A single-battery driven multi-layer polymer electric card device for human body thermal management and its preparation method

Abstract

The present invention relates to the field of wearable thermal management technology, and discloses a single-battery driven multi-layer polymer electric card device for human body thermal management and a preparation method thereof, wherein the electric card device comprises: a multi-layer polymer electric card film made of poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene), an Ag film covering the upper and lower surfaces of the polymer electric card film, and an insulating protective layer arranged at the bottom. The electric card device provided by the present invention not only has the advantages of miniaturization, environmental protection, and high efficiency, but also reduces the necessary high-voltage drive (≥2kV) in the electric card field to a safe voltage (36V), and has a good electric caloric effect, which is used for human body thermal management and can expand the human body's comfortable temperature zone by 8K. Based on the advantages of the present invention in flexibility and low-voltage drive, the electric card device has shown attractive application prospects in the field of wearable human body thermal management.

Description

Technical Field

[0001] The present invention relates to the field of wearable thermal management technology, and in particular to a single-battery driven multi-layer polymer electric card device for human body thermal management and a preparation method thereof. Background Art

[0002] Currently, various personalized temperature regulation systems have been developed, which can be divided into passive and active modes. Compared with passive personalized temperature regulation systems based on manipulation methods such as heat conduction, radiation, and humidity, active modes can actively optimize individual thermophysiological comfort over a wider range of ambient temperatures. Among the four major active temperature regulation strategies, namely electrothermal, microfluidics, thermoelectric effect, and differential thermal effect, the polymer-based electrocaloric effect has become one of the most competitive and promising alternatives to central air conditioning heating and cooling systems due to its bidirectional temperature regulation, easy integration, excellent wearable flexibility, and ultra-low energy consumption. To realize the practicality of electrocaloric polymers in personalized temperature regulation, people have made great efforts to improve the performance of electrocaloric polymers, simplify the cumbersome actuator structure of electrocaloric polymer-based devices, and optimize the bulky high-voltage power supply.

[0003] Molecular defect modification and electrocaloric polymer interface engineering have proven to be effective strategies for enhancing the performance of electrocaloric polymers. In addition to significantly improving the performance of electrocaloric polymers, electrocaloric polymer-based device architectures have also been explored to meet the needs of personalized temperature regulation. For cooling, heat must be transferred in a targeted manner from the human body to the electrocaloric polymer; for heating, heat must be transferred in a targeted manner from the electrocaloric polymer to the human body. Traditional complex actuator structures, such as motors and fluid pumps, increase energy consumption and increase the size and complexity of the system. Therefore, our previous research report proposed and successfully constructed an electrostatically driven structure that enables wearable electrocaloric polymer-based devices to achieve efficient heat transfer. Subsequently, we integrated a flexible organic photovoltaic module with this electrostatically driven electrocaloric polymer-based device to potentially replace traditional large-scale power sources. Despite a series of breakthroughs in personalized temperature regulation in electrocaloric polymers, electrocaloric polymer-based devices, and their power sources, high driving voltages (typically above 2 kV) have been a major obstacle to the practical application of electrocaloric polymer-based devices in the field of personalized temperature regulation. Therefore, if devices based on electrocaloric polymers can be driven at low voltage using compact power supplies, the gap between the electrocaloric effect and personalized temperature regulation can be bridged, which will help temperature regulation move towards a sustainable energy future. Summary of the Invention

[0004] In response to the deficiency of existing polymer-based electrocaloric devices that rely on high-voltage drive, the present invention provides a single-battery-driven multi-layer polymer electrocaloric device for human body thermal management. It also provides a method for improving the performance of polymer electrocaloric devices through quenching and obtaining a safe voltage-driven electrocaloric device by reducing the thickness of the polymer.

