Near-field radiation heat flow regulation and control device based on cylindrical resonant cavity effect and use method of near-field radiation heat flow regulation and control device

Abstract

The invention discloses a near-field radiation heat flow regulation and control device based on a cylindrical resonant cavity effect and a use method, belongs to the technical field of micro / nano-scale thermal regulation and control, and solves the key technical problems of poor adjustability, small range and the like in a micro / nano-scale non-contact thermal function device. The device comprises a transmitting end, a receiving end, a cylindrical resonant cavity and the like which are all made of the same insulator-metal phase change material, phase change is triggered through temperature, the distance is adjusted in combination with PZT piezoelectric ceramics, and self-driven dynamic regulation and control of heat flow are achieved through the resonant cavity effect. According to the invention, through cooperation of the cylindrical resonant cavity and the insulator-metal phase change material and combination of PZT spacing adjustment, near-field radiation heat flow can be self-driven and adjusted without an external field, the problems of poor adjustment performance and small range of a micro / nano-scale thermal function device are solved, and the heat transmission efficiency and the adjustment precision are improved.

Description

Technical Field

[0001] The present invention relates to the field of micro / nanoscale thermal control technology, and in particular to a near-field radiation heat flux control device based on a cylindrical resonant cavity effect and a method of using the device. Background Art

[0002] When the distance between two or more interacting objects is less than or equal to the characteristic wavelength of thermal emission, heat exchange between them occurs primarily in the near-field region, dominated by evanescent electromagnetic waves. This is known as near-field radiative heat transfer. Due to the excitation of surface electromagnetic modes (such as surface plasmons and surface phonons), near-field radiative heat transfer far exceeds the blackbody thermal radiation limit. In recent years, the continuous advancement of micro- and nanofabrication technologies has significantly promoted the development and application of typical thermal functional devices such as thermal diodes, heat storage elements, and thermal switches. Among these, functional devices that rely on heat conduction and convection as heat transfer mechanisms are limited by the interplay of Kapitza resistance, phonon velocity, and nonlinear phonon processes, which significantly impact the device's thermal performance and efficiency. Therefore, near-field radiative heat transfer holds great promise in the development and design of contactless thermal functional devices at the micro- and nanoscale. However, current inventions in the field of near-field radiative thermal control primarily focus on planar blocks, thin films, and metasurface structures, which can lead to technical challenges such as difficulty controlling structural flatness, poor heat flow control performance, and a limited adjustment range. The realization of efficient and reliable heat flux control devices through structural innovation remains a technical challenge in the field of micro- and nanoscale energy transfer. Furthermore, current inventions related to near-field radiative heat transfer rarely mention dynamic control due to external thermal excitation, and this dynamic control of heat flux is of great significance in the actual operation of devices. In the existing technology, vanadium dioxide (VO2) materials have attracted widespread attention due to their excellent insulator-metal phase transition properties, which also points to the development direction of dynamic heat flux control in micro- and nanoscale devices.

[0003] In summary, there is an urgent need to propose an efficient and reliable micro / nanoscale non-contact thermal flow dynamic control device and method to solve the above-mentioned technical problems. Summary of the Invention

[0004] This invention proposes a near-field radiation heat flow control device based on the cylindrical resonant cavity effect and its use method. By placing the transmitting end and the receiving end (VO2 nanoparticles) on the axis of the cylindrical resonant cavity, the distance between the two is precisely adjusted using PZT piezoelectric ceramics. d Combined with the insulator-metal phase transition characteristics of VO2 material at 341K, it relies on the resonant cavity effect to enhance heat flow and reduce energy loss without external field excitation, filling the technical gap in the dynamic regulation of near-field radiation heat flow, and solving the key technical problems of poor adjustable performance and small range in micro / nanoscale non-contact thermal functional devices.

