Hollow-structure S-shaped electrode flexible wearable thermoelectric device and preparation method and application thereof

Abstract

The invention belongs to the technical field of intelligent wearing, and particularly relates to a hollow-structure S-shaped electrode flexible wearable thermoelectric device and a preparation method and application thereof. The invention discloses a hollow-structure S-shaped electrode flexible wearable thermoelectric device array which can be self-powered, and belongs to the field of intelligent wearing. Comprising a miniature temperature monitoring array component and a local temperature adjusting array component. Each of the miniature temperature monitoring array component and the local temperature adjusting array component is composed of a self-designed block thermoelectric arm, a flexible insulation heat insulation substrate layer, a flexible insulation heat conduction covering layer, an elastic wire, a flexible electrode and the like. The thermoelectric arm is made of a block-shaped thermoelectric material pressed by a self-designed die. The array component has a hollow structure, so that the thermoelectric performance is improved. The elastic wire is an S-shaped elastic wire. According to the flexible wearable thermoelectric device array, a new method is provided for realizing synchronous temperature monitoring and regulation under the condition of self power supply and meeting the local thermal comfort requirement.

Description

Technical Field

[0001] The present invention belongs to the field of smart wearable technology, and specifically relates to a flexible wearable thermoelectric device with a hollow structure and an S-shaped electrode, as well as a preparation method and application thereof. Background Art

[0002] With the development of human society, the world's energy crisis and environmental problems have become more prominent. Traditional non-renewable energy such as coal, oil, and natural gas are becoming increasingly depleted. Environmental problems such as air pollution and greenhouse effect in the process of industrial social development also need to be solved urgently. Therefore, it is very necessary to develop green, new, renewable new energy and new energy conversion materials.

[0003] The thermoelectric effect is a phenomenon of direct energy conversion between heat and electricity due to the movement of electrons and holes in a material.

[0004] Thermoelectric materials are environmentally friendly functional materials that can achieve direct conversion between thermal energy and electrical energy. They can be used for cooling using the Peltier effect. U.S. Patent No. US20210135410A1 (published on May 6, 2021) discloses a thermoelectric device with enhanced heat dissipation and more efficient cooling capabilities. This is an important achievement in the practical application of the Peltier effect. The Peltier effect can not only use waste heat generated by the environment and the human body for energy conversion, but also reduce the energy consumption generated by space temperature control technology (air conditioning, etc.), effectively solving problems such as energy waste.

[0005] The use of thermoelectricity to generate electricity from waste heat and to regulate temperature and reduce energy consumption is of great development significance. Inorganic thermoelectric materials, which offer the best thermoelectric properties at room temperature, are the working materials for most Peltier coolers and thermoelectric generators.

[0006] At present, a variety of thermoelectric materials have been discovered, including Bi2Te3 and its related alloys, lead telluride (PbTe) and silicon germanium (SiGe) alloys. Among them, Bi2Te3-based composite thermoelectric materials are famous for their extremely high room temperature stability, easy deposition, high electrical conductivity and low thermal conductivity.

[0007] A Chinese patent with publication number CN 112331760A (publication date February 5, 2021) discloses a micro thermoelectric device and a method for preparing the same. The thermoelectric device includes a bottom substrate, a top substrate, and a thermoelectric unit. A patterned functional layer is prepared on the bottom substrate and the top substrate using mask technology, and vacuum array adsorption transfer and image recognition technology are used to sequentially transfer N-type thermoelectric particles and P-type thermoelectric particles to the bottom substrate according to a designed arrangement rule, and contact the welding coating; a top substrate with a coating is prepared on top, and the bonding and electrical connection of the thermoelectric device are achieved by pressurization and heating. However, this type of device array still has some defects. Summary of the Invention

[0008] In order to solve the above-mentioned technical problems, this application provides the following technical solutions:

[0009] The present invention provides a flexible wearable thermoelectric device with a hollow structure and an S-shaped electrode, comprising a flexible block thermoelectric arm, a flexible insulating and heat-insulating base layer, a flexible insulating and heat-conductive covering layer, and an S-shaped elastic wire;

[0010] The flexible block thermoelectric arm is composed of P-type thermocouples and N-type thermocouples in an alternating array;

[0011] The flexible insulating and heat-insulating base layer is symmetrically arranged on the top and bottom of the flexible block thermoelectric arm, and the top and bottom of the flexible block thermoelectric arm both pass through the flexible insulating and heat-insulating base layer in the vertical direction;

[0012] The flexible insulating heat-conducting covering layer is symmetrically arranged on a side of the flexible insulating heat-insulating base layer away from the flexible block thermoelectric arm;

[0013] The S-shaped elastic wire passes through the flexible insulating heat-conductive covering layer and connects all the P-type thermocouples and N-type thermocouples in series; both ends of the S-shaped elastic wire are also connected to flexible electrodes.

[0014] Preferably, the P-type thermocouple and the N-type thermocouple are obtained by pressing thermoelectric materials; the thermoelectric materials are selected from bismuth telluride, lead telluride, silicon germanium, tin selenide or copper selenide.

[0015] Preferably, the lengths of the P-type thermocouple and the N-type thermocouple are both 6-8 mm.

[0016] Preferably, the flexible insulating and heat-insulating base layer is obtained by curing a lightweight insulating material and a flexible thermoplastic elastomer material in a mass ratio of 1:4-6 for 20-30 minutes.

[0017] Furthermore, the lightweight heat-insulating material is selected from hollow glass microspheres, wherein the particle size of the hollow glass microspheres is 10-250 μm and the wall thickness is 1-2 μm.

[0018] Preferably, the flexible insulating thermally conductive covering layer is obtained by curing a thermally conductive filler and a flexible thermoplastic elastomer material in a mass ratio of 3:4-6; the thermally conductive filler is selected from one or more of carbon fiber, carbon nanotubes, graphite, graphene, aluminum oxide, aluminum nitride and boron nitride, and has a particle size of 1-100 μm.

[0019] Furthermore, the flexible thermoplastic elastomer material is selected from one or more of platinum-catalyzed silicone (ecoflex-0030 or ecoflex-0050) and polydimethylsiloxane.

[0020] Preferably, the flexible electrode is selected from liquid metal, gold-plated silver wire, silver alloy wire or welded copper electrode, and the S-shaped elastic wire is selected from one or more of conductive fibers and yarns.

[0021] The liquid metal is selected from gallium-indium alloy.

[0022] The present invention also provides a method for preparing the above-mentioned hollow structure S-shaped electrode flexible wearable thermoelectric device, comprising the following steps:

[0023] S11: hot pressing the thermoelectric powder in a flat vulcanizer at 160-200° C. and 4-7 MPa for 2-2.5 hours to obtain a flexible block thermoelectric arm;

[0024] S12: filling both ends of the flexible block thermoelectric arm with a lightweight insulation material and a flexible thermoplastic elastomer material in a solid mold and curing at 60-70° C.;

[0025] S13: connecting the flexible block thermoelectric arms in the device cured in step S12 in series using S-shaped elastic wires;

[0026] S14: filling the two ends of the device connected in series in step S13 with a thermally conductive filler and a flexible thermoplastic elastomer material, and curing them at 60-70° C.;

[0027] S15: Connecting the device cured in step S14 to an external flexible electrode to obtain the hollow structure S-shaped electrode flexible wearable thermoelectric device.

[0028] The mold is independently designed and has a geometric structure capable of accommodating powder and is resistant to high temperature and high pressure.