[0005] To achieve the above objectives, the present invention provides a method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management, comprising the following steps:

[0006] S1. dissolving poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder in N,N-dimethylformamide, and performing ultrasonic degassing in a water bath to obtain a polymer solution having a mass fraction of 0.1 to 1 wt.%, and then coating the polymer solution into a film by drop coating, blade coating, spin coating, or spray coating, and evaporating the solvent by heating to obtain an insulating layer;

[0007] S2. forming an Ag film on the surface of the insulating layer by vacuum evaporation;

[0008] S3, dissolving poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder in N,N-dimethylformamide, and performing ultrasonic degassing in a water bath to obtain a polymer solution with a mass fraction of 8 to 15 wt.%, and then coating the polymer solution into a film by drop coating, blade coating, spin coating, or spray coating, and evaporating the solvent by heating to obtain a polymer electrocaloric film;

[0009] S4. Continue to generate Ag films and polymer electrocardioid films alternately stacked in sequence according to the method of steps S2 and S3, wherein the polymer electrocardioid films are at least two layers, and the upper and lower surfaces of each polymer electrocardioid film are stacked with Ag films, and the overlapping areas of all polymer electrocardioid films and Ag films constitute the active area;

[0010] S5, the multilayer structure obtained in step S4 is kept in a vacuum oven at 115-160° C. for 120-180 min, and then immersed in -5-0° C. ice water for quenching;

[0011] S6. Two lead electrodes serving as positive and negative electrodes are respectively set with conductive materials on the outside of the active area of ​​the multilayer structure obtained in step S4. All Ag films are arranged in the order of their overlap so that the end of the Ag film located at the even position is electrically connected to one of the lead electrodes outside the active area, and the end of the Ag film located at the odd position is electrically connected to the other lead electrode outside the active area.

[0012] As a further preferred technical solution of the present invention, the thickness of the insulating layer is 100-500 nm, the thickness of the polymer electrocardial film is 0.5-10 μm, and the thickness of the Ag film is 10-100 nm.

[0013] As a further preferred technical solution of the present invention, the thickness of the insulating layer obtained in step S1 is 200 nm, and the mass fraction of the polymer solution used is 0.1 wt.%; the thickness of the polymer electrocaloric film obtained in steps S3 and S4 is 1 μm, and the mass fraction of the polymer solution used is 8 wt.%; the thickness of the Ag film is 30 nm.

[0014] As a further preferred technical solution of the present invention, in steps S1 and S3, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder is dissolved in N,N-dimethylformamide, stirred at 50-60° C. for 6-12 hours, and then degassed in a water bath with ultrasonication.

[0015] As a further preferred technical solution of the present invention, in steps S1 and S3, before water bath ultrasonic degassing, the N,N-dimethylformamide solution containing the poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder is filtered using a filter with a pore size of 0.22 μm.

[0016] As a further preferred technical solution of the present invention, in step S5, the vacuum oven temperature is 145°C, the holding time is 180 minutes, and the ice water temperature is 0°C.

[0017] As a further preferred technical solution of the present invention, in step S6, the lead electrodes are prepared using a conductive material such as carbon nanotubes, silver nanowires, PEDOT:PSS, graphite or graphene.

[0018] According to another aspect of the present invention, the present invention also provides a single-battery driven multi-layer polymer electric card device for human body thermal management, which is prepared by the above method.

[0019] According to another aspect of the present invention, the single-battery driven multi-layer polymer electric card device for human body thermal management of the present invention is used in human body thermal management.

[0020] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0021] 1) The present invention adopts a multi-layer stacking method to innovatively construct a multi-layer polymer-based electrocardiogram device, which is flexible and easy to adhere to human skin;

[0022] 2) The multilayer polymer electric card device constructed by the present invention can be driven by a single battery at low voltage, making the control system design simpler and the application more convenient;

[0023] 3) The multilayer polymer electrocaloric device constructed in the present invention has a good electrocaloric effect and can be used for human thermal management, which can expand the human body's comfortable temperature zone by 8K. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 This is a schematic structural diagram of the electric card device of Example 1.

[0026] Figure 2 This is a graph showing the electric card performance of the electric card device of Example 1 when driven by a 36V safety voltage.