[0005] A near-field radiation heat flux control device based on the cylindrical resonant cavity effect includes a transmitting end, a heat-conducting shell, a fixing device, a cylindrical resonant cavity, a receiving end, and a horizontal displacement device. The cylindrical resonant cavity is arranged in the heat-conducting shell, and the transmitting end and the receiving end are relatively arranged in the cylindrical resonant cavity, and the transmitting end and the receiving end are both located on the axis of the cylindrical resonant cavity. One end of the fixing device is fixedly connected to the transmitting end through an intermediate connecting rod, and the other end is fixedly connected to the inner wall of the heat-conducting shell. One end of the horizontal displacement device is fixedly connected to the receiving end through the intermediate connecting rod, and the other end is fixedly connected to the inner wall of the heat-conducting shell. The horizontal displacement device is used to change the position of the receiving end, thereby adjusting the distance between the transmitting end and the receiving end. d , The transmitting end, the receiving end and the cylindrical resonant cavity are made of the same insulator-metal phase change material.

[0006] Furthermore, the horizontal displacement device is made of lead zirconate titanate piezoelectric ceramics.

[0007] Furthermore, the transmitting end, the receiving end and the cylindrical resonant cavity are all made of VO2.

[0008] Furthermore, both the emitting end and the receiving end are nanoparticles with a radius of 5 to 100 nm, which are prepared by a sol-gel method.

[0009] Furthermore, the inner radius of the cylindrical resonant cavity R c The thickness is 0.1~10µm and the thickness is 10~100µm.

[0010] Furthermore, the fixing device is in the shape of a truncated cone.

[0011] A method for using a near-field radiation heat flux control device based on a cylindrical resonant cavity effect, based on the above-mentioned near-field radiation heat flux control device based on a cylindrical resonant cavity effect, comprises the following steps: S1. Connect the transmitting end to the heat-conducting shell through a fixing device, and fix the receiving end to the shell through a horizontal displacement device. The two are located on the axis of the cylindrical resonant cavity. Initially, the distance d and the radius of the cylindrical resonant cavity R c satisfy d , R c >4 times the nanoparticle radius; S2. When the ambient temperature T changes, the VO2 material exceeds the critical temperature of phase change. T c =341K, it begins to transition from an insulating state to a metallic state, and the optical properties change spontaneously; S3, when T <T c When , VO2 is in an insulating state, supporting surface phonon polaritons, and the cylindrical resonant cavity enhances the radiative heat flow; when T > T c When VO2 turns into metallic state, the heat flow decreases significantly; S4. Temperature changes simultaneously trigger the horizontal displacement device made of lead zirconate titanate piezoelectric ceramics. The horizontal displacement device automatically adjusts the position of the receiving end and accurately changes the spacing. d , compensating for the effect of phase change on heat flow; S5, cylindrical resonant cavity constrains electromagnetic mode and enhances heat flow control efficiency through cavity effect; S6, temperature response, phase change regulation and spacing adjustment work together to ultimately keep the radiative heat flux stable under temperature fluctuations.

[0012] Furthermore, in S4, when the temperature rises, the horizontal displacement device drives the receiving end away from the transmitting end, increasing d To weaken the heat flow; When the temperature drops, the horizontal displacement device drives the receiving end closer to the transmitting end, reducing d To enhance heat flow.

[0013] Beneficial effects of the present invention: 1. The two key components (transmitter and receiver) of the cylindrical resonant cavity-based near-field radiation heat flux control device described in this invention are both located inside the cylindrical resonant cavity. This arrangement not only stimulates the cylindrical resonant cavity effect (cavity mode) within the confined space to enhance energy transfer between the two terminals, but also helps reduce energy loss to the external environment, thereby improving the heat transfer efficiency and control performance of the thermal modulator.

