A temperature-sensitive self-regulating method for heating surface wettability and a heating device thereof

Abstract

The application discloses a temperature-sensitive self-regulating method and device for heating surface wettability. The method comprises the following steps: integrating a temperature-sensitive functional material layer and arranging a patterned microelectrode array on a heating surface, and dividing the heating surface into multiple electrically independent sub-regions; collecting the wall surface temperature and / or liquid film coverage state of each sub-region in real time to form a thermal-wettability state spatial distribution map; identifying high-risk sub-regions based on multi-level threshold value judgment, and applying an electro-wetting excitation voltage to the high-risk sub-regions only; and dynamically adjusting the voltage parameters according to the type of cooling medium and heat load, and automatically stopping the excitation after the wettability state is restored. The device comprises a heat-conducting substrate, a temperature-sensitive functional material layer, a partitioned microelectrode array, a multi-channel programmable power supply, a sensor and a central control unit. The scheme realizes local precise regulation and control, improves the critical heat flux density, significantly reduces the power consumption, and is suitable for chip heat dissipation, nuclear energy and space heat control fields.

Description

Technical Field

[0001] This invention belongs to the field of boiling heat transfer and thermal management technology, and more specifically, it relates to a temperature-sensitive self-regulating method for the wettability of a heating surface and a heating device thereof. Background Technology

[0002] In methods for controlling the wettability of heated surfaces using the electrowetting effect, a voltage is typically applied to the heated surface to alter the solid-liquid interfacial tension, thereby reducing the contact angle and enhancing the liquid's spreading ability, which is used to suppress the formation of dry spots during boiling. However, existing technical solutions have the following significant drawbacks in practical applications:

[0003] First, the spatial control precision is insufficient. Existing methods mostly employ a single electrode or a global energization approach, applying the same electrical excitation signal to the entire heating area. This "one-size-fits-all" global excitation mode cannot provide differentiated control based on the local thermal state differences at different locations on the heating surface. When local hot spots appear on the heating surface, global energization not only fails to accurately solve the local problem but may also cause unnecessary interference to the surrounding areas in stable nucleus boiling, and even induce abnormal bubble merging.

[0004] Secondly, there is a lack of real-time sensing and multi-level feedback mechanisms. These methods typically rely on fixed voltage parameters or preset time series for open-loop control during operation, lacking real-time synchronous acquisition and feedback of wall temperature distribution or liquid film coverage. Even if localized areas show signs of dry spots such as abnormal temperature increases or thinning of the liquid film, the system still operates according to a globally uniform strategy, making targeted intervention difficult. While some existing attempts have introduced external sensors to obtain overall temperature information, they have failed to construct a spatially resolved "thermal-wetting state spatial distribution map," and have not defined effective multi-level decision-making logic to distinguish between "global average temperature warning" and "local high-risk area identification," resulting in lagging and coarse control decisions.

[0005] Secondly, it suffers from low energy efficiency and a lack of adaptive capability. Existing control strategies typically apply electrowetting voltage continuously, regardless of whether the local wetting state has returned to a safe level. This causes the system to maintain high power consumption during unnecessary periods, violating the principle of energy-saving operation. Furthermore, under complex operating conditions with dynamic changes in the properties of the cooling medium (such as dielectric constant and conductivity) or heat load, the amplitude, frequency, or duration of the excitation voltage often remain fixed, unable to adaptively adjust according to real-time operating conditions. This rigid parameter setting limits the optimal performance of the electrowetting effect under different fluid environments and heat loads, affecting the stability of the control effect and the overall energy efficiency level of the system. Summary of the Invention

[0006] The purpose of this invention is to provide a temperature-sensitive self-regulating method and heating device for the wettability of a heated surface. By integrating a temperature-sensitive functional material layer and a patterned microelectrode array, a closed-loop control system is constructed to achieve precise electrowetting excitation only for local high-risk areas, thereby effectively suppressing the spread of dry spots, increasing the critical heat flux density, and reducing system energy consumption.

