Self-driven deformation thermoelectric device

Abstract

The invention discloses a self-driven deformation thermoelectric device, the self-driven deformation thermoelectric device is of a deformable structure, the deformable structure comprises a deformable area, and the self-driven deformation thermoelectric device comprises a flexible substrate; the thermoelectric material is located on the upper surface of the flexible substrate, and the thermoelectric material comprises a p-type thermoelectric material, an n-type thermoelectric material and a metal electrode material; the driving assembly is located on the lower surface of the flexible substrate or located on the lower surface of the flexible substrate and the upper surface of the metal electrode material in the deformable area at the same time, and the driving assembly is used for driving the shape of the self-driven deformable thermoelectric device to change correspondingly when the temperature or humidity of the external environment changes. The self-driven deformation thermoelectric device can realize self-driven response and actively optimize heat transmission and energy collection efficiency based on the change of external temperature or humidity.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal control and thermoelectric conversion, and in particular relates to a self-driven deformation thermoelectric device. Background Art

[0002] With the continuous development and progress of science and technology, wearable devices are gradually developing in the direction of lightweight and miniaturization. Therefore, the size of batteries in wearable devices also needs to be reduced. However, the reduction in battery size weakens its ability to store electricity, which cannot meet the endurance of wearable devices and limits the further development of wearable devices. The human body is a constant temperature heat source. Using energy harvesting technology to convert the heat energy released by the human body into electrical energy is an ideal choice for achieving continuous self-powering of wearable devices. Thermoelectric devices can convert human heat energy into electrical energy, thereby achieving continuous self-powering of wearable devices.

[0003] The invention patent with publication number CN111392690A discloses a pressure sensing system powered by a thin film thermoelectric device and a preparation method thereof. First, the thin film thermoelectric device is prepared by magnetron sputtering technology. A thermally conductive composite material with high thermal conductivity is encapsulated on the hot end of the thin film thermoelectric device, and a hydrogel is introduced as a heat sink on the cold end. When the thin film thermoelectric device is attached to a heat source to generate electricity, a large temperature difference with the environment can be established; the microstructure size of the organic polymer thin film material is controlled by laser engraving technology, and the thickness of the Ag / Ti conductive film is controlled by magnetron sputtering technology to regulate the resistance of the conductive film material, so as to realize the assembly of a high-sensitivity and low-working-current pressure sensor; finally, after the thin film thermoelectric device and the pressure sensor are integrated, a flexible thin film thermoelectric device with a high output voltage (15.8mV) is attached to the human skin to generate electricity and supply power to the pressure sensor, thereby obtaining a self-powered pressure sensing system, which can be used for real-time monitoring of the human pulse.

[0004] The invention patent with the publication number CN114038988A discloses a design and preparation method of a stretchable and formable thermoelectric device based on high-performance thin film materials. First, a regular "paper-kirigami structure" array pattern is cut on the substrate thin film material, and then high-performance p-type and n-type thermoelectric materials are deposited on the substrate in sequence, and then electrode materials are deposited to connect the p-type thermoelectric material and the n-type thermoelectric material in series. The thin-film thermoelectric device based on the paper-kirigami structure described in the present invention can be converted from a two-dimensional planar structure to a three-dimensional structure under the action of external force, so that the heat conduction in the device is converted from the in-plane direction to the vertical direction, maximizing the use of the temperature difference between the heat source and the environment, and improving the power generation performance of the device.

[0005] With the widespread application of thermoelectric devices in the fields of intelligent thermal control and energy collection, their adaptability and performance have become the main bottlenecks restricting their further promotion. The structural design and functional realization of the thermoelectric devices provided by the above patents have the following shortcomings: First, it is difficult for existing thermoelectric devices to deform. Traditional thermoelectric devices are mainly based on hard inorganic materials. Due to their rigid characteristics, they are difficult to adapt to complex application environments and diverse operating requirements. This fixed structure limits its use in dynamic and non-planar environments, reducing the applicability of thermoelectric devices in wearable devices, flexible electronic devices and other fields. On the other hand, there is a lack of intelligent control capabilities for environmental response: existing thermoelectric devices can usually only passively respond to temperature differences for energy conversion, and lack the ability to adaptively adjust to changes in external temperature or humidity. This deficiency not only limits its application scenarios, but also makes it difficult to meet the future demand for highly intelligent and multifunctional thermoelectric systems. Summary of the invention

[0006] The present invention provides a self-driven deformable thermoelectric device, which can achieve self-driven response based on changes in external temperature or humidity, and actively optimize heat transfer and energy collection efficiency.