[0014] 2. Based on VO2 material at temperature T = Insulator-to-metal phase transition characteristics at 341K. The near-field radiation heat flux control device based on the cylindrical resonant cavity effect described in this invention can spontaneously change the optical thermal properties of the material in response to external temperature, thereby achieving dynamic regulation of heat exchange between the transmitter and receiver. Furthermore, this control method is completely dependent on the system's inherent structure and material properties, and does not require the introduction of other external sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of a near-field radiation heat flux control device based on a cylindrical resonant cavity effect in an embodiment of the present invention; Figure 2 It is a fixed parameter R c = 0.1µm and d = 1µm, temperature TThe radiation heat conduction between the two terminals h The two curves in the figure respectively show the situation with the VO2 cylindrical resonant cavity and the vacuum state (without resonant cavity). In the case described above, the materials of the transmitting end and the receiving end are also made of VO2 material. T = T c A phase transition occurs when T < T c When VO2 is in an insulating state; when T When the temperature is >350K, VO2 is completely in the metallic state; when T c < T When the temperature is less than 350K, it is a mixed state of insulator and metal; Figure 3 It is a fixed parameter d = 1µm, when the temperature is T = Cavity radius at 330K and 360K R c and radiation thermal conductivity h relationship; Figure 4 It is a fixed parameter d = 1µm, cavity radius R c Compared with switch η Here we define the switching ratio η for T = 330K radiative thermal conductivity and T = the ratio of the radiation thermal conductivity at 330K, that is: η = h T (330 K) / h T (360 K); Figure 5 It is a fixed parameter R c = 0.1µm, when the temperature is T = Horizontal distance between transmitter and receiver at 330K and 360K d and radiation thermal conductivity h relationship.

[0016] Among them, 1 is the transmitting end, 2 is the heat-conducting shell, 3 is the fixing device, 4 is the cylindrical resonant cavity, 5 is the receiving end, and 6 is the horizontal displacement device. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] Reference Figure 1 As shown, a near-field radiation heat flow control device based on the cylindrical resonant cavity effect includes a transmitting end 1, a heat-conducting shell 2, a fixing device 3, a cylindrical resonant cavity 4, a receiving end 5 and a horizontal displacement device 6. The cylindrical resonant cavity 4 is arranged in the heat-conducting shell 2, and the transmitting end 1 and the receiving end 5 are relatively arranged in the cylindrical resonant cavity 4, and the transmitting end 1 and the receiving end 5 are both located on the axis of the cylindrical resonant cavity 4. One end of the fixing device 3 is fixedly connected to the transmitting end 1 through an intermediate connecting rod, and the other end is fixedly connected to the inner wall of the heat-conducting shell 2. One end of the horizontal displacement device 6 is fixedly connected to the receiving end 5 through an intermediate connecting rod, and the other end is fixedly connected to the inner wall of the heat-conducting shell 2. The horizontal displacement device 6 is used to change the position of the receiving end 5, thereby adjusting the distance between the transmitting end 1 and the receiving end 5. d , The transmitting end 1, the receiving end 5 and the cylindrical resonant cavity 4 are made of the same insulator-metal phase change material.

[0019] Specifically, the present invention arranges the transmitting end 1 and the receiving end 5 relative to each other in the cylindrical resonant cavity 4 and both are located on its axis, and uses a fixing device 3 and a horizontal displacement device 6 to connect with the heat-conducting housing 2 respectively to fix the transmitting end 1 and adjust the position of the receiving end 5, so that the transmitting end 1, the receiving end 5 and the cylindrical resonant cavity 4 use the same insulator-metal phase change material, which can stimulate the cylindrical resonant cavity effect in the confined space to enhance the energy transmission between the two terminals, and is also conducive to reducing the loss of energy to the external environment, thereby improving the heat transfer efficiency and control performance of the thermal modulator; and based on the insulator-metal phase change material at temperature T= The insulator-metal phase transition characteristics at 341K can spontaneously change the optical properties of the material according to the external temperature response, thereby realizing dynamic regulation of heat exchange between the transmitter and receiver. This regulation method relies entirely on the system's own structure and material properties and proceeds spontaneously without the introduction of other external source fields.

[0020] Furthermore, the horizontal displacement device 6 is made of lead zirconate titanate (PZT) piezoelectric ceramics.