[0027] Figure 3 1. A graph showing power consumption comparison test results of the electrocaloric device of Example 1 and a commercial thermoelectric device;

[0028] Figure 4 This is a structural diagram of the electric card device of Example 1 applied to human body thermal management.

[0029] Figure 5 This is a diagram showing the thermal management effect of the electric card device of Example 1 applied to human body thermal management.

[0030] Figure 6 The electrocaloric performance test results of the electrocaloric device obtained at different quenching temperatures and times based on the method of Example 1 are shown.

[0031] Figure 7 These are scanning electron microscope images of cross sections of multiple electrocaloric devices prepared according to the method of Example 1, with the total thickness of the device maintained at 50 μm.

[0032] In the figure: 1. Insulating layer, 2. Polymer electrochemical film, 3. Ag film, 4. Lead electrode, A. Active area.

[0033] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0034] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0035] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; the experimental methods described, unless otherwise specified, are conventional methods.

[0036] Example 1:

[0037] This embodiment provides a single-cell driven multi-layer polymer electric card device for human body thermal management, the structure of which is as follows: Figure 1As shown, the bottom layer is an insulating layer 1, followed by alternately stacked Ag films 3 and polymer electrocardioid films 2. The overlapping area of ​​all polymer electrocardioid films 2 and Ag films 1 constitutes the device's active area A. Lead electrodes 4 are located on the left and right sides, respectively. During use, lead electrodes 4 connect the multilayer polymer electrocardioid device to the power supply circuit. The method for preparing the multilayer polymer electrocardioid device is as follows:

[0038] 1) Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) powder was dissolved in N,N-dimethylformamide and degassed in a water bath using ultrasonic technology to obtain a polymer solution A with a mass fraction of 0.1 wt.% and a polymer solution B with a mass fraction of 8 wt.%.

[0039] 2) The polymer solution A was sprayed onto a glass substrate by spraying, and the solvent was evaporated on a hot plate at 90° C. for 30 minutes to obtain an insulating layer with a thickness of 200 nm. The insulating layer was used to adhere to human skin.

[0040] 3) forming a 30 nm thick Ag film on the upper surface of the insulating layer by vacuum evaporation;

[0041] 4) The polymer solution B was sprayed onto the Ag film, and the solvent was evaporated on a hot plate at 90° C. for 30 min to obtain a polymer electrocaloric film with a thickness of 1 μm.

[0042] 5) Continue to generate 30nm Ag film and 1μm polymer electrocaloric film alternately stacked in the same manner as steps 3) and 4) (for stacking method, refer to Figure 1 As shown in the figure, the total number of polymer electrocardioid films is five, and the upper and lower surfaces of each polymer electrocardioid film are laminated with Ag films (the total number of layers is six), and the overlapping areas of all polymer electrocardioid films and Ag films constitute an active area of ​​4 cm × 2 cm.

[0043] 5) The multilayer structure obtained in step 5) was kept at 145° C. in a vacuum oven for 180 min, and then immersed in 0° C. ice water for quenching.

[0044] 6) After quenching, 5 mg of carboxylated carbon nanotubes were dispersed in a mixture of 18 ml of isopropanol and 2 ml of deionized water. The mixture was sonicated using a probe for 1 hour and then centrifuged at 3500 rpm for 5 minutes. The supernatant was used as a carbon nanotube solution. The carbon nanotube solution was sprayed on the left and right ends of the multilayer structure obtained in step 5), and the solvent was evaporated on a 90°C hot plate for 30 minutes to obtain two lead electrodes serving as positive and negative poles. All Ag films were arranged in a stacked order, with the ends of the Ag films at even-numbered positions electrically connected to one of the lead electrodes outside the active area, and the ends of the Ag films at odd-numbered positions electrically connected to the other lead electrode outside the active area, ultimately obtaining a flexible multilayer polymer electrocaloric device.