[0007] The present invention provides a self-driven deformable thermoelectric device, wherein the self-driven deformable thermoelectric device is a deformable structure, wherein the deformable structure includes a deformable region, and wherein the self-driven deformable thermoelectric device includes:

[0008] Flexible substrate;

[0009] Thermoelectric materials and metal electrode materials, wherein the thermoelectric materials are located on the upper surface of the flexible substrate, and the thermoelectric materials include p-type thermoelectric materials, n-type thermoelectric materials and metal electrode materials;

[0010] A driving component is located on the lower surface of the flexible substrate or on the lower surface of the flexible substrate and the upper surface of the metal electrode material in the deformable area, and is used to drive the shape of the self-driven deformable thermoelectric device to change when the temperature or humidity of the external environment changes.

[0011] Preferably, the deformable structure is a "paper-kirigami structure" array pattern;

[0012] The driving component is located at a position corresponding to the metal electrode material and the lower surface of the flexible substrate, so that when the temperature or humidity changes, the "paper-kirigami structure" array pattern is driven to stretch and deform to form a three-dimensional structure.

[0013] Preferably, when the deformable structure is a "paper-kirigami structure" array pattern, the self-driven deformable thermoelectric device is prepared by the following method, including:

[0014] (1) cleaning and drying the flexible substrate, and then forming a thermoelectric material pattern on the upper surface of the flexible substrate to obtain a p-type thermoelectric material, an n-type thermoelectric material and a metal electrode material connected in series;

[0015] (2) injecting a driving component liquid onto the metal electrode material based on the first mask template, demolding after semi-curing, and then curing by gradient heating to form a driving component;

[0016] (3) Repeat step (2) to form a driving component at a corresponding position on the lower surface of the flexible substrate;

[0017] (4) Based on the second mask template, a femtosecond laser is used to process the flexible substrate to obtain a "paper-kirigami structure" array pattern, thereby obtaining a self-driven deformable thermoelectric device.

[0018] Preferably, when the deformable structure is a "paper-kirigami structure" array pattern, the self-driven deformable thermoelectric device is prepared by the following method, including:

[0019] (1) processing the flexible substrate using a femtosecond laser based on the second mask template to obtain a "paper-kirigami structure" array pattern, and then cleaning and drying the flexible substrate;

[0020] (2) A thermoelectric material pattern is formed on the upper surface of the flexible substrate to obtain a p-type thermoelectric material, an n-type thermoelectric material and a metal electrode material connected in series, and the cut driving component membrane is respectively pasted on the corresponding positions on the metal electrode material and the lower surface of the flexible substrate based on a stainless steel mask template, thereby obtaining a self-driven deformable thermoelectric device.

[0021] Preferably, the deformable structure is in a shape radiating outwards with the central axis as a reference, including a central portion and a plurality of radiating portions connected to the central portion and symmetrically distributed and radiating with the central axis of the central portion as a reference, and the area where each radiating portion is located is a deformable area;

[0022] Each radiation part includes a thermoelectric material, a flexible substrate and a driving component arranged in sequence from top to bottom, wherein the p-type thermoelectric material and the n-type thermoelectric material of each radiation part are connected in series through a metal electrode material;

[0023] When the temperature or humidity of the external environment changes, the shape of each radiating portion is changed by using a driving component.

[0024] Preferably, when the deformable structure is a shape radiating outward from the center, the self-driven deformable thermoelectric device is prepared by the following method, including:

[0025] (1) Cleaning and drying the flexible substrate;

[0026] (2) depositing a p-type thermoelectric material and an n-type thermoelectric material on each radiation portion on the upper surface of the flexible substrate, and depositing a metal electrode material at the same time, and connecting the p-type thermoelectric material and the n-type thermoelectric material in series through the metal electrode material;

[0027] (3) pasting the driving component film on the lower surface of the flexible substrate;

[0028] (4) A femtosecond laser is used to cut the flexible substrate into a shape radiating outward from the central axis of the center portion, thereby obtaining a self-driven deformable thermoelectric device.

[0029] Preferably, the deformable structure is a shape distributed by an array of window opening and closing units, and the area corresponding to each window opening and closing unit is a deformable area;

[0030] Each window opening and closing unit includes a thermoelectric material, a flexible substrate and a driving component arranged in sequence from top to bottom, wherein the p-type thermoelectric material and the n-type thermoelectric material of each window opening and closing unit are connected in series through a metal electrode material;

[0031] When the temperature or humidity of the external environment changes, the shape of each window opening and closing unit is changed by using a driving component.

[0032] Preferably, when the deformable structure is a shape distributed by an array of window opening and closing units, the self-driven deformable thermoelectric device is prepared by the following method, including:

[0033] (1) using a femtosecond laser to cut a flexible substrate into a shape distributed by an array of window opening and closing units, and cleaning and drying the flexible substrate;

[0034] (2) depositing a p-type thermoelectric material and an n-type thermoelectric material on each window opening and closing unit on the upper surface of the flexible substrate, and depositing a metal electrode material at the same time, and connecting the p-type thermoelectric material and the n-type thermoelectric material in series through the metal electrode material;

[0035] (3) The driving component film is pasted on the lower surface of each window opening and closing unit to obtain a self-driven deformable thermoelectric device.

