Temperature sensor and method of manufacturing and use thereof

Abstract

The application discloses a temperature sensor and a preparation method and application thereof. The temperature sensor comprises a first electrode and a second electrode, and a temperature-sensitive material layer electrically connecting the first electrode and the second electrode. The width of the temperature-sensitive material layer gradually changes along the connecting direction of the first electrode and the second electrode. The width of the temperature-sensitive material layer of the temperature sensor gradually changes along the connecting direction of the first electrode and the second electrode, so that the resistance (or resistance change rate) of the temperature sensor is different when a heat source with the same temperature size is located at different positions (along the connecting direction of the first electrode and the second electrode) of the temperature sensor. The position of the heat source to be measured can be calculated by reading the resistance value (or resistance change rate) of the temperature sensor. Therefore, the temperature sensor has a simple structure, and the position of the heat source can be monitored only by using the sensing information of a single sensor, so that the reliability of the device is high.

Description

Technical Field

[0001] This invention belongs to the field of temperature sensing equipment technology, specifically relating to a temperature sensor, its preparation method, and its application. Background Technology

[0002] Inflammation and infection are common pathological processes in the human body. When inflammation or infection occurs, the immune system is activated, leading to increased local blood flow and enhanced metabolic activity, which manifests as an abnormally high skin surface temperature. This phenomenon has wide applications in medicine; for example, during wound healing, changes in temperature distribution in and around the wound can be used to identify early signs of infection. Therefore, continuous monitoring of skin temperature changes, especially obtaining information on both temperature levels and the location of heat sources, is of great significance in clinical diagnosis, postoperative monitoring, chronic wound management, and infection control.

[0003] Currently, temperature sensors are widely used in the field for monitoring the temperature of the skin surface. Traditional temperature sensors, such as thermocouples or thermistors, mainly focus on single-point measurements. These devices can provide local temperature readings but cannot capture spatial distribution information. Therefore, the field is gradually shifting towards distributed temperature sensing technologies that can simultaneously monitor both temperature levels and the location of heat sources.

[0004] In existing technologies, the most common approach is to use array temperature sensors. By employing multiple temperature sensors arranged in an array, simultaneous detection of temperature levels and heat source locations can be achieved. For example, a Chinese patent entitled "Epidermal Device for Analyzing Temperature and Heat Transfer Characteristics" provides a device for interfacing with tissues in a biological environment, capable of detecting the spatial / temporal distribution of temperature caused by heating. However, to determine the spatial temperature (heat source location) information, this device uses multiple thermal sensors, each with its own wiring, resulting in complex wiring, large size, and the introduction of additional circuit noise and power consumption. This not only increases manufacturing costs but also reduces device reliability. These problems can be overcome if the sensing information from a single sensor can vary with the location of the heat source. Summary of the Invention

[0005] To address the problem that existing temperature sensors cannot detect the location of heat sources using only the information from a single sensor, this invention provides a temperature sensor that can detect the location of heat sources without using a sensor array structure. This not only simplifies the structure but also increases the reliability of the device.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned temperature sensor.

[0007] Another object of the present invention is to provide the application of the above-mentioned temperature sensor in heat source location and temperature monitoring.

[0008] Another object of the present invention is to provide a monitoring device.

[0009] Another object of the present invention is to provide a method for monitoring the location and temperature of a heat source.

[0010] The above-mentioned objective of this invention is achieved through the following technical solution:

[0011] A temperature sensor includes a first electrode and a second electrode, and a temperature-sensitive material layer electrically connecting the first electrode and the second electrode. The width of the temperature-sensitive material layer gradually changes along the line connecting the first electrode and the second electrode.

[0012] It should be noted that: In this invention, the temperature-sensitive material of the temperature-sensitive material layer refers to a material whose resistance changes with temperature.

[0013] The width of the temperature-sensitive material layer of the temperature sensor of the present invention gradually changes in the direction of the line connecting the first electrode and the second electrode. As a result, when a heat source of the same temperature is located at different positions of the temperature sensor (in the direction of the line connecting the first electrode and the second electrode), the resistance (or resistance change rate) of the temperature sensor is different. By reading the resistance value (or resistance change rate) of the temperature sensor, the position of the heat source to be measured can be calculated.

[0014] Furthermore, since the resistance (or rate of change of resistance) of the heat source under test is different at at least two different locations on the temperature sensor, the temperature of the heat source under test can be calculated from the resistance at at least two different locations.

[0015] Preferably, the temperature sensor further includes a substrate.

[0016] More preferably, the substrate is at least one of a silicon substrate, a germanium substrate, and a silicon carbide substrate.

