A temperature and humidity monitor

Abstract

The application discloses a temperature and humidity monitor and relates to the technical field of sensors, aiming to solve the problems of short signal propagation distance and the inability to directly read temperature and humidity data of the existing temperature and humidity monitor. The temperature and humidity monitor comprises a substrate and a shell, the shell is arranged on the substrate to form a cavity, an NFC chip, a microcontroller, a temperature sensor, a humidity sensor and a signal processing circuit are arranged in the cavity, the NFC chip is used for collecting current and supplying power for the microcontroller, the microcontroller is used for driving the temperature sensor and the humidity sensor to collect signals at different times, the signals are analog signals, the signal processing circuit sends the analog signals to the NFC chip after processing, the NFC chip converts temperature analog signals collected by the temperature sensor and humidity analog signals collected by the humidity sensor into digital signals, and the digital signals are sent to a mobile device with an NFC function. The temperature and humidity monitor is used for improving the transmission distance of collected temperature and humidity signals.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and more particularly to a temperature and humidity monitor. Background Technology

[0002] Passive wireless sensing devices have the advantages of requiring no power supply, wireless transmission, and theoretically unlimited lifespan. They are suitable for monitoring and recording the condition of goods during transportation and storage, as well as environmental conditions; calculating the shelf life of sealed food and medicine; and monitoring the temperature and humidity inside buildings.

[0003] Existing passive wireless temperature and humidity monitors primarily utilize LC resonant circuits or radio frequency antennas to transmit signals. However, LC resonant circuits have extremely short transmission distances, typically limited to the sensor's own size, making them unsuitable for practical applications. Radio frequency antennas require complex matching networks and processing circuits, hindering widespread adoption. Furthermore, existing passive wireless temperature and humidity monitors are rigid devices, unsuitable for curved surface applications. They also only collect temperature and humidity signals without analyzing or processing the data, requiring specialized equipment to process the collected signals and obtain the data, making them inconvenient to use. Summary of the Invention

[0004] The purpose of this invention is to provide a temperature and humidity monitor that solves the problems of short signal transmission distance and inability to directly read temperature and humidity data in existing temperature and humidity monitors.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention provides a temperature and humidity monitor, comprising: a substrate and a housing, wherein the housing is disposed on the substrate to form a cavity; an NFC chip, a microcontroller, a temperature sensor, a humidity sensor, and a signal processing circuit are disposed within the cavity;

[0007] The NFC chip is used to collect current and power the microcontroller. The microcontroller is used to drive the temperature sensor and the humidity sensor to collect signals at staggered times. The signals are analog signals. The signal processing circuit processes the analog signals and sends them to the NFC chip. The NFC chip converts the analog temperature signal collected by the temperature sensor and the analog humidity signal collected by the humidity sensor into digital signals and sends the digital signals to a mobile device with NFC functionality.

[0008] Compared with existing technologies, the present invention provides a temperature and humidity monitor, comprising: a substrate and a housing, the housing covering the substrate to form a cavity; an NFC chip, a microcontroller, a temperature sensor, a humidity sensor, and a signal processing circuit are disposed within the cavity; the NFC chip collects current, enabling the temperature and humidity monitor to provide power to all its components in a passive manner; the microcontroller uses staggered timing to drive the temperature and humidity sensors to collect signals; even with very low current, the strength of the collected signals can still be guaranteed to achieve the acquisition of analog temperature and humidity signals; the signal processing circuit processes the acquired analog signals into a stable signal that can be received by the NFC chip and transmitted via NFC. The chip converts analog temperature and humidity signals into digital signals and sends them to NFC-enabled mobile devices. The wireless transmission distance meets practical needs. Because NFC converts analog signals into digital signals, temperature and humidity values ​​can be directly read using an NFC-enabled mobile device without further processing. This is flexible and convenient. Furthermore, the temperature and humidity monitor houses all components within a cavity formed by the substrate and the outer shell. During use, simply attach the monitor to the surface of the object being monitored to perform temperature and humidity checks. It is easy to use, and the integrated functionality of the NFC chip significantly reduces the number of components, resulting in low component costs. The monitor has a simple, compact, and portable structure.

[0009] Optionally, the NFC chip includes: a signal receiving module, an analog-to-digital converter, a main controller, and a feedback unit; the signal receiving module receives the analog signal and sends it to the analog-to-digital converter, the analog-to-digital converter converts the analog signal into a digital signal and sends it to the main controller, and the main controller drives the feedback unit to generate an alternating current based on the digital signal and sends it to a mobile device with NFC functionality.