[0036] Preferably, the driving component comprises a moisture sensitive material or a temperature sensitive material;

[0037] The humidity sensitive material includes a shape memory hydrogel or a swellable polymer;

[0038] The temperature sensitive material is a liquid crystal elastomer or a bimetallic strip.

[0039] Preferably, the driving component is a humidity driven material or a temperature driven material;

[0040] The humidity driving material is Nafion material, polyurethane, sodium polyacrylate, natural polysaccharide material, polymer hydrogel and polyvinyl alcohol / polyacrylic acid composite material;

[0041] The temperature-driven material is a polymer-based shape memory material or a thermal response material, the polymer-based shape memory material is a polyurethane-based, polyether-based or polyester-based material, and the thermal response material is a liquid crystal polymer or a perovskite material;

[0042] The flexible substrate is polyimide or silicone rubber;

[0043] The metal electrode material is copper or silver;

[0044] The p-type thermoelectric material is a p-type-Sb2Te3-based thermoelectric material;

[0045] The n-type thermoelectric material is an n-type Bi2Te3-based thermoelectric material.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The present invention arranges a driving component in the variability area, so that the self-driven deformable device can change its shape through the driving component when stimulated by external temperature or humidity changes, thereby realizing autonomous heat dissipation to achieve the purpose of heat transfer. At the same time, due to the change in shape, the temperature difference between the material close to the heat source and the material far away from the heat source changes, thereby realizing power generation and energy collection of thermoelectric materials, thereby improving the energy collection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a flow chart of the preparation of the self-driven deformation thermoelectric device prepared in Example 1 of the present invention;

[0049] Figure 2 This is a diagram showing the shape change of the self-driven deformable thermoelectric device prepared in Example 1 of the present invention as the humidity changes;

[0050] Figure 3 This is a flow chart of the preparation of the self-driven deformation thermoelectric device prepared in Example 2 of the present invention;

[0051] Figure 4 This is a flow chart of the preparation of the self-driven deformation thermoelectric device prepared in Example 3 of the present invention;

[0052] Figure 5 This is a diagram showing the shape change of the self-driven deformable thermoelectric device prepared in Example 3 of the present invention as the humidity changes;

[0053] Figure 6 This is a flow chart of the preparation of the self-driven deformation thermoelectric device prepared in Example 4 of the present invention;

[0054] Figure 7This is a diagram showing the shape change of the self-driven deformable thermoelectric device prepared in Example 4 of the present invention as the humidity changes. DETAILED DESCRIPTION

[0055] In conjunction with the accompanying drawings, the specific embodiments of the present invention are further described. In order to realize that the thermoelectric device can realize self-driven reaction under external stimulation, realize intelligent heat transfer and maximize energy utilization, the specific embodiments of the present invention use a driving component to enable the self-driven deformable thermoelectric device of the deformable structure to change its shape under the stimulation of external temperature or humidity, realize automatic heat dissipation and increase the temperature difference between the hot and cold ends of the device, so as to realize intelligent heat transfer and maximize energy utilization. The specific description is as follows:

[0056] A specific embodiment of the present invention provides a self-driven deformable thermoelectric device, which is a deformable structure. Due to the existence of the deformable structure, it can be transformed from a two-dimensional structure to a three-dimensional structure. It can be understood that the deformable structure includes a deformable region.

[0057] The deformable structure provided in the specific embodiment of the present invention is to realize the self-deformation of the subsequent device structure. It is necessary to select a deformable thin-film thermoelectric device, such as a "paper-cut structure" array pattern, a shape radiating outward from the center, such as a flower-shaped structure, a shape distributed by an array of window opening and closing units, such as a window-shaped structure, etc., and design a specific geometric pattern to realize the deformation ability of the device. When preparing the deformable structure, cutting technology such as femtosecond laser precision machining can be used to process the designed deformable structure onto a flexible substrate and ensure the precise matching of the thermoelectric material layer and the substrate layer.

[0058] A self-driven deformable thermoelectric device provided in a specific embodiment of the present invention includes a flexible substrate, a thermoelectric material and a driving component.

[0059] The flexible substrate provided in the specific embodiment of the present invention uses polyimide or silicone rubber as a bearing structure to ensure that it has good mechanical flexibility and thermal stability.

[0060] The thermoelectric material provided in a specific embodiment of the present invention is located on the upper surface of the flexible substrate. The thermoelectric material includes a p-type thermoelectric material, an n-type thermoelectric material and a metal electrode material connected in series. The specific embodiment of the present invention can evenly coat the thermoelectric material and the electrode material on the flexible substrate through screen printing, spraying or mask-assisted deposition to form a thick film layer.

