Flexible-driving cable-free miniature robotic fish

Abstract

The invention discloses a cable-free miniature robotic fish driven flexibly. The flexible-drive cable-free miniature robotic fish comprises a butterfly-shaped thin plate body, and a DEA mounting hole is formed in the middle of the thin plate body; the dielectric elastomer actuator DEA is arranged in the DEA mounting hole, and the dielectric elastomer actuator DEA comprises an actuator top layer film, an actuator bottom layer film and a middle layer; and the floating plate is provided with an on-board driving circuit, the positive electrode end of the on-board driving circuit is connected with the middle layer, and the negative electrode end of the on-board driving circuit extends into water. The structural form of PET and the dielectric elastomer actuator DEA is used, and the light and miniature robotic fish is formed.

Description

Technical Field

[0001] This application relates to the technical field of underwater vehicles, and particularly to a flexible-driven cableless micro robotic fish. Background Art

[0002] The applications of traditional rigid robots are greatly limited in some specific scenarios due to their disadvantages such as fragile structures and large volumes. Flexible soft robots can achieve a high degree of biomimicry of organisms relying on their characteristics of softness, silence, and energy conservation. Among them, the micro flexible biomimetic fish is an important branch of biomimetic robots, and its flexibility and concealment can be used to perform tasks such as underwater exploration and detection.

[0003] At present, due to the need for the micro biomimetic fish to be light in weight, generally two schemes are adopted. One is the external energy supply method, where the biomimetic fish moves forward with a tow cable, which can ensure sufficient energy supply. The disadvantage of this scheme is that the movement range of the robotic fish is limited by the cable. The other is the method of using a small battery for power supply. In this case, the robotic fish can only carry a battery with a small capacity. The characteristic of this scheme is that the battery capacity is small and the endurance time is limited. Therefore, it is necessary to design a micro biomimetic fish that combines movement range and endurance time. Summary of the Invention

[0004] The purpose of the present invention is to provide a flexible-driven cableless micro robotic fish to solve at least one of the above technical problems.

[0005] In one aspect of the present invention, there is provided a flexible-driven cableless micro robotic fish, which comprises:

[0006] A thin plate body, which is in a butterfly shape, and a DEA mounting hole is provided in the middle of the thin plate body;

[0007] A dielectric elastomer actuator DEA, which is installed in the DEA mounting hole. The dielectric elastomer actuator DEA includes an actuator top layer film, an actuator bottom layer film, and an intermediate layer;

[0008] A floating plate, on which an on-board drive circuit is provided. The positive terminal of the on-board drive circuit is connected to the intermediate layer, and the negative terminal extends into the water; wherein,

[0009] The actuator top layer film is a dielectric elastomer DE film, the actuator bottom layer film is a dielectric elastomer DE film, and the intermediate layer is a flexible electrode composed of carbon powder and carbon paste is applied;

[0010] When in water, the flexible electrode of the intermediate layer of the dielectric elastomer actuator DEA is connected to the positive terminal of the drive voltage, and the surrounding water serves as the flexible electrode to connect to the negative terminal;

[0011] The on-board drive circuit is used to obtain radio waves, generate a square wave voltage with an amplitude of 4 kV according to the radio waves, so as to drive the dielectric elastomer actuator DEA to act.

[0012] Optionally, the on-board drive circuit includes a receiving coil and a boost circuit; the boost circuit includes a transformer and a 10-stage voltage multiplier rectifier circuit; wherein,

[0013] After the receiving coil receives radio waves, it is converted into alternating current with the same frequency through the transformer, and after passing through the 10-stage voltage multiplier rectifier circuit, 4 kV of direct current is generated.

[0014] Optionally, the on-board drive circuit further includes a discharge resistor, and the discharge resistor is connected in parallel with the 10-stage voltage multiplier rectifier circuit.

[0015] Optionally, the on-board drive circuit further includes a PET floating board, and the receiving coil, the discharge resistor and the boost circuit are arranged on the PET floating board.

[0016] Optionally, the flexible drive cable-free micro robotic fish further includes a wireless transmission circuit, and the wireless transmission circuit is used to provide electromagnetic waves for the on-board drive circuit.

[0017] Optionally, the flexible drive cable-free micro robotic fish further includes a power supply, and the power supply is used to supply power to the wireless transmission circuit.

[0018] Optionally, the receiving coil includes a top-layer receiving coil, a dielectric-layer receiving coil and a bottom-layer receiving coil, wherein,

[0019] The top-layer receiving coil has 12 turns, the bottom-layer receiving coil has 12 turns, and the dielectric-layer receiving coil is used to isolate the top-layer receiving coil and the bottom-layer receiving coil.

[0020] Optionally, the 10-stage voltage multiplier rectifier circuit further boosts the alternating current through the following formula:

[0021] Wherein,

[0022] V out is the output voltage of the voltage multiplier rectifier circuit, N is the number of voltage multiplier stages, V in_transformer is the output voltage of the transformer, η is the total efficiency of the transformer and the rectifier circuit, α is a loss coefficient related to the number of stages N, β is a loss coefficient related to capacitor leakage, C leak is the leakage capacitance, C total is the total capacitance.

