CN220602565U - Wearable embedded flexible electrothermal sensing structures, sensors and wearable devices - Google Patents

Abstract

The utility model discloses a wearable embedded flexible electric heating sensing structure, a sensor and wearable equipment. The wearable embedded flexible electric heating sensing structure comprises a sensing structure, at least one electric heating structure and at least one insulating structure, wherein the electric heating structure is embedded in the sensing structure, the insulating structure is arranged between the electric heating structure and the sensing structure, and the electric heating structure is electrically isolated from the sensing structure through the insulating structure. The wearable embedded flexible electric sensor provided by the utility model combines the electric heating layer and the sensing layer into a whole, can realize self-control temperature through controllable electric heating, can realize real-time body data monitoring through electric current transmission, monitors heart rate, unsmooth blood, blood pressure, joint fluctuation and the like through stress-strain sensing, and fills the blank of the wearable flexible sensor combining electric heating and sensing.

Description

Wearable embedded flexible electrothermal sensing structures, sensors and wearable devices

Technical field

The utility model particularly relates to a wearable embedded flexible electrothermal sensing structure, a sensor and a wearable device, and belongs to the technical field of flexible sensors.

Background technique

At present, the main base materials for preparing flexible electronic materials include rubber, plastic, silicone, etc. It is difficult to degrade, has a low recyclability ratio, poses a huge threat to the environment, and has a single sensing structure, lacking composite functions and complex scene applications. The weak affinity between the sensing material and the matrix directly limits its durability and fatigue resistance. Carbon-based sensing materials have not been able to solve the dispersion problem well. Most of them use ultrasonic oscillation and organic dispersants for dispersion. Organic dispersants can easily cause defects in the molded sensing materials, making it impossible to obtain good dispersion effects. At present, the preparation of wearable flexible electronic sensors cannot achieve real-time controllable sensitivity. Some usage scenarios that require high sensitivity are incompatible with some usage scenarios that require lower sensitivity, which limits the application scenarios of the sensor.

Patent 201910793284.7 discloses a method for preparing an antimony-doped SnO ₂ @carbon nanotube composite film. The hydrothermal method is used to load Sb-doped SnO ₂ onto the carbon nanotube film, and the electrothermal efficiency is significantly improved. It can be seen that the current electric heating films based on carbon nanotubes or reinforced materials do not solve the problem of easy agglomeration of carbon nanotubes, which will lead to uneven electric heating. Patent 201910967180.3 discloses a method for preparing a water-based carbon nanotube highly conductive film. The aqueous carbon nanotube dispersion is applied to the surface of a heated transfer roller to form a continuous carbon nanotube film and is then transferred to a film with hot melt by hot pressing. The plastic substrate is glued, and then the dispersant is cleaned through a plasma or arc etching process to obtain a highly conductive carbon nanotube layer. However, the carbon nanotube layer obtained after cleaning the dispersant will have inevitable defects. Patent 201510230768.2 discloses a method for applying carbon nanotubes to floor heating electric heating films. The method is to pass two copper foil wires vertically through both sides of the polyester cloth, and then pass the polyester cloth through the prepared carbon nanotubes. Liquid phase, although this material structure can solve the affinity problem between carbon-based materials and the matrix to a certain extent, it sacrifices a considerable part of the fatigue resistance and material recyclability.

Utility model content

The main purpose of this utility model is to provide a wearable embedded flexible electrothermal sensing structure, sensor and wearable device, which can simultaneously realize electrothermal and strain sensing monitoring through the same material layer, and the electrothermal unit and the sensing unit work separately. It can realize controllable temperature change and real-time sensing, and has strong functionality, thereby overcoming the shortcomings of the existing technology.

In order to achieve the aforementioned purpose of the utility model, the technical solutions adopted by the utility model include:

On the one hand, the utility model provides a wearable embedded flexible electrothermal sensing structure, which includes a sensing structure, at least one electrothermal structure and at least one insulation structure. The electrothermal structure is embedded in the sensing structure, and the An insulating structure is disposed between the electrothermal structure and the sensing structure, and the electrothermal structure and the sensing structure are electrically isolated by the insulating structure.

On the other hand, the utility model also provides a wearable embedded flexible electrothermal sensor, which includes a thermal conductive layer, a first insulating layer, an electrothermal sensing layer, a second insulating layer and a thermal insulation layer that are stacked in sequence, wherein the The electrothermal sensing layer includes the wearable embedded flexible electrothermal sensing structure.

