Intelligent switch for intelligent agricultural irrigation system and preparation method

Abstract

The invention discloses an intelligent switch for an intelligent agricultural irrigation system and a preparation method, and relates to the technical field of intelligent agricultural irrigation, the intelligent switch comprises a direct current power supply, a humidity memristor, a variable resistor, a resistor, a current-voltage converter, a light emitting diode and a light receiver; the active region of the humidity sensing memristor is composed of the graphene oxide, the graphene oxide contains rich hydrophilic groups including hydroxyl, epoxy group and carboxyl, and the hydrophilic groups can form hydrogen bonds with water molecules, so that the graphene oxide has high humidity sensitivity, and therefore, the humidity sensing memristor has high humidity sensitivity. The graphene oxide has huge application potential in the humidity sensing memristor. Besides, the graphene oxide is low in manufacturing cost, the graphene oxide serves as a humidity sensing memristor, development of a high-precision, low-cost and high-portability intelligent agricultural irrigation system is facilitated, the labor cost can be effectively saved, and the crop yield can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of smart agricultural irrigation, and in particular to an intelligent switch for a smart agricultural irrigation system and a preparation method thereof. Background Art

[0002] During the growth of crops, soil moisture directly affects the growth of crops. Too wet or too dry soil moisture will affect crop yields. In addition, different crops require different soil moisture. Therefore, in order to increase crop yields, precise and controllable agricultural irrigation devices are needed. Current agricultural irrigation technology relies heavily on manual irrigation, where farmers control the irrigation frequency and water volume based on their own experience. This method consumes a lot of manpower and cannot achieve precise and controllable agricultural irrigation.

[0003] In recent years, the use of humidity sensor systems to achieve smart agricultural irrigation has received widespread attention. This humidity sensor system is equipped with a separate humidity sensor to collect humidity information as an analog signal, then convert the data into digital form through analog-to-digital conversion, a memory to store information, a computing unit to perform calculations, and the calculation results are used to control the opening and closing of the irrigation switch. Complex circuit design and system construction require complex integration technology, which not only increases the latency and computing power of the entire system, but also inevitably affects the efficiency, portability and production cost of the system. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide an intelligent switch and a preparation method for a smart agricultural irrigation system, which integrates sensing, storage and computing into one intelligent switch to solve the problem that traditional switches require complex integration technology, which not only increases the delay and computing power of the entire system, but also inevitably affects the efficiency of the system, has poor portability and high production costs.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An intelligent switch for a smart agricultural irrigation system, comprising a DC power supply, a humidity memristor, a variable resistor, a resistor, a current-voltage converter, a light emitting diode, and a light receiver;

[0007] The DC power supply voltage is 3V;

[0008] The humidity memristor is a graphene oxide memristor with a thickness of 1-3 microns;

[0009] The electrode material used in the humidity memristor is an active metal electrode material with a thickness of 100-500 nanometers and an electrode size of 1-5 millimeters;

[0010] The resistance of the variable resistor is 0.5-2MΩ;

[0011] The light emitting diode is an infrared light emitting diode, and the operating voltage is 1.5-1.6V;

[0012] The light receiver is an infrared light receiver;

[0013] The DC power supply is connected to either end of the humidity memristor, and the other end is grounded through a variable resistor. The resistor is connected in parallel at both ends of the humidity memristor, and the current flowing through the resistor is connected to a current-voltage converter as an output end. The converted voltage is used to drive a light-emitting diode. When the soil humidity is low, the light-emitting diode emits light and is received by a light receiver, thereby triggering the irrigation switch to turn on; when the soil humidity is high, the light-emitting diode does not emit light, the light receiver does not receive the light signal, and the irrigation switch is turned off.

[0014] A method for preparing an intelligent switch for a smart agricultural irrigation system comprises the following steps:

[0015] Step A: preparing a graphene oxide film, specifically, dispersing 100-500 mg of graphene oxide in 200-1000 mL of ethanol and ultrasonically treating for 30-60 minutes to obtain a colloidal dispersion, then plasma cleaning the substrate, spin-coating the colloidal dispersion on the substrate, and drying at 50-100° C. for 1-2 hours;

[0016] Step B: preparing the graphene oxide into a humidity memristor, specifically by pasting a mask on the surface of the substrate on which the graphene oxide is spin-coated, and evaporating the active metal electrode on the substrate by thermal evaporation, wherein the rate during the evaporation process is 0.1-0.5 angstroms / second, and the vacuum degree is maintained below 5×10^-4Pa;

[0017] Step C: Assemble the humidity memristor and other circuit elements into an intelligent switch, specifically connect a DC power supply, a humidity memristor, a variable resistor, a resistor, a current-voltage converter, a light-emitting diode and a light receiver in the manner described in claim 1.

