Liquid metal heat pipe based on voltage regulation and control and preparation method

Abstract

The invention relates to the technical field of heat management, in particular to a liquid metal heat pipe based on voltage regulation and control and a preparation method. The liquid metal heat pipe comprises a pipe shell, a liquid metal working medium and a solid electrolyte capillary core, wherein the liquid metal working medium and the solid electrolyte capillary core are packaged in the pipe shell; the pipe shell sequentially comprises a heat absorption section in contact with a heat source, a heat insulation section and a heat dissipation section in contact with a cold source in the axial direction; the solid electrolyte capillary core is attached to the inner wall of the heat insulation section, the cross section area of the solid electrolyte capillary core is smaller than that of the tube shell, and the solid electrolyte capillary core is provided with a porous structure used for providing capillary force for backflow of the liquid metal working medium; and the voltage regulation and control system is configured to respond to the power change of the heat source and apply controllable voltage between the liquid metal working medium and the solid electrolyte capillary core so as to dynamically regulate the heat exchange power through the controllable voltage. The invention has the advantages of active regulation and control capability, high reliability and quick response, and meets the strict requirements of high-end equipment and electronic systems on heat management.

Description

Technical Field

[0001] This disclosure relates to the field of thermal management technology, and in particular to a voltage-controlled liquid metal heat pipe and its preparation method. Background Technology

[0002] As a highly efficient heat transfer element, the heat pipe operates on the principle that the working fluid absorbs heat and vaporizes in the evaporation section, releases heat and liquefies in the condensation section, and is driven to reflux by capillary force or gravity, forming a circulating heat transfer. Traditional heat pipe technology has been widely used in fields such as electronic device heat dissipation, aerospace thermal control, and industrial waste heat recovery. However, with the rapid development of high-power-density electronic devices, space exploration, and new energy vehicles, higher requirements are placed on the dynamic response capability, environmental adaptability, and reliability of thermal management systems. Due to limitations such as fixed heat exchange power and reliance on gravity or capillary action, traditional heat pipes are unable to meet the precise temperature control requirements under dynamic heat loads.

[0003] Among related technologies, active thermal control technologies, such as mechanical pump-driven fluid circuits, can achieve a certain degree of power regulation, but they suffer from problems such as fragile moving parts, slow response speed, system complexity, and high power consumption, which limit their application in high-reliability and high-dynamic-response scenarios. Furthermore, while liquid metal, as a heat transfer medium with high thermal conductivity and high boiling point, exhibits advantages in high-temperature and high-heat transfer, existing liquid metal heat pipes still lack effective and rapid power regulation methods, making it impossible to adjust heat transfer performance in real time according to changes in heat load. Summary of the Invention

[0004] This disclosure is made in view of the above-mentioned problems. This disclosure provides a voltage-controlled liquid metal heat pipe and its fabrication method.

[0005] According to one aspect of this disclosure, a voltage-regulated liquid metal heat pipe is provided, comprising a shell and a liquid metal working fluid and a solid electrolyte capillary core encapsulated inside the shell, wherein the shell comprises, in sequence along the axial direction, a heat-absorbing section in contact with a heat source, an insulation section, and a heat-dissipating section in contact with a cold source. The solid electrolyte capillary core is attached to the inner wall of the insulation section, and the cross-sectional area of ​​the solid electrolyte capillary core is smaller than the cross-sectional area of ​​the tube shell. The solid electrolyte capillary core has a porous structure for providing capillary force for the reflux of the liquid metal working fluid. The liquid metal heat pipe further includes a voltage regulation system configured to apply a controllable voltage between the liquid metal working fluid and the solid electrolyte capillary in response to a power change of the heat source, so as to dynamically adjust the heat exchange power of the liquid metal heat pipe through the controllable voltage.

[0006] According to another aspect of this disclosure, a method for preparing the above-mentioned voltage-controlled liquid metal heat pipe is provided, comprising: Provide a tube shell with an insulating section; A solid electrolyte capillary core is prepared and the solid electrolyte capillary core is fixed to the inner wall of the insulation section; The inside of the tube shell is evacuated to a vacuum state, and liquid metal working fluid is injected into the inside of the tube shell under vacuum or protective atmosphere; The tube shell is sealed after being filled with the liquid metal working fluid, and a voltage regulation system is installed on the outside of the tube shell to obtain the liquid metal heat pipe.

[0007] As will be described in detail below, a voltage-regulated liquid metal heat pipe according to an embodiment of the present disclosure includes a shell and a liquid metal working fluid and a solid electrolyte capillary wick encapsulated inside the shell. The shell includes, along the axial direction, a heat-absorbing section in contact with a heat source, an insulating section, and a heat-dissipating section in contact with a cold source. The solid electrolyte capillary wick is attached to the inner wall of the insulating section, and the cross-sectional area of ​​the solid electrolyte capillary wick is smaller than the cross-sectional area of ​​the shell. The solid electrolyte capillary wick has a porous structure for providing capillary force for the reflux of the liquid metal working fluid. The liquid metal heat pipe also includes a voltage regulation system configured to apply a controllable voltage between the liquid metal working fluid and the solid electrolyte capillary wick in response to power changes of the heat source, so as to dynamically adjust the heat exchange power of the liquid metal heat pipe through the controllable voltage. This liquid metal heat pipe has the advantages of active regulation capability, high reliability, and fast response, and can meet the stringent requirements of high-end equipment and electronic systems for thermal management. Attached Figure Description

[0008] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0009] Figure 1 A schematic diagram of the cross-sectional structure of a voltage-controlled liquid metal heat pipe provided in an exemplary embodiment of this disclosure is shown in the axial direction. Figure 2 A schematic diagram illustrating the mechanism by which a solid electrolyte capillary wick provides capillary force when no voltage is applied, provided by an exemplary embodiment of this disclosure; Figure 3 A schematic diagram illustrating the mechanism of voltage-induced liquid metal penetration effect of a solid electrolyte capillary wick when a voltage is applied, provided by an exemplary embodiment of this disclosure; Figure 4A graph showing the relationship between voltage and heat exchange power regulation provided in an exemplary embodiment of this disclosure is shown. Figure 5 A schematic flowchart of a method for fabricating a voltage-controlled liquid metal heat pipe according to an exemplary embodiment of the present disclosure is shown. Figure label: 100-Liquid metal heat pipe, 101-Pipe shell, 102-Heat absorption section, 103-Insulation section, 104-Heat dissipation section, 105-Solid electrolyte capillary wick, 106-Liquid metal working fluid, 107-Voltage control system, 1071-First electrode, 1072-Second electrode, 1073-Voltage control module, 1074-Temperature sensor, 108-Oxide layer. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this disclosure more apparent, exemplary embodiments according to this disclosure will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments of this disclosure. It should be understood that this disclosure is not limited to the exemplary embodiments described herein.