[0010] Optionally, the NFC chip further includes a rectifier unit and a power management module. The rectifier unit is connected to the power management module. The rectifier unit converts the collected current into DC current and supplies it to the power management module. The power management module supplies the DC current to the various structures and external circuits of the NFC chip.

[0011] Optionally, the temperature sensor and the humidity sensor are disposed on the same flexible substrate; the thermistor of the temperature sensor is integrated on the flexible substrate.

[0012] Optionally, the humidity sensor includes interdigitated electrodes and a nanoforest structure, wherein the interdigitated electrodes are integrated on the flexible substrate and the nanoforest structure covers the interdigitated electrodes.

[0013] Optionally, the nanoforest structure is composed of multiple nanopillars, the surface of which includes multiple hydrophilic carboxyl groups and hydroxyl groups.

[0014] Optionally, the temperature and humidity monitor further includes a copper coil, which is circumferentially arranged along the upper surface edge of the substrate and is used to generate an induced current according to changes in the electromagnetic field; and the copper coil converts the digital signal into an electromagnetic signal and sends it to a mobile device with NFC functionality.

[0015] Optionally, the signal processing circuit includes a signal amplifier and a filter. The signal amplifier and the filter are connected. The signal amplifier amplifies the analog signal, and the filter filters the amplified signal and sends it to the NFC chip.

[0016] Optionally, both the substrate and the outer shell are provided with vent holes, the outer surface of the substrate is coated with a biocompatible adhesive, and both the substrate and the outer shell are made of flexible materials.

[0017] Optionally, the temperature and humidity monitor is a flexible, passive, wireless temperature and humidity monitor that fits onto the surface of human skin or other curved surfaces. By bringing an NFC-enabled mobile device close to the temperature and humidity monitor, the temperature and humidity values ​​of the monitor can be read, thereby enabling temperature and humidity monitoring of the monitored object. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 This invention provides a schematic diagram of the internal structure of a temperature and humidity monitor.

[0020] Figure 2 This is a schematic diagram of the overall structure of a temperature and humidity monitor provided by the present invention;

[0021] Figure 3 This is a schematic diagram of the NFC chip structure provided by the present invention;

[0022] Figure 4 A schematic diagram of the temperature / humidity sensor structure without integrated nanoforest structure provided by the present invention;

[0023] Figure 5 A schematic diagram of the integrated nanoforest structure temperature / humidity sensor provided by the present invention;

[0024] Figure 6 This is a schematic diagram of the circuit connection provided by the present invention;

[0025] Figure 7 A schematic diagram of temperature / humidity signal output provided by this invention;

[0026] Figure 8 This is a schematic diagram illustrating an application scenario of a temperature and humidity monitor provided by the present invention;

[0027] Figure 9 The present invention provides a flowchart of the operation of a temperature and humidity monitor.

[0028] Figure label:

[0029] 1-Substrate, 2-Shell, 3-NFC chip, 31-Signal receiving module, 32-Analog-to-digital converter, 33-Main controller, 34-Feedback unit, 35-Rectifier unit, 36-Power management module, 4-Microcontroller, 5-Temperature sensor, 51-Thermistor, 6-Humidity sensor, 7-Signal processing circuit, 8-Copper coil, 9-Biocompatible adhesive, 10-First vent, 11-Second vent, 12-Flexible substrate, 61-Interdigital electrode, 62-Nanoforest structure, 621-Nanopillar. Detailed Implementation

[0030] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0031] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0033] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] Temperature and humidity are closely related to people's production and daily life. For example, temperature and humidity can be used to determine whether food has spoiled. Existing temperature and humidity sensors utilize the influence of changes in ambient temperature and humidity on the deformation of an inductive cantilever beam, thereby changing the resonant frequency of the inductive-capacitive resonant circuit. However, the transmission distance of the LC resonant circuit is extremely short, which is difficult to meet practical needs. If the transmission distance is to be increased, a complex processing circuit is required, resulting in a complex structure. In addition, existing temperature and humidity sensors can only collect temperature and humidity signals, and special equipment is needed to process the collected signals before the temperature and humidity values ​​can be read, which is inconvenient to use.