[0017] More preferably, the upper surface of the substrate is rectangular in shape.

[0018] More preferably, the substrate is used to support the temperature-sensitive material layer.

[0019] More preferably, the temperature-sensitive material is stacked on top of the substrate.

[0020] Commonly used temperature-sensitive materials in this field can be used as temperature-sensitive materials for the temperature-sensitive material layer of this invention.

[0021] Preferably, the temperature-sensitive material of the temperature-sensitive material layer is at least one of VO2 (undoped vanadium dioxide), W-doped VO2 (tungsten-doped vanadium dioxide), and poly-N-isopropylacrylamide.

[0022] More preferably, the temperature-sensitive material of the temperature-sensitive material layer is W-doped VO2.

[0023] Preferably, the upper surface of the temperature-sensitive material layer is triangular or trapezoidal; the base of the triangle and the opposite corner of the base are electrically connected to the first electrode and the second electrode, respectively, and the two bases of the trapezoid are electrically connected to the first electrode and the second electrode, respectively.

[0024] Preferably, the electrode is at least one of a Cu electrode, an Au electrode, and an Ag electrode.

[0025] Preferably, the first electrode and the second electrode are stacked on top of the temperature-sensitive material layer.

[0026] Preferably, the width of the temperature-sensitive material layer gradually increases or decreases along the line connecting the first electrode and the second electrode.

[0027] Specifically, the temperature sensor includes a substrate, a temperature-sensitive material layer, a first electrode, and a second electrode; the temperature-sensitive material layer is stacked on top of the substrate, and the first electrode and the second electrode are stacked on top of the temperature-sensitive material layer; the upper surface of the temperature-sensitive material layer is a right-angled triangle, the first electrode is electrically connected to one of the right-angled sides of the right-angled triangle, and the second electrode is electrically connected to the opposite diagonal of the right-angled side.

[0028] This invention also protects a method for manufacturing the above-mentioned temperature sensor, comprising the following steps: S1. Fabricate the temperature-sensitive material layer; S2. A first electrode and a second electrode are formed at both ends of the temperature-sensitive material layer to obtain the temperature sensor.

[0029] The temperature sensor of this invention has a simple manufacturing process and low manufacturing cost.

[0030] Preferably, the step of fabricating the temperature-sensitive material layer in step S1 is as follows: S11. Take a substrate and use a shielding material to cover part of the surface area of ​​the substrate, so that the width of the unshielded part of the substrate gradually changes along a certain direction to obtain the shielded substrate. S12. Deposit a temperature-sensitive material on the substrate after shielding as described in step S11, and then remove the shielding material on the substrate to obtain the temperature-sensitive material layer; When the shielding material on the substrate is removed in step S12, the temperature-sensitive material on the surface of the shielding material is also removed at the same time.

[0031] Preferably, the shielding material in step S11 is tape.

[0032] Preferably, the method for depositing the temperature-sensitive material in step S12 is magnetron sputtering.

[0033] Preferably, the temperature-sensitive material in step S12 is at least one of VO2, W-doped VO2, and poly-N-isopropylacrylamide.

[0034] More preferably, the temperature-sensitive material in step S2 is W-doped VO2.

[0035] This invention also protects the application of the above-mentioned temperature sensor in heat source location and temperature monitoring.

[0036] The present invention also protects a monitoring device comprising the above-mentioned temperature sensor.

[0037] Preferably, the monitoring device is a medical monitoring device or a routine health monitoring device.

[0038] The present invention also protects a method for monitoring the location and temperature of a heat source. Using the above-mentioned temperature sensor, the temperature sensor is moved so that at least two different locations of the temperature sensor are in contact with the heat source, and the resistance values ​​at at least two different locations are measured. Then, the temperature of the heat source is calculated based on the resistance values ​​at at least two different locations, and the location of the heat source is determined based on the temperature.

[0039] Preferably, before using the temperature sensor described above, a step of fitting a standard curve is further included.

[0040] More preferably, the specific process of the step of fitting the standard curve is as follows: the heat source is brought into contact with a certain position of the temperature sensor, and then the temperature value of the heat source is changed. At the same time, the resistance change rate value corresponding to different temperature values ​​of the heat source is recorded. The standard curve is obtained by linearly fitting the temperature value and the resistance change rate value.

[0041] More preferably, the number of standard curves is ≥2, such as 2, 3, 4, 5, 6, 7, 8, 9, 10.

[0042] The more standard curves there are, the higher the accuracy of the temperature sensor in determining the location and temperature of the heat source.