On the other hand, the present invention also provides a wearable device, including the wearable embedded flexible electrothermal sensing structure or the wearable embedded flexible electrothermal sensor.

Compared with the existing technology, the advantages of this utility model include:

1) The wearable embedded flexible electrothermal sensor provided by this utility model can simultaneously realize electrothermal and strain sensing monitoring through the same material layer, and the electrothermal unit and the sensing unit work separately, which can realize controllable temperature change and real-time sensing. Highly functional.

2) The utility model provides a wearable embedded flexible electrothermal sensor. When the stress range applied to the sensor surface is less than 40% to 80% of the damage stress, the resistance of the heating layer changes in a parabolic manner, and the fitting degree can reach 0.9914. Stress changes are accurately detected through resistance changes, and the sensing sensitivity is high.

3) All materials of the wearable embedded flexible electrothermal sensor provided by this utility model are made of degradable materials, and the core electrothermal sensing layer is made of all-carbon materials, which is highly environmentally friendly.

4) The wearable embedded flexible electrothermal sensor provided by this utility model has low preparation cost, can realize industrial mass production, and has high cost performance.

5) The electrothermal sensing layer in a wearable embedded flexible electrothermal sensor provided by this utility model can flexibly adjust the resistivity by adjusting the ratio between carbon nanotubes and graphene to achieve controllable electrothermal and high sensing sensitivity. , and the sensor sensitivity can be controlled in real time through controllable electric heating.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments recorded in this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a wearable embedded flexible electrothermal sensing structure provided in a typical implementation case of the present invention;

Figure 2 is a schematic diagram of the preparation process of a wearable embedded flexible electrothermal sensing structure provided in a typical implementation case of the present invention;

Figure 3 is a schematic diagram of the preparation process of a wearable embedded flexible electrothermal sensing structure provided in a typical implementation case of the present invention;

Figure 4 is a schematic structural diagram of a wearable embedded flexible electrothermal sensor provided in a typical implementation case of the present invention.

Detailed ways

In view of the deficiencies in the prior art, the inventor of this case was able to propose the technical solution of the present utility model after long-term research and extensive practice. The technical solution, its implementation process and principles will be further explained below.

In 1991, after Japanese electron microscope expert Lijima discovered multi-walled carbon nanotubes under a high-resolution transmission electron microscope, they quickly became the most popular carbon nanomaterial after C60. It has a large aspect ratio and low density, exhibits excellent mechanical properties, good thermal stability, electrical conductivity and chemical stability. With the deepening of research on carbon nanotubes (CNTs), it has been discovered that all-carbon film materials prepared from carbon nanotubes exhibit extremely low resistivity and high thermal conductivity, making it easy to design and regulate performance. Graphene nanosheets (GNSs) have a special two-dimensional structure and a large specific surface area, have extremely high current density and thermal conductivity, and are considered to be ideal conductors of thermoelectricity. Using van der Waals forces and the entanglement between structures, nanoscale carbon structures can be assembled to form thin paper-like structures with porous and loose structures, namely buckypaper. The randomly oriented carbon nanonetwork inside buckypaper ensures the stable conduction of electrical and mechanical signals. When combined with composite materials with high specific strength and specific modulus, it can smoothly transmit electrical signals when the laminate strain changes. , Based on this characteristic, it has the potential to become a flexible health monitoring sensor.

The utility model's paper-based flexible sensing material based on carbon material has the advantages of easy degradation, high sensing sensitivity, good electrothermal efficiency, and low cost. The wearable embedded flexible electrothermal sensor designed by this utility model combines the electric heating layer and the sensing layer into one. It can realize independent temperature control through controllable electric heating, and can also realize real-time body data monitoring through the introduction of electric current. The sensor monitors heart rate, blood congestion, blood pressure, joint abnormalities, etc., filling the gap in wearable flexible sensors that combine electric heating and sensing into one.

On the one hand, the utility model provides a wearable embedded flexible electrothermal sensing structure, which includes a sensing structure, at least one electrothermal structure and at least one insulation structure. The electrothermal structure is embedded in the sensing structure, and the An insulating structure is disposed between the electrothermal structure and the sensing structure. The electrothermal structure and the sensing structure are electrically isolated by the insulating structure. The wearable embedded flexible electrothermal sensing structure can realize electric heating at the same time. and strain monitoring.

Further, the sensing structure has at least one receiving hole, and each receiving hole is embedded with one of the electric heating structure and one of the insulating structure, and the insulating structure is filled between the electric heating structure and the receiving hole. within the gaps between the holes.

