Cross-medium communication method and device based on friction nano-generator and application of cross-medium communication method and device

Abstract

The invention relates to the technical field of cross-medium communication, in particular to a cross-medium communication method and device based on a friction nano-generator and application of the cross-medium communication method and device. According to the method, one output end of the friction nanometer generator is connected with a transmitting antenna in a parallel plate antenna, and the other output end of the friction nanometer generator is grounded; the receiver is electrically connected with the receiving antenna. And the transmitting antenna and the receiving antenna are arranged in two different media, so that signal transmission is realized between the transmitting antenna and the receiving antenna by utilizing a polarized electric field formed by Maxwell displacement current. The novel communication mode has excellent anti-interference capability and is almost not influenced by absorption attenuation of liquid media such as obstacles and seawater. The brand-new communication mode can be applied to the fields of hydrological monitoring, underwater robot operation, secret communication and the like. The method has great practical value and wide market potential.

Description

Technical Field

[0001] The present invention relates to the technical field of cross - medium communication, and particularly to a cross - medium communication method, device and its application based on a triboelectric nanogenerator. Background Art

[0002] With the rapid construction of the integrated land, sea and air network, the demand for information exchange between various network nodes is increasing day by day. Therefore, a cross - medium communication device with stable transmission is needed to transmit a large amount of data between different media. The cross - medium communication environment is mainly composed of air and water. When performing cross - medium communication, underwater signal attenuation, absorption and the interference of obstacles are the main factors affecting the transmission stability of the cross - medium communication device. At present, common cross - medium communication methods include optical communication, electromagnetic wave communication, acoustic communication, magnetic induction communication, etc. These cross - medium communication methods are all realized based on different physical fields. However, these cross - medium communication methods all have some defects. For example, for acoustic communication, since sound waves can propagate over long distances in both water and air, it is considered that a cross - medium communication device with sound waves is the most feasible carrier for realizing cross - medium communication between water and air. However, when sound waves directly impinge on the water - air interface, due to the huge difference in the ease of propagation of sound waves between water and air, only 0.1% of the sound energy can penetrate the water - air interface and propagate, which brings great challenges to water - air communication based on sound waves. When performing cross - medium communication with wireless electromagnetic waves or using magnetic induction communication for cross - medium communication, as the vibration frequency of the wireless electromagnetic waves or magnetic induction increases, the communication signals of such cross - medium communication devices attenuate severely, thus greatly affecting the communication effect of such cross - medium communication devices during cross - medium communication. Therefore, for the above - listed cross - medium communication methods, when transmitting communication signals between air and water, the communication signal transmission effect is not good. Summary of the Invention

[0003] In order to solve the technical problem of poor signal transmission effect existing in the cross - medium communication methods in the prior art, the present invention provides a cross - medium communication method, device and its application based on a triboelectric nanogenerator.

[0004] The present invention is implemented by adopting the following technical solutions:

[0005] A cross - medium communication method based on a triboelectric nanogenerator, which is used to realize wireless communication between water and air, and includes:

[0006] The transmitting antenna and the receiving antenna in a group of parallel - plate antennas are respectively arranged opposite to each other in two different media. The parallel - plate antenna realizes signal transmission through the polarization electric field formed by the Maxwell displacement current. The transmitting antenna is electrically connected to the triboelectric nanogenerator; the receiving antenna is connected to a signal receiver.

[0007] Encode the original information to be transmitted into an action for driving a triboelectric nanogenerator; drive the triboelectric nanogenerator in the medium at the transmitting end according to the specified action, and the electrical signal generated by the triboelectric nanogenerator is used as the transmitted signal to excite the transmitting antenna to generate a displacement current containing the information.

[0008] The receiving antenna receives the displacement current and generates a received signal; the signal receiver processes the received signal and then decodes the original information.

[0009] Wherein, the current density J of the displacement current in the cross-media transmission stage D varies as follows:

[0010]

[0011] In the above formula, P 2 represents the polarization intensity of the medium at the transmitting end; ε 2 represents the relative permittivity of the medium at the transmitting end; ε 0 represents the permittivity of free space; E 1 represents the original electric field intensity at the receiving end.

[0012] As a further improvement of the present invention, during the signal transmission process of the parallel plate antenna, the effective antenna area of the transmitting antenna is equal to its projected area on the receiving antenna.

[0013] As a further improvement of the present invention, the transmitting antenna and the receiving antenna are made of copper plates.