[0036] To address the aforementioned issues, this invention provides a temperature and humidity monitor that uses an NFC chip for data transmission. The transmission distance meets the requirements of practical applications, while reducing the number of components and simplifying signal processing. The monitored temperature and humidity values ​​can be directly read by exchanging signals with a reading device. The following is a detailed description in conjunction with the accompanying drawings.

[0037] Please see Figure 1 and Figure 2This invention provides a temperature and humidity monitor, comprising: a substrate 1 and a housing 2, the housing 2 covering the substrate 1 to form a cavity; an NFC chip 3, a microcontroller 4, a temperature sensor 5, a humidity sensor 6, a signal processing circuit 7, and a copper coil 8 are disposed within the cavity; the bottom surface of the substrate 1 is coated with a biocompatible adhesive 9, which can be MasterBond EP62-1LPSPMed; the copper coil 8 is circumferentially arranged along the upper surface edge of the substrate 1 and is used to generate an induced current based on changes in the electromagnetic field; the NFC chip 3 is used to collect the current generated by the copper coil 8 and power the microcontroller 4; the microcontroller 4 is used to drive the temperature sensor 5 and the humidity sensor 6 to collect signals at staggered times; the signals are analog signals; the signal processing circuit 7 processes the analog signals and sends them to the NFC chip 3; the NFC chip 3 converts the analog temperature signal collected by the temperature sensor 5 and the analog humidity signal collected by the humidity sensor 6 into digital signals and sends the digital signals to the copper coil 8; the copper coil 8 sends the digital signals as electromagnetic signals to a mobile device with NFC functionality. The mobile device with NFC functionality can be a mobile phone, iPad, etc.

[0038] The connecting wires between the NFC chip 3, microcontroller 4, temperature sensor 5, humidity sensor 6, signal processing circuit 7, and copper coil 8 can be aluminum wires. Both the substrate 1 and the outer shell 2 are made of flexible materials, such as polyimide and polyvinyl alcohol. The use of flexible materials in the substrate 1 and outer shell 2 allows the temperature and humidity monitor to be bent and folded, enabling better contact with the surface of the monitored object. Multiple first vent holes 10 are arranged circumferentially along the inner side of the copper coil 8 on the substrate 1, and a second vent hole 11 is arranged at the center of the outer shell 2, facilitating the capture of water molecules in the environment by the humidity-sensitive material with a nanoforest structure in the humidity sensor 6.

[0039] As an alternative approach, the structure of the NFC chip 3 in the above configuration can be combined with... Figure 3 Please provide an explanation, such as Figure 3As shown, the NFC chip 3 may include at least: a signal receiving module 31, an analog-to-digital converter 32, a main controller 33, a feedback unit 34, a rectifier unit 35, and a power management module 36. When the copper coil 8 is subjected to changes in the electromagnetic field, it generates an alternating current and sends it to the NFC chip 3. The rectifier unit 35 of the NFC chip 3 converts the alternating current into a direct current and sends the direct current to the power management module 36. The power management module 36 sends the direct current to the various structures of the NFC chip for operation, and the main controller 33 controls the power management module 36 to output the direct current to the external circuit, i.e., the microcontroller 4. The signal receiving module 31 receives the processed analog signal sent by the signal processing circuit 7 and sends it to the analog-to-digital converter 32. The analog-to-digital converter 32 converts the analog signal into a digital signal and sends it to the main controller 33. The main controller 33 drives the feedback unit 34 to generate an alternating current based on the digital signal and sends it to the copper coil 8. The copper coil 8 generates an electromagnetic signal based on the alternating current and sends it to the mobile device with NFC function.

[0040] As an alternative, temperature sensor 5 and humidity sensor 6 can be combined. Figure 4 and Figure 5 To illustrate, temperature sensor 5 and humidity sensor 6 can be mounted on the same flexible substrate 12. The thermistor 51 of temperature sensor 5 is integrated on the flexible substrate 12. The thermistor 51 can be made of aluminum or other metals or alloys, and its shape can be serpentine. Aluminum thermistors exhibit good linearity within the temperature range of 0℃ to 100℃. The flexible substrate 12 can be made of materials such as polyimide and polyvinyl alcohol. Humidity sensor 6 includes interdigitated electrodes 61 and a nanoforest structure 62. Interdigitated electrodes 61 are integrated on the flexible substrate 12 and can be interdigitated bipolar capacitors made of aluminum or other metals or alloys. The nanoforest structure 62 is disposed on the interdigitated electrodes 61, covering them. The nanoforest structure 62 is formed by spin-coating a polyimide film onto the interdigitated electrodes, followed by photolithography and dry etching. The nanoforest structure 62 includes multiple nanopillars 621. After the nanoforest structure 62 is bombarded with oxygen plasma, the surface of the nanopillars 621 can have many hydrophilic carboxyl groups (-COOH) and hydroxyl groups (-OH). The nanoforest structure has a large surface area and, due to the large number of hydrophilic groups, can provide a large number of active adsorption sites for water molecules. Therefore, the humidity sensor has high sensitivity.