Further, the insulation structure is distributed around the electrothermal structure.

Further, the receiving hole is a through hole penetrating the sensing structure in a selected direction.

Further, the surfaces of the sensing structure, the insulation structure, and the electrothermal structure are flush.

Further, the wearable embedded flexible electrothermal sensing structure includes: multiple electrothermal structures, and the multiple electrothermal structures are electrically connected.

Furthermore, the shape of the orthographic projection formed by the receiving hole along the selected direction is different from the shape of the orthographic projection formed by the electrothermal structure along the selected direction.

Further, the shape of the orthographic projection formed by the receiving hole along the selected direction is an octagon.

Further, the shape of the orthographic projection formed by the receiving hole along the selected direction is a regular octagon.

Further, the shape of the orthographic projection formed by the electrothermal structure along the selected direction is a rhombus.

It should be noted that the wearable embedded flexible electrothermal sensing structure can be a combination of a sensing structure and multiple rhombus-shaped electrothermal structures. The current flows through the multiple electrothermal structures through the circuit. The sensing structure and the electrothermal structure are connected to each other. The wires are separated by an insulating gel structure to eliminate the influence of current.

Further, the sensing structure is a Bass paper sensing film mainly composed of single-walled carbon nanotubes and multi-walled carbon nanotubes. The combination of single-walled carbon nanotubes and multi-walled carbon nanotubes in the Bass paper sensing film is The mass ratio is 0.1~2:1.

Further, the thickness of the Bass paper sensing film is 0.1-0.3 mm.

Further, the electrothermal structure is a Bass paper electric heating film mainly composed of single-walled carbon nanotubes, multi-walled carbon nanotubes and graphene nanosheets. The single-walled carbon nanotubes and multi-walled carbon nanotubes in the Bass paper electric heating film are The mass ratio of the tubes is 0.1 to 2:1, and the mass ratio of the graphene nanosheets to the carbon nanotubes (the whole of single-walled carbon nanotubes and multi-walled carbon nanotubes) is 0.3 to 1:1.

Further, the thickness of the Bath paper electric heating film is 0.1 to 0.3 mm.

In a more specific embodiment, a method for manufacturing a wearable embedded flexible electrothermal sensing structure may include the following steps:

(1) Modification of single-walled carbon nanotubes and multi-walled carbon nanotubes:

Configure an organic solution or acidic solution with a modification function, mix the organic solution or acidic solution with multi-walled carbon nanotubes and single-walled carbon nanotubes and ultrasonically disperse them to form a mixed system. The ultrasonic dispersion time is 10 to 30 minutes, and the power It is 120-180W, and the organic solution or acidic solution with modification function includes aminopropyltriethoxysilane (APTES), H ₂ SO ₄ or HNO ₃ .

Vacuum filter the obtained mixed system, and then put the obtained sample into a vacuum oven to dry, to obtain a modified mixture of single-walled carbon nanotubes and multi-walled carbon nanotubes;

Mix the modified single-walled carbon nanotubes and multi-walled carbon nanotubes mixture and the specified solvent to form the bucky paper sensing structure precursor liquid. Divide the bucky paper sensing structure precursor liquid into two parts, and add one part to Graphene nanosheets are used to form the buckypaper electrothermal structure precursor liquid, and the graphene nanosheets include functionalized graphene nanosheets or graphene oxide nanosheets;

(2) Dispersed carbon nanotubes and graphene nanosheets:

Add dispersant to the two prepared precursor liquids, pour the mixed solution into a micro-jet ultra-fine powder airflow pulverizer and disperse it. The pressure of the micro-jet ultra-fine powder airflow pulverizer is 20,000 to 25,000 PSI, and the number of passes of the solution is: 4 to 6 times;

Finally, the dispersed solution is put into an ultrasonic crusher for final dispersion. The power of the ultrasonic crusher when processing the solution is 120-180W, and the ultrasonic time is 10-20 minutes. The two precursor liquids after dispersion are vacuum filtered. The film is formed and dried to form an electrothermal sensing structure. The vacuum filtration membrane includes an aqueous filtration membrane and an organic filtration membrane. The pore size of the aqueous filtration membrane and the organic filtration membrane is 0.22 μm or 0.45 μm. Drying means are used during the drying process. It includes three types: drying table, oven and room temperature. The drying table temperature is 60~80℃ and the drying time is 0.5~2h. The oven temperature is 80~100℃ and the drying time is 1~3h. Depending on the temperature, the drying time is approximately 48~72h. .