[0014] As a further improvement of the present invention, the triboelectric nanogenerator adopts an oscillating generator; and during the signal encoding stage, the original information to be transmitted is encoded into a vibration driving force with a specified amplitude and frequency varying according to a specified waveform. Alternatively, the triboelectric nanogenerator adopts a rotary generator; and during the signal encoding stage, the original information to be transmitted is encoded into a rotary driving force with a rotational speed varying according to a specified waveform.

[0015] The present invention further includes a cross-media communication device based on a triboelectric nanogenerator, which includes: an antenna assembly, a triboelectric nanogenerator, and a signal receiver.

[0016] Wherein, the antenna assembly includes a plate-shaped transmitting antenna and a receiving antenna, both of which are made of metal. The transmitting antenna and the receiving antenna are located in different media and are arranged parallel and facing each other, and the signal transmission is realized through the polarization electric field formed by the Maxwell displacement current.

[0017] The output end of the triboelectric nanogenerator is electrically connected to the transmitting wire and is used to generate an electrical signal to be transmitted when being externally driven.

[0018] The input end of the signal receiver is electrically connected to the receiving antenna; the signal receiver is used to acquire the electrical signal on the receiving wire and perform signal processing.

[0019] As a further improvement of the present invention, the triboelectric nanogenerator includes a container with a plurality of square cavities inside. Two non-touching metal thin film electrodes are pasted on the inner walls of each cavity in the container, and at least one small ball made of PTFE material is also arranged in the cavity. When the triboelectric nanogenerator is oscillated by an external stress, the small ball rolls between the two metal thin film electrodes and charge transfer occurs, thereby causing a potential difference to be generated between the two metal thin film electrodes and corresponding electrical signals to be output.

[0020] As a further improvement of the present invention, the antenna assembly further includes a relay board, and the relay board is made of a metal plate; the relay board is located between the transmitting antenna and the receiving antenna and is parallel to the transmitting antenna and the receiving antenna.

[0021] The present invention also includes a secure communication method, which includes:

[0022] (1) Encoding the information to be transmitted into a driving force for driving the triboelectric nanogenerator to achieve data encryption.

[0023] (2) Under the action of the driving force, using the cross-media communication device based on the triboelectric nanogenerator as described above for signal transmission.

[0024] (3) Sampling, amplifying, filtering and decoding the signal received by the signal receiver, and then restoring the original information.

[0025] The present invention also includes an application of the cross-media communication device based on the triboelectric nanogenerator as described above in hydrological monitoring, including: deploying the triboelectric nanogenerator and the transmitting antenna underwater, and the triboelectric nanogenerator generates electrical signals under the drive of waves and transmits them to the water surface through the transmitting antenna.

[0026] Deploying the receiving antenna and the signal receiver on the unmanned aerial vehicle, the unmanned aerial vehicle flies above the transmitting antenna, and the receiving antenna receives the transmitted signal of the transmitting antenna; the signal receiver preprocesses the received signal and inversely calculates the current wind and wave state underwater according to the corresponding signal.

[0027] The present invention also includes an application of the cross-media communication device based on the triboelectric nanogenerator as described above in the operation of underwater electromechanical equipment, which includes:

[0028] Deploying the triboelectric nanogenerator and the transmitting antenna on the vibration equipment on the water surface; encoding the control signal into the operating parameters of the vibration equipment to drive the triboelectric nanogenerator to generate electrical signals and transmit them to the underwater through the transmitting antenna.

[0029] Deploy a receiving antenna and a signal receiver underwater, and communicatively connect the signal receiver to the electromechanical device to be manipulated; the receiving antenna receives the transmitted signal from the transmitting antenna; the signal receiver preprocesses the received signal and decodes the corresponding control instruction, and the electromechanical device performs corresponding actions according to the decoded control instruction.

[0030] The technical solution provided by the present invention has the following beneficial effects:

[0031] The present invention designs a novel cross-media wireless communication scheme using a triboelectric nanogenerator, a parallel plate antenna and a signal receiver. This scheme connects the TENG to the transmitting antenna in the parallel plate antenna, and the receiver is electrically connected to the receiving antenna. The transmitting antenna and the receiving antenna are placed in two different media, and then the signal transmission is realized by using the polarization electric field formed by the Maxwell displacement current.

[0032] The communication scheme provided by the present invention can successfully achieve wireless communication through two media, liquid and gas. Compared with the traditional cross-media communication method, this method has excellent anti-interference ability and is hardly affected by the absorption attenuation of obstacles and liquid media such as seawater. In addition, this embodiment provides a triboelectric nanogenerator for signal generation and encoding, which can thus achieve self-driving and contribute to improving the security and confidentiality of communication, and has great practical value and broad market potential. Description of the Drawings

[0033] Figure 1 It is the architecture diagram of the wireless communication system constructed in the cross-media communication method based on triboelectric nanogenerator provided in Embodiment 1 of the present invention.