[0041] Microcontroller 4 supplies power to temperature sensor 5 and humidity sensor 6 sequentially to drive them at staggered times. Its wiring connections can be combined... Figure 6To illustrate, microcontroller 4 is connected to the positive terminals of the interdigitated electrodes and the thermistor, respectively. The negative terminals of the interdigitated electrodes and the thermistor are connected to the signal processing circuit. All connections can be made of aluminum wire. The temperature and humidity sensors are driven at staggered intervals. The output signals can be as follows: Figure 7 As shown, a temperature simulation signal is output within 0-1s, a humidity simulation signal is output within 1s-2s, and so on. Since the temperature sensor and humidity sensor work at different times, the collected temperature simulation signal and humidity simulation signal are also output at different times.

[0042] As an alternative, the signal processing circuit 7 in the above structure includes a signal amplifier and a filter, which are connected together. The signal amplifier amplifies the temperature analog signal collected by the temperature sensor and the humidity analog signal collected by the humidity sensor, and the filter filters the amplified signals and sends them to the NFC chip.

[0043] As an optional approach, the temperature and humidity monitor provided by this invention can be used in conjunction with dedicated application software. The application of the temperature and humidity monitor can be combined with... Figure 8 Please provide an explanation, such as Figure 8 As shown, this temperature and humidity monitor can be used for skin monitoring, food and drug monitoring, and building monitoring. When in use, attach the temperature and humidity monitor to the surface of human skin or other curved surfaces, then open the application and bring an NFC-enabled mobile device close to the temperature and humidity monitor. The mobile device receives the temperature and humidity values ​​from the monitor, and the application software will continuously display the current temperature and humidity values, thus realizing the monitoring of the temperature and humidity of the monitored object. Simultaneously, the application software allows users to select the current application scenario for the temperature and humidity monitor. After selecting the scenario, the software compares the current temperature and humidity values ​​with the theoretically influential data for that scenario and provides the current scenario status. The software then provides prompts based on this status. For example, when monitoring skin, it determines whether the skin is dry, stuffy, comfortable, or humid based on the detected temperature and humidity values, reminding the user to hydrate promptly, be careful of heatstroke, or be prone to illness. When monitoring food and medicine, it determines whether the food or medicine is normal, possibly spoiled, or has deteriorated based on the detected temperature and humidity values, reminding the user to consume with caution or discard it. When monitoring buildings, it analyzes whether the building is in a normal or high-humidity state based on the detected temperature and humidity values, reminding the user to dehumidify. This temperature and humidity monitor is a flexible, passive, wireless device.

[0044] In specific implementation, combined with Figure 9To explain, firstly, an external reading device, i.e., a mobile device with NFC functionality, is brought close to the temperature and humidity monitor. The copper coil of the temperature and humidity monitor generates an induced current based on the change in the electromagnetic field. The NFC chip collects the current generated by the copper coil and sends it to the microcontroller. The microcontroller supplies power to the temperature and humidity sensors at staggered intervals. When the temperature and humidity sensors receive the current, they collect signals and send the collected signals to the signal processing circuit. The signal processing circuit processes the analog signals collected by the temperature and humidity sensors to obtain a stable analog signal, which is then sent to the NFC chip. The NFC chip converts the analog signal into a digital signal and sends it to the copper coil via alternating current. The copper coil generates an electromagnetic signal based on the alternating current to communicate with the external reading device.

[0045] Based on the above structural description and detailed implementation instructions, it can be seen that the temperature and humidity monitor provided by the present invention has the following technical effects:

[0046] Integrated nanoforest structures, as humidity-sensitive materials, have greater hydrophilicity and specific surface area than ordinary humidity-sensitive materials, which can significantly improve humidity-sensing performance and effectively enhance the accuracy of humidity monitors.