[0061] The p-type thermoelectric material and n-type thermoelectric material provided in the specific embodiment of the present invention use high-performance thick-film thermoelectric materials as the core functional layer based on their excellent thermoelectric properties. The metal electrode material is copper or silver, and its micro-nano structure is designed to optimize electrical conductivity and thermal conductivity.

[0062] The driving component provided in a specific embodiment of the present invention is located on the lower surface of the flexible substrate or on the lower surface of the flexible substrate and the upper surface of the metal electrode material within the deformable area, and is used to drive the shape of the self-driven deformable thermoelectric device to change accordingly when the temperature or humidity of the external environment changes.

[0063] The specific embodiment of the present invention uses humidity-sensitive materials (such as shape memory hydrogels, expandable polymers) and temperature-sensitive materials (such as liquid crystal elastomers, bimetallic strips) as driving components.

[0064] A specific embodiment of the present invention utilizes a deposition or spraying process to uniformly coat the driving material to the target area of ​​the paper-kirigami structure, i.e., the lower surface of the flexible substrate or the lower surface of the flexible substrate and the upper surface of the metal electrode material that are simultaneously located in the deformable area. The driving material is firmly bonded to the substrate through a photocuring or heat treatment process to ensure that it closely coordinates with the paper-kirigami structure during the deformation process.

[0065] The specific embodiment of the present invention optimizes the microstructure of the driving material to improve its response sensitivity, deformation amplitude and mechanical stability, optimizes the geometric parameters of the humidity / temperature driving structure (such as the position, thickness and area distribution of the deformation area) through finite element simulation, ensures that the driving material can achieve controllable deformation under environmental changes, and integrates humidity / temperature sensitive materials at key positions of the deformable thermoelectric device structure (on the outside of the structural deformation protrusion) to enable the driving structure to work together with the deformable paper-cut structure.

[0066] The specific embodiment of the present invention realizes reliable self-deformation from a two-dimensional planar structure to a three-dimensional deformable structure by designing and processing a regular structure on a flexible substrate material, and then combining high-performance thermoelectric materials with humidity / temperature sensitive materials. Specifically, the present invention first processes an array pattern with geometric rules on a flexible substrate, then uniformly deposits high-performance thick-film thermoelectric materials on the surface of the structure, and designs an electrode structure to connect p-type and n-type thermoelectric materials in series, and finally introduces humidity or temperature sensitive materials in the key deformation area to construct an intelligent thermoelectric device that can achieve self-driven deformation.

[0067] The specific embodiments of the present invention introduce humidity / temperature sensitive materials to achieve dynamic response and automatic deformation of the paper-cut structure when the external humidity or temperature changes, so that the device can intelligently adjust the structure and performance according to environmental changes to meet the application requirements of intelligent thermal control and energy collection. Through this innovative design, the device of the present invention exhibits excellent performance in a variety of scenarios, especially in body temperature power generation, environmental thermal control and energy collection systems in wearable devices. It has broad application prospects, and provides important reference and technical support for the future development of intelligent thermoelectric devices.

[0068] In a specific embodiment, the deformable structure provided in this embodiment is a "paper-kirigami structure" array pattern, which is obtained from the invention patent application with publication number CN114038988A. The driving component is located at a position corresponding to the metal electrode material and the lower surface of the flexible substrate, so that when the temperature or humidity changes, the metal electrode material and the lower surface of the flexible substrate are pulled at the same time, driving the "paper-kirigami structure" array pattern to stretch and deform to form a three-dimensional structure, so that heat can be dissipated from the three-dimensional structure more easily. At the same time, since the heat of the stretched part in the air is lower, a suitable temperature difference is autonomously formed to realize material power generation and energy collection.

[0069] The self-driven deformable thermoelectric device with a deformable structure of a "paper-cut structure" array pattern provided by the specific embodiment of the present invention has good heat dissipation and heat storage when applied to the human body. The specific description is as follows: Sweating is a physiological function of the human body to excrete and regulate body temperature. Sweating has only one purpose - that is heat dissipation. Studies have shown that when the human body is in a quiet state, the human body begins to sweat when the temperature reaches about 30°C; if the air humidity is relatively high, the ambient temperature reaches 25°C, which can cause sweating; when people exercise, due to the large amount of heat generated by the body and the temperature rises, the amount of sweating usually increases sharply to facilitate heat dissipation. The structural changes of the PI / Nafion double-layer membrane structure during the absorption of water, as the amount of moisture absorption increases, the structure will bend toward the PI side. Therefore, this characteristic of the Nafion membrane hygroscopic expansion can be used to combine it with a thin film thermoelectric device to prepare a humidity-driven deformable wearable intelligent thermoelectric device. For the paper-cut structure, the window is closed in the initial state and is in a heat preservation state. When the temperature rises, the human body will sweat. The Nafion membrane absorbs sweat and expands, causing the structure to change. The window of the paper-cut structure is opened for heat dissipation, and it can generate electricity while having intelligent thermal control function. Another advantage of this design is that when the device is deformed, the direction of heat transfer inside the thin-film thermoelectric device also changes, which can change the heat transfer direction of the thermoelectric device to the same direction as the human body-environment temperature gradient, thereby increasing the temperature difference utilization efficiency of the device. In addition, the deformed three-dimensional structure can directly use air convection to dissipate heat without the need for an additional heat dissipation module.