[0034] Figure 2 It is the electrical model of the wireless communication system constructed in Embodiment 1 of the present invention.

[0035] Figure 3 It is the schematic diagram of the wireless communication system constructed in Embodiment 1 of the present invention.

[0036] Figure 4 It is the scenario simulation diagram of using the cross-media communication device based on triboelectric nanogenerator to realize hydrological monitoring in Embodiment 2 of the present invention.

[0037] Figure 5 It is the schematic diagram of the test platform built in the performance test experiment.

[0038] Figure 6 It is the curve of the communication voltage and communication current varying with distance in the pure air electric field communication and pure underwater electric field communication scenarios in the performance test experiment.

[0039] Figure 7 It is the potential simulation result of the communication in air and water in CMOSOL in the performance test experiment.

[0040] Figure 8 It is a schematic diagram of the experimental scenario for the influence of the distance of the water medium on the communication performance in the performance test experiment.

[0041] Figure 9 It is a curve showing the variation of signal voltage and signal current with the distance of the water medium in the performance test experiment.

[0042] Figure 10 It is a schematic diagram of the experimental scenario for the influence of the distance of the air medium on the communication performance in the performance test experiment.

[0043] Figure 11 It is a curve showing the variation of signal voltage and signal current with the distance of the air medium in the performance test experiment.

[0044] Figure 12 It is a schematic diagram of the experimental scenario for the influence of different types of obstacles on the communication performance in the performance test experiment.

[0045] Figure 13 It is a comparison chart of signal voltage and signal current under the influence of different types of obstacles in the performance test experiment. Specific implementation manner

[0046] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] Embodiment 1

[0048] This embodiment provides a cross-media communication method based on a triboelectric nanogenerator. The scheme is mainly used to achieve cross-media wireless communication between water and air, including both transmitting information from a device in water to a device in air and transmitting information from a device in air to a device in water. Specifically, as Figure 1 shown, the cross-media communication method provided in this embodiment includes:

[0049] I. Constructing a cross-media wireless communication system

[0050] The wireless communication system constructed in this embodiment that can achieve cross-media signal transmission includes a signal transmitter, a transmitting antenna, a receiving antenna, and a signal receiver. Specifically, the transmitting antenna and the receiving antenna in a set of parallel plate antennas are oppositely arranged in two different media. The parallel plate antenna realizes signal transmission through the polarization electric field formed by the Maxwell displacement current. The transmitting antenna is electrically connected to a triboelectric nanogenerator in one of the media; the receiving antenna is connected to a signal receiver in the other medium.

[0051] In the parallel plate antenna used in this embodiment, the transmitting antenna and the receiving antenna should be metal antennas. Preferably, copper plates are used as the antennas, namely the transmitting plate and the receiving plate. Among them, in the signal transmission process of the parallel plate antenna, the effective antenna area of the transmitting antenna is equal to its projected area on the receiving antenna. Therefore, in practical applications, the two antennas should be kept as parallel as possible and directly opposite to each other. And in order to ensure the maximum utilization of the area of the transmitting antenna, the area of the receiving antenna should not be less than that of the transmitting antenna. In the optimal solution, the transmitting antenna and the receiving antenna adopt a set of copper plates with the same shape and size.

[0052] II. Signal Encoding and Transmission

[0053] In this embodiment, the original information to be transmitted is encoded into an action for driving the triboelectric nanogenerator; in the medium at the transmitting end, the triboelectric nanogenerator is driven according to the specified action, and the electrical signal generated by the triboelectric nanogenerator is used as the transmitted signal and excites the transmitting antenna to generate a displacement current containing information.

[0054] At the transmitting end, this embodiment outputs the electrical signal to be transmitted through the triboelectric nanogenerator. In order to use the electrical signal generated by the triboelectric nanogenerator to carry information and transmit it, this embodiment encodes the data to be transmitted into a driving action for driving the triboelectric nanogenerator to operate. The triboelectric nanogenerator is essentially an energy converter that converts mechanical energy into electrical energy. In practical applications, for a specific triboelectric nanogenerator product, when the triboelectric nanogenerator moves according to the specified action within a certain period of time, the electrical signal it outputs usually also shows correlation. Therefore, a corresponding mapping can be established among the three according to the natural correlation of "data information - action - electrical signal". On this basis, using the established mapping, on the one hand, information can be encoded into an action and the corresponding electrical signal can be generated, and on the other hand, the electrical signal can be decoded back into the original information.