[0007] A temperature-sensitive self-regulating method for the wettability of a heated surface includes the following steps:

[0008] S1: A temperature-sensitive functional material layer is integrated on the heating surface, and a patterned microelectrode array is formed on the surface of the temperature-sensitive functional material layer; the microelectrode array divides the heating surface into multiple electrically independent sub-regions, each sub-region is equipped with an independent temperature sensing unit and an electrical connection port, the temperature sensing unit is used to monitor the local temperature of the corresponding sub-region in real time, and the electrical connection port is used to receive independent electrical excitation signals;

[0009] S2: Real-time synchronous acquisition of wall temperature data and liquid film thickness data of each sub-region, and construction of a thermal-wetting state spatial distribution map of the heating surface based on the wall temperature data and liquid film thickness data; wherein, the liquid film thickness data is obtained by inverting the dielectric constant change by measuring the embedded capacitive sensor;

[0010] S3: Based on the aforementioned thermal-wetting state spatial distribution map, execute multi-level threshold determination logic:

[0011] (a) Calculate the overall average wall temperature of the heating surface, and trigger a global early warning signal when the overall average wall temperature reaches a first preset threshold.

[0012] (b) Traverse each sub-region and identify the target sub-region that meets the local high-risk condition, wherein the local high-risk condition is: the liquid film thickness is lower than a preset safety threshold;

[0013] S4: Apply an electrowetting excitation pulse voltage only to the target sub-region identified in step S3 (b) to change the solid-liquid contact angle of the temperature-sensitive functional material layer in the target sub-region, induce the surrounding liquid to flow back to the target sub-region for wetting, and inhibit the formation of gas film.

[0014] S5: Based on the type of cooling medium and the current heat load state, dynamically adjust the amplitude, frequency, or duration of the electrowetting excitation pulse voltage applied to the target sub-region, and perform closed-loop adjustment based on the real-time feedback thermal-wetting state spatial distribution map until the liquid film thickness of the target sub-region recovers to above the preset safety threshold, so as to maintain the system in the nucleate boiling state.

[0015] Furthermore, the temperature-sensitive functional material layer is composed of an inorganic-organic hybrid hydrogel, configured to undergo a reversible hydrophilic-hydrophobic transition within a preset phase transition temperature range, and its dielectric constant undergoes a nonlinear abrupt change with the phase transition process, which is used to respond to local temperature changes and characterize the thermal state of the sub-region.

[0016] Furthermore, in step S4, the parameters of the electrowetting excitation pulse voltage are automatically generated by the central control unit based on the dielectric constant, conductivity and current heat flux density of the cooling medium; when the liquid film thickness of the target sub-region recovers to above the preset safety threshold and the local wall temperature drops below the third preset threshold, the application of the electrowetting excitation pulse voltage to the target sub-region is automatically stopped.

[0017] Furthermore, the multi-level threshold determination logic in step S3 also includes a time filtering mechanism: only when the condition that the liquid film thickness is lower than the preset safety threshold continues for more than a preset time window is it confirmed as a valid high-risk sub-region and step S4 is triggered to filter out instantaneous noise interference.

[0018] A heating apparatus for carrying out the method, comprising:

[0019] Thermally conductive substrate;

[0020] A temperature-sensitive functional material layer disposed on the surface of the thermally conductive substrate is composed of an inorganic-organic hybrid hydrogel with low critical dissolution temperature characteristics, and is configured to undergo a reversible hydrophilic-hydrophobic transition within a preset phase transition temperature range.

[0021] A patterned microelectrode array disposed on the surface of the temperature-sensitive functional material layer divides the heating surface into multiple electrically independent sub-regions. Each electrode is electrically isolated from each other and is configured with an independent electrical connection port.