[0018] As a preferred technical solution of the present invention, in step A, the spin coating speed of graphene oxide is 1000-3000 rpm, and the spin coating time is 10-40 seconds.

[0019] As a preferred technical solution of the present invention, the active metal electrode material in step B includes Ag, Cu or Al, the electrode shape is square or rectangular, and the electrode spacing is 100-500 microns.

[0020] As a preferred technical solution of the present invention, step C also includes converting the current flowing through the resistor into a voltage through a current-voltage converter, and using the voltage to drive a light-emitting diode to control the opening and closing of the irrigation switch according to changes in soil moisture.

[0021] The present invention has the following benefits:

[0022] By using graphene oxide humidity memristor, the switch can have high humidity sensitivity. Graphene oxide is cheap, harmless and environmentally friendly. At the same time, using graphene oxide humidity sensing memristor as an intelligent switch for smart agricultural irrigation system can help develop high-precision, low-cost and highly portable smart agricultural irrigation system, which can effectively save labor costs and help increase crop yields. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the structure of an intelligent switch used in a smart agricultural irrigation system.

[0024] Figure 2 Schematic diagram of the structure of a graphene oxide humidity memristor in an intelligent switch used in a smart agricultural irrigation system.

[0025] Figure 3 Schematic diagram of the resistance change curve of a graphene oxide humidity memristor in a smart switch used in a smart agricultural irrigation system under different humidity conditions.

[0026] Figure 4 Schematic diagram of the turn-on voltage of a graphene oxide humidity memristor in a smart switch used in a smart agricultural irrigation system under different humidity conditions. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0028] Example 1, please refer to Figure 1 , an intelligent switch for a smart agricultural irrigation system, comprising a power supply 1, a humidity memristor 2, a variable resistor 3, a resistor 4, a current-voltage converter 5, a light emitting diode 6, and a light receiver 7;

[0029] The power supply 1 is a DC power supply, and the voltage of the DC power supply is 3V;

[0030] The humidity memristor 2 is a graphene oxide memristor with a thickness of 1-3 microns; graphene oxide contains abundant hydrophilic groups, including hydroxyl, epoxy and carboxyl groups, which can form hydrogen bonds with water molecules, making graphene oxide highly sensitive to humidity. Therefore, graphene oxide has great application potential in humidity sensing memristor 2. In addition, graphene oxide is cheap to manufacture. Using graphene oxide as humidity sensing memristor 2 is conducive to the development of high-precision, low-cost and highly portable smart agricultural irrigation systems, which can not only effectively save labor costs, but also help increase crop yields.

[0031] The electrode material used in the humidity memristor 2 is an active metal electrode material, including but not limited to Ag, Cu, or Al, with a thickness of 100-500 nanometers, an electrode size of 1-5 millimeters, an electrode spacing of 100-500 microns, and an electrode shape of square or rectangle.

[0032] The resistance of the variable resistor 3 is 0.1-1.1 MΩ.

[0033] The resistance of the resistor 4 is 0.5-1.5 MΩ.

[0034] The model of the current-voltage converter 5 is LMC62CN.

[0035] The working voltage of the light emitting diode 6 is 1.2-1.5V, and the emitted light is infrared light.

[0036] The light receiver 7 can receive infrared light from the light emitting diode 6, and control the opening and closing of irrigation according to the presence or absence of infrared light.

[0037] Wherein, the DC power supply is connected to either end of the humidity memristor 2, and the other end is grounded through a variable resistor 3. The resistor 4 is connected in parallel to both ends of the humidity memristor 2, and the current flowing through the resistor 4 is connected to a current-voltage converter 5 as an output end. The converted voltage is used to drive a light-emitting diode 6. When the soil humidity is low, the light-emitting diode 6 emits light and is received by a light receiver 7, thereby triggering the irrigation switch to turn on; when the soil humidity is high, the light-emitting diode 6 does not emit light, the light receiver 7 does not receive the light signal, and the irrigation switch is turned off.

[0038] A method for preparing an intelligent switch for a smart agricultural irrigation system comprises the following steps:

[0039] Step A, preparing a graphene oxide film; first, placing 100-500 mg of graphene oxide in 200-1000 ml of ethanol and ultrasonically treating it for 30-60 minutes to prepare a graphene oxide colloidal dispersion; then, placing the substrate in a plasma cleaning machine for cleaning, the cleaning atmosphere is oxygen, the time is 30-60 seconds, the pressure is 10-20 Pa, and the power is 10-20 W; spin coating the graphene oxide colloidal dispersion on the surface of the substrate, the spin coating speed is 1000-3000 rpm, and the spin coating time is 10-40 seconds; after spin coating, the sample is placed on a hot plate for drying, the drying temperature is 50-100° C., and the time is 1-2 hours.