[0055] For example, in practical applications, when the triboelectric nanogenerator in this embodiment adopts an oscillating generator, the original information to be transmitted can be encoded into a vibration driving force with a specified amplitude and frequency changing according to a specified waveform during the signal encoding stage. Correspondingly, when the triboelectric nanogenerator in this embodiment adopts a rotary generator, during the signal encoding stage, the original information to be transmitted is encoded into a rotary driving force with a rotational speed changing according to a specified waveform.

[0056] II. Signal Reception and Decoding

[0057] In this embodiment, the receiving antenna receives the displacement current and generates a received signal; the signal receiver processes the received signal and then decodes the original information. Among them, the current density J D of the displacement current during the cross - medium transmission stage changes to satisfy the following formula:

[0058]

[0059] In the above formula, P 2 represents the polarization intensity of the medium at the transmitting end; ε 2 represents the relative permittivity of the medium at the transmitting end; ε 0 represents the permittivity of free space; E 1 represents the original electric field intensity at the receiving end.

[0060] Maxwell's equations describe the relationship between the electric field and the magnetic field and are the basis of modern electromagnetic theory. Wang Zhonglin et al. proposed an extension of Maxwell's equations, emphasizing the Maxwell displacement current generated by the motion of polarized media, providing a new method for realizing cross-media communication. On this basis, the cross-media communication method based on the triboelectric nanogenerator provided in this embodiment is realized based on the following basic principle:

[0061] The wireless cross-media communication method in this embodiment can be understood through a capacitor model such as Figure 2 . The following analyzes the transmission of the electric field in air and water from the perspective of displacement current. In the communication system of this embodiment, the TENG acts as a displacement current source, and the transmitting antenna and the receiving antenna form the positive and negative electrodes of the capacitor. Air and water are used as dielectric media. Once the transmitting antenna generates a main electric field E under the excitation of the displacement current source, it will polarize to generate a polarization electric field Po in the medium.

[0062] It should be noted that due to the different molecular structures, the molecules constituting the dielectric medium can be composed of non-polar molecules and polar molecules, and the interior of the homogeneous medium is initially electrically neutral everywhere. When the electric field propagates into the medium, the originally overlapping positive and negative charges in the non-polar molecules will undergo relative displacement to form electric dipoles, and some dipoles will penetrate the surface of the medium. For polar molecules, the originally disordered electric dipoles will rotate and rearrange to become more ordered, as shown in Figure 3 . Eventually, charges will be generated on the surface and inside of the dielectric. These charges can neither move freely within the dielectric nor leave the dielectric to move to other charged bodies; they are called polarization charges. Different from the free charges that can be carried away by conduction in a conductor, these bound charges in the dielectric will produce a phenomenon under the influence of an external electric field, that is, polarization charges.

[0063] Combining Figure 2 and Figure 3 , in the capacitor model of cross-media communication, assuming that the charge quantity of the transmitting antenna is Q, the primary electric field excited by the transmitting antenna is E, the relative permittivity of air is ε, the primary electric field is generated by the antenna in the air and causes polarization in the air, then the polarization electric field generated in the air is P. According to Gauss's law, it can be obtained that

[0064]

[0065] In the above formula, ρ is the free charge density; D represents the electric displacement vector; represents the Hamiltonian operator.

[0066] The original electric field E 1 generated by free charges has the following expression:

[0067]

[0068] In the above formula, σ 1 represents the original charge density on the emitting electrode, and ε 0 is the vacuum permittivity.

[0069] Among them, the electric displacement vector D 1 at this stage is given by the following formula:

[0070] D 1 =(ε 0 E 1 +P 1 ),

[0071] In the above formula, E 1 is the original electric field strength in air, and P 1 is the polarization electric field strength in air.

[0072] The change of the Maxwell displacement current density J D during transmission satisfies the following formula:

[0073]

[0074] It can be seen from the above formula that the Maxwell displacement current density J D has two components. The first part is the electromagnetic wave widely used in traditional communication methods, and the second part is the Maxwell displacement current caused by electric field polarization. And the solution of this embodiment mainly uses the second component to achieve wireless communication across media. It should be noted that the propagation of electromagnetic waves does not require a medium and has the best propagation effect in a vacuum. The field must rely on the existence of a medium. In a vacuum, reaches the maximum value, while is zero. And in the cross-media environment composed of air and water, the relative permittivity of water is much larger than that of air, and theoretically, it is more conducive to the formation of a polarization electric field. Therefore, taking the example from air to underwater, the derivation process of the Maxwell displacement current density is introduced as follows:

[0075] In air, it satisfies:

[0076] E air =E1 -E′,

[0077] In the above formula, E air represents the electric field generated in the air; E′ represents the electric field caused by the polarized charges in the air.