[0022] A multi-channel programmable power supply electrically connected to the microelectrode array is used to apply an electrowetting excitation pulse voltage to a selected sub-region;

[0023] The multimodal sensing unit integrated with each sub-region includes a temperature sensing unit and an embedded capacitive sensor. The temperature sensing unit is used to collect local wall temperature, and the embedded capacitive sensor is used to collect liquid film thickness data by measuring the change in dielectric constant.

[0024] The central control unit is communicatively connected to the multimodal sensing unit and the multi-channel programmable power supply, respectively. The central control unit is configured to: receive data from the multimodal sensing unit and construct a thermal-wetting state spatial distribution map; execute multi-level threshold determination logic to identify target sub-regions where the liquid film thickness is lower than a preset safety threshold; control the multi-channel programmable power supply to apply electrowetting excitation pulse voltage only to the target sub-regions, and dynamically adjust the voltage parameters according to feedback data.

[0025] Furthermore, the device is encapsulated within an electronic chip heat sink.

[0026] Furthermore, the central control unit is embedded with an adaptive control algorithm, which is configured to predict potential areas of reduced liquid film thickness based on historical heat load fluctuation patterns and apply a pre-excitation voltage in advance.

[0027] The central control unit is embedded with an adaptive control algorithm, which is configured to: calculate the rate of change d of the liquid film thickness in each sub-region in real time. h / d t and wall temperature rise rate d T / d t When a certain sub-region d is detected h / d t If N consecutive sampling periods (e.g., N=3, corresponding to 0.3 seconds) are below the negative threshold and d T / d t If the liquid film thickness exceeds the positive threshold, the area is identified as a potentially high-risk area; the system then proceeds to check if the liquid film thickness in this area has reached the preset safety threshold h. min Previously, a low-amplitude pre-excitation voltage (50%-70% of the normal intervention voltage) was applied in advance to suppress further expansion of dry spots.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) This invention divides the heating surface into multiple electrically independent sub-regions by setting a patterned microelectrode array on the surface of the temperature-sensitive functional material layer of the heating surface, and equips each sub-region with an independent temperature sensing unit and an embedded capacitive sensor. The system can synchronously collect wall temperature data and liquid film thickness data of each sub-region in real time to construct a high-resolution "thermal-wetting state spatial distribution map". Based on this map, this invention executes a multi-level threshold judgment logic: first, it monitors the overall average wall temperature to trigger a global early warning, and then identifies local high-risk sub-regions that meet the specific condition of "liquid film thickness is lower than a preset safety threshold". The system applies an electrowetting excitation pulse voltage only to these identified target sub-regions, using the electric field to change the solid-liquid contact angle and induce the surrounding liquid to flow back to the dried area. This shift from "global blind control" to "local fine control" effectively suppresses the early formation of the gas film and significantly improves the timeliness and accuracy of dry spot intervention.

[0030] (2) The electrowetting excitation pulse voltage in this invention only applies to the target sub-region currently identified as high-risk, while the remaining normal sub-regions remain in a zero-voltage state, greatly reducing the basic power consumption. More importantly, the system monitors the feedback data of the target sub-region in real time. Once it is determined that the liquid film thickness has recovered to above the preset safety threshold and the local wall temperature has dropped to a safe range, the central control unit automatically stops the voltage output to that region, avoiding redundant energy consumption after the wetting state has been restored. This solves the problem of maintaining high power consumption in non-necessary periods in the prior art and significantly optimizes the overall energy efficiency ratio of the system.

[0031] (3) This invention achieves deep adaptive adjustment of electrowetting excitation parameters through a central control unit. The system can dynamically match and adjust the amplitude, frequency, and duration of the pulse voltage applied to the target sub-region according to the specific physical properties of the cooling medium and the current real-time heat load. This dynamic adjustment strategy ensures that the electrowetting effect is always maintained within the optimal range under conditions of drastic fluctuations in different working fluids or heat flux densities, effectively maintaining the system in a highly efficient nucleate boiling state, preventing control failures caused by parameter mismatch, and further improving the critical heat flux density (CHF), thus enhancing the applicability and reliability of the device in complex thermal management scenarios such as electronic chip heat dissipation and nuclear reactor cooling.