[0070] Flexible electronic devices based on paper-cut structures have great advantages in the wearable field. Due to the unique deformation characteristics of the paper-cut structure, the size of its window can change with the elongation of the structure, so the air permeability can be adjusted according to the actual situation to adjust the temperature and humidity of the skin surface. The test results of the wind speed at the outlet of the paper-cut structure with its elongation are shown in the figure below. When its elongation is 0%, the window of the paper-cut structure is in a closed state, and the wind speed at the outlet is 0m s -1When it starts to stretch, the window opens and the wind speed at the outlet increases rapidly. As the elongation of the paper-cut structure increases, the wind speed at the outlet also increases, but the growth rate slows down. When the elongation is higher than 40%, the wind speed at the outlet tends to be stable at 2.52ms. -1 , gradually approaching the inlet wind speed (2.56ms -1 ).

[0071] In a specific embodiment, the deformable structure provided in this embodiment is a shape that radiates outwards based on the central axis, including a central portion and a plurality of radiating portions connected to the central portion and symmetrically distributed and radiating based on the central axis of the central portion. In one embodiment, its shape is as follows: Figure 4 In the flower structure shown, the area where each radiation portion is located is a deformable area.

[0072] Each radiation part provided by the specific embodiment of the present invention includes a thermoelectric material, a flexible substrate and a driving component arranged in sequence from top to bottom, wherein the p-type thermoelectric material and the n-type thermoelectric material of each radiation part are connected in series through a metal electrode material; when the temperature or humidity of the external environment changes, the shape of each radiation part is changed accordingly by using the driving component, thereby achieving the purpose of heat transfer and energy collection. Compared with the paper-cut structure, the deformable structure of this embodiment is simpler to prepare. Since only a single deformation occurs, it is only necessary to integrate the driving material on one side of the substrate. Similar to the paper-cut structure, the flower structure thermoelectric device of this embodiment can be driven by humidity to change from a planar structure to a three-dimensional structure, which changes the heat transfer direction of the device. The heat transfer direction of the device is the same as the direction of the heat source-environment temperature difference, which improves the thermal utilization efficiency of the device; on the other hand, the three-dimensional structure formed increases the heat dissipation area of ​​the cold end of the device, improves the heat dissipation efficiency, further improves the effective temperature difference established at both ends of the TEG thermoelectric arm, and improves the power generation performance of the device.

[0073] In a specific embodiment, the deformable structure provided by the specific embodiment of the present invention is in a shape distributed by an array of window opening and closing units, and the area corresponding to each window opening and closing unit is a deformable area.

[0074] Each window opening and closing unit includes a thermoelectric material, a flexible substrate and a driving component arranged in sequence from top to bottom, wherein the p-type thermoelectric material and the n-type thermoelectric material of each window opening and closing unit are connected in series through a metal electrode material; when the temperature or humidity of the external environment changes, the driving component is used to make the shape of each window opening and closing unit change accordingly, thereby achieving the purpose of heat transfer and energy collection. Compared with the paper-cut structure, the deformable structure of this embodiment is simpler to prepare. Since only a single deformation occurs, it is only necessary to integrate the driving material on one side of the substrate. The deformation law of the window structure of this embodiment is similar to that of the flower structure. With the increase of the expansion rate of the Nafion membrane, the degree of the window tilting continues to increase, and the plane structure changes to a three-dimensional structure, which changes the heat transfer direction of the device. The heat transfer direction of the device is the same as the direction of the heat source-environment temperature difference, which improves the heat utilization efficiency of the device; on the other hand, the three-dimensional structure formed increases the heat dissipation area of ​​the cold end of the device, improves the heat dissipation efficiency, further improves the effective temperature difference established at both ends of the TEG thermoelectric arm, and improves the power generation performance of the device. In addition, as the degree of tilting increases, the heat exchange area on the surface of the heat source increases, which can further improve the heat dissipation efficiency of the heat source.

