Flexible capacitive temperature sensor based on three-dimensional modular layout and preparation method thereof
By adopting a three-dimensional modular layout and kirigami structure in the flexible temperature sensor, the problems of low sensitivity and insufficient tensile resistance of traditional flexible temperature sensors are solved, and the temperature sensing function with high accuracy and high stability is achieved.
Patent Information
- Application Number
- CN202510261656.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-06
- Publication Date
- 2025-05-09
AI Technical Summary
Existing flexible temperature sensors have low sensitivity, low temperature signal detection accuracy and low tensile resistance.
A flexible capacitive temperature sensor based on a three-dimensional modular layout is adopted, including a flexible stretchable substrate and a uniformly distributed flexible temperature sensing element. The sensing element adopts a three-layer ultra-thin film structure. The conductor is composed of silver wires and conductive silver glue, and is designed through serpentine wires and kirigami paper-cut structures to improve tensile resistance.
It realizes high sensitivity and high precision temperature signal detection, and has excellent tensile resistance, ensuring the stability and reliability of the temperature sensing function.
Smart Images
Figure CN119958717A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of flexible electronic technology, and in particular to a flexible capacitive temperature sensor based on a three-dimensional modular layout and a preparation method thereof. Background Art
[0002] A temperature sensor is a sensor that can sense temperature and convert it into a usable output signal. Temperature sensors are the core of temperature measuring instruments and come in many varieties. Traditional temperature sensing elements are mostly arranged in a straight line, which can easily lead to wire breakage due to stress concentration during dynamic stretching, and the signal is easily disturbed when coupled with pressure sensing elements. In addition, most sensors lack modular design, which limits the flexibility of large-scale array integration.
[0003] The flexible design of wearable devices has been rapidly developed in a short period of time due to its comfort and long-term reusability, and has great potential in human health monitoring, continuous disease monitoring and medical equipment. Flexible sensors are an important part of wearable devices, including pressure sensors, strain sensors, temperature sensors and humidity sensors. These sensors have been widely used in daily life in the fields of physical health detection, automatic control, smart home and wearable devices.
[0004] However, with the development of flexible sensing technology, people have an increasing demand for complex application environments and special applications, requiring flexible sensors and other electronic devices to be wearable or to be applied in different scenarios, such as fitting to biological surfaces, replacing robot movable joints, etc. In these applications, although existing flexible sensors have many advantages, there are still many challenges in terms of sensitivity and stability, which require further research and improvement. However, due to the rigidity and brittleness of traditional silicon-based electronic devices, it is difficult to continuously fit with biological surfaces, which not only affects the comfort of the human body, but may even reduce the accuracy and reliability of sensor measurements, and its repeatability is difficult to guarantee.
[0005] Therefore, according to the above-mentioned related technologies, it is urgent to develop a flexible capacitive temperature sensor based on a three-dimensional modular layout and a preparation method thereof. Summary of the invention
[0006] In view of this, the purpose of the present invention is to propose a flexible capacitive temperature sensor based on a three-dimensional modular layout to solve the problems of low sensitivity, low temperature signal detection accuracy and low tensile strength of flexible temperature sensors in the prior art.
[0007] Based on the above purpose, the present invention provides a flexible capacitive temperature sensor based on a three-dimensional modular layout, characterized in that it includes a flexible stretchable substrate and a plurality of flexible temperature sensing elements evenly distributed thereon, wherein the flexible temperature sensing elements are connected to each other by conductive parts;
[0008] The thickness of the flexible stretchable substrate is 0.2 mm ± 5 μm;
[0009] The flexible temperature sensing element is a three-layer integrated ultra-thin film;
[0010] The conducting piece is composed of silver wire and conductive silver glue.
[0011] The flexible stretchable substrate is any one of a PDMS substrate, a SEBS substrate and a TPU substrate.