[0078] The electric field E generated in the air air and the original electric field E 1 The relationship between them can also be expressed as:

[0079]

[0080] In the above formula, ε 1 represents the relative permittivity of air.

[0081] Combining the above two formulas, the electric field E′ caused by the polarized charges in the air is related to the relative permittivity ε of the air 1 and the original electric field E 1 to obtain the following formula:

[0082]

[0083] Among them, since ε 1 ≈1, then E′≈0, σ 1 ≈0, P 1 ≈0. That is: Almost no polarized charges and obvious polarization are generated in the air.

[0084] Furthermore, in water, it satisfies:

[0085] E water = E 1 - E″,

[0086] In the above formula, E water represents the electric field generated in the water; E″ represents the electric field caused by the polarized charges in the water.

[0087] The electric field E generated in the water water and the original electric field E 1 The relationship between them can also be expressed as:

[0088]

[0089] In the above formula, ε 2 represents the relative permittivity of water.

[0090] Relate the electric field E″ caused by the polarized charges in the water to the relative permittivity ε of the water 2 and the original electric field E 1 to obtain the following formula:

[0091]

[0092] At this time, the relationship between the polarization charge density σ″ and the polarization charge quantity in water can be expressed by the following dielectric constant:

[0093]

[0094] In the above formula, Q 1 represents the original charge quantity on the transmitting antenna.

[0095] On this basis, the polarization electric field strength P in water 2 satisfies the following formula:

[0096]

[0097] In the above formula, ∑p represents the vector sum of the electric dipole moments in water; ΔV represents the unit volume of the water medium; Δsd represents the volume change of the liquid-phase medium.

[0098] Therefore, the calculation formula of the polarization electric field strength P in water 2 is as follows:

[0099]

[0100] To sum up, in the cross-media transmission between water and air, the change of the Maxwell current density J D is as follows:

[0101]

[0102] Embodiment 2

[0103] On the basis of the solution of Embodiment 1, this embodiment further provides a cross-media communication device based on a triboelectric nanogenerator. The cross-media communication device includes: an antenna assembly, a triboelectric nanogenerator, and a signal receiver.

[0104] Among them, the antenna assembly includes a plate-shaped transmitting antenna and a receiving antenna, both of which are made of metal. The transmitting antenna and the receiving antenna are located in different media and are arranged parallel and facing each other. The signal transmission is realized through the polarization electric field formed by the Maxwell displacement current.

[0105] The output end of the triboelectric nanogenerator is electrically connected to the transmitting wire; the triboelectric nanogenerator and the transmitting antenna are located in the same dielectric environment and are used to generate an electrical signal to be transmitted when subjected to an external drive. In a typical solution provided in this embodiment, the triboelectric nanogenerator includes a container with multiple square cavities inside. Two non-touching metal thin-film electrodes are pasted on the inner walls of each cavity in the container, and at least one small ball made of PTFE material is also arranged in the cavity. When the triboelectric nanogenerator is oscillated under the action of an external stress, the small ball rolls between the two metal thin-film electrodes and charge transfer occurs, thereby causing a potential difference to be generated between the two metal thin-film electrodes and outputting a corresponding electrical signal.

[0106] The input end of the signal receiver is electrically connected to the receiving antenna; the signal receiver is used to acquire the electrical signal on the receiving wire and perform signal processing. In a further optimized solution provided in this embodiment, the antenna assembly further includes a relay board, and the relay board is made of a metal plate; the relay board is located between the transmitting antenna and the receiving antenna and is parallel to the transmitting antenna and the receiving antenna.

[0107] A typical application scenario of the cross-media communication device based on the triboelectric nanogenerator provided in this embodiment is to implement secure communication, and this secure communication method includes:

[0108] (1) Encoding the information to be transmitted into a driving force for driving the triboelectric nanogenerator to achieve data encryption.

[0109] (2) Under the action of the driving force, using the cross-media communication device based on the triboelectric nanogenerator as described above for signal transmission;

[0110] (3) Sampling, amplifying, filtering and decoding the signal received by the signal receiver, and then restoring the original information.