[0021] Specifically, the horizontal displacement device 6 in the present invention is made of lead zirconate titanate piezoelectric ceramics, which can use its piezoelectric effect to achieve nanometer-level precision displacement adjustment. When the ambient temperature changes, it can automatically trigger the lead zirconate titanate piezoelectric ceramics to drive the position change of the receiving end, accurately changing the distance between the transmitting end and the receiving end. d When the temperature rises, the receiving end 5 is driven away from the transmitting end 1 to increase the distance and weaken the heat flow. When the temperature drops, the receiving end 5 is driven close to the transmitting end 1 to reduce the distance and enhance the heat flow, thereby dynamically compensating for the heat flow change caused by the phase change, ensuring the accuracy and response speed of heat flow regulation. At the same time, the piezoelectric properties of the material make the regulation process without additional energy and completely rely on temperature change triggering, further improving the self-driven regulation capability and structural stability of the device of the present invention.

[0022] Furthermore, the transmitting end 1, the receiving end 5 and the cylindrical resonant cavity 4 are all made of vanadium dioxide VO2, which is an insulator-metal phase change material.

[0023] Specifically, the transmitting end, receiving end and cylindrical resonant cavity are all made of VO2, which can be used to T =341K insulator-metal phase transition characteristics. When the ambient temperature exceeds the critical temperature of phase transition, the material spontaneously changes from the insulating state to the metallic state and changes the optical properties. T <T c When it is in the insulating state, it supports surface phonon polaritons, and the cylindrical resonant cavity enhances the radiation heat flow. T>T c When it turns into a metallic state, the heat flow is significantly reduced, thereby realizing the dynamic "on-off" regulation of the heat flow. The phase change characteristics of the VO2 material and the cylindrical resonant cavity effect work together to make the heat flow switching ratio reach 160. At the same time, the phase change process of the material does not require external field excitation and relies entirely on temperature response, ensuring the reliability and efficiency of the device's self-driven regulation.

[0024] Furthermore, both the transmitting end 1 and the receiving end 5 are nanoparticles with a radius of 5 to 100 nm, which are prepared by a sol-gel method.

[0025] Specifically, both the transmitting end 1 and the receiving end 5 are nanoparticles with a radius of 5 to 100 nm and are prepared by the sol-gel method, which can ensure that the nanoparticles have a uniform particle size distribution and good crystallinity, thereby forming a stable radiation heat flow transmission path on the axis of the cylindrical resonant cavity 4, and the nanoscale size makes the distance between the transmitting end 1 and the receiving end 4 d and the inner radius of the cylindrical resonant cavity 4 R c Easy to satisfy d , R cThe radiation electric dipole approximation condition of >4 times the nanoparticle radius effectively enhances the near-field radiation heat transfer efficiency. At the same time, the phase change characteristics of VO2 nanoparticles prepared by the sol-gel method are stable, which can accurately trigger the insulator-metal phase transition when the temperature changes, and cooperate with the cylindrical resonant cavity 4 effect to achieve efficient regulation of heat flow.

[0026] Furthermore, the inner radius of the cylindrical resonant cavity 4 R c The thickness is 0.1~10µm and the thickness is 10~100µm.

[0027] Specifically, the inner radius of the cylindrical resonant cavity 4 is R c The size of the cylindrical resonant cavity 4 can match the radius of the nanoparticles at the transmitting end 1 and the receiving end 5, ensuring the spacing d and the cylindrical resonant cavity radius 4 R c satisfy d 、 R c The radiative electric dipole approximation condition of >4 times the radius of the nanoparticle is met, thereby effectively stimulating the cylindrical resonant cavity effect to enhance the radiative heat flow. At the same time, the reasonable radius and thickness design can optimize the confinement ability of the cylindrical resonant cavity 4 on the electromagnetic mode, inhibit the loss of energy to the external environment, and improve the efficiency of heat flow regulation. In addition, this size range is easy to be compatible with micro-nano processing technology, ensuring the preparation accuracy and structural stability of the cylindrical resonant cavity 4, so that it can undergo phase change synchronously with the VO2 material at the transmitting end 1 and the receiving end 5 when the temperature changes, and synergistically realize the dynamic regulation of heat flow.

[0028] Furthermore, the fixing device 3 is in the shape of a truncated cone.