[0075] Example 1

[0076] One embodiment of the present invention is a preparation process for preparing a humidity-driven paper-kirigami structure-shaped thermoelectric device based on Nafion solution. The detailed flow chart is as follows: Figure 1 As shown, the steps are as follows:

[0077] (1) Figure 1 As shown in ①, a femtosecond laser is used to cut a PI (polyimide) flexible substrate, but a paper-cut pattern is not cut out to prevent leakage of the Nafion solution along the cut during the curing process.

[0078] (2) Cleaning the PI flexible substrate to remove pollutants and particles on the surface of the substrate and reduce defects in the subsequent film preparation process; improve the adhesion between the film and the substrate. The cleaning method is to soak it in detergent water, acetone, anhydrous ethanol and deionized water for 15 minutes in sequence, and finally blow dry the substrate with nitrogen and then send it to a microwave plasma cleaner for further cleaning.

[0079] (3) Figure 1 As shown in ②-④, magnetron sputtering is used to deposit p-Sb2Te3, n-Bi2Te3 and Cu / Ti electrodes in sequence. Considering that high-performance thermoelectric materials can only be obtained at a higher substrate temperature (≥350°C), and Nafion membrane is a polymer material that cannot withstand high temperatures for a long time, the functional membrane layer of the thermoelectric device is deposited first, and then the Nafion membrane layer is integrated on the device.

[0080] (4) Mold preparation: Use single-sided adhesive PI tape as a template and use femtosecond laser to process the designed shape to obtain a PI tape mask.

[0081] (5) Use a syringe to absorb the Nafion solution and inject it onto the PI flexible substrate with the PI tape mask attached, then place it in a vacuum drying oven for heating and curing. Control the heating temperature to 50°C ± 5°C and cure for ~1 hour to concentrate the solution concentration to about 80%, which is in a semi-cured state, and then demold it.

[0082] (6) The demolded PI flexible substrate is placed in a vacuum oven and a gradient temperature rise method is used to completely solidify the Nafion. The oven temperature is set in four stages: first, the temperature is raised to 130°C at a rate of 10°C per minute, and then kept at this temperature for 4 hours to allow the solvent to completely evaporate. Next, the temperature is raised to 150°C at a rate of 10°C per minute, and then kept at this temperature for 14 hours to allow the Nafion to completely crystallize. Finally, the temperature is naturally cooled to room temperature to form a pattern, such as Figure 1 As shown in (41).

[0083] (7) Repeat steps (5) and (6) to solidify the Nafion membrane on the other side of the PI flexible substrate; the specific structure of the Nafion membrane layer solidified on the other side of the PI flexible substrate is as follows: Figure 2 As shown in (a).

[0084] (8) Figure 1 As shown in ⑦, a femtosecond laser is used to cut a paper-cut pattern on a PI substrate with a Nafion film cured thereon to obtain a self-driven deformable thermoelectric device, such as Figure 2 As shown in (b)-(e), when the humidity in the environment increases, the self-driven deformable thermoelectric device changes shape as the Nafion membrane expansion rate changes from 0% to 4%. When the expansion rate increases, the heat dissipation is accelerated and more energy can be collected.

[0085] Example 2

[0086] One embodiment of the present invention is a process for preparing a humidity-driven kirigami structured device based on a commercial Nafion membrane. The kirigami structured humidity-driven kirigami thermoelectric device consists of three parts: a PI substrate, a thermoelectric / electrode material, and a Nafion membrane. The process for preparing a humidity-driven kirigami structured device based on a commercial Nafion membrane is as follows: Figure 3 The preparation method is roughly the same as the process of Example 1 based on Nafion solution preparation, and the difference is mainly in two aspects:

[0087] (1) First, when laser cutting the PI flexible substrate in the first step, the paper-cut pattern is cut out, and then the flexible substrate is cleaned, eliminating the last step of preparing the Nafion membrane and then aligning and cutting, thereby reducing the number of processing times;

[0088] (2) Another difference is that the preparation method of the humidity-driven deformation structure is different. After the thermoelectric material pattern is formed on the upper surface of the flexible substrate, the commercial Nafion membrane is first cut into a set size and then pasted to the specified position of the paper-cut structure. The advantages of this method are simple processing, high preparation efficiency, and no need for long-term heating to solidify the polymer solution into a film. In this regard, the present invention uses a stainless steel mask to assist the Nafion membrane pasting to improve the device integration accuracy.

[0089] Example 3

[0090] One embodiment of the present invention is a preparation process of a humidity-driven flower-shaped device based on a commercial Nafion membrane. The detailed flow chart is as follows: Figure 4 As shown, the specific steps are as follows:

[0091] (1) A femtosecond laser is used to cut a PI flexible substrate to cut out a marking pattern, which is a cross alignment mark for alignment during subsequent thin film deposition.