[0040] Step A is specifically as follows: first, 100 mg of graphene oxide is placed in 200 ml of ethanol and ultrasonically treated for 40 minutes to prepare a graphene oxide colloidal dispersion; then, the Si / SiO2 substrate is placed in a plasma cleaner for cleaning, the cleaning atmosphere is oxygen, the time is 40 seconds, the pressure is 20 Pa, and the power is 20 W; the graphene oxide colloidal dispersion is spin-coated on the surface of the substrate, the spin-coating speed is 2000 rpm, and the spin-coating time is 30 seconds; after spin-coating, the sample is placed on a hot plate for drying, the drying temperature is 80°C, and the time is 1.5 hours.

[0041] Step B, preparing graphene oxide into humidity memristor 2; preparing humidity memristor by preparing active metal electrodes on the surface of graphene oxide, the active metal electrodes are prepared by thermal evaporation, and are paired electrodes with a thickness of 100-500 nanometers, an electrode size of 1-5 millimeters, an electrode spacing of 100-500 microns, and an electrode shape of square or rectangle. Paste a mask on the surface of the substrate on which graphene oxide is spin-coated, and use thermal evaporation to evaporate active metal electrodes such as Ag, Cu, or Al on the substrate. During the evaporation process, the rate is 0.1-0.5 angstroms / second, and the vacuum degree is below 5×10^-4Pa.

[0042] Step B is specifically as follows: pasting a mask plate on the substrate, the mask plate has a size of 2cm×2cm, contains 5×5 pairs of electrodes, the electrode shape is square, the size is 1 mm, the spacing is 100 microns, and the thickness of the evaporated electrode is 100 nanometers.

[0043] Ag with a thickness of about 100 nanometers was deposited on the substrate by vacuum thermal evaporation. During the deposition process, the rate was 0.1 angstrom / second and the vacuum degree was below 5×10^-4Pa.

[0044] Step C: Prepare the humidity memristor into an intelligent switch; the structural diagram of the intelligent switch is as follows Figure 1The intelligent switch includes a DC power supply 1, a humidity memristor 2, a variable resistor 3, a resistor 4, a current-voltage converter 5, a light emitting diode 6, and a light receiver 7; the DC power supply 1 is connected to either end of the humidity memristor 2, and the other end is connected to the variable resistor 3 and then grounded, and resistors 4 are connected in parallel at both ends of the humidity memristor 2, and the current flowing through the resistor 4 is used as the output end, and the current-voltage converter 5 is connected to forward the output current to a voltage to drive the load light emitting diode 6. When the soil humidity is low and irrigation is required, the light emitting diode 6 emits light, and the emitted light is received by the light receiver 7, thereby turning on the irrigation switch. When the soil humidity is high and irrigation is not required, the light emitting diode 6 does not emit light, and the light receiver 7 cannot receive the light signal, and the irrigation switch is turned off.

[0045] like Figure 2 , Structural diagram of graphene oxide humidity memristor, where (a) is the active metal electrode, (b) is graphene oxide, (c) is SiO2, and (d) is Si.

[0046] like Figure 3 ,The resistance change curves of graphene oxide humidity memristor under different humidity conditions. It can be seen from the figure that the graphene oxide humidity memristor has sensitive humidity response and shows volatility, and has the potential to be applied to smart switches.

[0047] like Figure 4 ,The turn-on voltage of graphene oxide humidity memristor under different humidity conditions. It can be seen from the figure that the graphene oxide humidity memristor has different turn-on voltages under different humidity conditions. It is expected to control the voltage drop through humidity, thereby realizing the turning on and off of the irrigation switch.

[0048] The graphene oxide humidity memristor of the present invention has high humidity sensitivity, and graphene oxide is inexpensive, harmless and environmentally friendly. Using the graphene oxide humidity sensing memristor as an intelligent switch for a smart agricultural irrigation system contributes to the development of a high-precision, low-cost, and highly portable smart agricultural irrigation system, which can not only effectively save labor costs, but also help to increase crop yields.