[0011] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0012] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc., used in this disclosure are only used to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0013] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0014] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0015] As a highly efficient heat transfer element, the heat pipe works by absorbing heat and vaporizing in the heat-absorbing section, releasing heat and liquefying in the heat-dissipating section, and then circulating the liquid working fluid through capillary action or gravity, thus achieving rapid and efficient heat transfer. Traditional heat pipe technology has been widely used in various fields such as electronic device cooling, aerospace thermal control, and industrial waste heat recovery. However, with technological advancements, especially in high-power-density electronic devices, space exploration, and new energy vehicles, higher demands are being placed on the dynamic response capabilities, environmental adaptability, and reliability of thermal management systems. Traditional heat pipes, due to their inherent structural and operational limitations, struggle to meet the complex thermal control requirements of these emerging application scenarios.

[0016] The limitations of traditional heat pipes are reflected in the following two aspects: First, the heat transfer capacity is fixed and cannot adapt to dynamic heat loads. Traditional heat pipes, whether gravity-assisted or capillary-driven, have their maximum heat transfer capacity largely determined during design and manufacturing. The heat transfer limits of a heat pipe, such as the capillary limit, carry-over limit, and boiling limit, are jointly determined by the properties of the internal working fluid, capillary structure parameters (such as pore size and porosity), and the shell material. During operation, the heat transfer capacity of a heat pipe mainly depends on the temperature difference between the evaporation and condensation sections and the latent heat of phase change of the working fluid; it lacks an effective active adjustment mechanism. This means that when the heat load of an external heat source fluctuates drastically, traditional heat pipes cannot dynamically adjust their heat dissipation capacity to match the changing heat flow. For example, when electronic devices start up, operate under high load, or enter standby mode, their heat transfer capacity will experience rapid changes from low to high or from high to low. Under such dynamic heat load conditions, traditional heat pipes either overheat due to insufficient heat dissipation or cause unnecessary energy waste and excessively low system temperatures due to continuous operation at maximum capacity, affecting equipment performance and efficiency. This "passive" working mode limits its applicability in high-end applications requiring precise temperature control and efficient energy management.

[0017] Second, reliance on gravity or capillary action leads to insufficient reliability. Traditional heat pipes rely on two basic driving forces for heat transfer: gravity or capillary action. Gravity heat pipes are simple in structure and inexpensive, but their operating direction is strictly limited; the condenser section must be above the evaporator section, and they cannot operate in weightless environments. Capillary heat pipes generate capillary pumping force through their internal porous wick structure, driving the liquid working fluid backflow. This allows them to operate in any direction and provides some resistance to gravity. However, the magnitude of the capillary force is closely related to the microstructure of the wick (such as pore size and porosity), and the driving force it generates is relatively limited. When the heat load is too high or the heat pipe length is too long, the capillary force may be insufficient to overcome all the resistances in the working fluid flow process (including liquid backflow resistance and vapor pressure drop), thus reaching the "capillary limit," causing the evaporator section to dry out and the heat pipe to fail. Furthermore, the wick structure may become clogged, corroded, or degraded during long-term use, leading to a decline in capillary performance and affecting the long-term stability and reliability of the heat pipe. This reliance on a single, relatively fragile physical mechanism makes traditional heat pipes inherently less reliable when faced with complex and ever-changing operating conditions.

[0018] The shortcomings of existing active thermal control technology are reflected in the following three aspects: First, mechanical pump-driven systems have moving parts, resulting in low reliability. To overcome the passivity and limitations of traditional heat pipes, researchers have developed various active thermal control technologies, the most common of which is a single-phase or two-phase fluid loop driven by a mechanical pump. These systems use a pump to force the cooling medium (such as water, ethylene glycol solution, or liquid metal) to circulate within the loop, thereby achieving efficient heat transfer and precise control. However, the introduction of mechanical pumps brings new problems. First, as a moving part, the pump itself is subject to wear, fatigue, and potential mechanical failure risks, especially under long-term operation or extreme environments (such as alternating high and low temperatures or strong vibrations), where its reliability significantly decreases. Second, pump operation consumes additional electrical energy, increasing the system's total energy consumption. Furthermore, pump operation generates noise and vibration, which is unacceptable for some noise- and vibration-sensitive applications (such as high-precision optical instruments and satellite payloads). Therefore, although mechanical pump-driven systems are superior to traditional heat pipes in terms of adjustment range and heat transfer capacity, the inherent reliability, energy consumption, and noise issues caused by their moving parts limit their application in fields with high reliability requirements.

[0019] Second, the response speed is slow and the adjustment range is limited. The response speed and adjustment range of existing active thermal control systems often fail to meet the needs of certain extreme application scenarios. For mechanically pump-driven systems, the response speed is limited by the pump start-up time, the fluid transmission delay in the pipeline, and the overall high thermal inertia of the system. From receiving the control signal to the system reaching a new stable heat transfer state, it usually takes several seconds or even longer. This second-level response delay is far from sufficient for high-power electronic devices (such as laser diodes and high-performance CPUs) that need to cope with millisecond-level thermal shocks. In terms of adjustment range, although the flow rate can be changed by adjusting the pump speed, its adjustment range is still limited, and the pump efficiency drops sharply at low flow rates. Other active control methods, such as variable heat pipes (VCHP), which change the effective working area of ​​the condenser section by controlling non-condensable gases or excess liquid, also have slow response speeds and low adjustment accuracy. These limitations make it difficult for existing active thermal control technologies to achieve accurate and timely temperature control when faced with rapid and drastic fluctuations in heat load.

[0020] Third, the system is complex and consumes a lot of power. Active thermal control systems are typically much more complex than passive heat pipe systems. Mechanical pump-driven systems require additional pumps, valves, sensors, controllers, and complex piping connections, which not only increases the system's size and weight but also raises manufacturing costs and maintenance difficulties. System complexity means more potential points of failure, thus reducing overall reliability. Furthermore, the components driving the mechanical pumps and controlling the valves continuously consume electrical energy, which is a significant consideration in energy-constrained applications such as satellites and portable devices. High power consumption not only shortens the device's battery life but also generates heat that can become a secondary heat load requiring additional handling, further increasing the complexity of thermal management. Therefore, maintaining system simplicity, low power consumption, and high reliability while achieving active control is a major challenge in the development of active thermal control technology.