[0111] Combined with the foregoing content, it can be seen that the cross-media communication device adopted in the secure communication method provided in this embodiment mainly relies on the mapping relationship among "data information - action - electrical signal" to achieve data encoding and signal decoding. For each triboelectric nanogenerator, under the drive of the same action, the electrical signals generated by it are different. Each triboelectric nanogenerator is equivalent to a natural encryption tool, which generates a unique electrical signal according to the action corresponding to the original data information. This makes it difficult to decipher the data encoding and decoding strategy of the cross-media communication device based on the triboelectric nanogenerator adopted in the secure communication method provided in this embodiment. In addition, the communication method in this embodiment also adopts a signal transmission scheme based on Maxwell displacement current that is completely different from the traditional communication method in the signal transmission stage, which further increases the difficulty of cracking this communication method. To sum up, the communication method provided in this embodiment has higher security and stronger confidentiality compared with the existing solutions.

[0112] On this basis, this embodiment also provides an application of a cross-media communication device based on a triboelectric nanogenerator in hydrological monitoring. As Figure 4 shown, this application method specifically includes: deploying the triboelectric nanogenerator and the transmitting antenna underwater. The triboelectric nanogenerator generates electrical signals under the drive of waves and transmits them to the water surface through the transmitting antenna. Deploy the receiving antenna and the signal receiver on the unmanned aerial vehicle (UAV). The UAV flies above the transmitting antenna, and the receiving antenna receives the transmitted signal of the transmitting antenna; the signal receiver preprocesses the received signal and inversely calculates the current wind and wave conditions underwater according to the corresponding signal.

[0113] Combined with the previous content, it can be known that the output of the triboelectric nanogenerator is related to the amplitude and frequency of the vibration it bears. Under different wind and wave conditions, the device will generate corresponding electrical signals. When the wind and waves on the water surface are more violent, the amplitude and frequency of the output signal of the triboelectric nanogenerator are higher; conversely, when the wind and waves on the water surface are milder, the amplitude and frequency of the output signal of the triboelectric nanogenerator are lower. Therefore, the output of the triboelectric nanogenerator can be determined according to the electrical signal received by the UAV, and the wind and wave conditions in its current environment can be further inversely calculated according to the output of the triboelectric nanogenerator.

[0114] In addition, this embodiment also provides an application of a cross-media communication device based on a triboelectric nanogenerator as described above in the operation of underwater electromechanical equipment, which includes: deploying the triboelectric nanogenerator and the transmitting antenna on a vibration device on the water surface; encoding the control signal as the operating parameters of the vibration device to drive the triboelectric nanogenerator to generate electrical signals and transmit them to the underwater through the transmitting antenna. Deploy the receiving antenna and the signal receiver underwater. The signal receiver is communicatively connected to the electromechanical equipment to be operated, such as an underwater robot; the receiving antenna receives the transmitted signal of the transmitting antenna; the signal receiver preprocesses the received signal and decodes the corresponding control instruction, and the underwater robot executes corresponding actions according to the decoded control instruction, such as floating, diving, moving forward, moving backward, etc.

[0115] Performance Test

[0116] In order to verify the advantages of the cross-media communication method based on a triboelectric nanogenerator provided in this embodiment, technical personnel designed a test experiment to test the communication performance of this solution under different conditions.

[0117] I. Design of the test platform

[0118] The test platform designed in this experiment is as Figure 5As shown, a triboelectric nanogenerator (TENG) is installed on an experimental trolley, which is shaken by a linear actuator; one end of the two output terminals of the TENG is grounded, and the other end is connected to a transmitting antenna. The transmitting antenna is placed in the air. An acrylic water tank is set opposite the transmitting antenna. A receiving antenna is immersed in the water in the water tank and is arranged opposite to the transmitting antenna. The receiving antenna is electrically connected to a signal receiver.

[0119] II. Experimental Contents and Results

[0120] 2.1. Influence of Dielectric on Communication Performance

[0121] The complexity of cross - dielectric electric - field communication lies in that the electric - field signal needs to penetrate air and water, and the relative dielectric constants of air and water are different, so the transmission characteristics are also different. To quantitatively analyze these differences, this experiment first compared the absolute values and attenuation rates of pure - air electric - field communication and pure - water electric - field communication at the same distance. The experimental results obtained are as Figure 6 shown.