[0032] (4) The adaptive control strategy adopted in this invention not only includes feedback regulation, but also introduces a feedforward prediction mechanism based on real-time change rate. By monitoring the rate of change of liquid film thickness and wall temperature, the system can intervene in advance at the budding stage before dry spots are fully formed, and apply a pre-excitation voltage. This 'prevention-oriented' control method further shortens the response time, minimizes the hysteresis of dry spot suppression, and significantly improves the robustness of the system under conditions of drastic heat load fluctuations. Attached Figure Description

[0033] Figure 1 This is a schematic cross-sectional view of the heating device of the present invention; Figure 2 This is a schematic diagram of the planar layout of the microelectrode array on the heating surface; Figure 3 This is a flowchart of the temperature-sensitive self-regulating method of the present invention;

[0034] The reference numerals in the attached drawings are as follows: 1. Thermally conductive substrate; 2. Temperature-sensitive functional material layer; 3. Patterned microelectrode array; 4. Multi-channel programmable power supply; 5. Multimodal sensing unit; 6. Central control unit. Detailed Implementation

[0035] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0036] Example 1:

[0037] like Figures 1-2 As shown, a heating device for implementing a temperature-sensitive self-regulating method for the wettability of a heated surface is mainly composed of four parts working together: a physical stacked structure, a multimodal sensing system, a drive execution system, and a central control system.

[0038] In this design, the substrate of the device is a thermally conductive substrate 1, preferably made of oxygen-free copper or aluminum alloy, to ensure efficient heat transfer to the working fluid. A temperature-sensitive functional material layer 2 is precisely deposited on the upper surface of the thermally conductive substrate 1 using a spin-coating process.

[0039] The second layer of the temperature-sensitive functional material is an inorganic-organic hybrid hydrogel. Specifically, it uses poly(N-isopropylacrylamide) (PNIPAM) as the organic framework, doped with silica (SiO2) nanoparticles or graphene oxide (GO) as the inorganic reinforcing phase, and is fixed by constructing a double cross-linked network through chemical cross-linking and physical hydrogen bonding. This unique hybrid structure raises the thermal decomposition temperature of the material to above 150°C, enabling it to operate stably for a long time under intense boiling conditions. The material has a well-defined low critical solution temperature (LCST, set at 35°C-40°C). When the local temperature exceeds the LCST, the material undergoes an initial hydrophobic-philic transition (contact angle increases from <60° to approximately 90°). At this point, the material is in a metastable hydrophobic region, which is conducive to the nucleation and detachment of boiling bubbles, enhancing nucleation boiling heat transfer. When the local temperature continues to rise to a high-risk range (e.g., >90°C), the hydrophobicity of the material further increases (contact angle >110°) and the dielectric constant undergoes a nonlinear abrupt change. At this point, without external intervention, a stable gas film (dry spot) is easily formed. Therefore, the control logic of this system is set to utilize the material's natural hydrophobicity above the LCST to promote conventional boiling, and only when the liquid film thickness is detected to be below the safety threshold (usually corresponding to a local overheating state with a wall temperature >100°C) is electrowetting excitation triggered to forcibly pull the contact angle back to the hydrophilic state (<60°) to induce reflux. This dual mechanism of 'passive material response + active electric field control' utilizes material properties to optimize conventional heat transfer while avoiding energy waste caused by premature intervention.