[0021] The advantages of using liquid metals as working fluids are manifested in several ways: Due to their unique physicochemical properties, liquid metals are considered a highly promising next-generation heat pipe working fluid. Compared with traditional working fluids (such as water, ammonia, and acetone), liquid metals have significant advantages. First, liquid metals (such as gallium and gallium-indium-tin alloys) have extremely high thermal conductivity and specific heat capacity, meaning they can absorb and transfer heat more efficiently, thus achieving higher heat transfer efficiency. Second, liquid metals have extremely high boiling points and extremely low vapor pressures, allowing heat pipes to operate at temperatures far exceeding those allowed by traditional working fluids (such as above 500°C), making them suitable for extreme environments such as high-temperature industrial processes and nuclear reactors. Furthermore, liquid metals have extremely high electrical conductivity, a characteristic that enables non-contact driving and control via electromagnetic fields (such as electromagnetic pumps), thus avoiding the reliability issues of mechanical pumps. Finally, many gallium-based liquid metals have low toxicity and good chemical stability, making them safer in applications. These advantages make liquid metal heat pipes a promising candidate for applications in high heat flux density heat dissipation and high-temperature heat transfer.

[0022] However, existing liquid metal heat pipes still lack effective power control methods. Although liquid metal has many advantages as a working fluid, current research on liquid metal heat pipes is mostly limited to passive heat transfer. Researchers mainly focus on optimizing the wick structure (such as sintered powder, microchannels) to improve capillary performance, or exploring the heat transfer characteristics of different liquid metal alloys. However, these studies have not fundamentally solved the problem of the inability to dynamically adjust the heat pipe power. Although theoretically, electromagnetic pumps can be used to drive the liquid metal to achieve active control, this returns to the dilemma of system complexity, high power consumption, and low reliability faced by mechanical pump drive systems. Therefore, how to achieve active, rapid, and efficient control of the heat transfer power of liquid metal heat pipes without introducing complex mechanical components remains a core technical challenge that has not yet been solved in this field. The embodiments disclosed in this paper address this technical gap by proposing a novel solution based on voltage regulation.

[0023] Therefore, in order to solve the above problems, the present disclosure provides a voltage-controlled liquid metal heat pipe that has the advantages of active control capability, high reliability, fast response and compact structure, and can meet the stringent requirements of high-end equipment and electronic systems for thermal management.

[0024] Figure 1 A schematic cross-sectional view of a voltage-controlled liquid metal heat pipe provided in an exemplary embodiment of this disclosure is shown in the axial direction. Figure 1As shown, the voltage-controlled liquid metal heat pipe 100 includes a shell 101 and a liquid metal working fluid 106 and a solid electrolyte capillary 105 encapsulated inside the shell 101. The shell 101 includes, along the axial direction, a heat-absorbing section 102 in contact with a heat source, a heat-insulating section 103, and a heat-dissipating section 104 in contact with a cold source.

[0025] Here, the shell 101 is typically made of a metal with good thermal conductivity (such as copper or stainless steel). The heat absorption section 102 (also called the evaporation section) is the part of the liquid metal heat pipe 100 that contacts the heat source, responsible for absorbing heat and raising the temperature of the internal liquid metal working fluid 106. To improve heat absorption efficiency, the outer wall of the heat absorption section 102 is usually designed with fins or made of a high thermal conductivity material to increase the contact area with the heat source. The heat dissipation section 104 (also called the condensation section) is the part of the liquid metal heat pipe 100 that contacts the cold source (such as heat sinks or coolant), where the high-temperature liquid metal working fluid 106 releases heat and lowers its temperature. Similarly, the heat dissipation section 104 is also designed with an efficient heat dissipation structure. The adiabatic section 103 is located between the heat absorption section 102 and the heat dissipation section 104, and its function is to reduce heat loss during the transmission process and ensure that heat can be efficiently transferred to the heat dissipation section 104.

[0026] Furthermore, the amount of liquid metal working fluid 106 charged needs to be precisely calculated to ensure that the solid electrolyte capillary 105 of the heat absorption section 102 is fully wetted when the liquid metal heat pipe 100 is working, while avoiding excessive liquid metal working fluid 106 submerging the heat dissipation section 104 and affecting the steam flow and condensation efficiency. The purity of the liquid metal working fluid 106 is also crucial, and impurities must be avoided to prevent them from affecting its physicochemical properties and compatibility with the capillary wick material.

[0027] like Figure 1 As shown, the solid electrolyte capillary 105 is attached to the inner wall of the insulation section 103, and the cross-sectional area of ​​the solid electrolyte capillary 105 is smaller than the cross-sectional area of ​​the shell 101. The solid electrolyte capillary 105 has a porous structure for providing capillary force for the reflux of the liquid metal working fluid 106.

[0028] like Figure 1As shown, the solid electrolyte capillary 105 can be a sintered body in the shape of a strip or sheet, which can be fixed to the inner wall of the shell 101 of the insulation section 103 by means of high-temperature ceramic adhesive or mechanical snap-fit. Here, the solid electrolyte capillary 105 does not fill the entire inner diameter space of the shell 101, and the cross-sectional area of ​​the solid electrolyte capillary 105 is smaller than the cross-sectional area of ​​the shell 101. That is to say, the width or thickness (i.e., radial dimension) of the solid electrolyte capillary 105 itself is much smaller than the inner diameter of the shell 101, so that a continuous axial channel is naturally formed between the outer surface of the solid electrolyte capillary 105 (the side away from the inner wall of the shell 101) and the opposite surface of the inner wall of the shell 101 to allow the liquid metal working fluid 106 to pass through. Using a solid electrolyte capillary with a small cross-sectional area reduces the amount of expensive solid electrolyte material used and lowers the manufacturing cost. Meanwhile, these sheet-like or strip-shaped solid electrolyte capillary cores are easier to bend and fit into the inner walls of tubes of different shapes, enhancing the flexibility of heat pipe structure design and allowing them to adapt to more complex installation spaces.

[0029] The solid electrolyte capillary wick 105 has a porous structure, which is the physical basis for generating capillary force. The surface of the solid electrolyte capillary wick 105 has good wettability with the liquid metal working medium 106. When no voltage is applied, the liquid metal working medium 106 can spontaneously permeate into the pore network of the solid electrolyte capillary wick 105 by virtue of its own surface tension and the wetting effect of the porous solid electrolyte capillary wick 105, generating a capillary pumping force that drives the backflow of the liquid metal working medium 106.

[0030] The heat exchange power of traditional heat pipes is determined during the design phase and cannot be adjusted according to fluctuations in the actual heat load during operation, which often leads to energy waste or insufficient heat dissipation. However, the liquid metal heat pipe 100 provided in this embodiment can dynamically adapt to changes in external heat load, and its heat exchange power can be changed in real time and continuously through voltage regulation.

[0031] like Figure 1 As shown, the liquid metal heat pipe 100 also includes a voltage regulation system 107, configured to apply a controllable voltage between the liquid metal working fluid 106 and the solid electrolyte capillary wick 105 in response to power changes of the heat source, so as to dynamically adjust the heat transfer power of the liquid metal heat pipe 100 through the controllable voltage. Here, the power change of the heat source can specifically be reflected in the temperature or heat load change of the heat source.