[0029] Specifically, the fixing device 3 is in the shape of a truncated cone, which can achieve a stable connection between the transmitting end 1 and the thermally conductive shell 2 through the structural design of the truncated cone. The conical surface structure of the truncated cone can evenly disperse the mechanical stress on the transmitting end 1, avoid position displacement due to stress concentration, and ensure that the transmitting end 1 is always located on the axis of the cylindrical resonance cavity 4, thereby maintaining the stability of the cylindrical resonance cavity effect. At the same time, the truncated cone shape is convenient for fixed connection with the intermediate connecting rod and the inner wall of the thermally conductive shell 2. While ensuring the structural strength, it reduces the interference with the electromagnetic mode inside the cylindrical resonance cavity 4, so that the coordinated control effect of the transmitting end 1, the receiving end 5 and the cylindrical resonance cavity 4 can be fully exerted, thereby improving the accuracy and reliability of heat flow control.

[0030] A method for using a near-field radiation heat flux control device based on a cylindrical resonant cavity effect, based on the above-mentioned near-field radiation heat flux control device based on a cylindrical resonant cavity effect, comprises the following steps: S1. Connect the transmitting end 1 to the heat-conducting housing 2 through the fixing device 3, and fix the receiving end 5 to the housing through the horizontal displacement device 6. The two are located on the axis of the cylindrical resonant cavity 4. Initially, the distance d and the radius of the cylindrical resonant cavity 4 R c satisfy d , R c >4 times the nanoparticle radius; S2. When the ambient temperature T When the temperature of VO2 material exceeds the critical temperature of phase change, T c =341K, it begins to transition from an insulating state to a metallic state, and the optical properties change spontaneously; S3, when T < T c When , VO2 is in an insulating state, supporting surface phonon polaritons, and the cylindrical resonant cavity 4 enhances the radiative heat flow; when T > T c When VO2 turns into metallic state, the heat flow decreases significantly; S4. Temperature changes simultaneously trigger the horizontal displacement device 6 made of lead zirconate titanate piezoelectric ceramics. The horizontal displacement device 6 automatically adjusts the position of the receiving end and accurately changes the spacing. d , compensating for the effect of phase change on heat flow; S5, cylindrical resonant cavity 4 constrains the electromagnetic mode and enhances the efficiency of heat flow control through the cavity effect; S6, temperature response, phase change regulation and spacing adjustment work together to ultimately keep the radiative heat flux stable under temperature fluctuations.

[0031] Specifically, the present invention connects the transmitting end 1 to the heat-conducting housing 2 through the fixing device 3, and fixes the receiving end 5 to the heat-conducting housing 2 through the horizontal displacement device 6, and the two are located on the axis of the cylindrical resonant cavity 4, so that the initial spacing d and the radius of the cylindrical resonant cavity 4 R c Satisfying the radiation electric dipole approximation condition, when the ambient temperature changes, the insulator-metal phase transition characteristics of VO2 material are used to spontaneously change the optical properties. T <T c Supporting surface phonon polaritons and cylindrical resonant cavity 4 to enhance radiation heat flow, T >T c When it turns into a metallic state, it suppresses the heat flow, and the distance is automatically adjusted by the lead zirconate titanate piezoelectric ceramic horizontal displacement device 6 dCompensate for the effect of phase change on heat flow, enhance the control efficiency with the help of 4 constrained electromagnetic modes of the cylindrical resonant cavity, and ultimately keep the radiant heat flow stable under temperature fluctuations through the synergistic effect of temperature response, phase change control and spacing adjustment. This method does not require external field excitation and relies entirely on the system structure and material properties to achieve self-driven dynamic control. It can effectively solve the problems of poor adjustable performance and small range in micro / nanoscale non-contact thermal functional devices, and achieve efficient control of heat flow with a switching ratio of 160.

[0032] Furthermore, in S4, when the temperature rises, the horizontal displacement device 6 drives the receiving end 5 away from the transmitting end 1, increasing d To weaken the heat flow; when the temperature drops, the horizontal displacement device 6 drives the receiving end 5 closer to the transmitting end 1, reducing d To enhance heat flow.