[0043] Compared with the prior art, the present invention has the following beneficial effects: In this invention, the width of the temperature-sensitive material layer in the temperature sensor gradually changes along the line connecting the first and second electrodes. This results in different resistances (or rates of change of resistance) of the temperature sensor at different positions of a heat source of the same temperature along the line connecting the first and second electrodes. By reading the resistance value (or rate of change of resistance) of the temperature sensor, the location of the heat source can be calculated. Therefore, the temperature sensor of this invention has a simple structure, achieves heat source location monitoring using only the sensing information of a single sensor, and the device has high reliability. Attached Figure Description

[0044] Figure 1 This is a three-dimensional structural diagram of the temperature sensor in Example 1.

[0045] Figure 2 for Figure 1 A top-view structural diagram.

[0046] Figure 3 This is a top view of the temperature sensor in Example 2.

[0047] Figure 4 a~b are top and front view structural diagrams of the temperature sensor in Comparative Example 1, respectively.

[0048] Figure 5 The temperature-resistivity curve of the temperature sensor in Example 1 is shown.

[0049] Figure 6 The temperature-resistivity curve of the temperature sensor in Comparative Example 1 is shown. Detailed Implementation

[0050] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0051] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0052] Example 1 This embodiment provides a temperature sensor, the three-dimensional structural schematic diagram of which is shown below. Figure 1 As shown, the top view of the structure is as follows: Figure 2 As shown, it includes a substrate 4, a temperature-sensitive material layer 3, and electrodes stacked sequentially from bottom to top. The electrodes include a first electrode 1 and a second electrode 2. The upper surface of the temperature-sensitive material layer 3 is a right-angled triangle. The second electrode 2 is electrically connected to the short right-angled side of the right-angled triangle, and the first electrode 1 is electrically connected to the diagonal of the short right-angled side.

[0053] The substrate is a Si substrate with a rectangular upper surface, 60 mm long and 5 mm short. The temperature-sensitive material layer is a W-doped VO2 layer covering the upper surface of the substrate. The coverage area of ​​the temperature-sensitive material layer is half of the upper surface area of ​​the substrate, i.e., the lengths of the two right-angled sides of the upper surface of the temperature-sensitive material layer are 60 mm and 5 mm, respectively, and the thickness of the temperature-sensitive material layer is 160 nm. The first electrode 1 and the second electrode 2 are both Ag electrodes, and the lengths of the first electrode 1 and the second electrode 2 are the same as the length of the right-angled side a.

[0054] The method for fabricating a temperature sensor provided in this embodiment includes the following steps: (1) Take a Si substrate and use tape to cover half of the upper surface of the Si substrate, using the diagonal of the upper surface of the Si substrate as the boundary, to obtain the covered substrate. (2) Using magnetron sputtering, W-doped VO2 was deposited on the upper surface of the shielded substrate. The operation steps are as follows: After cleaning the shielded substrate, it was mounted on the substrate holder, and the substrate stage height was pre-calibrated to 0 mm; the W-doped VO2 target (Hebei Jiuyue New Material Technology Co., Ltd.) was installed, and the equipment valves, pump group, RF power supply and Ar gas path were checked to be normal. The mechanical pump was turned on to pre-evacuate the vacuum, and the molecular pump was turned on to continue evacuating the gas until the background vacuum of the vacuum chamber reached 1.2 × 10⁻⁶. -3 Pa, stabilize for 10 min. Close the molecular pump pre-stage valve, open the Ar gas valve, set the Ar gas flow rate to 40 sccm, and adjust the vent valve to stabilize the process pressure at 0.92 Pa. Turn on the RF power supply and adjust the output power to 120W. When uniform plasma appears on the target, record the start time. Keep the Ar flow rate, process pressure, RF power, and substrate stage height constant, and continue deposition for 25 min. After 25 min of deposition, turn off the RF power supply and maintain Ar gas for 5 min; close the Ar valve, turn on the mechanical pump to evacuate for 5 min, and then purge with nitrogen to balance the gas pressure, thus obtaining the deposited substrate. (3) After deposition, the adhesive tape is removed from the substrate, and the W-doped VO2 layer on the surface of the adhesive tape is also removed at the same time, resulting in a substrate with a temperature-sensitive material layer deposited. (4) Apply silver paste above both ends of the substrate with the temperature-sensitive material layer deposited along the length direction to form the first electrode 1 and the second electrode 2, thus obtaining the temperature sensor.

[0055] Example 2 This embodiment provides a temperature sensor, the structure of which is as follows: Figure 3 As shown, it includes a substrate 4, a temperature-sensitive material layer 3, and electrodes stacked sequentially from bottom to top. The electrodes include a first electrode 1 and a second electrode 2. The upper surface of the temperature-sensitive material layer 3 is a right-angled trapezoid. The first electrode 1 is electrically connected to the upper base of the right-angled trapezoid, and the second electrode 2 is electrically connected to the lower base of the right-angled trapezoid.