[0032] When the power of the heat source increases, the voltage regulation system 107 can immediately increase the voltage applied between the liquid metal working fluid 106 and the solid electrolyte capillary wick 105, enhancing the penetration effect of the liquid metal working fluid and thus rapidly improving the heat dissipation capacity of the heat pipe to prevent overheating. Conversely, when the power of the heat source decreases, the voltage can be reduced to decrease the heat dissipation power and avoid overcooling, thereby achieving on-demand heat dissipation and maximizing energy utilization efficiency. This dynamic adaptability is crucial for applications with drastic changes in heat load, such as modern high-performance electronic devices (e.g., CPUs, GPUs) and spacecraft.

[0033] The most unique design of the solid electrolyte capillary 105 during the application of a controllable voltage lies in its dual function: it is not only a capillary structure in the traditional sense, providing capillary driving force for the reflux of the liquid metal working fluid, the specific mechanism of which is as follows: Figure 2 As shown; simultaneously, it also acts as an electrode or ion conductor, and is the core component for realizing voltage regulation function, the specific mechanism of which is as follows. Figure 3 As shown.

[0034] Figure 2 A schematic diagram illustrating the mechanism by which a solid electrolyte capillary wick provides capillary force when no voltage is applied, as provided in an exemplary embodiment of this disclosure, is shown. Figure 2 As shown, when no voltage is applied, the liquid metal working fluid 106 has poor wettability and flows slowly in the pores of the solid electrolyte capillary 105 due to its high surface tension.

[0035] Figure 3 This illustration shows a mechanism diagram of the voltage-induced liquid metal penetration effect of a solid electrolyte capillary wick when a voltage is applied, as provided in an exemplary embodiment of this disclosure. Figure 3 As shown, when an external voltage is applied between the liquid metal working fluid 106 and the solid electrolyte capillary 105, the solid electrolyte can conduct ions (such as O2). 2- An electric field drives ion migration, initiating an electrochemical reaction at the interface between the liquid metal working medium 106 and the solid electrolyte capillary wick 105. This forms an oxide layer 108 on the surface of the liquid metal, causing a sharp decrease in its surface tension and entering a "quasi-superfluid" state. At this point, the liquid metal exhibits superwetting properties, easily penetrating the tiny pores of the capillary wick, and the reflux rate is significantly accelerated.

[0036] The formation of this oxide layer 108 is key to reducing the surface tension of the liquid metal working fluid 106. This design, which integrates capillary actuation and electrochemical regulation, is the core innovation that distinguishes this embodiment from all existing heat pipe technologies, making it possible to actively control the flow of the working fluid inside the heat pipe without introducing any external moving parts.

[0037] Compared to traditional mechanical pump-driven active thermal control systems, the liquid metal heat pipe provided in this disclosure has an extremely fast response speed. Since the control mechanism is based on the direct effect of an electric field on the surface tension of the liquid metal, its response time can reach the millisecond level. This means the heat pipe can react to thermal shocks instantaneously, effectively protecting sensitive components from damage caused by instantaneous high temperatures. In contrast, the response time of mechanical pump systems is typically in the second range, making it difficult to cope with rapidly changing heat loads. Furthermore, the adjustment range of this disclosure is very wide. Theoretically, by adjusting the voltage, stepless adjustment can be achieved from zero (off state) to the maximum design power, with an adjustment range far greater than that of mechanical pump systems, enabling better adaptation to a wide range of heat load changes from extremely low to extremely high.

[0038] The core advantage of this disclosed embodiment lies in its design without moving parts, resulting in high reliability. The entire power regulation process is achieved entirely through an electric field; there are no mechanical pumps, valves, or moving parts inside the heat pipe. This fundamentally eliminates problems caused by mechanical wear, fatigue, vibration, and noise, significantly improving the long-term operational reliability and stability of the system. This characteristic is irreplaceable for critical systems requiring long-term, highly reliable operation, such as spacecraft, nuclear power plants, and data centers. Compared to mechanical pump systems containing vulnerable components, the heat pipes of this disclosed embodiment have a longer lifespan, lower maintenance requirements, and higher system safety.

[0039] During voltage regulation, the ultimate effect is reflected in the enhanced circulation of the working fluid inside the heat pipe, specifically an increase in the reflux rate and volume of the liquid metal working fluid. Due to the voltage-induced "superfluid-like" penetration effect, the permeability of the solid electrolyte capillary wick is greatly enhanced, significantly increasing the speed and flow rate of the liquid metal working fluid returning from the heat dissipation section to the heat absorption section. This means that more liquid metal can reach the heat absorption section per unit time, and after absorbing heat and heating up, it flows back to the heat dissipation section by gravity. This improved working fluid reflux capability breaks through the heat transfer bottlenecks in traditional heat pipes limited by capillary or viscous limits.

[0040] The increased reflux rate and volume of the liquid metal working fluid directly leads to enhanced heat absorption capacity in the heat-absorbing section. The heat transfer process in the heat-absorbing section is mainly convective heat transfer between the liquid metal and the shell of the heat-absorbing section. Faster reflux of the working fluid means higher flow velocity and flow rate, which increases the convective heat transfer coefficient and heat transfer capacity, meaning that more heat can be absorbed per unit time, thereby significantly improving the total heat absorption power of the heat-absorbing section.

[0041] In the heat dissipation section, the enhanced working fluid circulation also improves heat release capacity. More high-temperature liquid metal flows at high speed into the heat dissipation section, increasing the flow velocity within it, which helps improve the convective heat transfer coefficient. Simultaneously, the dissipated liquid can be absorbed by the capillary wick more quickly and return, preventing excessive liquid accumulation in the heat dissipation section and thus avoiding submersion of the heat exchange surface, ensuring effective utilization of the heat exchange area. These factors work together to improve the heat transfer efficiency of the heat dissipation section, enabling faster heat transfer to the external heat sink.

[0042] In summary, the embodiments of this disclosure achieve active acceleration of the working fluid circulation within the heat pipe by applying voltage, thereby increasing the overall heat exchange power of the liquid metal heat exchanger. From the increase in the working fluid reflux velocity to the enhanced heat absorption capacity of the heat absorption section, and then to the improved heat release capacity of the heat dissipation section, a complete and positive causal chain is formed. The ultimate result of this chain is a significant increase in the overall heat exchange power of the heat pipe. Furthermore, by adjusting the applied voltage, the degree of each link in this causal chain can be precisely controlled, thereby achieving dynamic and stepless adjustment of the overall heat exchange power of the heat pipe. This active and controllable power adjustment capability is the fundamental advantage of the embodiments of this disclosure compared to all traditional heat pipe technologies.

[0043] In some embodiments, the liquid metal working medium is a gallium-based liquid metal; the gallium-based liquid metal is a eutectic alloy containing gallium, indium and tin.