[0040] A patterned microelectrode array 3 is disposed on the surface of the temperature-sensitive functional material layer 2. This electrode array is fabricated using photolithography, logically dividing the entire heating surface into M×N electrically independent sub-regions (e.g., a 10×10 matrix). The electrodes in each sub-region are strictly electrically isolated from each other and have independent electrical connection ports led to the edge of the device for individual addressing. To prevent electrolytic reactions when high voltage is applied and to ensure the effectiveness of the electrowetting effect, the electrode surface is also covered with a high-dielectric-constant insulating layer with a thickness of approximately 200 nm.

[0041] To accurately sense the complex states under boiling conditions, this device integrates multimodal sensing units that correspond one-to-one or partition-to-partition with the aforementioned sub-regions. These multimodal sensing units include a temperature sensing unit and a liquid film state sensor.

[0042] The temperature sensing unit uses a thin-film platinum resistance thermometer, which is directly integrated on the back of the thermally conductive substrate to collect the wall temperature data T of each sub-region in real time. wall .

[0043] The liquid film state sensor incorporates two complementary detection mechanisms: firstly, an embedded interdigital capacitor electrode, utilizing some electrodes in the microelectrode array 3 as both transmitter and receiver to form an interdigital capacitor structure. This module is configured to transmit multi-frequency AC excitation signals from 1kHz to 1MHz. Due to the significant difference in dielectric constants between bubbles and liquids, the central control unit 6 can fit an equivalent circuit through impedance spectroscopy analysis, utilizing the substantial difference in dielectric constants between bubbles and liquids (ε...). gas ≈1,ε water (≈80), combined with the preset multi-frequency dielectric response model, directly strips away the capacitive interference caused by bubbles, thereby independently reproducing the true equivalent thickness h of the liquid film. film .

[0044] Furthermore, as a preferred embodiment, the device can also integrate an optical reflection detection module. A miniature LED light source and photodiode are integrated into the sidewall or top of the heating cavity. The light beam illuminates the surface of a sub-region at a specific angle, utilizing the characteristics of low reflectivity when covered by liquid and high reflectivity when covered by dry spots or bubbles, to output a reflectivity signal, Ropt. During system initialization and calibration or under extremely complex operating conditions, the optical signal can serve as an auxiliary correction reference for capacitance data, used to update the parameters of the dielectric response model online. However, in normal operating mode, the system mainly relies on the embedded capacitance sensor to achieve real-time measurement of the liquid film thickness.

[0045] In terms of drive and control systems, the device is equipped with a multi-channel programmable power supply 5 and a central control unit 6. The multi-channel programmable power supply 5 is connected to the electrical connection ports of each sub-region, has multi-waveform output capability, and can independently control the output voltage waveform, frequency, and amplitude of each channel. The central control unit 6 adopts a high-performance FPGA or embedded GPU processor, with a built-in thermal-wetting coupling calculation engine. It receives data from all sensors through a high-speed bus and executes the core control algorithm to achieve closed-loop control from data acquisition to command output.

[0046] Example 2

[0047] like Figure 3 As shown, in this embodiment, the temperature-sensitive self-regulation method for the wettability of the heated surface is executed according to the following process, and all operating parameters can be automatically configured and dynamically adjusted by the central control unit:

[0048] S1: Constructing a heating surface with local sensing and excitation capabilities: After completing the manufacturing of the above device, the system is initialized to confirm that each sub-region has an independent temperature sensing unit and electrical connection port, capable of receiving independent electrical excitation signals from the multi-channel programmable power supply 5. At this time, the dielectric response characteristics of the temperature-sensitive functional material layer 2 are activated, serving as an auxiliary characterization basis for the local thermal state, and the system enters a standby state.

[0049] S2: Real-time acquisition of thermal-wetting state data and construction of spatial distribution map: After system startup, the central control unit 6 synchronously reads multi-dimensional data from 100 sub-regions at a sampling frequency of 10 Hz. This includes the wall temperature T(x,y) output by the platinum resistance thermometer, the liquid film thickness h(x,y) obtained by calibration and inversion from the capacitive sensor, and the dry spot identifier D(x,y) generated in real time by an external high-speed camera and image processing algorithm. After the three are integrated, the system dynamically constructs a two-dimensional "thermal-wetting state spatial distribution map" in memory, with an update cycle controlled within 100 ms, reflecting the transient thermal-hydraulic state of the heating surface in real time.