[0033] Specifically, when the temperature rises, the horizontal displacement device 6 drives the receiving end 5 away from the transmitting end 1, increasing the distance to weaken the heat flow. When the temperature drops, the receiving end 5 is driven close to the transmitting end 1, reducing the distance to enhance the heat flow. Through this precise dynamic adjustment of the distance, the influence of the phase change of the VO2 material on the heat flow can be compensated in real time, so that the temperature response, phase change regulation and distance regulation form a synergistic effect, further improving the accuracy and dynamic response capability of the heat flow regulation, ensuring that the radiant heat flow remains stable when the temperature fluctuates, and realizing precise self-driven heat flow regulation without external field excitation, effectively solving the technical problems of small heat flow regulation range and poor response in micro / nanoscale non-contact thermal functional devices.

[0034] The following are embodiments of the present invention: Specific implementation method 1: through Figure 1 This embodiment describes a near-field radiation heat flux control device based on the cylindrical resonant cavity effect, comprising a heat-conducting housing 2, a fixture 3, a transmitter 1, a cylindrical resonant cavity 4, a horizontal displacement device 6, and a receiver 5. One end of the fixture 3 is connected to the transmitter 1 inside the cylindrical resonant cavity 3 via an intermediate connecting rod, and the other end is directly connected to the outermost heat-conducting housing 2. During actual operation, the relative position of the transmitter 1 and the heat-conducting housing 2 remains unchanged.

[0035] Specific implementation method 2: through Figure 1 This embodiment describes a near-field radiation heat flux control device based on the cylindrical resonant cavity effect. Similarly, one end of the horizontal displacement device 6 is connected to the receiving end 5 inside the cylindrical resonant cavity 3 through an intermediate connecting rod, and the other end is connected to the heat-conducting housing 2. The distance between the transmitting end 1 and the receiving end 5 is d ; The separation distance can be precisely adjusted by the nano-scale horizontal displacement device 6, thereby regulating the radiative heat exchange between the two terminals.

[0036] Specific implementation method three: through Figure 1 This embodiment describes a near-field radiation heat flux control device based on the cylindrical resonant cavity effect. The horizontal displacement device 6 is manufactured using lead zirconate titanate (PZT) piezoelectric ceramic technology. It can shift horizontally (axially) in response to external signals, thereby precisely controlling the position of the receiving end. This technology is suitable for displacement control in nanoscale devices such as scanning probe microscopes, nanoscale actuators, and sensors.

[0037] Specific implementation method four: through Figure 1 This embodiment describes a near-field radiation heat flux control device based on the cylindrical resonant cavity effect. The transmitting terminal 1 and the receiving terminal 5 are both located on the axis of the cavity, with no direct contact between them. When the cylindrical resonant cavity is absent (in a vacuum state), there is only a single transmission channel for radiation heat exchange between the two terminals, namely, heat channel 1. However, when the cylindrical resonant cavity of the present invention is present, the interaction of the electromagnetic modes within the cavity provides an additional channel for energy transfer between the transmitting and receiving terminals, namely, heat channel 2. The introduction of this heat channel also makes it possible to control the radiation heat exchange between the two terminals.

[0038] Specific implementation method five: through Figure 1 This embodiment describes a near-field radiative heat flow control device based on the cylindrical resonant cavity effect. The transmitter 1, receiver 5, and cylindrical resonant cavity 4 all utilize the phase-change material VO2. When the system's external temperature dynamically responds, the VO2 material undergoes a reversible transition between insulating and metallic states, dynamically controlling the radiative heat transfer between the two terminals. The transmitter 1 and receiver 5 can be fabricated using a sol-gel method; the cylindrical resonant cavity 4 is fabricated by cutting nanowires or nanorods using focused ion beam etching.

[0039] Specific implementation method six: through Figure 1 This embodiment describes a near-field radiation heat flux control device based on the cylindrical resonant cavity effect. All components of the regulator are located inside the heat-conducting shell 2. This arrangement can make the structure of the entire modulator more compact, which is more conducive to saving internal space of micro / nano devices and improving efficiency.