[0092] (2) Cleaning the substrate to remove pollutants and particles on the substrate surface, reduce defects in the subsequent film preparation process, and improve the adhesion between the film and the substrate. The cleaning method is to soak in detergent water, acetone, anhydrous ethanol and deionized water for 15 minutes, and finally blow dry the substrate with nitrogen; then send it to a microwave plasma cleaner for further cleaning.

[0093] (3) Figure 4 As shown in ②, ③ and ④, p-Sb2Te3, n-Bi2Te3 and Cu / Ti electrodes are deposited in sequence by magnetron sputtering, so that p-Sb2Te3, n-Bi2Te3 and Cu / Ti electrodes are located on each radiation portion, and p-Sb2Te3, n-Bi2Te3 and Cu / Ti electrodes are connected in series.

[0094] (4) The commercial Nafion membrane is pasted on the bottom of the device deposited in the previous step. The device is cut using a femtosecond laser to cut out a flower pattern to obtain a self-driven deformable thermoelectric device. As the Nafion membrane expands, the structure changes as shown in the figure below. Figure 5As shown in ①-⑤, when the expansion rate is 0-8% respectively, the amplitude of the warping of the radiation part of the self-driven deformable thermoelectric device obtained in this embodiment gradually increases. When the expansion rate increases, the deformation degree of the structure increases, the heat dissipation efficiency of the device is improved, and the effective temperature difference established at both ends of the TEG thermoelectric arm is further improved, thereby improving the power generation performance of the device.

[0095] Example 4

[0096] One embodiment of the present invention is a preparation process for preparing a humidity-driven window structure shapeable device based on a commercial Nafion membrane, and the specific steps are as follows:

[0097] (1) Figure 6 As shown in ①, a femtosecond laser is used to cut a PI flexible substrate to cut out a shape distributed by an array of window opening and closing units, namely a window pattern;

[0098] (2) Cleaning the substrate to remove pollutants and particles on the substrate surface, reduce defects in the subsequent film preparation process, and improve the adhesion between the film and the substrate. The cleaning method is to soak in detergent water, acetone, anhydrous ethanol and deionized water for 15 minutes, and finally blow dry the substrate with nitrogen; then send it to a microwave plasma cleaner for further cleaning;

[0099] (3) Figure 6 As shown in ②, ③ and ④, magnetron sputtering is used to deposit p-Sb2Te3, n-Bi2Te3 and Cu / Ti electrodes on each window opening and closing unit in turn, and p-Sb2Te3 and n-Bi2Te3 are connected in series through Cu / Ti electrodes.

[0100] (4) Figure 7 As shown in (a), the cut commercial Nafion membrane is pasted to the bottom of each window opening and closing unit in the previous step, as shown in Figure 7 As shown in (b), when the expansion rate is 0-8% respectively, the tilting amplitude of each window opening and closing unit of the self-driven deformable thermoelectric device obtained in this embodiment gradually increases. When the expansion rate increases, the deformation degree of the structure increases, the heat dissipation efficiency of the device is improved, and the effective temperature difference established at both ends of the TEG thermoelectric arm is further improved, thereby improving the power generation performance of the device.

Claims

1. A self-driven deformation thermoelectric device, characterized in that: The self-driven deformable thermoelectric device is a deformable structure, the deformable structure includes a deformable region, and the self-driven deformable thermoelectric device includes: Flexible substrate; Thermoelectric materials and metal electrode materials, wherein the thermoelectric materials are located on the upper surface of the flexible substrate, and the thermoelectric materials include p-type thermoelectric materials, n-type thermoelectric materials and metal electrode materials; A driving component is located on the lower surface of the flexible substrate or on the lower surface of the flexible substrate and the upper surface of the metal electrode material in the deformable area, and is used to drive the shape of the self-driven deformable thermoelectric device to change when the temperature or humidity of the external environment changes.

2. The self-driven deformation thermoelectric device according to claim 1, characterized in that: The deformable structure is a "paper-kirigami structure" array pattern; The driving component is located at a position corresponding to the metal electrode material and the lower surface of the flexible substrate, so that when the temperature or humidity changes, the "paper-kirigami structure" array pattern is driven to stretch and deform to form a three-dimensional structure.

3. The self-driven deformation thermoelectric device according to claim 2, characterized in that: When the deformable structure is a "paper-kirigami structure" array pattern, the self-driven deformable thermoelectric device is prepared by the following method, including: (1) cleaning and drying the flexible substrate, and then forming a thermoelectric material pattern on the upper surface of the flexible substrate to obtain a p-type thermoelectric material, an n-type thermoelectric material and a metal electrode material connected in series; (2) injecting a driving component liquid onto the metal electrode material based on the first mask template, demolding after semi-curing, and then curing by gradient heating to form a driving component; (3) Repeat step (2) to form a driving component at a corresponding position on the lower surface of the flexible substrate; (4) Based on the second mask template, a femtosecond laser is used to process the flexible substrate to obtain a "paper-kirigami structure" array pattern, thereby obtaining a self-driven deformable thermoelectric device.