On the other hand, the utility model also provides a wearable embedded flexible electrothermal sensor, which includes a thermal conductive layer, a first insulating layer, an electrothermal sensing layer, a second insulating layer and a thermal insulation layer that are stacked in sequence, wherein the The electrothermal sensing layer includes the wearable embedded flexible electrothermal sensing structure.

Further, the thermal conductive layer includes a thermal conductive gel layer.

Further, the thickness of the thermal conductive layer is 0.2-0.5 mm.

Further, the first insulating layer includes an insulating cloth and an insulating gel layer, and the insulating gel layer is covered on the surface of the insulating cloth.

Further, the thickness of the first insulating layer is 0.4-0.7 mm.

Further, the thickness of the electrothermal sensing layer is 0.1 to 0.3 mm.

Further, the second insulating layer includes an insulating cloth and an insulating gel layer, and the insulating gel layer is covered on the surface of the insulating cloth.

Further, the thickness of the second insulating layer is 0.4-0.7 mm.

Further, the heat insulation layer includes a heat insulation cotton layer.

Further, the thickness of the heat insulation layer is 0.2-0.5 mm.

Further, the wearable embedded flexible electrothermal sensor further includes a wear-resistant layer, the wear-resistant layer is stacked on the side of the thermal insulation layer facing away from the second insulation layer.

Further, the wear-resistant layer includes a nylon fabric layer.

Further, the thickness of the wear-resistant layer is 0.5-0.7mm.

Further, the wearable embedded flexible electrothermal sensor further includes a skin-friendly layer, and the skin-friendly layer is stacked on the side of the thermal conductive layer facing away from the first insulating layer.

Further, the skin-friendly layer includes a natural fiber layer.

Further, the thickness of the skin-friendly layer is 0.4-0.7 mm.

Further, the electrothermal sensing layer in the wearable embedded flexible electrothermal sensor is covered with an insulating layer up and down, the upper surface of the second insulating layer is close to the heat insulating layer, and the outside of the heat insulating layer is covered with a wear-resistant layer. The first The insulation layer is close to the thermal conductive layer and conducts heat to the skin-friendly layer below the thermal conductive layer.

On the other hand, the present invention also provides a wearable device, including the wearable embedded flexible electrothermal sensing structure or the wearable embedded flexible electrothermal sensor.

The technical solution, its implementation process and principles will be further explained below with reference to the accompanying drawings and specific implementation cases. It should be noted that the embodiments of the present utility model are intended to provide a wearable embedded flexible electrothermal sensor. The structural composition and effects of the structure, sensor and wearable device are explained and described. Unless otherwise specified, the materials used in the embodiments of the present invention are used to form the wearable embedded flexible electrothermal sensing structure and sensor. and raw materials for wearable devices are all known to those skilled in the art and can be purchased commercially, and are not specifically limited here.

Example 1

Referring to Figure 1, a wearable embedded flexible electrothermal sensing structure 18 includes a sensing structure 18, a plurality of electrothermal structures 15 and a plurality of insulating structures 26. The sensing structure 18 has a plurality of receiving holes 17. The receiving holes 17 are spaced apart along the plane extension direction of the sensing structure 18 . Each receiving hole 17 penetrates the sensing structure 18 along the thickness direction of the sensing structure 18 . Each electrothermal structure 15 and each insulation structure 26 are correspondingly embedded in the sensing structure 18 . In a receiving hole 17, an insulating structure 26 is disposed between the electrothermal structure 15 and the sensing structure 18. The sensing structure 18 and the electrothermal structure 15 are electrically isolated by the insulating structure 26, wherein the sensing structure 18 serves as a sensor. The sensing unit can realize strain monitoring, and the electrothermal structure 15 can realize the electric heating function as an electric heating unit. That is, the wearable embedded flexible electrothermal sensing structure 18 can realize electric heating and strain monitoring at the same time.

Specifically, the sensing structure 18 is a Bass paper sensing film mainly composed of single-walled carbon nanotubes and multi-walled carbon nanotubes. The relationship between single-walled carbon nanotubes and multi-walled carbon nanotubes in the Bass paper sensing film is The mass ratio is 0.1 to 2:1, and the thickness of the bass paper sensing film is 0.1 to 0.3 mm. It can be understood that the depth of the plurality of aforesaid receiving holes 17 is the same as the thickness of the bass paper sensing film.