[0029] Specifically, the method for preparing the hollow structure S-shaped electrode flexible wearable thermoelectric device includes the following steps:

[0030] S1. Weigh a certain mass of thermoelectric powder, fill it into a self-designed mold, and hot-press it using a flat-plate vulcanizer at a first temperature and a first pressure for 2-2.5 hours to obtain a flexible block thermoelectric arm; the first temperature is 160°C-200°C; the first pressure is 4-7 MPa;

[0031] S2. Place the flexible block thermoelectric arm on the solid mold surface. Fill the ends of the thermoelectric arm in the local temperature control array component with two layers of highly flexible insulating and heat-insulating base layers that are 1 / 3 of the thermoelectric arm height (the micro temperature monitoring array component is filled with a flexible insulating and heat-insulating base layer that is the same height as the thermoelectric arm), separated by an air insulation layer of the same height, and cure at a second temperature of 60°C-70°C.

[0032] S3. Connecting a circuit using an S-shaped flexible electrode material on the surface of the flexible block thermoelectric arm exposed outside the flexible insulating base layer;

[0033] S4. Covering the flexible insulating and thermally conductive covering layer on both sides of the array component with perfect connection circuits, curing at a second temperature;

[0034] S5. Connect the external flexible electrode to the array component.

[0035] The present invention also provides a local temperature regulation array device, which adopts the above-mentioned hollow structure S-shaped electrode flexible wearable thermoelectric device.

[0036] The present invention also provides a micro temperature monitoring array device, which adopts the above-mentioned hollow structure S-shaped electrode flexible wearable thermoelectric device.

[0037] The technical solution of the present invention has the following advantages over the prior art:

[0038] 1. The present invention utilizes thermoelectricity to perform wearable power generation and temperature regulation design, which is small in size, light and easy to carry, and has good human affinity.

[0039] 2. This invention's hollow-structured, S-shaped electrode flexible wearable thermoelectric cooling device utilizes a central hollow structure, leveraging the low thermal conductivity of air to enhance the device's thermal insulation, reducing the rate of heat transfer from the device's hot to cold surfaces and improving thermoelectric durability and efficiency. The S-shaped elastic conductors provide the entire device with independent stretchability.

[0040] 3. The hollow structure S-shaped electrode flexible wearable thermoelectric cooling device of the present invention adopts arrays with two specifications and functions: local temperature regulation and micro-monitoring, providing new possibilities for the application of thermoelectrics in the field of flexible wearables. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the front and back structures of the hollow structure S-shaped electrode flexible wearable thermoelectric device array of the present invention;

[0042] Figure 2 This is a graph showing the temperature difference power generation change of the hollow structure S-shaped electrode flexible wearable thermoelectric device array of Example 1;

[0043] Figure 3 This is a graph showing the temperature difference power generation change of the flexible wearable thermoelectric device array with S-shaped electrodes without hollow structure in comparative example 1;

[0044] Explanation of the accompanying reference numerals: 1 - flexible insulating thermal conductive covering layer, 2 - P-type thermocouple, 3 - N-type thermocouple, 4 - flexible insulating thermal insulation base layer, 5 - S-shaped elastic wire. DETAILED DESCRIPTION

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not intended to limit the present invention. Unless otherwise stated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0047] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0048] like Figure 1 As shown, a hollow structure S-shaped electrode flexible wearable thermoelectric device is provided, the middle part of the device is hollowed out, and includes: a flexible block thermoelectric arm, a flexible insulating and heat-insulating base layer 4, a flexible insulating and heat-conductive covering layer 1 and an S-shaped elastic wire 5; the flexible block thermoelectric arm is composed of P-type thermocouples 2 and N-type thermocouples 3 in an alternating array; the flexible insulating and heat-insulating base layer 4 is symmetrically arranged at the top and bottom of the flexible block thermoelectric arm, and the top and bottom of the flexible block thermoelectric arm both pass through the flexible insulating and heat-insulating base layer 4 in the vertical direction; the flexible insulating and heat-conductive covering layer 1 is symmetrically arranged on the side of the flexible insulating and heat-insulating base layer 4 away from the flexible block thermoelectric arm; the S-shaped elastic wire 5 passes through the flexible insulating and heat-conductive covering layer 1 to connect all the P-type thermocouples 2 and N-type thermocouples 3 in series; the two ends of the S-shaped elastic wire 5 are also connected to flexible electrodes.