[0044] like Figure 1 As shown, the liquid metal heat pipe 100 is filled with a gallium-based liquid metal working fluid 106. This gallium-based liquid metal serves as the heat transfer medium, which is crucial for achieving high performance and voltage regulation. The gallium-based liquid metal can be a eutectic gallium indium tin alloy (EGaInSn). Eutectic gallium indium tin alloy is liquid at room temperature and possesses extremely high thermal conductivity (approximately 16.5 W / m·K), high electrical conductivity, a high boiling point (>1300℃), and extremely low saturated vapor pressure. These properties make it an ideal heat pipe working fluid, especially suitable for high heat flux and high-temperature environments.

[0045] In some embodiments, such as Figure 1 As shown, the liquid metal working medium 106 contains dispersed boron nitride nanosheets, which form a passivation protective layer on the surface of the liquid metal working medium.

[0046] While liquid metal working fluids (such as gallium-based liquid metals) are relatively chemically stable, they can still undergo slow alloying or corrosion reactions with certain materials (such as copper and aluminum) under long-term high-temperature operation or specific electric fields. To address this issue, an effective solution is to coat the liquid metal with boron nitride (BN) nanosheets. Boron nitride possesses excellent chemical inertness, high thermal conductivity, and electrical insulation. By uniformly dispersing BN nanosheets within the liquid metal, a dense protective layer can be formed on its surface, effectively isolating the liquid metal from direct contact with surrounding materials, thereby reducing the corrosion rate by more than 90% and improving interfacial stability. This composite material not only solves the corrosion problem, but the high thermal conductivity of the BN nanosheets also helps improve the overall thermal conductivity of the working fluid.

[0047] In some embodiments, such as Figure 1 As shown, the solid electrolyte capillary 105 is made of solid electrolyte material, which is yttrium oxide stabilized zirconia ceramic.

[0048] This disclosure embodiment utilizes a solid electrolyte material to construct the solid electrolyte capillary wick 105. The selection of the solid electrolyte material is crucial and must simultaneously meet three conditions: first, it must have a porous structure to provide sufficient capillary force; second, it must possess good ionic conductivity to participate in or promote electrochemical reactions under the influence of an electric field; and finally, it must have good chemical compatibility with gallium-based liquid metals to avoid severe corrosion or adverse reactions, which is fundamental to ensuring the long-term stable operation of the liquid metal heat pipe.

[0049] The choice of solid electrolyte material directly affects the heat pipe's control performance and operating temperature range. Preferred solid electrolyte materials are oxide ceramics, with zirconia (ZrO2) and its composites (such as yttrium-stabilized zirconia (YSZ)) being ideal choices. YSZ is an excellent oxygen ion conductor, exhibiting high ionic conductivity at high temperatures, chemical stability, and good compatibility with gallium-based liquid metals.

[0050] Studies have shown that zirconia ceramics exhibit excellent chemical stability with various metals (such as palladium) at high temperatures, capable of withstanding multiple melting / solidification cycles without cracking or significant chemical reactions. Furthermore, zirconia itself demonstrates good inertness to gallium-based liquid metals. By carefully selecting material combinations, electrochemical reactions and corrosion problems at the interface can be fundamentally avoided, ensuring stable and reliable operation of the heat pipe for thousands of hours or even longer.

[0051] In some embodiments, such as Figure 1 As shown, the porous structure has a gradient pore size distribution, and the average pore size of the solid electrolyte capillary 105 near the heat absorption section 102 is smaller than the average pore size near the heat dissipation section 104.

[0052] Here, the microstructure of the solid electrolyte capillary wick 105 is crucial in determining its capillary performance. To provide a strong capillary pumping force to drive the reflux of liquid metal, the solid electrolyte capillary wick 105 must possess a highly developed porous structure. These pores need to be interconnected, forming a complex network of channels. The magnitude of the capillary force is inversely proportional to the pore size; the smaller the pore size, the greater the capillary pressure. However, excessively small pore sizes increase resistance to liquid flow and reduce permeability. Therefore, the pore size distribution and porosity of the capillary wick need to be optimized to achieve the best balance between capillary force and permeability. Based on this, embodiments of this disclosure can employ a structure with gradient pore sizes, i.e., smaller pore sizes are used near the heat-absorbing section 102 to provide greater capillary force, while larger pore sizes are used in the liquid reflux channels near the heat-dissipating section 104 to reduce flow resistance. This porous structure can be prepared using various processes such as powder sintering, phase separation, and template methods.

[0053] Based on this, the embodiments of this disclosure can further optimize the spatial distribution of capillary force and improve reflux efficiency by designing gradient apertures, using a finer aperture at the end near the heat absorption section to generate greater capillary force, and using a slightly larger aperture in the reflux main channel to reduce flow resistance.

[0054] In some embodiments, such as Figure 1 As shown, the voltage regulation system 107 includes: The first electrode 1071 is electrically connected to the liquid metal working fluid 106 of the heat dissipation section 104; The second electrode 1072 is electrically connected to the solid electrolyte capillary 105; The voltage control module 1073, which is electrically connected to both the first electrode 1071 and the second electrode 1072, is configured to apply a controllable voltage between the first electrode 1071 and the second electrode 1072 in response to a power change of the heat source.

[0055] Specifically, to achieve voltage regulation of the liquid metal working fluid 106 inside the liquid metal heat pipe 100, external electrodes are required. There are various ways to arrange the electrodes; a preferred method is to arrange two electrodes on the casing 101 of the liquid metal heat pipe 100, corresponding to the heat dissipation section 104 and the insulation section 103, respectively. One electrode (i.e., the first electrode 1071) is electrically connected to the internal liquid metal working fluid 106 (for example, by providing a conductive probe on the casing 101 that contacts the liquid metal working fluid 106), and the other electrode (i.e., the second electrode 1072) is electrically connected to the solid electrolyte capillary 105 (for example, by depositing a conductive thin film on the solid electrolyte capillary 105 and extending the film to the outside of the casing 101). Thus, when a voltage is applied between the two external electrodes, an electric field can act on the interface between the liquid metal working fluid 106 and the solid electrolyte capillary 105.

[0056] The electrode materials for the first electrode 1071 and the second electrode 1072 need to be selected from materials with good conductivity and compatibility with the heat pipe's working environment, such as copper, stainless steel, or coated metal.

[0057] like Figure 1 As shown, the voltage control module 1073 (HMS) can be electrically connected to the first electrode 1071 and the second electrode 1072 via wires. The voltage control module 1073 is the brain behind intelligent thermal management, and it mainly consists of a programmable DC power supply and corresponding control circuitry. When the voltage control module 1073 detects an increase in the power of the heat source, it can increase the applied voltage to enhance the "superfluid-like" effect and improve the heat transfer power of the heat pipe; conversely, when the voltage control module 1073 detects a decrease in the power of the heat source, it decreases the voltage, allowing the heat pipe to operate in a low-power state.