Specifically, in the radial direction of the receiving hole 17, there is a gap between the receiving hole 17 and the electric heating structure 15, that is, there is no direct contact between the sensing structure 18 and the electric heating structure 15, and the insulating structure 26 is provided in the receiving hole 17. In the gap between the hole 17 and the electrothermal structure 15, the insulating structure 26 can not only limit and fix the electrothermal structure 15 in the receiving hole 17, but also electrically isolate (insulate) the electrothermal structure 15 and the sensing structure 18. It can be understood that by filling the gap between the electrothermal structure 15 and the sensing structure 18 with the insulating structure 26, the movement of the electrothermal structure 15 can be restricted, thereby achieving the fixation of the electrothermal structure 15. It can be understood that the insulating structure 26 is surrounding the electrothermal structure. Structure 15 is set.

Specifically, the contour shapes of the radial cross sections formed along the radial direction of the receiving hole 17 and the electrothermal structure 15 are preferably different. In order to take into account the strain monitoring effect of the sensing structure 18 and the electrothermal effect of the electrothermal structure 15, it is preferable to The receiving hole 17 is set as a regular octagonal structure, and the electrothermal structure 15 is set as a rhombus structure, thereby ensuring that the wearable embedded flexible electrothermal sensing structure 18 has a good strain monitoring effect and at the same time has a good strain monitoring effect. Electric heating effect. After testing, when the electrothermal structure 15 and the sensing structure 18 are arranged in a circular structure or a square structure, the overall electrothermal effect is not good.

Specifically, the electrothermal structure 15 is a Bath paper electric heating film mainly composed of single-walled carbon nanotubes, multi-walled carbon nanotubes and graphene nanosheets. The single-walled carbon nanotubes and multi-walled carbon in the Bath paper electric heating film are The mass ratio of nanotubes is 0.1 to 2:1, and the mass ratio of graphene nanosheets to carbon nanotubes (the whole of single-walled carbon nanotubes and multi-walled carbon nanotubes) is 0.3 to 1:1. Specifically, as described The thickness of Bath paper electric heating film is 0.1~0.3mm.

Specifically, the plurality of electric heating structures 15 may be formed by cutting a piece of Bath paper electric heating film.

Specifically, the insulating structure 26 may be an insulating gel structure or the like.

Specifically, the surfaces of the sensing structure 18 , the insulation structure 26 , and the electrothermal structure 15 are flush. This surface refers to the two surfaces/two end surfaces of each structure that are arranged back-to-back along the axial direction of the receiving hole 17 , that is, it can be understood that the thickness of the sensing structure 18, the insulation structure 26, and the electrothermal structure 15 are all 0.1 to 0.3 mm.

Specifically, the plurality of electric heating structures 15 are electrically connected. More specifically, the plurality of electric heating structures 15 are combined into one or more groups of electric heating structures 15. Each group of electric heating structures 15 includes a plurality of spaced apart electric heating structures 15. , multiple electrothermal structures 15 included in the same group of 15 electrothermal structures are arranged in series and/or in parallel.

Specifically, the plurality of electrothermal structures 15 are electrically connected through wires, etc., and the wires and the sensing structure 18 are also insulated. For example, an insulating gel can be provided between the conductive and sensing structures 18. wait.

It should be noted that the wearable embedded flexible electrothermal sensing structure 18 can be a combination of one sensing structure 18 and multiple rhombus-shaped electrothermal structures 15. The current flows through the multiple electrothermal structures 15 through the circuit. The sensing structure 18 is connected with the electrothermal structure 15. The structure 15 and the wires connected to the electrothermal structure 15 are separated by an insulating gel structure to eliminate the influence of current.

Example 2

Please refer to Figure 4. A wearable embedded flexible electrothermal sensor includes a skin-friendly layer 25, a thermal conductive layer 24, a first insulating layer 23, an electrothermal sensing layer 19, a second insulating layer 22, and a thermal insulation layer that are stacked in sequence. 21 and wear-resistant layer 20, that is, the electrothermal sensing layer 19 in the wearable embedded flexible electrothermal sensor is covered with insulating layers up and down, the upper surface of the second insulating layer 22 is close to the heat insulation layer 21, and the heat insulation layer 21 The outside is covered with a wear-resistant layer 20 , and the first insulating layer 23 is close to the thermal conductive layer 24 to conduct heat to the skin-friendly layer 25 below the thermal conductive layer 24 .

