in that, The current and voltage detection and measurement module (13) adopts a precision high-end current detection amplifier chip with integrated internal resistors. Its detection capability range is 0 to 3A. The output terminal can provide a voltage signal proportional to the input current and has the characteristic that it can be directly powered by the detected signal without external power supply. The signal conversion delay of the current and voltage detection and measurement module (13) is ≤10μs.

7. The ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect according to claim 1, characterized in that, The computation and display module (14) can output the liquid-solid interface temperature in real time based on the preset "voltage or current-temperature" response model. The temperature measurement accuracy can reach ±0.5℃ and the detection response time is ≤0.5s.

8. The method for preparing the ultrafast response self-powered liquid-solid interface temperature detection device based on the hydrothermal effect according to any one of claims 1 to 7, characterized in that, The specific steps are as follows: Step 1: Flexible substrate pretreatment PEN film was selected as the flexible substrate material for the patch. First, the PEN film was cut to the required size, and then ultrasonically cleaned with deionized water and anhydrous ethanol in sequence to remove surface dust, oil and organic impurities. After cleaning, the PEN film was dried by nitrogen blowing and drying to obtain a clean and dry flexible PEN film, which is the flexible PEN substrate (17). Step 2: Deposition of transparent conductive film The flexible PEN substrate (17) obtained in step one is fixed on the sample stage of the magnetron sputtering instrument, and an ITO thin film is deposited using the magnetron sputtering process; After deposition, the material is placed in a tube furnace under nitrogen protection for annealing treatment. Finally, an ITO film is uniformly covered on the surface of the flexible PEN substrate (17) to form an ITO film / PEN substrate composite sheet. Step 3: Fabrication of PTFE functional layer The ITO film / PEN substrate composite sheet obtained in step two is placed on a spin coater, and polytetrafluoroethylene concentrated dispersion is uniformly coated on the surface of the ITO film using a spin coating process. After spin coating is completed, it is dried, so that a uniform and dense PTFE film is covered on the surface of the ITO film, which is the PTFE / ITO / PEN composite sheet. Step 4: Pt electrode deposition The PTFE / ITO / PEN composite sheet obtained in step three is fixed on the sample stage of a magnetron sputtering instrument, and a noble metal Pt thin film is deposited as an electrode using a DC magnetron sputtering process. The deposition area of ​​the electrode is controlled by a masking process, covering 40% to 60% of the surface area of ​​the PTFE / ITO / PEN composite sheet, forming a local electric field difference and temperature gradient response region, and finally obtaining a Pt electrode / PTFE / ITO / PEN multilayer composite structure. Step 5: Electrode Connection and Packaging The Pt electrode of the Pt electrode / PTFE / ITO / PEN multilayer composite structure obtained in step four is led out with wires as the electrical signal output terminals; the wires are connected to the electrode by silver spot welding or conductive adhesive bonding. After curing, the overall structure is flexibly encapsulated with encapsulation materials, including transparent silicone elastomer or polyurethane film, with an encapsulation thickness of 100μm to 300μm; after encapsulation, a flexible water-voltaic device patch (1) is obtained. Step 6: Finally, connect and assemble the flexible water-voltaic device patch (1) with the voltage amplifier (9), the current and voltage detection and measurement module (13) and the calculation and display module (14) to obtain an ultrafast response self-powered liquid-solid interface temperature detection device based on the water-voltaic thermal effect; wherein, the flexible water-voltaic device patch (1) is attached to the object to be measured by high temperature tape (2), the voltage amplifier (9), the current and voltage detection and measurement module (13) and the calculation and display module (14) are packaged separately, and the voltage amplifier (9) and the current and voltage detection and measurement module (13) are both packaged below the calculation and display module (14).

9. The preparation method according to claim 8, characterized in that, In step one, the PEN film is cut into square sheets of 20mm × 20mm, and the ultrasonic cleaning time is 10-15 minutes; the drying conditions are: drying at 60℃~80℃ for 10 minutes. Step 2: During the sputtering process, the working atmosphere is Ar, the working pressure is maintained at 0.5 Pa to 1.0 Pa, the target power is controlled at 100 W to 150 W, and the deposition time is 10 to 15 minutes, so that the film thickness is controlled at 150 nm to 200 nm; the annealing temperature is 250 °C to 300 °C, and the time is 30 to 40 minutes. In step three, the spin coating parameters are set to a rotation speed of 2000 rpm to 3000 rpm and a spin coating duration of 30 s, so as to control the PTFE film thickness within the range of 500 nm to 5 μm; the solid content of the polytetrafluoroethylene concentrated dispersion is 60 wt%; the drying is carried out in a constant temperature oven at 90 to 100 ℃ for 10 to 15 minutes. Step 4 in the DC magnetron sputtering process: the working gas is Ar, the working pressure is 0.3Pa~0.8Pa, the target power is 50W~100W, the deposition time is 5~10 minutes, and the thickness of the control electrode is 20nm~100nm.

10. The preparation method according to claim 8, characterized in that, The curing conditions in step five are heating at 80°C for 10 minutes; the high-temperature tape (2) mentioned in step six includes PET high-temperature tape.

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