[0045] The multilayer polymer electric card device obtained in Example 1 was connected to a 36V single battery through two lead electrodes and a wire, and its electric card performance under 36V safety voltage was measured. The results are shown in Figure 2. Figure 2 It can be seen that the P (VDF-TrFE-CFE) film with a thickness of 1 micron per layer can achieve a thermal management effect of 1.4K heating and 1.3K cooling when driven by a safe voltage of 36V.

[0046] The power consumption of the multilayer polymer electrocardioid device of Example 1 and the commercial thermoelectric device was compared and tested. To achieve the same 4K cooling / heating effect, the multilayer polymer electrocardioid device needs to apply a voltage of 100V, while the commercial thermoelectric device needs a voltage of 0.35V. Figure 3 It can be seen that when simultaneously outputting a heating / cooling effect of 1 watt of power, the operating time of the multilayer polymer electrocaloric device of Example 1 (178 hours) is 7.4 times that of the commercial thermoelectric device (24 hours).

[0047] like Figure 4 As shown, the multilayer polymer electric card device of Example 1 is applied to human body thermal management. The multilayer polymer electric card device is attached to the human skin through an insulating layer, connected to the power supply circuit of the AA battery (36 volts) through the lead electrode, and controlled by a voltage amplifier in series. It can be seen that the multilayer polymer electric card device of Example 1 has the properties of miniaturization and wearability. The multilayer polymer electric card device of Example 1 is applied to human body thermal management, and the surface temperature change of the human body is directly tested with an infrared camera. The thermal management effect is as follows Figure 5 As shown, it can be seen that as the voltage is added and removed, the human body experiences a 4K heating and cooling effect.

[0048] To further demonstrate the beneficial effects of the present invention, based on the method of Example 1, multilayer polymer electrocaloric devices were prepared at different quenching temperatures and times. The electrocaloric performance test results are shown in FIG. Figure 6 As shown, it can be seen that the performance of the electric card has certain fluctuations. Figure 6 a is the X-ray diffraction pattern of the product after being kept at 115℃~160℃ for 180 minutes and then immersed in 0℃ ice water for quenching. It can be seen that obvious crystal regions are formed at different quenching temperatures; Figure 6 b is the hysteresis loop of the sample after being heated at 145℃ for 10 to 300 minutes and then immersed in 0℃ ice water for quenching. It can be seen that the sample has excellent polarization strength at different heating times, and the sample heated at 145℃ for 180 minutes has both the maximum polarization strength and the minimum planned loss. Figure 6 c is the temperature change diagram of different electric field strengths after being kept at 115℃~160℃ for 180 minutes and then immersed in 0℃ ice water for quenching. It can be seen that the temperature change increases with the increase of electric field, and the maximum temperature change is obtained when the temperature is kept at 145℃ for 180 minutes; Figure 6Figure d shows the temperature change at different electric field strengths after being held at 145°C for 10 to 300 minutes and then quenched in 0°C ice water. The temperature change increases with increasing electric field, with the maximum temperature change occurring at 145°C for 180 minutes. Overall, different quenching methods can improve the electrocaloric properties of the P(VDF-TrFE-CFE) polymer, with the optimal performance achieved at 145°C for 180 minutes.

[0049] To further demonstrate the beneficial effects of the present invention, based on the method of Example 1, multiple electrocardioid devices with a total thickness of 50 μm were prepared by changing the number of layers and thickness of the polymer electrocardioid film. The scanning electron microscopy images of the prepared P(VDF-TrFE-CFE) polymer electrocardioid films with different numbers of layers are shown in the following figure: Figure 7 As shown. Figure 7 As can be seen from a, the thickness of the single-layer P (VDF-TrFE-CFE) polymer electrocardiogram film is uniformly 50 μm; Figure 7 b It can be seen that the total thickness of the five-layer P (VDF-TrFE-CFE) polymer electrocardiogram film is uniformly 50 μm; Figure 7 c It can be seen that the total thickness of the ten-layer P (VDF-TrFE-CFE) polymer electrocardiogram film is uniformly 50 μm; Figure 7 As can be seen from the image d, the total thickness of the fifteen-layer P(VDF-TrFE-CFE) polymer electrocardiographic film is a uniform 50 μm. This indicates that the preparation method provided by the present invention can produce P(VDF-TrFE-CFE) polymer electrocardiographic films with varying layer thicknesses, thereby enabling the fabrication of electrocardiographic devices with varying numbers of layers to meet diverse application requirements. The preferred thickness of a single-layer polymer electrocardiographic film is 0.5 to 10 μm.