Specifically, the skin-friendly layer 25 includes a natural fiber layer, and the thickness of the skin-friendly layer 25 is 0.4-0.7 mm. The thermal conductive layer 24 includes a thermal conductive gel layer, and the thickness of the thermal conductive layer 24 is 0.2-0.5 mm. mm. The first insulating layer 23 includes an insulating cloth and an insulating gel layer. The insulating gel layer is covered on the surface of the insulating cloth. The thickness of the first insulating layer 23 is 0.4-0.7 mm. The electrothermal sensing layer 19 is the wearable embedded flexible electrothermal sensing structure 18 in Embodiment 1, and the thickness of the electrothermal sensing layer 19 is 0.1 to 0.3 mm. The second insulating layer 22 includes an insulating cloth and an insulating gel layer. The insulating gel layer is covered on the surface of the insulating cloth. The thickness of the second insulating layer 22 is 0.4-0.7 mm. The heat insulation layer 21 includes a heat insulation cotton layer, and the thickness of the heat insulation layer 21 is 0.2-0.5 mm. The wear-resistant layer 20 includes a nylon fabric layer, and the thickness of the wear-resistant layer 20 is 0.5-0.7 mm.

Example 3

The raw materials used in the present utility model can all be purchased in the market. Among them, the multi-walled carbon nanotubes used in this embodiment have an outer diameter of 30 to 50 nm, a purity of greater than 98%, and a length of 0.5 to 2 μm. Shorter carbon nanotubes. The single-walled carbon nanotubes used in this embodiment have an outer diameter of 1 to 2 nm, a purity of greater than 95%, and a length of 5 to 30 μm, and are relatively long single-walled carbon nanotubes. The graphene nanosheets used in this embodiment are graphene oxide, in which carbon element is greater than or equal to 70%, and oxygen element is greater than or equal to 10%.

Please refer to Figure 2, Figure 3 and Figure 4. A method for preparing a wearable embedded flexible electrothermal sensor includes the following steps:

1) Carboxylation of single-walled carbon nanotubes and multi-walled carbon nanotubes.

Mix 7.5 ml of modification solution 1 (concentrated sulfuric acid with a concentration of 98%) and 2.5 ml of modification solution 2 (concentrated nitric acid with a concentration of 68%) to prepare an acidic modification solution 3, and then add 190 ml of deionized water to dilute;

Add raw material 4 (0.03g of multi-walled carbon nanotubes) and raw material 5 (0.01g of single-walled carbon nanotubes) to the diluted modified solution 3, and then proceed to step 7 (ultrasonic dispersion). The ultrasonic dispersion power is 150W. After 30 minutes, vacuum filter the obtained solution 6. After the filtration is completed, rinse the obtained sample with deionized water, and then put the sample into a vacuum oven to dry. The drying temperature is 80°C and the drying time is 2 hours;

Finally, after the sample is dried, it is taken out and crushed using a ball mill to obtain a mixture of carboxylated single-walled carbon nanotubes and multi-walled carbon nanotubes;

Configure 0.03g multi-walled carbon nanotubes and 0.01g single-walled carbon nanotubes after carboxylation into bucky paper sensing structure precursor liquid, and combine 0.03g multi-walled carbon nanotubes and 0.01g single-walled carbon nanotubes after carboxylation. The tube and raw material 8 (0.01g of graphene oxide nanosheets) were mixed into deionized water to prepare a Bucky paper electrothermal structure precursor liquid.

(2) Disperse carbon nanotubes and graphene oxide nanosheets.

Add dispersion liquid 9 (anionic surfactant polyacrylamide) to the prepared precursor liquid (bucky paper electrothermal structure precursor liquid/bucky paper sensing structure precursor liquid, the same below), and add the dispersant precursor liquid 10 is placed in equipment 11 (high pressure homogenizer) and vacuumed to disperse evenly. The rotation speed is set to 2500rpm and the mixing time is 7 minutes. Then pour the preliminary evenly dispersed precursor liquid 12 into equipment 13 (micro-jet ultrafine powder airflow pulverizer). For dispersion, the pressure of the micro-jet ultrafine powder grinder is set to 25000 PSI, and the number of passes of the precursor liquid is 5 times. Finally, the dispersed precursor liquid is put into the ultrasonic crusher for final dispersion. The dispersion power is 160W and the ultrasonic time is 10 minutes. .

(3) The precursor liquid is vacuum filtered and then dried to form a film.