[0122] Analysis Figure 6 From the experimental data, it can be found that: when keeping the distance between the plates unchanged, the intensity of the electric - field signal underwater is significantly stronger than that in the air. Numerically, at the same distance between the plates, the electric - field signal underwater is at least 95 times that of the air electric - field signal. In terms of the attenuation rate, the current signal in the air drops from 20 nA to 7.6 nA, a decrease of 62%, while when the distance increases by 20 cm, the underwater - transmitted current signal only drops by 5.6%. These experimental results show that compared with the pure - air environment, the pure - water environment is more suitable for electric - field signal transmission.

[0123] This experiment further verified the experimental phenomenon that the underwater electric - field transmission is stronger than the air electric - field transmission through the potential - simulation function of COMSOL. The simulation results obtained are as Figure 7 shown. Analyzing the data in the figure, it can be seen that: in the air, the dielectric is not polarized, and the electric - field lines (red lines) become very sparse after leaving the transmitting antenna. In contrast, obvious polarization occurs underwater, and within the same distance, the electric - field lines (yellow lines) are still relatively dense, which is consistent with the experimental observations and theoretical derivations.

[0124] 2.2. Influence of Distance on Communication Performance

[0125] First, as Figure 8 shown, in this experiment, when the transmitting antenna in the air is fixed and only the receiving antenna in the water is moved, the distance between the antennas gradually increases from 5 cm to 120 cm. The changes in the signal voltage and signal current obtained are as Figure 9As shown in the figure, it can be seen that when the receiving antenna in water is far away, the fluctuations of both the voltage signal and the current signal are less than 0.2%. And the waveform analysis of three distance nodes (10 cm, 50 cm, and 90 cm) shows that the voltage and current waveforms are similar. This indicates that during the cross-media communication process, the depth of the water body has little effect on the communication performance.

[0126] As Figure 10 shown, in this experiment, the position of the receiving antenna in water was further fixed, while the transmitting antenna in air gradually moved horizontally away from the receiving antenna. The changes in the signal voltage and signal current obtained are as Figure 11 shown. Analyzing the results in the figure, it can be seen that when the distance increases from 0 cm to 120 cm, the voltage signal drops from 50 V to 5 V, a decrease of 90%, while the current signal drops from 135 nA to 40 nA, a decrease of approximately 74%. It is worth noting that within the first 20 cm of the distance increase, the signal attenuation rate is the highest, and the attenuation rate in the latter section tends to be flat.

[0127] 2.3. Influence of Obstacles on Communication Performance

[0128] As Figure 12 shown, in this experiment, the signal changes in three cases were further compared: no obstacle was set between the transmitting antenna and the receiving antenna, an insulating obstacle was set, and a metal obstacle between plates was set. The experimental results obtained are as Figure 13 shown.

[0129] Analyzing the data in the figure, it can be seen that when an insulating obstacle is added, the measured voltage and current signal waveforms are highly consistent with the waveforms without obstacles, and the signal difference is always less than 2%. However, when a metal obstacle is introduced, the measured signal peak value will increase, the voltage signal increases by approximately 28%, and the current signal increases by approximately 23%.

[0130] The above experimental phenomena prove that adding a metal object between the transmitting plate and the receiving plate can slightly enhance the received signal. And the insulating obstacle has almost no impact on the performance of the communication device of the present invention. Analyzing the internal mechanism of the above phenomena may be: when the obstacle is an insulating object, it has little interference on the propagation of the electric field. The density of the electric field lines remains unchanged before and after passing through the acrylic plate, so the change in the received electric field signal can be ignored. When the obstacle is a metal plate, both the metal obstacle and the transmitting metal plate will store a certain amount of charge. The transmitting plate and the metal obstacle are essentially like charge reservoirs, containing freely movable charges. The metal obstacle can be regarded as a secondary transmitter. The finally received electric signal is the result of two transmissions: part of the electric field intensity comes from the transmitting plate, and the other part comes from the metal obstacle. Therefore, the signal received by the receiving antenna side will be enhanced.

[0131] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A cross-medium communication method based on a triboelectric nanogenerator, which is used to realize wireless communication between water and air, characterized in that: It includes: The transmitting antenna and the receiving antenna in a set of parallel plate antennas are respectively arranged facing each other in two different media; The parallel plate antenna realizes signal transmission through the polarized electric field formed by the Maxwell displacement current; the transmitting antenna is electrically connected to the friction nanogenerator; and the receiving antenna is connected to the signal receiver; Encoding the original information to be transmitted into an action for driving the friction nanogenerator; driving the friction nanogenerator in the medium of the transmitting end according to the specified action, and the electrical signal generated by the friction nanogenerator is used as a transmitting signal and stimulates the transmitting antenna to generate a displacement current containing information; The receiving antenna receives the displacement current and generates a receiving signal; the signal receiver processes the receiving signal and decodes the original information; Among them, the current density J of the displacement current in the cross-medium transmission stage is D The change satisfies the following formula: In the above formula, P2 represents the polarization intensity of the transmitting medium; ε2 represents the relative dielectric constant of the transmitting medium; ε0 represents the vacuum dielectric constant; and E1 represents the original electric field strength at the receiving end.