[0012] The preparation process of the PDMS substrate is as follows:
[0013] The PDMS prepolymer and curing agent were mixed, mechanically stirred for 2 minutes, a surfactant was added, vacuum degassing was performed, and after degassing, the mixture was added to a glass mold and scraped, and then cured and demolded to obtain a PDMS substrate;
[0014] Preferably, the mass ratio of the PDMS prepolymer to the curing agent is 8-10:1-1.5;
[0015] Preferably, the surfactant is Triton X-100, and the mass fraction of the surfactant in the system is 0.5wt%;
[0016] Preferably, the vacuum degassing time is 30 minutes;
[0017] Preferably, the glass mold is silanized, and the specifications of the glass mold are 30mm×30mm×0.25mm;
[0018] Preferably, in the scraping process, a precision scraper with a blade gap of 0.2 mm is used, and the scraping speed is 1 mm / s;
[0019] Preferably, the curing temperature is 80° C. and the curing time is 2 hours.
[0020] The preparation process of the SEBS substrate is as follows:
[0021] The SEBS prepolymer and solvent were mixed, stirred at room temperature for 6 hours, and additives were added. After ultrasonic treatment for 1 hour, the mixture was added into a polytetrafluoroethylene mold for casting, and then dried and demolded to obtain a SEBS substrate;
[0022] Preferably, the solvent is toluene, the additive is carbon nanotubes to enhance mechanical properties, and the mass fraction ratio of the SEBS prepolymer to the carbon nanotubes in the system is 10-12wt%:0.3-0.5wt%;
[0023] Preferably, the specification of the polytetrafluoroethylene mold is 30mm×30mm×0.2mm;
[0024] Preferably, the casting process is to allow the solution to self-level for 10 minutes;
[0025] Preferably, the drying temperature is 50° C. and the drying time is 4 hours.
[0026] The preparation process of the TPU substrate is as follows:
[0027] The TPU prepolymer was dissolved in a solvent, magnetically stirred at 60°C for 4 hours, an additive was added, ultrasonicated for 20 minutes, added to a PET substrate for spin coating, and then dried and demolded to obtain a TPU substrate;
[0028] Preferably, the solvent is DMAc, the additive is nano-silicon dioxide to enhance mechanical properties, and the mass fraction ratio of the TPU prepolymer to the nano-silicon dioxide in the system is 13-15wt%:1-1.2wt%;
[0029] Preferably, the surface roughness of the PET substrate is Ra<0.1 μm;
[0030] Preferably, the rotation speed of the spin coater is 3000 rpm, and the spin coating time is 30 s;
[0031] Preferably, the drying temperature is 80° C. and the drying time is 2 hours.
[0032] The preparation process of the flexible temperature sensing element is as follows:
[0033] PVA aqueous solution was added to MXene aqueous solution, magnetically stirred at 90°C for 0.5h, glycerol and borax aqueous solution were added, magnetically stirred at 95°C for 2h, and then dripped into the mold. After spin coating using a spin coater, it was cured to obtain an ultra-thin film. The dripping and spin coating was repeated twice to finally obtain a three-layer integrated ultra-thin film. Then, the upper and lower bottom surfaces of the film were gold-plated using vacuum ion sputtering, and then patterned using a laser cutting machine to finally obtain a flexible temperature sensor element.
[0034] Preferably, the mass fraction of the PVA is 5-15wt%;
[0035] Preferably, the volume fraction ratio of the glycerol to the borax aqueous solution is 1v%-3v%: 1v%-3v%; the mass fraction of borax in the borax aqueous solution is 5wt%;
[0036] Preferably, the rotation speed of the spin coater is 3000 rpm, and the spin coating time is 30 s;
[0037] Preferably, the curing temperature is 80°C and the curing time is 2h;
[0038] Preferably, the thickness of the three-layer integrated ultra-thin film is 0.1 mm±5 μm.