The dispersed precursor liquid is formed into a film through a vacuum filtration instrument. The filter membrane used in the vacuum filtration instrument is a 0.45 μm organic microporous filter membrane. After vacuum filtration of the precursor liquid, alcohol is added to rinse it once, and finally the filter paper is Dry in a vacuum oven at a temperature of 80°C and a drying time of 2 hours. After drying, peel off the bucky paper 14 from the filter paper to make a bucky paper electric heating film 16 and a bucky paper sensing film.

(3) Use Bucky paper electric heating film and sensing film to prepare the electrothermal sensing layer.

Please refer to Figure 3. Cut the prepared bucky paper electric heating film into a rhombus-shaped electric heating structure 15, make the bucky paper sensing film into a sensing structure 18, connect multiple rhombus-shaped electric heating structures 15 with a circuit, and then Embed multiple rhombus-shaped electrothermal structures 15 into the octagonal storage hole 17 of the sensing structure 18 , and set insulating gel between the sensing structure and the circuit, the storage hole 17 and the electrothermal structure to prevent current interference, and finally connect The current interface is made into an electrothermal sensing layer.

(4) Preparation of wearable embedded flexible electrothermal sensors.

Please refer to Figure 4 again. The skin-friendly layer 25, the thermal conductive layer 24, the first insulating layer 23, the electrothermal sensing layer 19, the second insulating layer 22, the heat insulating layer 21 and the wear-resistant layer 20 are sequentially stacked to form a laminate. Thus, a wearable embedded flexible electrothermal sensor is obtained.

Specifically, the first insulating layer 23 and the second insulating layer 22 are made of cotton fiber material as the skin-friendly layer 25 and insulating cloth coated with insulating gel on both sides. In order to ensure that the electrothermal film will not be affected by external resistance changes and avoid adverse effects on the accuracy of stress monitoring, the thermal conductive layer 24 is made of thermal conductive gel, which can guide the heat of the electrothermal sensing layer 19 to the sensor surface to reduce heat loss. The wear-resistant layer 20 is made of nylon fabric, and the heat-insulating layer 21 is made of heat-insulating cotton. The heat-insulating layer 21 can effectively prevent heat from escaping and save energy consumption.

After testing, when a voltage of 20V is applied at room temperature, the surface electric heating temperature of the electrothermal sensing layer 19 can reach 59°C, the heating efficiency is good, and the stress range applied to the sensor surface is less than 40% to 80% of the damage stress. The resistance of the lower heating layer changes in a parabola-like manner, and the fitting degree can reach 0.9914. The sensor stress change can be accurately detected through the resistance change.

The embodiments mentioned in this patent are only some of the embodiments in this patent, not all the embodiments in this patent. The embodiments described in detail in this patent are not intended to limit the scope of the claimed patent but are indicative of some selected embodiments of the patent. Based on the embodiments described in this patent, all other embodiments obtained by those of ordinary skill in the art without any creative work fall within the scope of protection of this patent.

The utility model provides a wearable embedded flexible electrothermal sensor that can simultaneously realize electrothermal and strain sensing monitoring through the same material layer, and the electrothermal unit and the sensing unit work separately, which can realize controllable temperature change and real-time sensing, and has high functionality. Strong, and the electrothermal sensing layer of the wearable embedded flexible electrothermal sensor achieves uniform distribution of carbon nanotubes and graphene nanosheets into a film through modification and dispersion steps, achieving high electrothermal uniformity and electrothermal efficiency, and uniform electrothermal sex.

The utility model provides a wearable embedded flexible electrothermal sensor. When the stress range applied to the sensor surface is less than 40% to 80% of the damage stress, the resistance of the heating layer changes in a parabola-like manner, and the fitting degree can reach 0.9914. It can be passed through the resistance Changes can accurately detect stress changes and have high sensing sensitivity. Moreover, the structural layer of a wearable embedded flexible electrothermal sensor provided by this utility model pays attention to insulation treatment. The upper limit of electric heating is 60°C, which can prevent safety accidents such as leakage or electric heat burns. Safe and reliable.

All materials of the wearable embedded flexible electrothermal sensor provided by the utility model are made of degradable materials, and the core electrothermal sensing layer is made of all carbon materials, which is highly environmentally friendly. At the same time, the utility model provides a wearable embedded flexible electrothermal sensor. The preparation cost of the embedded flexible electrothermal sensor is not high, industrial mass production can be achieved, and the cost performance is high. In addition, the electrothermal sensing layer in the wearable embedded flexible electrothermal sensor provided by the utility model can be made by blending carbon nanotubes and graphene. The ratio between them can be flexibly adjusted to achieve controllable electrothermal and sensing sensitivity.