[0058] As can be seen, the voltage regulation system 107 of this embodiment consists of only two low-power external electrodes (first electrode 1071 and second electrode 1072) and a voltage control module 1073. It eliminates the need for complex piping, liquid reservoirs, and large pump bodies, significantly saving space and weight. It features a compact heat pipe structure and ease of integration, which is particularly important for spacecraft with scarce space resources and portable electronic devices with stringent requirements for miniaturization and lightweighting. Furthermore, its power consumption is extremely low; the regulation process consumes only a small amount of energy when changing the voltage, and almost no energy is consumed when maintaining a specific heat transfer power. Compared to mechanical pump systems that require continuous power to drive the pump, this has significant energy-saving advantages and aligns with the trend of green and low-carbon technological development.

[0059] In some embodiments, the voltage regulation system 107 further includes: Temperature sensor 1074 is located at the location of the heat source and is electrically connected to voltage control module 1073. It is configured to output the temperature signal of the heat source to voltage control module 1073. The voltage control module 1073 is also configured to receive a temperature signal and determine the power change of the heat source based on the temperature signal.

[0060] Here, the temperature sensor 1074 monitors the temperature of the heat source in real time to generate a temperature signal, which is then output to the voltage control module 1073. Upon receiving the temperature signal, the voltage control module 1073 determines the temperature change of the heat source based on the signal, and then, through a preset control algorithm, automatically adjusts the magnitude and polarity of the voltage output to the first electrode 1071 and the second electrode 1072 based on the temperature change.

[0061] The temperature sensor 1074 can also be replaced by a heat flow sensor, which is configured to output a heat load signal of the heat source to the voltage control module 1073. The voltage control module 1073 is also configured to receive the heat load signal, determine the heat load change of the heat source based on the heat load signal, and then automatically adjust the magnitude and polarity of the voltage output to the first electrode 1071 and the second electrode 1072 based on the change in heat load through a preset control algorithm.

[0062] Here, the control algorithm can employ simple proportional-integral-derivative (PID) control, or more complex fuzzy control or neural network control, to achieve better dynamic response and stability. The voltage control module is designed to achieve precise, rapid, and intelligent regulation of the heat pipe's heat exchange power.

[0063] In some embodiments, the controllable voltage is a forward voltage or a reverse voltage.

[0064] The core physical mechanism of dynamically adjusting the heat exchange power in this embodiment is based on the voltage-induced oxidation effect on the surface of liquid metal. When a positive voltage is applied between the liquid metal working fluid 106 and the solid electrolyte capillary 105 (assuming the liquid metal working fluid 106 is the anode), the anions (such as O2) in the solid electrolyte capillary 105... 2-Under the influence of an electric field, these highly reactive anions migrate to the surface of the liquid metal. They then undergo an electrochemical reaction with gallium atoms in the liquid metal working medium (such as gallium-based liquid metals), rapidly forming an extremely thin layer of gallium oxide (Ga₂O₃) solid film at the liquid-solid interface. This process is reversible; when the voltage is removed or a reverse voltage is applied, the oxide layer may be reduced or dissolved. This dynamically generated oxide layer is the starting point for a series of subsequent effects, and its thickness can be controlled by adjusting the voltage magnitude and application time, typically at the nanometer scale (e.g., 2-3 nm). This ability to precisely control surface chemical reactions through an electric field is the foundation for active regulation.

[0065] Liquid metals (such as pure gallium) possess extremely high surface tension (approximately 700 mN / m), which makes them prone to forming spherical droplets on a macroscopic scale, making them difficult to spread on solid surfaces. However, the situation changes fundamentally when a thin layer of gallium oxide is formed on the surface. Gallium oxide has a much lower surface energy than pure gallium, and its presence significantly reduces the surface tension of the liquid metal, bringing it close to zero. This dramatic decrease in surface tension causes the liquid metal to exhibit "superfluid" properties similar to liquid helium at extremely low temperatures, meaning it can flow through extremely small channels without resistance. In the embodiments of this disclosure, this "superfluid-like" effect is utilized to overcome the viscous resistance and capillary pressure limitations of liquid metal flow in a capillary wick.

[0066] The direct consequence of surface tension approaching zero is that the contact angle between the liquid metal and the solid wall also approaches zero degrees, achieving "superwetting" or "complete spreading." In a superwetting state, the liquid metal can easily spread on any solid surface and spontaneously penetrate into the tiny pores and cracks of the solid material. For the porous solid electrolyte capillary wick in this embodiment, this means that after applying voltage, the liquid metal, which was originally "stuck" due to high surface tension, can now effortlessly penetrate the entire pore network of the capillary wick. This greatly enhances the effective permeability of the capillary wick, equivalent to instantly increasing its "conductivity." This dramatic increase in permeability is the direct cause of the significant increase in the subsequent working fluid reflux rate and flow rate.

[0067] In some embodiments, the controllable voltage ranges from 0.1V to 10V.

[0068] The applied voltage range and control strategy in the embodiments of this disclosure are crucial for achieving efficient and safe operation. According to relevant research, inducing a significant reduction in the surface tension of gallium-based liquid metals typically requires applying a DC voltage of several volts. For example, in an electrolyte environment, a significant penetration effect can be observed by applying a voltage of 5V. However, in the solid-state electrolyte system of the embodiments of this disclosure, the specific optimal voltage range needs to be determined experimentally, as it depends on the ionic conductivity of the solid-state electrolyte, the structural parameters of the capillary wick, and the composition of the liquid metal. Too low a voltage may fail to effectively induce surface oxidation, while too high a voltage may result in an excessively thick oxide layer, hindering the flow of the liquid metal and even triggering unnecessary side reactions. Therefore, the embodiments of this disclosure propose a preferred voltage control range of 0.1V to 10V.

[0069] In terms of control strategy, either a continuously adjustable approach or a tiered control approach can be adopted. For example, several different voltage levels can be preset, corresponding to different heat exchange power levels, and switching can be performed according to the heat load demand. This strategy can simplify the control logic and improve the system's response speed.

[0070] Here, the relationship between the controllable voltage and surface tension is as follows: The relationship between the surface tension (γ) of liquid metals and the applied voltage (V) is fundamental to its control. In the region dominated by electrocapillary action, this relationship can be described by the integral form of the Lippmann equation: γ = γ0 - (1 / 2) × c × V², where γ0 represents the initial surface tension at zero voltage and c represents the capacitance per unit area of ​​the electric double layer. However, when electrochemical oxidation is involved, the relationship becomes more complex, typically exhibiting stronger nonlinearity and hysteresis effects. Experimental studies have shown that in alkaline electrolytes, applying an oxidation potential of approximately 1 V can cause the surface tension of gallium-based liquid metals to drop sharply from approximately 470 mN / m to near zero. This vast range of variation is key to achieving efficient control.