[0039] The preparation process of the MXene aqueous solution is as follows:
[0040] The Ti3AlC2 matrix was added to the HCl / LiF mixed solution and magnetically stirred at room temperature for 0.5 h, then etched at 40 °C for 45 h, then ultrasonicated and centrifuged, and finally the upper layer solution was taken to obtain a uniformly dispersed MXene solution;
[0041] Preferably, the mass ratio of HCl, LiF and Ti3AlC2 is 25:2:1;
[0042] Preferably, the ultrasonic treatment is carried out under an argon atmosphere, and the ultrasonic treatment time is 1 h;
[0043] Preferably, the centrifugation is carried out in a test tube, the centrifuge speed is no more than 3500 r / min, and the centrifugation time is 1 h.
[0044] Preferably, the vacuum ion sputtering time is not less than 15 seconds to obtain a dense gold-plated layer.
[0045] Preferably, the patterning process is: placing the film on a laser cutter into a regular hexagonal shape, processing the interior to obtain a kirigami structure, and keeping the entire unit connected, the deformation can be compensated by waveform expansion during stretching to maintain the stability of the electrical signal; then starting the cutting machine to finally obtain a flexible temperature sensor element.
[0046] Preferably, silver wires are arranged orthogonally on the upper surface of the flexible temperature sensing unit; the silver wires in the conductive part are glued to the flexible substrate with ultra-thin double-sided tape; the silver wires are arranged orthogonally on the flexible temperature sensing element; the silver wires are a serpentine structure; the conductive silver glue in the conductive part is used to fix the silver wires and the central contact point of the temperature sensing element.
[0047] Beneficial effects of the present invention:
[0048] The present invention adopts a dynamic adaptive design. The serpentine wire adopts a periodic sine wave structure with an amplitude of 3-5 times the wire width. The flexible temperature sensing element adopts a kirigami paper-cut structure. The flexible temperature sensing element is a three-layer integrated ultra-thin film. When stretched, the deformation is compensated by waveform expansion to maintain the stability of the electrical signal. The temperature sensitivity is high and it has excellent temperature sensing function.
[0049] This flexible sensor uses a unique structural design to achieve high-precision detection of temperature signals and anti-stretching properties. BRIEF DESCRIPTION OF THE DRAWINGS
[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0051] Figure 1 Schematic diagram of the distribution of the flexible temperature sensing element of the present invention in the flexible stretchable substrate;
[0052] Figure 2 Schematic diagram of the distribution of the single-response flexible temperature sensing element of the present invention in a flexible stretchable substrate. DETAILED DESCRIPTION
[0053] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.
[0054] Embodiment 1: A method for preparing a flexible capacitive temperature sensor based on a three-dimensional modular layout, comprising the following steps:
[0055] S1. Mix the PDMS prepolymer and curing agent in a mass ratio of 10:1, stir mechanically for 2 minutes, then add TritonX-100 with a mass fraction of 0.5wt%, and vacuum degas for 30 minutes. After degassing, inject the PDMS solution into a glass mold (30mm×30mm×0.25mm) with a silanized surface, and use a precision scraper (blade gap 0.2mm) to scrape at a uniform speed, controlling the scraping speed to 1mm / s. Then place the mold in an oven at 80℃ to dry for 2h, and after demolding, a PDMS flexible substrate with a thickness of about 0.2mm is obtained.
[0056] S2. Add Ti3AlC2 matrix into HCl / LiF mixed solution with the mass ratio of HCl, LiF and Ti3AlC2 being 25:2:1. After magnetic stirring at room temperature for 0.5 h, ultrasonic treatment was performed for 1 h under argon atmosphere. The solution was transferred to a test tube and centrifuged at 3000 r / min for 0.5 h. Then, the upper layer of the solution in the test tube was taken to obtain a uniformly dispersed MXene solution.