2. The cross-medium communication method based on the friction nanogenerator according to claim 1, characterized in that: During signal transmission of the parallel plate antenna, the effective antenna area of ​​the transmitting antenna is equal to its projected area on the receiving antenna.

3. The cross-medium communication method based on a triboelectric nanogenerator as claimed in claim 2, characterized in that: The transmitting antenna and the receiving antenna adopt copper plates.

4. The cross-medium communication method based on a triboelectric nanogenerator according to claim 1, characterized in that: The friction nanogenerator adopts an oscillating generator; and in the signal encoding stage, the original information to be transmitted is encoded with a vibration driving force with a specified amplitude and frequency changing according to a specified waveform; Alternatively, the friction nanogenerator is a rotary generator; and in the signal encoding stage, the original information to be transmitted is encoded into a rotary driving force whose rotation speed changes according to a specified waveform.

5. A cross-medium communication device based on a friction nanogenerator, characterized in that: It includes: The antenna assembly includes a plate-shaped transmitting antenna and a receiving antenna, both of which are made of metal; The transmitting antenna and the receiving antenna are located in different media and are arranged in parallel and facing each other, and the two realize signal transmission through the polarized electric field formed by the Maxwell displacement current; A triboelectric nanogenerator, the output end of which is electrically connected to the transmitting wire and is used to generate an electrical signal to be transmitted when driven externally; A signal receiver, whose input end is electrically connected to the receiving antenna; the signal receiver is used to obtain the electrical signal on the receiving wire and perform signal processing.

6. The cross-medium communication method based on the triboelectric nanogenerator according to claim 5, characterized in that: The friction nanogenerator includes a container containing multiple square cavities, two non-contacting metal film electrodes are pasted on the inner walls of each cavity in the container, and at least one small ball made of PTFE is also arranged in the cavity; when the friction nanogenerator is vibrated by external stress, the small ball rolls between the two metal film electrodes and charge transfer occurs, thereby causing an electric potential difference between the two metal film electrodes and outputting a corresponding electrical signal.

7. The cross-medium communication device based on the friction nanogenerator according to claim 6, characterized in that: The antenna assembly also includes a relay board, which is made of a metal plate; the relay board is located between the transmitting antenna and the receiving antenna and is parallel to the transmitting antenna and the receiving antenna.

8. A confidential communication method, characterized in that: It includes: (1) Encoding the information to be sent into the driving force for driving the friction nanogenerator to achieve data encryption; (2) Under the action of the driving force, a cross-medium communication device based on a friction nanogenerator as described in any one of claims 5 to 7 is used to transmit signals; (3) Sampling, amplifying, filtering and decoding the signal received by the signal receiver to restore the original information.

9. An application of the cross-medium communication device based on the friction nanogenerator as claimed in claim 6 or 7 in hydrological monitoring, characterized in that: It includes: The friction nanogenerator and the transmitting antenna are deployed underwater. The friction nanogenerator generates electrical signals driven by waves and transmits them to the surface of the water through the transmitting antenna. The receiving antenna and signal receiver are deployed on the UAV. The UAV flies above the transmitting antenna, and the receiving antenna receives the transmitting signal of the transmitting antenna. The signal receiver pre-processes the received signal and inverts the current wind and wave conditions underwater based on the corresponding signal.

10. An application of the cross-medium communication device based on the triboelectric nanogenerator as claimed in claim 6 or 7 in underwater electromechanical equipment manipulation, characterized in that: It includes: The friction nanogenerator and the transmitting antenna are deployed on a vibration device on the water; the control signal is encoded into the operating parameters of the vibration device to drive the friction nanogenerator to generate an electrical signal and transmit it underwater through the transmitting antenna; The receiving antenna and the signal receiver are deployed underwater, and the signal receiver is connected to the electromechanical equipment to be controlled; the receiving antenna receives the transmission signal of the transmitting antenna; the signal receiver pre-processes the received signal and decodes the corresponding control instruction, and the electromechanical equipment performs corresponding actions according to the decoded control instruction.

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