[0071] The relationship between voltage and the penetration rate of liquid metal is as follows: The permeation rate (v) of liquid metal in porous media is proportional to the driving pressure (ΔP), which in turn is related to the surface tension (γ) and contact angle (θ) (ΔP ∝ γ × cos(θ)). Since voltage can simultaneously decrease both γ and θ, the permeation rate is highly sensitive to voltage. In a study using a sponge as the porous medium, when the NaOH electrolyte concentration was fixed at 0.25 mol / L, increasing the voltage from 2.5 V to 5 V increased the diffusion rate of the liquid metal from 0.3 mm / s to 0.8 mm / s, more than doubling it. This demonstrates that the flow rate of liquid metal can be linearly or approximately linearly controlled by adjusting the voltage.

[0072] The fitting formula for voltage and heat exchange power is as follows: The heat transfer power (Q) of a heat pipe is related to the mass flow rate of the working fluid. The heat flux density (h×A×ΔT) is directly proportional to the heat flux density (Q= ×h×A×ΔT). And mass flow rate ( The heat transfer coefficient (h) is directly proportional to the permeation velocity (v) and the cross-sectional area of ​​the capillary wick, and is related to the physical properties of the permeation velocity (v). Therefore, a complete transfer function from voltage (V) to heat transfer power (Q) can be established. Although the specific formula varies depending on the geometry of the heat pipe, the capillary wick parameters, and the type of working fluid, its basic form can be expressed as: Q(V) = k × v(V) × ΔT, where k represents a constant related to the heat pipe structure, and v(V) is a function of voltage, describing the effect of voltage on the permeation velocity. Through experimental calibration, the following can be obtained: Figure 4 The QV relationship curve of the heat pipe shown is typically a non-linear growth curve, which grows rapidly in the low-pressure region and may tend to saturate in the high-pressure region. Figure 4 A graph showing the relationship between voltage and heat exchange power regulation provided in an exemplary embodiment of this disclosure is shown.

[0073] As shown in the figure, when no voltage is applied (V=0), the heat pipe has a baseline heat transfer power (Q0) driven by conventional capillary force. With increasing voltage, the heat transfer power increases rapidly, exhibiting a non-linear growth relationship. Once the voltage reaches a certain value, the power growth tends to level off, eventually reaching a saturation value (Q0). MAX By adjusting the voltage, it is possible to adjust Q0 and Q... MAX This allows for continuous and dynamic adjustment of the heat exchange power.

[0074] The voltage-regulated liquid metal heat pipe disclosed in this embodiment can actively and dynamically adjust itself in real time, continuously, and over a wide range according to changes in external heat load. By introducing an innovative voltage regulation mechanism, it aims to achieve precise control of the circulation rate of the working fluid inside the heat pipe, thereby enabling its heat exchange capacity to actively match various operating conditions from low to high loads. This dynamic adjustment capability will greatly expand the application range of the heat pipe, making it suitable for applications with stringent requirements for temperature control accuracy and response speed, such as heat dissipation of high-performance computer chips, cooling of laser weapons, and thermal management of new energy vehicle battery packs. The goal of this disclosure is to transform the heat pipe from a passive heat transfer element into an intelligent, proactively responsive thermal management unit, providing crucial assurance for the stable operation of modern electronic devices and complex systems.

[0075] This disclosure provides a voltage-regulated liquid metal heat pipe, aiming to achieve a highly reliable active thermal control technology with no moving parts. Existing active thermal control solutions, such as mechanical pump-driven systems, while capable of power regulation, suffer from wear, noise, vibration, and power consumption issues caused by moving parts, leading to reduced reliability – significant drawbacks. The voltage regulation mechanism proposed in this disclosure is entirely based on electrochemical reactions and electric field forces, with no mechanical movement involved in the entire regulation process. The solid electrolyte capillary wick and liquid metal working fluid inside the heat pipe are both solid and liquid, eliminating vulnerable components such as pumps and valves. This "all-solid-state" regulation method fundamentally eliminates the risk of mechanical failure, greatly improving the long-term operational reliability and stability of the system. Simultaneously, since regulation requires only a low voltage, the system's power consumption is extremely low. The goal of this disclosure is to provide an ideal thermal control solution that combines the flexibility of active control with the high reliability of passive systems.

[0076] This disclosure also provides a method for preparing a voltage-controlled liquid metal heat pipe. Figure 5 A schematic flowchart illustrating a method for fabricating a voltage-controlled liquid metal heat pipe according to an exemplary embodiment of this disclosure is shown. Figure 5 As shown, the fabrication method of this voltage-controlled liquid metal heat pipe includes: S501 provides a tube shell with an insulating section; S502, prepare a solid electrolyte capillary core and fix the solid electrolyte capillary core to the inner wall of the insulation section; S503, the inside of the tube shell is evacuated to a vacuum state, and liquid metal working fluid is injected into the inside of the tube shell under vacuum or protective atmosphere; S504 involves sealing the tube shell after it has been filled with liquid metal working fluid, and installing a voltage regulation system on the outside of the tube shell to obtain a liquid metal heat pipe.

[0077] Specifically, the steps for preparing a solid electrolyte capillary core may include: selecting high-purity zirconium oxide (ZrO2) powder and incorporating approximately 8 mol% yttrium oxide (Y2O3) as a stabilizer to form yttrium oxide-stabilized zirconium oxide (YSZ) powder. The YSZ powder is then uniformly mixed with an appropriate amount of organic binder (such as polyvinyl alcohol) and pore-forming agent (such as starch or graphite powder), and pressed into a green body of the desired shape (such as a cylindrical tube or sheet) using dry pressing or isostatic pressing techniques. Subsequently, the green body is sintered in a high-temperature furnace. The sintering temperature is a key process parameter, typically controlled between 1400℃ and 1600℃. At this temperature, a solid-phase reaction occurs between the powder particles, forming a dense ceramic body. Simultaneously, the pore-forming agent volatilizes, leaving uniformly distributed micropores inside the ceramic, forming a preliminary porous structure. After sintering, the green body is cooled to room temperature in the furnace to obtain a YSZ ceramic capillary core green body with a preliminary shape and porosity.

[0078] To further optimize the pore structure of solid electrolyte capillary wicks and increase specific surface area and capillary force, surface porosification treatment is required for the sintered green body. One effective method is chemical etching. The YSZ ceramic capillary wick is immersed in a solution of hydrofluoric acid (HF) or hot phosphoric acid (H3PO4) of a specific concentration. By controlling the etching time and temperature, the grain boundary phase on the ceramic surface is selectively dissolved, thereby forming a richer and smaller micro / nanopore structure based on the original sintered pores. Another method is physical vapor deposition (PVD)-assisted pore-forming technology. For example, a layer of nanoparticles is deposited on the surface of the solid electrolyte capillary wick, and then partially melted by heat treatment to form a porous layer with a rough surface. After this step, the porosity and specific surface area of ​​the solid electrolyte capillary wick are significantly increased, providing stronger capillary driving force and more contact interfaces for the liquid metal.