[0057] S3. Add 5wt% PVA aqueous solution to MXene aqueous solution, and after completely dissolving under magnetic stirring at 90℃ for 2h, add glycerol and borax aqueous solution, the volume fraction of glycerol added is 1v%, the volume fraction of borax aqueous solution added is 2v%, and the mass fraction of borax is 4wt%. After completely dissolving under magnetic stirring, drip into the mold, use a spin coater to spin coat at a speed of 3000rpm for 30s, and place it in an oven at 80℃ for curing for 2h to obtain a layer of ultra-thin film, repeat the dripping and spin coating twice, and finally obtain a three-layer integrated ultra-thin film with a thickness of about 0.1mm; then use vacuum ion sputtering for 15s to gold-plate the film, and then place the film on a laser cutting machine, which is designed to be a regular hexagonal shape in the program, and the inside is hollowed out to obtain a kirigami structure, and then start the cutting machine to finally obtain a flexible temperature sensor element.
[0058] S4. Arrange the flexible temperature sensor element array with a hexagonal honeycomb structure on a flexible substrate, use ultra-thin double-sided tape to stick the serpentine silver wire with a diameter of <0.1mm to the flexible substrate, arrange the silver wire orthogonally on the flexible temperature sensor element, and fix the silver wire and the center contact point of the temperature sensor element with conductive silver glue.
[0059] Embodiment 2: A method for preparing a flexible capacitive temperature sensor based on a three-dimensional modular layout, comprising the following steps:
[0060] S1. Mix the PDMS prepolymer and curing agent in a mass ratio of 12:1.5, stir mechanically for 2 minutes, then add TritonX-100 with a mass fraction of 0.5wt%, and vacuum degassing for 30 minutes. After degassing, inject the PDMS solution into a glass mold (30mm×30mm×0.25mm) with a silanized surface, and use a precision scraper (blade gap 0.2mm) to scrape at a uniform speed, controlling the scraping speed to 1mm / s. Then place the mold in an 80℃ oven to dry for 2h, and after demolding, a PDMS flexible substrate with a thickness of about 0.2mm is obtained.
[0061] S2. Add Ti3AlC2 matrix into HCl / LiF mixed solution with the mass ratio of HCl, LiF and Ti3AlC2 being 25:2:1. After magnetic stirring at room temperature for 0.5 h, ultrasonic treatment was performed for 1 h under argon atmosphere. The solution was transferred to a test tube and centrifuged at 3000 r / min for 0.5 h. Then, the upper layer of the solution in the test tube was taken to obtain a uniformly dispersed MXene solution.
[0062] S3. Add a 10wt% PVA aqueous solution to the MXene aqueous solution. After completely dissolving under magnetic stirring at 90°C for 2h, add glycerol and borax aqueous solutions. The volume fraction of glycerol added is 2v%, the volume fraction of borax aqueous solution added is 2v%, and the mass fraction of borax is 4wt%. After completely dissolving under magnetic stirring, drip into the mold, use a spin coater to spin coat at a speed of 3000rpm for 30s, and place it in an oven at 80°C for curing for 2h to obtain a layer of ultra-thin film. Repeat the dripping and spin coating twice to finally obtain a three-layer integrated ultra-thin film with a thickness of about 0.1mm; then use vacuum ion sputtering for 15s to gold-plate the film, and then place the film on a laser cutting machine, which is designed to be a regular hexagonal shape in the program, and the interior is hollowed out to obtain a kirigami structure. Then start the cutting machine to finally obtain a flexible temperature sensor element.
[0063] S4. Arrange the flexible temperature sensor element array with a hexagonal honeycomb structure on a flexible substrate, use ultra-thin double-sided tape to stick the serpentine silver wire with a diameter of <0.1mm to the flexible substrate, arrange the silver wire orthogonally on the flexible temperature sensor element, and fix the silver wire and the center contact point of the temperature sensor element with conductive silver glue.