[0049] The preparation and working principle of the above-mentioned intelligent switch can be: first, prepare a graphene oxide film. Disperse 200 mg of graphene oxide in 500 mL of ethanol, and after 45 minutes of ultrasonic treatment, obtain a uniform graphene oxide colloidal dispersion. Subsequently, a substrate with Si / SiO2 is selected, and after plasma cleaning, the colloidal dispersion is spin-coated on the substrate at a spin-coating speed of 2000 rpm, and the spin-coating time is 20 seconds. After that, dry at a temperature of 80°C for 1.5 hours to obtain a graphene oxide film.

[0050] Next, the humidity memristor was prepared. On the substrate where graphene oxide had been spin-coated, a mask was used to define the shape and position of the electrode, and then a 200-nanometer-thick silver (Ag) electrode was evaporated by thermal evaporation. The electrode was square in shape, 2 mm in size, and 200 microns apart. During the evaporation process, the rate was controlled at 0.3 angstroms / second and the vacuum was maintained at 4×10^-4Pa.

[0051] Finally, the smart switch is assembled. The DC power supply (3V), humidity memristor, variable resistor (resistance value is 1MΩ), resistor (resistance value is 1MΩ), current-voltage converter (model LMC62CN), infrared light emitting diode (operating voltage is 1.55V) and infrared light receiver are connected according to the predetermined circuit connection method. When the soil humidity is low, the resistance of the humidity memristor changes, causing the current flowing through the resistor to increase. The voltage converted by the current-voltage converter drives the infrared light emitting diode to emit light, and the light signal is received by the infrared light receiver, thereby triggering the irrigation switch to turn on. Conversely, when the soil humidity is high, the infrared light emitting diode does not emit light, and the irrigation switch is turned off.

[0052] The standard parts used in the present invention can all be purchased from the market, and the special-shaped parts can be customized according to the description and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0053] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0057] In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

[0058] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent switch for a smart agricultural irrigation system, characterized in that: Includes DC power supply, humidity memristor, variable resistor, resistor, current-voltage converter, light emitting diode, optical receiver; The DC power supply voltage is 3V; The humidity memristor is a graphene oxide memristor with a thickness of 1-3 microns; The electrode material used in the humidity memristor is an active metal electrode material with a thickness of 100-500 nanometers and an electrode size of 1-5 millimeters; The resistance of the variable resistor is 0.5-2MΩ; The light emitting diode is an infrared light emitting diode, and the operating voltage is 1.5-1.6V; The light receiver is an infrared light receiver; The DC power supply is connected to either end of the humidity memristor, and the other end is grounded through a variable resistor. The resistor is connected in parallel at both ends of the humidity memristor, and the current flowing through the resistor is connected to a current-voltage converter as an output end. The converted voltage is used to drive a light-emitting diode. When the soil humidity is low, the light-emitting diode emits light and is received by a light receiver, thereby triggering the irrigation switch to turn on; when the soil humidity is high, the light-emitting diode does not emit light, the light receiver does not receive the light signal, and the irrigation switch is turned off.

2. The method for preparing a smart switch for a smart agricultural irrigation system according to claim 1, characterized in that: The following steps are involved: Step A: preparing a graphene oxide film, specifically, dispersing 100-500 mg of graphene oxide in 200-1000 mL of ethanol and ultrasonically treating for 30-60 minutes to obtain a colloidal dispersion, then plasma cleaning the substrate, spin-coating the colloidal dispersion on the substrate, and drying at 50-100° C. for 1-2 hours; Step B: preparing the graphene oxide into a humidity memristor, specifically by pasting a mask on the surface of the substrate on which the graphene oxide is spin-coated, and evaporating the active metal electrode on the substrate by thermal evaporation, wherein the rate during the evaporation process is 0.1-0.5 angstroms / second, and the vacuum degree is maintained below 5×10^-4Pa; Step C: Assemble the humidity memristor and other circuit elements into an intelligent switch, specifically connect a DC power supply, a humidity memristor, a variable resistor, a resistor, a current-voltage converter, a light-emitting diode and a light receiver in the manner described in claim 1.

3. The method for preparing an intelligent switch for a smart agricultural irrigation system according to claim 2, characterized in that: In the step A, the spin coating speed of graphene oxide is 1000-3000 rpm, and the spin coating time is 10-40 seconds.

4. The method for preparing an intelligent switch for a smart agricultural irrigation system according to claim 2, characterized in that: The active metal electrode material in step B includes Ag, Cu or Al, the electrode shape is square or rectangular, and the electrode spacing is 100-500 microns.

5. The method for preparing an intelligent switch for a smart agricultural irrigation system according to claim 2, characterized in that: The step C also includes converting the current flowing through the resistor into a voltage through a current-voltage converter, and using the voltage to drive a light-emitting diode to control the opening and closing of the irrigation switch according to changes in soil moisture.

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