[0079] To achieve voltage regulation, a conductive electrode layer needs to be fabricated in a specific region of the YSZ capillary core. Magnetron sputtering is a high-precision option. The prepared YSZ capillary core is placed in a sputtering apparatus, using platinum (Pt) or gold (Au) as the target. Under vacuum, argon ions bombard the target, sputtering platinum or gold atoms, which then deposit on a predetermined region of the solid electrolyte capillary core (located in the adiabatic section), forming a second electrode to be electrically connected to the voltage regulation system. By controlling the sputtering power, time, and gas pressure, the thickness and uniformity of the electrode layer can be precisely controlled, typically ranging from tens to hundreds of nanometers. After deposition, the electrode layer bonds firmly to the YSZ ceramic, exhibiting good conductivity and chemical stability, and can serve as a counter electrode to form a complete electrochemical circuit with the internal liquid metal.

[0080] The prepared YSZ ceramic capillary wick was carefully installed into the heat pipe housing, ensuring its position was fixed and it was in close contact with the inner wall of the housing. Then, the inside of the heat pipe was evacuated to a high vacuum state (e.g., below 10 °C) using a vacuum system. -3 To remove air and other non-condensable gases, a precisely metered amount of gallium-based liquid metal (such as Galinstan) is injected into the heat pipe under vacuum, ensuring complete saturation of the capillary wick. The injection volume must be precisely calculated based on the heat pipe's internal volume and the capillary wick's porosity to ensure complete saturation of the capillary wick with the liquid metal at normal operating temperatures. After injection, the heat pipe is permanently sealed. Finally, the heat pipe is connected to an external voltage regulation system for performance testing. The tests include measuring the heat transfer power, thermal resistance, and response time of the heat pipe under different heat loads and applied voltages to verify its dynamic regulation performance.

[0081] Application of Liquid Metal Heat Pipes in Heat Dissipation of High-Power Electronic Devices: For high-performance computing chips, high-power laser diodes, and other electronic devices, the heat flux density is high and fluctuates dramatically, placing extremely high demands on the response speed and temperature control accuracy of the heat dissipation system. The liquid metal heat pipes of this disclosure can be integrated into the heat dissipation modules of these devices. The heat absorption section is tightly bonded to the chip surface via a high thermal conductivity interface material, while the heat dissipation section is connected to an air-cooled or liquid-cooled heat sink. By monitoring the chip temperature in real time, the voltage control module can quickly adjust the heat dissipation power of the heat pipe. When the chip temperature rises sharply due to a sudden computing task, the system can increase the voltage within milliseconds, instantly enhancing heat dissipation and stabilizing the chip temperature below a safe threshold, preventing performance degradation or damage due to overheating. This on-demand heat dissipation mode not only ensures the performance and reliability of the devices but also effectively reduces the overall energy consumption and noise of the heat dissipation system.

[0082] The above description is merely an illustration of some embodiments of this disclosure and the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

[0083] While specific embodiments of this disclosure have been described in detail by way of example, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A voltage-controlled liquid metal heat pipe, characterized in that: It includes a tube shell and a capillary core containing a liquid metal working fluid and a solid electrolyte encapsulated inside the tube shell. The tube shell includes, along the axial direction, a heat-absorbing section in contact with a heat source, a heat-insulating section in contact with a cold source, and a heat-dissipating section in contact with a cold source. The solid electrolyte capillary core is attached to the inner wall of the insulation section, and the cross-sectional area of ​​the solid electrolyte capillary core is smaller than the cross-sectional area of ​​the tube shell. The solid electrolyte capillary core has a porous structure for providing capillary force for the reflux of the liquid metal working fluid. The liquid metal heat pipe further includes a voltage regulation system configured to apply a controllable voltage between the liquid metal working fluid and the solid electrolyte capillary in response to a power change of the heat source, so as to dynamically adjust the heat exchange power of the liquid metal heat pipe through the controllable voltage.

2. The voltage-controlled liquid metal heat pipe as described in claim 1, characterized in that, The liquid metal working medium is a gallium-based liquid metal; the gallium-based liquid metal is a eutectic alloy containing gallium, indium and tin.

3. The voltage-controlled liquid metal heat pipe as described in claim 1, characterized in that, The liquid metal working fluid contains dispersed boron nitride nanosheets, which form a passivation protective layer on the surface of the liquid metal working fluid.

4. The voltage-controlled liquid metal heat pipe as described in claim 1, characterized in that, The solid electrolyte capillary core is made of a solid electrolyte material, which is yttrium oxide stabilized zirconia ceramic.

5. The voltage-controlled liquid metal heat pipe as described in claim 1, characterized in that, The porous structure has a gradient pore size distribution, and the average pore size of the solid electrolyte capillary core near the heat absorption section is smaller than the average pore size near the heat dissipation section.

6. The voltage-controlled liquid metal heat pipe as described in claim 1, characterized in that, The voltage regulation system includes: The first electrode is electrically connected to the liquid metal working fluid of the heat dissipation section; The second electrode is electrically connected to the capillary core of the solid electrolyte. A voltage control module, electrically connected to both the first and second electrodes, is configured to apply a controllable voltage between the first and second electrodes in response to power changes of the heat source.

7. The voltage-controlled liquid metal heat pipe as described in claim 6, characterized in that, The voltage regulation system also includes: A temperature sensor is disposed at the location of the heat source and electrically connected to the voltage control module, and is configured to output the temperature signal of the heat source to the voltage control module; The voltage control module is also configured to receive the temperature signal and determine the power change of the heat source based on the temperature signal.

8. The voltage-controlled liquid metal heat pipe as described in claim 1, characterized in that, The controllable voltage is either a forward voltage or a reverse voltage.

9. The voltage-controlled liquid metal heat pipe according to any one of claims 1 to 8, characterized in that, The controllable voltage range is 0.1V to 10V.

10. A method for preparing a voltage-controlled liquid metal heat pipe as described in any one of claims 1 to 9, characterized in that, include: Provide a tube shell with an insulating section; A solid electrolyte capillary core is prepared and fixed to the inner wall of the insulating section; The inside of the tube shell is evacuated to a vacuum state, and liquid metal working fluid is injected into the inside of the tube shell under vacuum or protective atmosphere; The tube shell is sealed after being filled with the liquid metal working fluid, and a voltage regulation system is installed on the outside of the tube shell to obtain the liquid metal heat pipe.

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