[0050] S3: Perform multi-level threshold judgment to identify high-risk sub-regions: Based on the constructed spatial distribution map, the central control unit executes strict multi-level judgment logic: First, (a) calculate the overall average wall temperature Tˉ; if Tˉ≥T1 (the first preset threshold, set to 90°C), the system enters a global early warning state, indicating an increase in heat load. Second, (b) in the early warning state, perform local high-risk condition judgment for each sub-region i, which must simultaneously or individually meet one of the following conditions:

[0051] T i >T2 (Second preset threshold, set to 110°C);

[0052] h i <h min (Preset safety threshold, set to 10 μm);

[0053] D i =1 (Dry spot formation is defined as a liquid-free area with a diameter ≥50 μm in two consecutive frames).

[0054] If any condition is met, sub-region i is immediately marked as a "high-risk sub-region" and used as the target for subsequent intervention.

[0055] S4: Apply electrowetting excitation voltage only to high-risk sub-regions: Once a high-risk sub-region is identified, the central control unit immediately sends a command to the corresponding power channel to apply the electrowetting excitation voltage only to these specific regions, while maintaining zero voltage output in the remaining regions. This embodiment uses a pulsed DC signal, and the specific parameters are automatically matched according to the characteristics of the cooling medium: for deionized water (relative permittivity ε...r With an amplitude of approximately 80V and a conductivity of σ≈1μS / cm, the system uses a pre-stored mapping table to set the amplitude V=80V, frequency f=1Hz, and duty cycle of 50%, and employs alternating positive and negative polarities to reduce electrode polarization. After applying voltage, the solid-liquid contact angle of the target sub-region rapidly decreases from 75° to approximately 45°, inducing rapid backflow of the surrounding liquid and effectively suppressing the formation and expansion of the gas film.

[0056] S5: Dynamically adjust excitation parameters and implement event-driven exit: During the excitation process, the system executes a dynamic adjustment and exit mechanism.

[0057] Dynamic adjustment: If the heat flux density q′′=k·∇T (k is the thermal conductivity of copper) increases by more than 150W / cm², the system will automatically increase the voltage to 90V to enhance the driving force; if the bubble detachment frequency is detected to be lower than 20 Hz, a 5 kHz AC component (amplitude 20 V) will be superimposed on the DC to promote bubble detachment.

[0058] Exit mechanism: When a high-risk sub-region simultaneously satisfies T i ≤100℃, h i ≥20μm, D i When the value is 0 and the duration of this state is ≥2 seconds, the system determines that the wetting state has been restored, automatically stops the excitation of the area, and puts it into a low-power standby state.

[0059] To verify the technical effectiveness of this invention, a comparative experiment was conducted on a standard pool boiling test platform (compatible with ASTM D7263 standard). The heating surface size was 10 mm × 10 mm, and the cooling medium was deionized water (atmospheric pressure, saturation temperature 99.6°C). Three control strategies were tested: Control Group A (Prior Technology 1: No electrowetting, smooth copper surface); Control Group B (Prior Technology 2: Global constant voltage electrowetting, a fixed 80 V DC voltage is applied to the entire continuous electrode); Example C (Invention Scheme: 10×10 partitioned microelectrode array, applying pulsed electrowetting only to high-risk sub-regions, with multi-level threshold judgment and event-driven exit mechanism).