[0056] The substrate is a Si substrate with a rectangular upper surface, 60 mm long and 5 mm short. The temperature-sensitive material layer is a W-doped VO2 layer covering the upper surface of the substrate. The upper base of the temperature-sensitive material layer is 3 mm, the lower base is 5 mm, the height is 60 mm, and the thickness of the temperature-sensitive material layer is 160 nm. The first electrode 1 and the second electrode 2 are both Ag electrodes, and the length of the first electrode 1 and the second electrode 2 is the same as the length of the lower base.

[0057] The method for fabricating the temperature sensor provided in this embodiment is similar to that in Embodiment 1, except that the area covering the upper surface of the Si substrate is different.

[0058] Example 3 This embodiment provides a temperature sensor, which differs from Embodiment 1 in that the temperature-sensitive material layer is an undoped VO2 layer.

[0059] The method for preparing the temperature sensor provided in this embodiment is similar to that in embodiment 1. The difference is that in step (2), the material deposited on the upper surface of the shielded substrate is undoped VO2.

[0060] Comparative Example 1 This comparative example provides a temperature sensor, the structure of which is as follows: Figure 4 As shown in a~b, it includes a substrate 4, a temperature-sensitive material layer 3 and electrodes stacked sequentially from bottom to top. The electrodes include a first electrode 1 and a second electrode 2. The upper surface of the temperature-sensitive material layer 3 is rectangular and coincides with the upper surface of the substrate 4.

[0061] The substrate is a Si substrate with a rectangular upper surface, 60 mm long and 5 mm short. The temperature-sensitive material layer is a W-doped VO2 layer with a long side of 60 mm and a short side of 5 mm, and a thickness of 160 nm. The first electrode 1 and the second electrode 2 are both Ag electrodes, and the lengths of the first electrode 1 and the second electrode 2 are the same as the length of their short sides.

[0062] The method for fabricating the temperature sensor provided in this comparative example is similar to that in Example 1, except that the step of covering the upper surface of the Si substrate is omitted.

[0063] Performance testing At 25°C, the resistance change rate of the temperature sensors in each embodiment was tested using heat sources of different temperatures. The steps are as follows: (1) Connect the DC power supply, temperature control module, and heating ceramic plate in sequence. Set the maximum temperature of the temperature control module to 43℃. After the heating ceramic plate heats up normally during the power-on test, turn off the power and leave it for later use. Connect the digital bridge to the first and second electrodes of the temperature sensor. The heating ceramic plate is in contact with the temperature-sensitive material layer at position A (the center point is 10mm from the left end of the sensor). After the temperature and resistance stabilize, record the initial resistance R0 of the temperature sensor (i.e., the resistance at 25℃). Turn on the DC power supply and start heating from room temperature to 43℃. After reaching 43℃, turn off the power supply. During the cooling process, record the temperature and the real-time resistance R of the sensor every degree, and calculate the difference between the initial resistance ΔR=R-R0 and the resistance change rate ΔR / R0, until 25℃.

[0064] (2) Based on the temperature and ΔR / R0 data, perform linear fitting to obtain the standard curves at each location.

[0065] (3) Move the heating ceramic plate to positions B, C, and D (the center point is 20mm, 40mm, and 50mm away from the left end of the sensor, respectively), and perform measurement and standard curve fitting using the same method.

[0066] The resistance change rate test was performed on the temperature sensor of Comparative Example 1. The steps were similar to those of Example 1, with the heat source locations being A and D (the center point was 10mm and 50mm away from the left end of the sensor, respectively).

[0067] The temperature-resistivity standard curve of the temperature sensor in Example 1 is as follows: Figure 5 As shown. The standard curve function equations (positions A, B, C, D) of the temperature sensor in Example 1 are as follows: y A =-0.035x+1.007 y B =-0.068x+2.002 y C =-0.274x+8.219 y D =-0.308x+8.863; Depend on Figure 5 It is known that when the heated ceramic plate (i.e., the heat source) is located at different positions along the length of the sensor, the slope of the obtained standard curve varies significantly. In other words, when the same heat source is located at different positions along the length of the temperature sensor, the resistance (or rate of change of resistance) of the temperature sensor is significantly different. Therefore, the location of the heat source can be determined based on the difference in resistance (or rate of change of resistance). The temperature sensors in Examples 2 and 3 can also achieve similar effects.