[0047] Integrating a temperature sensor next to the humidity sensor can help calibrate the temperature drift of the humidity sensor while detecting the ambient temperature. Moreover, the combined humidity and temperature signals can more accurately analyze the state of the application scenario.

[0048] The NFC chip can transmit data to mobile devices at a distance of up to 10cm, and the integrated functions of the NFC chip can significantly reduce the number of components.

[0049] The temperature and humidity sensor uses a flexible integrated nanoforest structure and a polyimide shell. The device has a biocompatible adhesive on the bottom, which can be bonded to human skin and simple curved surfaces.

[0050] NFC-enabled mobile devices can wirelessly transmit data when near a flexible, passive wireless temperature and humidity monitor, reading the monitor's temperature and humidity values. Combined with dedicated application software, this allows for a more intuitive and convenient acquisition of scene status.

[0051] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed invention. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0052] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely exemplary descriptions of the invention as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A temperature and humidity monitor, characterised in that, The application relates to a temperature and humidity monitor. The temperature and humidity monitor comprises a substrate and a shell, the shell is arranged on the substrate to form a cavity; The cavity is provided with an NFC chip, a microcontroller, a temperature sensor, a humidity sensor and a signal processing circuit; The NFC chip comprises a signal receiving module, an analog-digital signal converter, a main controller and a feedback unit; The signal receiving module receives an analog signal and sends the analog signal to the analog-digital signal converter, the analog-digital signal converter converts the analog signal into a digital signal and sends the digital signal to the main controller, and the main controller drives the feedback unit to generate an alternating current according to the digital signal and sends the alternating current to a mobile device with NFC function; The NFC chip is used for collecting current and supplying power to the microcontroller, the microcontroller is used for driving the temperature sensor and the humidity sensor to collect signals at staggered times; the signals are analog signals, the signal processing circuit sends the analog signals to the NFC chip after processing the analog signals, the NFC chip converts temperature analog signals collected by the temperature sensor and humidity analog signals collected by the humidity sensor into digital signals, and sends the digital signals to the mobile device with NFC function.

2. The temperature and humidity monitor of claim 1, wherein, The NFC chip further comprises a rectifier unit and a power management module, the rectifier unit is connected with the power management module, the rectifier unit converts the collected current into direct current and delivers the direct current to the power management module, and the power management module delivers the direct current to each structure of the NFC chip and external circuits.

3. The temperature and humidity monitor of claim 1, wherein, The temperature sensor and the humidity sensor are arranged on the same flexible substrate; a thermistor of the temperature sensor is integrated on the flexible substrate.

4. The temperature and humidity monitor of claim 3, wherein, The humidity sensor comprises interdigital electrodes and a nano-forest structure, the interdigital electrodes are integrated on the flexible substrate, and the nano-forest structure covers the interdigital electrodes.

5. The temperature and humidity monitor of claim 4, wherein, The nano-forest structure is composed of a plurality of nano columns, the surfaces of the nano columns comprise a plurality of hydrophilic carboxyl groups and hydroxyl groups.

6. The temperature and humidity monitor of claim 1, wherein, The temperature and humidity monitor further comprises a copper coil, the copper coil is arranged along the edge of the upper surface of the substrate in a circumferential direction and is used for generating induced current according to electromagnetic field change; and the copper coil converts the digital signals into electromagnetic signals and sends the electromagnetic signals to the mobile device with NFC function.

7. The temperature and humidity monitor of claim 1, wherein, The signal processing circuit comprises a signal amplifier and a filter, the signal amplifier and the filter are connected, the signal amplifier amplifies the analog signals, and the filter filters and processes the amplified signals and sends the processed signals to the NFC chip.

8. The temperature and humidity monitor of claim 1, wherein, Vent holes are arranged on the substrate and the shell, the outer surface of the substrate is coated with a biocompatible adhesive, and the materials of the substrate and the shell are flexible materials.

9. The temperature and humidity monitor of claim 1, wherein, The temperature and humidity monitor is a flexible passive wireless temperature and humidity monitor which is attached to the surface of human skin or the curved surface of other objects, a mobile device with NFC function is close to the temperature and humidity monitor to read the temperature and humidity values of the temperature and humidity monitor, and the temperature and humidity of the monitored object is monitored.

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