[0060] The test results are shown in the table below:

[0061] Table 1: Experimental Comparison Data

[0062] index Control group A Control group B Example C (This invention) Increase / decrease magnitude (vs B) Critical heat flux (CHF) 112 W / cm² 135 W / cm² 163 W / cm² +20.7% Average power consumption (electrowetting module) 0 W 4.8 W 2.1 W -56.3% Dry spot inhibition response time — >800 ms <150 ms Significantly accelerated <![CDATA[Wall temperature fluctuation under high heat flux (q′′ = 150 W / cm 2 )]]> ±22°C ±9°C ±4°C Significantly improved stability

[0063] Referring to the table above, in Example C, when dry spots (such as central hot spots) appear in a local sub-region, the system can identify and apply electrowetting only to that 3×3 sub-region within 120 ms, rapidly inducing the recirculation of surrounding liquid and preventing the lateral expansion of the gas film. In contrast, although the overall surface wettability of control group B is enhanced, it cannot specifically enhance high-risk areas, and the ineffective excitation in the edge regions does not contribute to CHF gain.

[0064] In Example C, under steady-state high heat flux conditions, only an average of 12% of the sub-regions were active. It is noteworthy that, due to the nonlinear threshold characteristics of the electrowetting effect, to overcome dynamic contact angle hysteresis and induce rapid reflow within a very short time (<150ms), this invention applies a high-frequency pulsed voltage (peak voltage 90V, duty cycle dynamically adjusted) to the target sub-region. Its instantaneous power density is higher than the constant DC voltage (80V) of the control group B. Despite the higher instantaneous power, due to spatial locality (only 12% of the region is active) and temporal intermittency (stopping as soon as the dry spot disappears, average duty cycle approximately 30%), the time-averaged power consumption of Example C is still significantly reduced. The specific calculation logic is as follows: P avg ≈P base ×Area%×DutyCycletime. In this experiment, although the local peak power was relatively high, after considering the overall time and space duty cycle, the total power consumption decreased from 4.8W in the control group B to 2.1W, achieving an energy saving effect of 56.3%.

[0065] This solution avoids the disordered bubble behavior caused by the global electric field by dynamically adjusting the excitation duration (such as immediately stopping after the dry spots are eliminated) and precise local intervention, thus making the boiling state more stable.

[0066] In practical applications, this device can be integrated into the heat sink of electronic chips, or, with appropriate materials, used in scenarios such as nuclear reactor fuel element cladding and spacecraft thermal control modules, serving as a core unit for active thermal management. The device is compact, responds quickly, and reliably supports the temperature-sensitive self-regulation method described in Example 1, achieving synergistic optimization of high critical heat flux density (CHF) and low power consumption.

[0067] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A temperature-sensitive self-regulating method for the wettability of a heated surface, characterized in that, Includes the following steps: S1: A temperature-sensitive functional material layer is integrated on the heating surface, and a patterned microelectrode array is formed on the surface of the temperature-sensitive functional material layer; the microelectrode array divides the heating surface into multiple electrically independent sub-regions, each sub-region is equipped with an independent temperature sensing unit and an electrical connection port, the temperature sensing unit is used to monitor the local temperature of the corresponding sub-region in real time, and the electrical connection port is used to receive independent electrical excitation signals; S2: Real-time synchronous acquisition of wall temperature data and liquid film thickness data of each sub-region, and construction of a thermal-wetting state spatial distribution map of the heating surface based on the wall temperature data and liquid film thickness data; wherein, the liquid film thickness data is obtained by inverting the dielectric constant change by measuring the embedded capacitive sensor; S3: Based on the aforementioned thermal-wetting state spatial distribution map, execute multi-level threshold determination logic: (a) Calculate the overall average wall temperature of the heating surface, and trigger a global early warning signal when the overall average wall temperature reaches a first preset threshold. (b) Traverse each sub-region and identify the target sub-region that meets the local high-risk condition, wherein the local high-risk condition is: the liquid film thickness is lower than a preset safety threshold; S4: Apply an electrowetting excitation pulse voltage only to the target sub-region identified in step S3 (b) to change the solid-liquid contact angle of the temperature-sensitive functional material layer in the target sub-region, induce the surrounding liquid to flow back to the target sub-region for wetting, and inhibit the formation of gas film. S5: Based on the type of cooling medium and the current heat load state, dynamically adjust the amplitude, frequency, or duration of the electrowetting excitation pulse voltage applied to the target sub-region, and perform closed-loop adjustment based on the real-time feedback thermal-wetting state spatial distribution map until the liquid film thickness of the target sub-region recovers to above the preset safety threshold, so as to maintain the system in the nucleate boiling state.