[0068] The temperature-resistivity curve of the temperature sensor in Comparative Example 1 is as follows: Figure 6 As shown. The standard curve function equations (positions A and D) of the temperature sensor in Comparative Example 1 are as follows: y A =-1.488x+41.565 y D =-1.655x+46.161; Depend on Figure 6 It can be seen that at positions A and D, the resistance change rate ΔR / R0 does not change significantly with temperature. When the same heat source is at different positions along the length of the temperature sensor, the resistance (or resistance change rate) of the temperature sensor is not significantly different, making it difficult to determine the position of the heat source based on the difference in resistance (or resistance change rate).

[0069] Application examples Simulated unknown heat source test (1) A heating ceramic plate at 40°C was placed at a certain position X on the temperature sensor of Example 1 (X is located between position B and position C, and is closer to position B and farther from position C) to verify the unknown heat source to be measured: First, the sensor resistance value R at this time was read, and combined with the initial resistance R0 of the sensor, the resistance change rate (ΔR / R0) at this time was calculated. X =-0.73%; Then remove the ceramic plate and wait for the sensor to cool to room temperature. Place the ceramic plate at positions A and D respectively (the sensor must be cooled to room temperature before each test). Read the resistance of the sensor at positions A and D respectively, and calculate the resistance change rate y at the two positions based on the initial resistance R0 of the sensor. A =(ΔR / R0) A =-0.39%, y D =(ΔR / R0) D =-3.51%; then, based on the temperature-resistivity equations at locations A and D, the temperature can be deduced, and the heat source temperature can be obtained as x≈40℃; then, x=40℃ is substituted into each equation of the function equation system, and the y obtained from each equation is compared with (ΔR / R0). X The difference was found in y. B (-0.718%) and (ΔR / R0) X The difference is the smallest, which means that the heat source is located near location B.

[0070] (2) Use a 40°C heating ceramic plate to place another position Y of the sensor (Y is located between position B and position C, and is farther from position B and closer to position C) as the unknown heat source to be tested for verification. The method is similar to step (2), and the heat source position can be determined to be near position C.

[0071] (3) By comparing the test results of steps (1) and (2), it can be determined that the temperature sensor of Example 1 can not only determine the relative position of the heat source, but also the absolute position determined is very close to or even consistent with the actual position.

[0072] The temperature sensors of Examples 2 and 3 were subjected to simulated unknown heat source tests using the same method, and the test results for the heat source temperature and location were consistent with the actual results.

[0073] The above application examples further demonstrate that the temperature sensor of the present invention can not only measure the temperature of a heat source, but also measure the relative / absolute position of the heat source; furthermore, by fitting standard curves for more positions, a more accurate measurement of the absolute position of the heat source can be achieved.

[0074] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A temperature sensor, characterized in that, The temperature sensor includes a first electrode and a second electrode, and a temperature-sensitive material layer that electrically connects the first electrode and the second electrode. The width of the temperature-sensitive material layer gradually changes along the line connecting the first electrode and the second electrode.

2. The temperature sensor according to claim 1, characterized in that, The temperature sensor also includes a substrate.

3. The temperature sensor according to claim 2, characterized in that, The upper surface of the substrate is rectangular in shape.

4. The temperature sensor according to claim 1, characterized in that, The temperature-sensitive material of the temperature-sensitive material layer is at least one of VO2, W-doped VO2, and poly(N-isopropylacrylamide).

5. The temperature sensor according to claim 1, characterized in that, The upper surface of the temperature-sensitive material layer is triangular or trapezoidal in shape; the base of the triangle and the opposite corner of the base are electrically connected to the first electrode and the second electrode, respectively, and the two bases of the trapezoid are electrically connected to the first electrode and the second electrode, respectively.

6. The temperature sensor according to claim 1, characterized in that, The first electrode and the second electrode are stacked on top of the temperature-sensitive material layer.

7. A method for preparing the temperature sensor according to any one of claims 1 to 6, characterized in that, It includes the following steps: S1. Fabricate the temperature-sensitive material layer; S2. A first electrode and a second electrode are formed at both ends of the temperature-sensitive material layer to obtain the temperature sensor.

8. The application of the temperature sensor according to any one of claims 1 to 6 in heat source location and temperature monitoring.

9. A monitoring device, characterized in that, It includes the temperature sensor described in any one of claims 1 to 6.

10. A method for monitoring the location and temperature of a heat source, characterized in that, Using any one of the temperature sensors described in claims 1 to 6, the temperature sensor is moved so that it contacts the heat source at least two different locations, and the resistance values ​​at at least two different locations are obtained from the measurements; then the temperature of the heat source is calculated from the resistance values ​​at at least two different locations, and the location of the heat source is determined based on the temperature.

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