[0040] Figure 2 Shows the cavity radius under fixed parameters R c = 0.1µm and d = 1µm, temperature T and radiation thermal conductivity h The two curves show the situation in the presence of VO2 cylindrical resonant cavity and vacuum state (no cylindrical resonant cavity). It can be found that VO2 material T =T c A phase transition occurs when T < T c When , VO2 is in an insulating state; at this time, the radiation thermal conductivity between the two terminals is high, and the modulator is in the open state. T When the temperature is >350K, VO2 is in a metallic state; the radiation thermal conductivity is low and it is considered to be in a closed state. T c < T Below 350K, VO2 is in a mixed state of insulator and metal, and the radiative thermal conductivity gradually decreases within this temperature range. Comparing the two curves reveals that within the temperature range explored, the radiative thermal conductivity between the two terminals in the presence of the cylindrical resonant cavity is much higher than that in a vacuum state (without the resonant cavity), confirming that the introduction of the cylindrical resonant cavity can significantly enhance the radiative heat transfer between the two terminals.

[0041] Figure 3 Shown is the fixed parameter d = 1µm, the temperatures are T = Cavity radius at 330K and 360K R c and radiation thermal conductivity h It can be found that the radiation heat conductance between the two terminals of the cylindrical resonant cavity is higher than the radiation heat conductance in the vacuum state at the same temperature at a small radius, and as the cavity radius increases, they gradually converge to their respective corresponding vacuum states.

[0042] Figure 4 Shown is the fixed parameter d = 1µm, the thermal regulator's on / off ratio [ η = h T (330 K) / h T (360K)] and cavity radius R c It can be found that at a small radius, the on-off ratio between the two terminals can reach 160, which is higher than the control ratio in the vacuum state under the same conditions. As the radius increases, the on-off ratio of the thermal modulator in the presence of the cylindrical resonant cavity is lower than that in the vacuum state. This is because at a large radius, the cylindrical resonant cavity effect has an effect on the metallic state ( T = 360K) than the insulating state ( T = 330K) is more obvious.

[0043] Figure 5 Shown is the fixed parameter R c = 0.1µm, pitch dThe relationship between the thermal conductivity and the radiation. It can be found that as the spacing d With the increase of , the radiative heat conduction decreases gradually in all cases. T = 330K (or T = 360K) and found that when the spacing is small, the radiation heat conduction generated by the cylindrical resonant cavity case and the vacuum state case is not much different. d As the cavity increases, the cylindrical resonant cavity effect gradually becomes more prominent. Therefore, the radiation thermal conductivity in the presence of the cavity is much higher than that in the vacuum state.

[0044] The present invention proposes a near-field radiation heat flux control device based on the cylindrical resonant cavity effect and a method of use. By placing the transmitting end 1 and the receiving end 5 on the axis of the cylindrical resonant cavity 4 and using PZT piezoelectric ceramics to adjust the spacing, combined with the insulator-metal phase change characteristics of the VO2 material, in the absence of external field excitation, the heat flux is enhanced and energy loss is reduced by relying on the resonant cavity effect. The cylindrical resonant cavity effect in a confined space can be stimulated to enhance energy transmission, reduce energy loss to the external environment, and improve the heat transfer efficiency and control performance of the thermal modulator. At the same time, the optical properties of the material are changed according to the external temperature response to achieve dynamic regulation of the heat flux. The regulation is completely dependent on the system's own structure and material properties and is carried out spontaneously without the introduction of other external fields. The precise spacing dynamic adjustment can also compensate for the influence of phase change on the heat flux in real time, ensuring that the radiation heat flux is stable when the temperature fluctuates. This solves the problems of poor adjustable performance and small range in micro / nanoscale non-contact thermal functional devices, and realizes efficient and reliable heat flux regulation.

[0045] While the specific embodiments of the present invention have been described in detail above, these are intended to be exemplary only, and the present invention is not limited thereto. Any equivalent modifications or substitutions to the present invention that would be apparent to those skilled in the art are also within the scope of the present invention. Therefore, any equivalent modifications or substitutions made without departing from the spirit and scope of the present invention are intended to be encompassed within the scope of the present invention.