[0064] Embodiment 3: A method for preparing a flexible capacitive temperature sensor based on a three-dimensional modular layout, comprising the following steps:
[0065] S1. The SEBS prepolymer was dissolved in toluene solvent and stirred at room temperature for 6 hours. Then, carbon nanotubes were added to enhance the mechanical properties. The mass fraction ratio of SEBS prepolymer and carbon nanotubes in the system was 10wt%:0.3wt%. After ultrasonic treatment for 1 hour, the SEBS solution was injected into a polytetrafluoroethylene mold (30mm×30mm×0.2mm). The solution was allowed to stand for 10 minutes to allow self-leveling of the solution. The solution was then transferred to a 50°C oven for drying for 4 hours. After demolding, a SEBS flexible substrate with a thickness of about 0.2 mm was obtained.
[0066] S2. Add Ti3AlC2 matrix into HCl / LiF mixed solution with the mass ratio of HCl, LiF and Ti3AlC2 being 25:2:1. After magnetic stirring at room temperature for 0.5 h, ultrasonic treatment was performed for 1 h under argon atmosphere. The solution was transferred to a test tube and centrifuged at 3000 r / min for 0.5 h. Then, the upper layer of the solution in the test tube was taken to obtain a uniformly dispersed MXene solution.
[0067] S3. Add a 15wt% PVA aqueous solution to the MXene aqueous solution. After completely dissolving under magnetic stirring at 90°C for 2h, add glycerol and borax aqueous solutions. The volume fraction of the added glycerol is 3v%, the volume fraction of the added borax aqueous solution is 1v%, and the mass fraction of borax is 4wt%. After completely dissolving under magnetic stirring, drip into the mold, use a spin coater to spin coat at a speed of 3000rpm for 30s, and place it in an oven at 80°C for curing for 2h to obtain a layer of ultra-thin film. Repeat the dripping and spin coating twice to finally obtain a three-layer integrated ultra-thin film with a thickness of about 0.1mm; then use vacuum ion sputtering for 15s to gold-plate the film, and then place the film on a laser cutting machine, which is designed to be a regular hexagonal shape in the program, and the interior is hollowed out to obtain a kirigami structure. Then start the cutting machine to finally obtain a flexible temperature sensor element.
[0068] S4. Arrange the flexible temperature sensor element array with a hexagonal honeycomb structure on a flexible substrate, use ultra-thin double-sided tape to stick the serpentine silver wire with a diameter of <0.1mm to the flexible substrate, arrange the silver wire orthogonally on the flexible temperature sensor element, and fix the silver wire and the center contact point of the temperature sensor element with conductive silver glue.
[0069] Embodiment 4: A method for preparing a flexible capacitive temperature sensor based on a three-dimensional modular layout, comprising the following steps:
[0070] S1. The SEBS prepolymer was dissolved in toluene solvent and magnetically stirred at 60°C for 4 hours. Then, carbon nanotubes were added to enhance the mechanical properties. The mass fraction ratio of SEBS prepolymer and carbon nanotubes in the system was 12wt%:0.5wt%. After ultrasonic treatment for 1 hour, the SEBS solution was injected into a polytetrafluoroethylene mold (30mm×30mm×0.2mm), allowed to stand for 10 minutes to allow the solution to self-level, and then transferred to a 50°C oven for drying for 4 hours. After demolding, a SEBS flexible substrate with a thickness of about 0.2 mm was obtained.
[0071] S2. Add Ti3AlC2 matrix into HCl / LiF mixed solution with the mass ratio of HCl, LiF and Ti3AlC2 being 25:2:1. After magnetic stirring at room temperature for 0.5 h, ultrasonic treatment was performed for 1 h under argon atmosphere. The solution was transferred to a test tube and centrifuged at 3000 r / min for 0.5 h. Then, the upper layer of the solution in the test tube was taken to obtain a uniformly dispersed MXene solution.