[0050] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. A method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management, characterized in that: The following steps are involved: S1. dissolving poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder in N,N-dimethylformamide, and performing ultrasonic degassing in a water bath to obtain a polymer solution having a mass fraction of 0.1 to 1 wt.%, and then coating the polymer solution into a film by drop coating, blade coating, spin coating, or spray coating, and evaporating the solvent by heating to obtain an insulating layer; S2. forming an Ag film on the surface of the insulating layer by vacuum evaporation; S3, dissolving poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder in N,N-dimethylformamide, and performing ultrasonic degassing in a water bath to obtain a polymer solution with a mass fraction of 8 to 15 wt.%, and then coating the polymer solution into a film by drop coating, blade coating, spin coating, or spray coating, and evaporating the solvent by heating to obtain a polymer electrocaloric film; S4. Continue to generate Ag films and polymer electrocardioid films alternately stacked in sequence according to the method of steps S2 and S3, wherein the polymer electrocardioid films are at least two layers, and the upper and lower surfaces of each polymer electrocardioid film are stacked with Ag films, and the overlapping areas of all polymer electrocardioid films and Ag films constitute the active area; S5, the multilayer structure obtained in step S4 is kept in a vacuum oven at 115-160° C. for 120-180 min, and then immersed in -5-0° C. ice water for quenching; S6. Two lead electrodes serving as positive and negative electrodes are respectively set with conductive materials on the outside of the active area of ​​the multilayer structure obtained in step S4. All Ag films are arranged in the order of their overlap so that the end of the Ag film located at the even position is electrically connected to one of the lead electrodes outside the active area, and the end of the Ag film located at the odd position is electrically connected to the other lead electrode outside the active area.

2. The method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management according to claim 1, characterized in that: The thickness of the insulating layer is 100-500 nm, the thickness of the polymer electrocardial film is 0.5-10 μm, and the thickness of the Ag film is 10-100 nm.

3. The method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management according to claim 2, characterized in that: The thickness of the insulating layer obtained in step S1 is 200 nm, and the mass fraction of the polymer solution used is 0.1 wt.%. The thickness of the polymer electrocaloric film obtained in steps S3 and S4 is 1 μm, and the mass fraction of the polymer solution used is 8 wt.%. The thickness of the Ag film is 30 nm.

4. The method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management according to claim 1, characterized in that: In steps S1 and S3, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder is dissolved in N,N-dimethylformamide, stirred at 50-60° C. for 6-12 hours, and then degassed in a water bath using ultrasonic waves.

5. The method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management according to claim 1, characterized in that: In steps S1 and S3, before the water bath ultrasonic degassing, the N,N-dimethylformamide solution containing the poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) powder is filtered using a filter with a pore size of 0.22 μm.

6. The method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management according to claim 1, characterized in that: In step S5, the vacuum oven temperature is 145°C, the holding time is 180 min, and the ice water temperature is 0°C.

7. The method for preparing a single-cell driven multi-layer polymer electric card device for human body thermal management according to claim 1, characterized in that: In step S6, a conductive material such as carbon nanotubes, silver nanowires, PEDOT:PSS, graphite or graphene is used to prepare lead electrodes.

8. A single-cell driven multi-layer polymer electric card device for human body thermal management, characterized in that: The method according to any one of claims 1 to 7 is used for preparation.

9. Application of the single-battery driven multi-layer polymer electric card device for human body thermal management as claimed in claim 8 in human body thermal management.

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