4. The self-driven deformation thermoelectric device according to claim 2, characterized in that: When the deformable structure is a "paper-kirigami structure" array pattern, the self-driven deformable thermoelectric device is prepared by the following method, including: (1) Using a femtosecond laser to process the flexible substrate based on the second mask template to obtain a "paper-kirigami structure" array pattern, and then cleaning and drying the flexible substrate; (2) A thermoelectric material pattern is formed on the upper surface of the flexible substrate to obtain a p-type thermoelectric material, an n-type thermoelectric material and a metal electrode material connected in series, and the cut driving component membrane is respectively pasted on the corresponding positions on the metal electrode material and the lower surface of the flexible substrate based on a stainless steel mask template, thereby obtaining a self-driven deformable thermoelectric device.

5. The self-driven deformation thermoelectric device according to claim 1, characterized in that: The deformable structure is in a shape that radiates outwards based on the central axis, including a central portion and a plurality of radiating portions connected to the central portion and symmetrically distributed and radiating based on the central axis of the central portion, and the area where each radiating portion is located is a deformable area; Each radiation part includes a thermoelectric material, a flexible substrate and a driving component arranged in sequence from top to bottom, wherein the p-type thermoelectric material and the n-type thermoelectric material of each radiation part are connected in series through a metal electrode material; When the temperature or humidity of the external environment changes, the shape of each radiating portion is changed by using a driving component.

6. The self-driven deformation thermoelectric device according to claim 5, characterized in that: When the deformable structure is a shape radiating outward from the center, the self-driven deformable thermoelectric device is prepared by the following method, including: (1) Cleaning and drying the flexible substrate; (2) depositing a p-type thermoelectric material and an n-type thermoelectric material on each radiation portion on the upper surface of the flexible substrate, and depositing a metal electrode material at the same time, and connecting the p-type thermoelectric material and the n-type thermoelectric material in series through the metal electrode material; (3) pasting the driving component film on the lower surface of the flexible substrate; (4) A femtosecond laser is used to cut the flexible substrate into a shape radiating outward from the central axis of the center portion, thereby obtaining a self-driven deformable thermoelectric device.

7. The self-driven deformation thermoelectric device according to claim 1, characterized in that: The deformable structure is a shape distributed by an array of window opening and closing units, and the area corresponding to each window opening and closing unit is a deformable area; Each window opening and closing unit includes a thermoelectric material, a flexible substrate and a driving component arranged in sequence from top to bottom, wherein the p-type thermoelectric material and the n-type thermoelectric material of each window opening and closing unit are connected in series through a metal electrode material; When the temperature or humidity of the external environment changes, the shape of each window opening and closing unit is changed by using a driving component.

8. The self-driven deformation thermoelectric device according to claim 7, characterized in that: When the deformable structure is a shape distributed by an array of window opening and closing units, the self-driven deformable thermoelectric device is prepared by the following method, including: (1) using a femtosecond laser to cut a flexible substrate into a shape distributed by an array of window opening and closing units, and cleaning and drying the flexible substrate; (2) depositing a p-type thermoelectric material and an n-type thermoelectric material on each window opening and closing unit on the upper surface of the flexible substrate, and depositing a metal electrode material at the same time, and connecting the p-type thermoelectric material and the n-type thermoelectric material in series through the metal electrode material; (3) The driving component film is pasted on the lower surface of each window opening and closing unit to obtain a self-driven deformable thermoelectric device.

9. The self-driven deformation thermoelectric device according to claim 1, characterized in that: The driving component includes a humidity sensitive material or a temperature sensitive material; The humidity sensitive material includes a shape memory hydrogel or a swellable polymer; The temperature sensitive material is a liquid crystal elastomer or a bimetallic strip.

10. The self-driven deformation thermoelectric device according to claim 1, characterized in that: The driving component is a humidity driven material or a temperature driven material; The humidity driving material is Nafion material, polyurethane, sodium polyacrylate, natural polysaccharide material, polymer hydrogel and polyvinyl alcohol / polyacrylic acid composite material; The temperature-driven material is a polymer-based shape memory material or a thermal response material, the polymer-based shape memory material is a polyurethane-based, polyether-based or polyester-based material, and the thermal response material is a liquid crystal polymer or a perovskite material; The flexible substrate is polyimide or silicone rubber; The metal electrode material is copper or silver; The p-type thermoelectric material is a p-type-Sb2Te3-based thermoelectric material; The n-type thermoelectric material is an n-type Bi2Te3-based thermoelectric material.

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