[0049] The flexible, wearable thermoelectric cooling device array of the present invention comprises an S-shaped elastic conductor 1, a hollowed-out structure in the middle, and a flexible, insulating base layer 4 at the outer ends to ensure flexibility. The hollowed-out structure, constructed from a water-soluble material, effectively improves the heatsink's thermal insulation. The S-shaped elastic conductor 5 also enables the array to be stretched. The array, with its dual specifications and functions of local temperature control and micro-monitoring, offers new possibilities for thermoelectric applications in the flexible wearable field.

[0050] Example 1

[0051] This embodiment provides a method for preparing the above-mentioned hollow structure S-shaped electrode flexible wearable thermoelectric device array, and the steps are as follows:

[0052] 1) Providing raw materials: P-type bismuth telluride powder, N-type bismuth telluride powder, flexible substrate material platinum-catalyzed silicone rubber (ecoflex-0030) component A and component B curing agent, boron nitride, hollow glass microspheres, gold-plated silver wire, conductive silver paste, paraffin wax (melting point 35°C);

[0053] 2) P-type bismuth telluride powder and N-type bismuth telluride powder were filled into a self-designed iron mold, compacted using a pressing tool, and hot-pressed for 2 hours at a first temperature and a first pressure using a flat-plate vulcanizer to produce 4 mm thick bismuth telluride blocks. The first temperature was 180°C, and the first pressure was 5 MPa.

[0054] 3) Place the PI tape adhesive side up on a self-designed plate mold. Alternately arrange the P-type and N-type blocks into a 4x4 array in the frame mold, spacing them 3mm apart to maintain stability. Mix 1g of component A of the flexible substrate material, 1g of component B curing agent, and 0.2g of hollow glass microspheres at room temperature. Pour the resulting slurry into the frame mold along the side wall until the liquid level reaches 1 / 3 of the block height. Dry at a second temperature of 60°C for 20 minutes.

[0055] 4) Pour the melted phase change paraffin wax into the frame mold along the side wall until the liquid level reaches 2 / 3 of the block height. After the paraffin wax solidifies at room temperature, use the above-mentioned flexible base material mixed solution to level the liquid level with the block height. Figure 1 The circuit connects all the bulk thermoelectric arms into a series circuit.

[0056] 5) A mixed solution of flexible thermally conductive filler boron nitride and flexible substrate material is applied to the circuit surfaces on both sides to encapsulate and preserve the circuits. Local temperature control arrays and micro-monitoring arrays of varying sizes are prepared.

[0057] Figure 2 This figure shows how the voltage of the fabricated hollow S-shaped electrode flexible wearable thermoelectric device array changes with temperature. It can be seen that the hollow S-shaped electrode flexible wearable thermoelectric device array can generate a voltage of 35.06mV at a temperature difference of 14.6K.

[0058] Comparative Example 1

[0059] This comparative example provides a method for preparing a flexible wearable thermoelectric device array with an S-shaped electrode without a hollow structure, comprising the following steps:

[0060] 1) Raw materials: P-type bismuth telluride powder, N-type bismuth telluride powder, flexible substrate material platinum-catalyzed silicone rubber (ecoflex-0030) component A and component B curing agent, boron nitride, hollow glass microspheres, gold-plated silver wire, and conductive silver paste.

[0061] 2) P-type bismuth telluride powder and N-type commercial powder were filled into a self-designed iron mold. Using a press tool, the powders were compacted. The mold was then hot-pressed for 2 hours at a first temperature and a first pressure using a flat-plate vulcanizer to produce 4 mm thick bismuth telluride blocks. The first temperature was 180°C, and the first pressure was 5 MPa.