[0072] S3. Add 8wt% PVA aqueous solution to MXene aqueous solution, and after completely dissolving under magnetic stirring at 90℃ for 2h, add glycerol and borax aqueous solution, the volume fraction of glycerol added is 1v%, the volume fraction of borax aqueous solution added is 1v%, and the mass fraction of borax is 4wt%. After completely dissolving under magnetic stirring, drip into the mold, use a spin coater to spin coat at a speed of 3000rpm for 30s, and place it in an oven at 80℃ for curing for 2h to obtain a layer of ultra-thin film, repeat the dripping and spin coating twice, and finally obtain a three-layer integrated ultra-thin film with a thickness of about 0.1mm; then use vacuum ion sputtering for 15s to gold-plate the film, and then place the film on a laser cutting machine, which is designed to be a regular hexagonal shape in the program, and the inside is hollowed out to obtain a kirigami structure, and then start the cutting machine to finally obtain a flexible temperature sensor element.
[0073] S4. Arrange the flexible temperature sensor element array with a hexagonal honeycomb structure on a flexible substrate, use ultra-thin double-sided tape to stick the serpentine silver wire with a diameter of <0.1mm to the flexible substrate, arrange the silver wire orthogonally on the flexible temperature sensor element, and fix the silver wire and the center contact point of the temperature sensor element with conductive silver glue.
[0074] Embodiment 5: A method for preparing a flexible capacitive temperature sensor based on a three-dimensional modular layout, comprising the following steps:
[0075] S1. Dissolve TPU prepolymer in DMAc solvent, stir magnetically at 60°C for 4h, add nano-silica, the mass fraction ratio of TPU prepolymer and carbon nano-silica in the system is 13wt%:1.0wt%, and after dissolution is completed by ultrasonic treatment for 20min, drip the TPU solution on a PET substrate (surface roughness Ra<0.1μm), and use a spin coater to spin coat at 3000rpm for 30s, transfer it to a vacuum oven, dry it at 80°C for 2h, and finally demold to obtain a TPU flexible substrate with a thickness of about 0.2mm.
[0076] S2. Add Ti3AlC2 matrix into HCl / LiF mixed solution with the mass ratio of HCl, LiF and Ti3AlC2 being 25:2:1. After magnetic stirring at room temperature for 0.5 h, ultrasonic treatment was performed for 1 h under argon atmosphere. The solution was transferred to a test tube and centrifuged at 3000 r / min for 0.5 h. Then, the upper layer of the solution in the test tube was taken to obtain a uniformly dispersed MXene solution.
[0077] S3. Add a 10wt% PVA aqueous solution to the MXene aqueous solution. After completely dissolving under magnetic stirring at 90°C for 2h, add glycerol and borax aqueous solutions. The volume fraction of the added glycerol is 1v%, the volume fraction of the added borax aqueous solution is 2v%, and the mass fraction of borax is 4wt%. After completely dissolving under magnetic stirring, drip into the mold, use a spin coater to spin coat at a speed of 3000rpm for 30s, and place it in an oven at 80°C for curing for 2h to obtain a layer of ultra-thin film. Repeat the dripping and spin coating twice to finally obtain a three-layer integrated ultra-thin film with a thickness of about 0.1mm; then use vacuum ion sputtering for 25s to gold-plate the film, and then place the film on a laser cutting machine, which is designed to be a regular hexagonal shape in the program, and the interior is hollowed out to obtain a kirigami structure. Then start the cutting machine to finally obtain a flexible temperature sensor element.
[0078] S4. Arrange the flexible temperature sensor element array with a hexagonal honeycomb structure on a flexible substrate, use ultra-thin double-sided tape to stick the serpentine silver wire with a diameter of <0.1mm to the flexible substrate, arrange the silver wire orthogonally on the flexible temperature sensor element, and fix the silver wire and the center contact point of the temperature sensor element with conductive silver glue.