It should be understood that the above embodiments are only for illustrating the technical concepts and features of the present invention. Their purpose is to enable those familiar with the technology to understand the contents of the present invention and implement it accordingly. This does not limit the protection of the present invention. scope. All equivalent changes or modifications made based on the spirit and essence of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A wearable embedded flexible electrothermal sensing structure, comprising: the sensing structure is embedded in the sensing structure, the insulating structure is arranged between the electric heating structure and the sensing structure, and the electric heating structure is electrically isolated from the sensing structure through the insulating structure.

2. The wearable embedded flexible electrothermal sensing structure of claim 1, wherein: the sensing structure is provided with at least one accommodating hole, each accommodating hole is internally embedded with one electric heating structure and one insulating structure, and the insulating structure is filled in a gap between the electric heating structure and the accommodating hole;

and/or, the insulating structures are distributed around the electrothermal structures;

and/or the accommodating hole is a through hole penetrating the sensing structure along a selected direction;

and/or the surfaces of the sensing structure, the insulating structure and the electrothermal structure are flush.

3. The wearable embedded flexible electrothermal sensing structure of claim 2, comprising: the electric heating structures are electrically connected with each other.

4. A wearable embedded flexible electrothermal sensing structure according to claim 2 or 3, wherein: the shape of orthographic projection formed by the accommodating hole along the selected direction is different from that of orthographic projection formed by the electrothermal structure along the selected direction;

and/or the shape of the orthographic projection of the accommodating hole formed along the selected direction is octagonal;

and/or the shape of the orthographic projection of the accommodating hole formed along the selected direction is regular octagon;

and/or, the orthographic projection of the electrothermal structure along the selected direction is diamond-shaped.

5. A wearable embedded flexible electrothermal sensing structure according to claim 1 or 2 or 3, wherein: the sensing structure is a Bass paper sensing film mainly formed by single-wall carbon nanotubes and multi-wall carbon nanotubes;

and/or the thickness of the Bass paper sensing film is 0.1-0.3 mm.

6. A wearable embedded flexible electrothermal sensing structure according to claim 1 or 2 or 3, wherein: the electric heating structure is a bas paper electric heating film mainly formed by single-wall carbon nanotubes, multi-wall carbon nanotubes and graphene nanoplatelets;

and/or the thickness of the bas paper electrothermal film is 0.1-0.3 mm.

7. A wearable embedded flexible electrical heat sensor, comprising: the heat conduction layer, first insulating layer, electric heat sensing layer, second insulating layer and the insulating layer of range upon range of setting in proper order, wherein, electric heat sensing layer includes the wearable embedded flexible electric heat sensing structure of any one of claims 1-6.

8. The wearable embedded flexible electrical heat sensor of claim 7, wherein: the thermally conductive layer comprises a thermally conductive gel layer; and/or the thickness of the heat conduction layer is 0.2-0.5 mm;

and/or, the first insulating layer comprises an insulating cloth and an insulating gel layer, and the insulating gel layer is covered on the surface of the insulating cloth; and/or the thickness of the first insulating layer is 0.4-0.7 mm;

and/or the thickness of the electrothermal sensing layer is 0.1-0.3 mm;

and/or, the second insulating layer comprises an insulating cloth and an insulating gel layer, and the insulating gel layer is covered on the surface of the insulating cloth; and/or the thickness of the second insulating layer is 0.4-0.7 mm;

and/or, the thermal insulation layer comprises a thermal insulation cotton layer; and/or the thickness of the heat insulation layer is 0.2-0.5 mm.

9. The wearable embedded flexible electrical heat sensor of claim 7, further comprising a wear layer disposed in a stack on a side of the insulating layer opposite the second insulating layer;

and/or the wear-resistant layer comprises a nylon fabric layer, and/or the thickness of the wear-resistant layer is 0.5-0.7 mm;

and/or the wearable embedded flexible electric thermal sensor further comprises a skin-friendly layer, wherein the skin-friendly layer is arranged on one side of the heat conduction layer, which is opposite to the first insulating layer;

and/or, the skin-friendly layer comprises a natural fiber layer; and/or the thickness of the skin-friendly layer is 0.4-0.7 mm.

10. A wearable device characterized by comprising the wearable embedded flexible electrothermal sensing structure of any one of claims 1-6 or the wearable embedded flexible electrothermal sensor of any one of claims 7-9.