Claims

1. A near-field radiation heat flux control device based on cylindrical resonant cavity effect, characterized in that: The invention comprises a transmitting end (1), a heat-conducting shell (2), a fixing device (3), a cylindrical resonant cavity (4), a receiving end (5) and a horizontal displacement device (6), wherein the cylindrical resonant cavity (4) is arranged in the heat-conducting shell (2), the transmitting end (1) and the receiving end (5) are relatively arranged in the cylindrical resonant cavity (4), and the transmitting end (1) and the receiving end (5) are both located on the axis of the cylindrical resonant cavity (4), one end of the fixing device (3) is fixedly connected to the transmitting end (1) through an intermediate connecting rod, and the other end is fixedly connected to the inner wall of the heat-conducting shell (2), and one end of the horizontal displacement device (6) is fixedly connected to the receiving end (5) through the intermediate connecting rod, and the other end is fixedly connected to the inner wall of the heat-conducting shell (2); The horizontal displacement device (6) is used to change the position of the receiving end (5), thereby adjusting the distance between the transmitting end (1) and the receiving end (5). d ; The transmitting end (1), the receiving end (5) and the cylindrical resonant cavity (4) are made of the same insulator-metal phase change material.

2. The near-field radiation heat flux control device based on cylindrical resonant cavity effect according to claim 1, characterized in that: The horizontal displacement device (6) is made of lead zirconate titanate piezoelectric ceramics.

3. The near-field radiation heat flux control device based on cylindrical resonant cavity effect according to claim 1, characterized in that: The transmitting end (1), the receiving end (5) and the cylindrical resonant cavity (4) are all made of VO2.

4. The near-field radiation heat flux control device based on cylindrical resonant cavity effect according to claim 3, characterized in that: The emitting end (1) and the receiving end (5) are both nanoparticles with a radius of 5 to 100 nm, which are prepared by the sol-gel method.

5. The near-field radiation heat flux control device based on cylindrical resonant cavity effect according to claim 3, characterized in that: Inner radius of the cylindrical resonant cavity (4) R c The thickness is 0.1~10µm and the thickness is 10~100µm.

6. The near-field radiation heat flux control device based on cylindrical resonant cavity effect according to claim 1, characterized in that: The fixing device (3) is in the shape of a truncated cone.

7. A method for using a near-field radiation heat flux control device based on a cylindrical resonant cavity effect, based on the near-field radiation heat flux control device based on a cylindrical resonant cavity effect according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Connect the transmitting end (1) to the heat-conducting housing (2) through the fixing device (3), and fix the receiving end (5) to the housing through the horizontal displacement device (6). Both are located on the axis of the cylindrical resonant cavity (4). Initially, the spacing d and the radius of the cylindrical resonant cavity (4) R c satisfy d , R c > 4 times the nanoparticle radius; S2. When the ambient temperature T When the temperature of VO2 material exceeds the critical temperature of phase change, T c =341K, it begins to transition from an insulating state to a metallic state, and the optical properties change spontaneously; S3, when T < T c When , VO2 is in an insulating state, supporting surface phonon polaritons, and the cylindrical resonant cavity (4) enhances the radiative heat flow; when T > T c When VO2 turns into metallic state, the heat flow decreases significantly; S4. Temperature changes simultaneously trigger the horizontal displacement device (6) made of lead zirconate titanate piezoelectric ceramics. The horizontal displacement device (6) automatically adjusts the position of the receiving end and accurately changes the spacing. d , compensating for the effect of phase change on heat flow; S5, cylindrical resonant cavity (4) constrains the electromagnetic mode and enhances the efficiency of heat flow control through the cavity effect; S6, temperature response, phase change regulation and spacing adjustment work together to ultimately keep the radiative heat flux stable under temperature fluctuations.

8. The method for using the near-field radiation heat flux control device based on the cylindrical resonant cavity effect according to claim 7, characterized in that: In S4, When the temperature rises, the horizontal displacement device (6) drives the receiving end (5) away from the transmitting end (1), increasing d To weaken the heat flow; When the temperature decreases, the horizontal displacement device (6) drives the receiving end (5) closer to the transmitting end (1), reducing d To enhance heat flow.

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