[0062] 3) Place the PI tape, adhesive side up, on a self-designed plate mold. Alternately arrange the P-type and N-type blocks into a 4x4 array within the frame mold, spacing them 3mm apart for stability. Mix 1g of Component A of the flexible substrate material, 1g of Component B curing agent, and 0.2g of hollow glass microspheres at room temperature. Pour the resulting slurry into the frame mold along the sidewalls until the liquid level reaches the height of the blocks. Dry at a second temperature of 60°C for 20 minutes.

[0063] 4) The four strands of gold-plated silver wires are integrated into a single strand structure through a twisting process, bent into an S shape, and the two ends are connected to the block thermoelectric arms respectively through conductive silver paste. Figure 1 The circuit pattern connects all bulk thermoelectric arms into a series circuit.

[0064] 5) A mixed solution of flexible thermally conductive filler boron nitride and flexible substrate material is applied to the circuit surfaces on both sides to encapsulate and preserve the circuits. Local temperature control arrays and micro-monitoring arrays of varying sizes are prepared.

[0065] Figure 3 This is a graph showing the temperature difference power generation changes of the flexible wearable thermoelectric device array with S-shaped electrodes without a hollow structure in Example 1.

[0066] Comparative Example 2

[0067] This comparative example provides a method for preparing a hollow structure liquid metal electrode flexible wearable device array, comprising the following steps:

[0068] 1) Providing raw materials: P-type bismuth telluride powder, N-type bismuth telluride powder, flexible substrate material platinum-catalyzed silicone rubber (ecoflex-0030), component A and component B curing agent, boron nitride, hollow glass microspheres, ethanol, and liquid metal;

[0069] 2) P-type bismuth telluride powder and N-type commercial powder were filled into a self-designed iron mold. Using a press tool, the powders were compacted. The mold was then hot-pressed for 2 hours at a first temperature and a first pressure using a flat-plate vulcanizer to produce 4 mm thick bismuth telluride blocks. The first temperature was 180°C, and the first pressure was 5 MPa.

[0070] 3) Place the PI tape, adhesive side up, on a self-designed plate mold. Alternately arrange the P-type and N-type blocks into a 4x4 array within the frame mold, spacing them 3mm apart for stability. Mix 1g of Component A of the flexible substrate material, 1g of Component B curing agent, and 0.2g of hollow glass microspheres at room temperature. Pour the resulting slurry into the frame mold along the sidewalls until the liquid level reaches the height of the blocks. Dry at a second temperature of 60°C for 20 minutes.

[0071] 4) Slowly inject liquid paraffin into the constructed frame mold along the side wall to make full contact with the substrate until the liquid level reaches 2 / 3 of the total height of the block. After the paraffin is completely solidified at room temperature, fill it with the mixed solution of the flexible substrate material mentioned above so that the liquid level is flush with the height of the block. Mix the liquid metal and ethanol in a mass ratio of 1:3 and perform ultrasonic treatment. The ultrasonic treatment parameters are set to: power 80%, working cycle 5 seconds (including 3 seconds of operation time and 2 seconds of rest time), and the total treatment time is 5 minutes. After the ultrasonic treatment is completed, use a pipette to absorb the micro / nano droplets formed by the crushing of the gallium indium alloy in the ethanol solution and drip them into the sprayer. Using the filled sprayer, perform graphic deposition on both sides of the device to achieve the purpose of selective coating to ensure that the circuit on the surface of the device is formed as follows. Figure 1 Finally, remove the polyimide tape pattern mask so that all thermocouples are as shown. Figure 1 Designed for tandem molding.

[0072] 5) A mixed solution of flexible thermally conductive filler boron nitride and flexible substrate material is applied to the circuit surfaces on both sides to encapsulate and preserve the circuits. Local temperature control arrays and micro-monitoring arrays of varying sizes are prepared.