2. The temperature-sensitive self-regulating method for the wettability of a heated surface as described in claim 1, characterized in that: The temperature-sensitive functional material layer is composed of an inorganic-organic hybrid hydrogel, configured to undergo a reversible hydrophilic-hydrophobic transition within a preset phase transition temperature range, and its dielectric constant undergoes a nonlinear abrupt change with the phase transition process, which is used to respond to local temperature changes and characterize the thermal state of the sub-region.

3. The temperature-sensitive self-regulating method for the wettability of a heated surface as described in claim 1, characterized in that: In step S4, the parameters of the electrowetting excitation pulse voltage are automatically generated by the central control unit based on the dielectric constant, conductivity and current heat flux density of the cooling medium; when the liquid film thickness of the target sub-region recovers to above the preset safety threshold and the local wall temperature drops below the third preset threshold, the electrowetting excitation pulse voltage for the target sub-region is automatically stopped.

4. The temperature-sensitive self-regulating method for the wettability of a heated surface as described in claim 1, characterized in that: The multi-level threshold determination logic in step S3 also includes a time filtering mechanism: only when the condition that the liquid film thickness is lower than the preset safety threshold continues for more than a preset time window is it confirmed as a valid high-risk sub-region and step S4 is triggered to filter out instantaneous noise interference.

5. A heating apparatus for implementing the method as described in any one of claims 1–4, characterized in that, include: Thermally conductive substrate (1); A temperature-sensitive functional material layer (2) is disposed on the surface of the thermally conductive substrate (1). The temperature-sensitive functional material layer (2) is composed of an inorganic-organic hybrid hydrogel with low critical dissolution temperature characteristics and is configured to undergo a reversible hydrophilic-hydrophobic transition within a preset phase transition temperature range. A patterned microelectrode array (3) is disposed on the surface of the temperature-sensitive functional material layer (2). The microelectrode array (3) divides the heating surface into multiple electrically independent sub-regions. Each electrode is electrically isolated from each other and is equipped with an independent electrical connection port. A multi-channel programmable power supply (4) electrically connected to the microelectrode array (3) is used to apply an electrowetting excitation pulse voltage to a selected sub-region; The multimodal sensing unit (5) integrated with each sub-region includes a temperature sensing unit and an embedded capacitive sensor. The temperature sensing unit is used to collect local wall temperature, and the embedded capacitive sensor is used to collect liquid film thickness data by measuring the change in dielectric constant. The central control unit (6) is communicatively connected to the multimodal sensing unit (5) and the multi-channel programmable power supply (4); the central control unit (6) is configured to: receive data from the multimodal sensing unit (5) and construct a thermal-wetting state spatial distribution map; execute multi-level threshold judgment logic to identify target sub-regions where the liquid film thickness is lower than a preset safety threshold; control the multi-channel programmable power supply (4) to apply electrowetting excitation pulse voltage only to the target sub-regions and dynamically adjust the voltage parameters according to the feedback data.

6. The heating device as described in claim 5, characterized in that: The device is encapsulated in an electronic chip heat sink.

7. The heating device as described in claim 5, characterized in that: The central control unit is embedded with an adaptive control algorithm, which is configured to predict potential liquid film thickness reduction areas by short-time linear extrapolation based on the real-time collected liquid film thickness change rate and wall temperature rise rate, and apply a pre-excitation voltage in advance before the liquid film thickness reaches a preset safety threshold.

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