[0079] Embodiment 6: A method for preparing a flexible capacitive temperature sensor based on a three-dimensional modular layout, comprising the following steps:
[0080] S1. Dissolve TPU prepolymer in DMAc solvent, stir magnetically at 60°C for 4h, add nano-silica, the mass fraction ratio of TPU prepolymer and carbon nano-silica in the system is 15wt%:1.2wt%, and after ultrasonic dissolution for 20min, drip the TPU solution on the PET substrate (surface roughness Ra<0.1μm), and use a spin coater to spin coat at 3000rpm for 30s, transfer it to a vacuum oven, dry it at 80°C for 2h, and finally demold to obtain a TPU flexible substrate with a thickness of about 0.2mm.
[0081] S2. Add Ti3AlC2 matrix into HCl / LiF mixed solution with the mass ratio of HCl, LiF and Ti3AlC2 being 25:2:1. After magnetic stirring at room temperature for 0.5 h, ultrasonic treatment was performed for 1 h under argon atmosphere. The solution was transferred to a test tube and centrifuged at 3000 r / min for 0.5 h. Then, the upper layer of the solution in the test tube was taken to obtain a uniformly dispersed MXene solution.
[0082] S3. Add a 12wt% PVA aqueous solution to the MXene aqueous solution. After completely dissolving under magnetic stirring at 90°C for 2h, add glycerol and borax aqueous solutions. The volume fraction of the added glycerol is 1v%, the volume fraction of the added borax aqueous solution is 3v%, and the mass fraction of the borax is 4wt%. After completely dissolving under magnetic stirring, drip into the mold, use a spin coater to spin coat at a speed of 3000rpm for 30s, and place it in an oven at 80°C for curing for 2h to obtain a layer of ultra-thin film. Repeat the dripping and spin coating twice to finally obtain a three-layer integrated ultra-thin film with a thickness of about 0.1mm; then use vacuum ion sputtering for 30s to gold-plate the film, and then place the film on a laser cutting machine, which is designed to be a regular hexagonal shape in the program, and the interior is hollowed out to obtain a kirigami structure. Then start the cutting machine to finally obtain a flexible temperature sensor element.
[0083] S4. Arrange the flexible temperature sensor element array with a hexagonal honeycomb structure on a flexible substrate, use ultra-thin double-sided tape to stick the serpentine silver wire with a diameter of <0.1mm to the flexible substrate, arrange the silver wire orthogonally on the flexible temperature sensor element, and fix the silver wire and the center contact point of the temperature sensor element with conductive silver glue.
[0084] The flexible temperature sensing element module of the present invention has high capacitance signal stability, high temperature sensitivity, and excellent temperature sensing function, thereby achieving high-precision detection of temperature signals and anti-stretching performance.
[0085] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.
[0086] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A flexible capacitive temperature sensor based on a three-dimensional modular layout, characterized in that: It comprises a flexible stretchable substrate and a plurality of flexible temperature sensing elements arranged in an array thereon, wherein the flexible temperature sensing elements are connected in pairs by conductive members; The thickness of the flexible stretchable substrate is 0.2 mm ± 5 μm; The flexible temperature sensing element is a three-layer integrated ultra-thin film; The conducting piece is composed of silver wire and conductive silver glue.
2. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 1 is characterized in that: The flexible stretchable substrate is any one of a PDMS substrate, a SEBS substrate and a TPU substrate.
3. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 2 is characterized in that: The preparation process of the PDMS substrate is as follows: The PDMS prepolymer and curing agent were mixed, mechanically stirred for 2 minutes, a surfactant was added, vacuum degassing was performed, and after degassing, the mixture was added to a glass mold and scraped, and then cured and demolded to obtain a PDMS substrate; The mass ratio of the PDMS prepolymer to the curing agent is 8-10:1-1.5; The surfactant is Triton X-100, and the mass fraction of the surfactant in the system is 0.5wt%; The vacuum degassing time is 30min; The glass mold is silanized and has a specification of 30 mm×30 mm×0.25 mm; In the scraping process, a precision scraper with a blade gap of 0.2 mm is used, and the scraping speed is 1 mm / s; The curing temperature is 80° C. and the curing time is 2 hours.
4. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 2 is characterized in that: The preparation process of the SEBS substrate is as follows: The SEBS prepolymer and solvent were mixed, stirred at room temperature for 6 hours, and additives were added. After ultrasonic treatment for 1 hour, the mixture was added into a polytetrafluoroethylene mold for casting, and then dried and demolded to obtain a SEBS substrate; The solvent is toluene, and the additive is carbon nanotubes; the mass fraction ratio of the SEBS prepolymer to the carbon nanotubes in the system is 10wt%-12wt%: 0.3wt%-0.5wt%; The specification of the polytetrafluoroethylene mold is 30mm×30mm×0.2mm; The casting process is to let the solution stand for 10 minutes to allow it to self-level; The drying temperature is 50° C. and the drying time is 4 hours.
5. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 2, characterized in that: The preparation process of the TPU substrate is as follows: The TPU prepolymer was dissolved in a solvent, magnetically stirred at 60°C for 4 hours, an additive was added, ultrasonicated for 20 minutes, added to a PET substrate for spin coating, and then dried and demolded to obtain a TPU substrate; The solvent is DMAc, the additive is nano-silicon dioxide, and the mass fraction ratio of the TPU prepolymer to the nano-silicon dioxide in the system is 13wt%-15wt%: 1wt%-1.2wt%; The surface roughness of the PET substrate Ra is less than 0.1 μm; The rotation speed of the spin coater is 3000 rpm, and the spin coating time is 30 s; The drying temperature is 80° C. and the drying time is 2 hours.
6. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 1, characterized in that: The preparation process of the flexible temperature sensing element is as follows: PVA aqueous solution was added to MXene aqueous solution, magnetically stirred at 90°C for 0.5h, glycerol and borax aqueous solution were added, magnetically stirred at 95°C for 2h, and then dripped into the mold. After spin coating using a spin coater, it was cured to obtain an ultra-thin film. The dripping and spin coating was repeated twice to finally obtain a three-layer integrated ultra-thin film. Then, the upper and lower bottom surfaces of the film were gold-plated using vacuum ion sputtering, and then patterned using a laser cutting machine to finally obtain a flexible temperature sensor element. The mass fraction of the PVA is 5-15wt%; The volume fraction ratio of the glycerol to the borax aqueous solution is 1v%-3v%: 1v%-3v%; the mass fraction of borax in the borax aqueous solution is 5wt%; The rotation speed of the spin coater is 3000 rpm, and the spin coating time is 30 s; The curing temperature is 80°C and the curing time is 2h; The thickness of the three-layer integrated ultra-thin film is 0.1 mm±5 μm.
7. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 6, characterized in that: The preparation process of the MXene aqueous solution is as follows: The Ti3AlC2 matrix was added to the HCl / LiF mixed solution and magnetically stirred at room temperature for 0.5 h, then etched at 40 °C for 45 h, then ultrasonicated and centrifuged, and finally the upper layer solution was taken to obtain a uniformly dispersed MXene solution; The mass ratio of HCl, LiF and Ti3AlC2 is 25:2:1; The ultrasonication was carried out under an argon atmosphere, and the ultrasonication time was 1 h; The centrifugation is carried out in a test tube, the centrifuge speed is no more than 3500 r / min, and the centrifugation time is 1 hour.
8. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 6, characterized in that: The vacuum ion sputtering time is not less than 15s.
9. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 6, characterized in that: The patterning process is as follows: placing the film on a laser cutting machine into a regular hexagonal shape, processing the inside to obtain a kirigami structure, and then starting the cutting machine to finally obtain a flexible temperature sensing element.
10. The flexible capacitive temperature sensor with three-dimensional modular layout according to claim 1, characterized in that: The silver wires in the conductive part are glued to the flexible substrate with ultra-thin double-sided adhesive; the silver wires are orthogonally arranged on the flexible temperature sensing element; the silver wires are serpentine structures; the conductive silver glue in the conductive part is used to fix the central contact point between the silver wires and the temperature sensing element.