[0073] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A hollow structure S-shaped electrode flexible wearable thermoelectric device, characterized in that: It includes a flexible block thermoelectric arm, a flexible insulating heat-insulating base layer, a flexible insulating heat-conducting cover layer and an S-shaped elastic wire; The flexible block thermoelectric arm is composed of P-type thermocouples and N-type thermocouples in an alternating array; The flexible insulating and heat-insulating base layer is symmetrically arranged on the top and bottom of the flexible block thermoelectric arm, and the top and bottom of the flexible block thermoelectric arm both pass through the flexible insulating and heat-insulating base layer in the vertical direction; The flexible insulating heat-conducting covering layer is symmetrically arranged on a side of the flexible insulating heat-insulating base layer away from the flexible block thermoelectric arm; The S-shaped elastic wire passes through the flexible insulating heat-conductive covering layer and connects all the P-type thermocouples and N-type thermocouples in series; both ends of the S-shaped elastic wire are also connected to flexible electrodes.

2. The hollow structure S-shaped electrode flexible wearable thermoelectric device according to claim 1, characterized in that: The P-type thermocouple and the N-type thermocouple are obtained by pressing thermoelectric materials; the thermoelectric materials are selected from bismuth telluride, lead telluride, silicon germanium, tin selenide or copper selenide.

3. The hollow structure S-shaped electrode flexible wearable thermoelectric device according to claim 1, characterized in that: The flexible insulating and heat-insulating base layer is obtained by curing a lightweight heat-insulating material and a flexible thermoplastic elastomer material in a mass ratio of 1:4-6 for 20-30 minutes.

4. The hollow structure S-shaped electrode flexible wearable thermoelectric device according to claim 3, characterized in that: The lightweight heat-insulating material is selected from hollow glass microspheres.

5. The hollow structure S-shaped electrode flexible wearable thermoelectric device according to claim 1, characterized in that: The flexible insulating thermally conductive covering layer is obtained by curing a thermally conductive filler and a flexible thermoplastic elastomer material in a mass ratio of 3:4-6; the thermally conductive filler is selected from one or more of carbon fiber, carbon nanotubes, graphite, graphene, aluminum oxide, aluminum nitride and boron nitride.

6. The hollow structure S-shaped electrode flexible wearable thermoelectric device according to claim 3 or 5, characterized in that: The flexible thermoplastic elastomer material is selected from one or more of platinum-catalyzed silica gel and polydimethylsiloxane.

7. The hollow structure S-shaped electrode flexible wearable thermoelectric device according to claim 1, characterized in that: The flexible electrode is selected from liquid metal, gold-plated silver wire, silver alloy wire or welded copper electrode, and the S-shaped elastic wire is selected from one or more of conductive fibers and yarns.

8. A method for preparing a flexible wearable thermoelectric device with a hollow S-shaped electrode according to any one of claims 1 to 7, characterized in that: The steps include: S11: hot pressing the thermoelectric powder in a flat vulcanizer at 160-200° C. and 4-7 MPa for 2-2.5 hours to obtain a flexible block thermoelectric arm; S12: filling both ends of the flexible block thermoelectric arm with a lightweight insulation material and a flexible thermoplastic elastomer material in a solid mold and curing at 60-70° C.; S13: connecting the flexible block thermoelectric arms in the device cured in step S12 in series using S-shaped elastic wires; S14: filling the two ends of the device connected in series in step S13 with a thermally conductive filler and a flexible thermoplastic elastomer material, and curing them at 60-70° C.; S15: Connecting the device cured in step S14 to an external flexible electrode to obtain the hollow structure S-shaped electrode flexible wearable thermoelectric device.

9. A local temperature control array device, characterized in that: A flexible wearable thermoelectric device with a hollow S-shaped electrode as described in any one of claims 1 to 7.

10. A micro temperature monitoring array device, characterized in that: A flexible wearable thermoelectric device with a hollow S-shaped electrode as described in any one of claims 1 to 7.

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