[0023] Beneficial effects

[0024] The flexible-driven cableless micro robotic fish of the present application has the following advantages:

[0025] 1. The present application uses the structural form of PET and dielectric elastomer actuator DEA to form a lightweight and micro robotic fish.

[0026] 2. The present application uses radio transmission to remove the external cable of the robotic fish, enabling it to overcome the problem of difficulty in combining endurance and range of motion.

[0027] 3. The present application uses the method of radio transmission of electric energy and signals to drive the robotic fish, simplifying the structural form of the robotic fish and further reducing its mass and volume. Description of the Drawings

[0028] Figure 1 is a schematic diagram of the overall structure of the flexible-driven cableless micro robotic fish according to an embodiment of the present application.

[0029] Figure 2 is an exploded view of the structure of the flexible-driven cableless micro robotic fish according to an embodiment of the present application.

[0030] Figure 3 is a driving schematic diagram of the flexible-driven cableless micro robotic fish according to an embodiment of the present application.

[0031] Figure 4 is a schematic diagram of the principle of the receiving circuit according to an embodiment of the present application.

[0032] Figure 5 is a schematic diagram of the receiving circuit according to an embodiment of the present application.

[0033] Figure 6 is a schematic diagram of the principle of the transmitting circuit according to an embodiment of the present application.

[0034] Figure 7 is a schematic diagram of the transmitting circuit according to an embodiment of the present application.

[0035] Reference Signs:

[0036] 1 - Thin plate body; 2 - Dielectric elastomer actuator DEA; 21 - Actuator top layer film; 22 - Toner; 23 - Carbon paste; 24 - Actuator bottom layer film; 121 - Adhesive area; 122 - Deformation area; 123 - Uncoated area; 3 - Onboard drive circuit; 31 - Transformer; 32 - Receiver coil; 33 - Negative output line; 34 - Positive output line; 311 - Top layer receiver coil; 312 - Dielectric layer receiver coil; 313 - Bottom layer receiver coil; 12 - Boost circuit; 122 - 10 - stage voltage - doubling rectifier circuit; 124 - Discharge resistor; 21 - Wireless transmission circuit; 211 - Transmission coil; 221 - MOS transistor; 231 - Drive board; 2311 - Gate drive IC; 2321 - Crystal oscillator; 241 - Step - down module; 251 - MCU controller; 5 - Wireless transmission circuit; 51 - Transmission coil, 52 - MOS transistor, 53 - Drive board, 54 - Gate drive IC; 55 - And crystal oscillator, 56 - MCU controller; 57 - Step - down module. Detailed implementation manner

[0037] To make the purpose, technical solutions, and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings in the embodiments of this application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described embodiments are some, but not all, of the embodiments of this application. The embodiments described below by referring to the drawings are exemplary and are intended to explain this application and should not be construed as limiting this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the drawings.

[0038] As Figure 1 shown, the flexible - driven cable - free micro robotic fish includes a thin plate body 1, a dielectric elastomer actuator DEA 2, and a floating plate. Among them,

[0039] The thin plate body 1 is in a butterfly shape, and a DEA mounting hole is provided in the middle of the thin plate body 1;

[0040] The dielectric elastomer actuator DEA 2 is installed in the DEA mounting hole. The dielectric elastomer actuator DEA 2 includes an actuator top layer film 21, an actuator bottom layer film 24, and an intermediate layer;

[0041] The floating plate is provided with an onboard drive circuit 3. The positive terminal of the onboard drive circuit 3 is connected to the intermediate layer, and the negative terminal extends into the water. Among them,

[0042] The top layer membrane 21 of the actuator is a dielectric elastomer (DE) membrane, the bottom layer membrane 24 of the actuator is a dielectric elastomer (DE) membrane, the intermediate layer is a flexible electrode composed of toner 22, and a carbon paste 23 is applied.

[0043] When in water, the flexible electrode of the intermediate layer of the dielectric elastomer actuator (DEA) is connected to the positive terminal of the driving voltage, while the surrounding water serves as the flexible electrode and is connected to the negative terminal.

[0044] The on-board driving circuit is used to acquire radio signals and generate a square wave voltage with an amplitude of 4 kV according to the radio signals, thereby driving the dielectric elastomer actuator DEA2 to act.

[0045] In this embodiment, a polyethylene terephthalate (PET) thin plate material is used as the trunk of the robotic fish, i.e., the thin plate body. The two sides of the trunk extend outward and backward to form the wide wings of the robotic fish. A round hole is reserved in the center of the trunk to place the flexible dielectric elastomer actuator (DEA) to act as muscles. Driven by the muscles, the two wings of the robotic fish can perform up-and-down flapping motions. By pushing the surrounding water backward, the two wings can generate a forward thrust for the robotic fish. By controlling the periodic flapping of the two wings at a certain frequency and amplitude, the robotic fish can continuously swim in water.

[0046] The thin plate body serves as a flexible support frame here. A radially pre-stretched dielectric elastomer is used as the dielectric elastomer actuator DEA. The undriven dielectric elastomer actuator DEA, due to its own elasticity, will apply an inward pulling force to the flexible frame, causing it to bend. Due to the certain toughness of the thin plate body 1, there will continuously be a pre-tension force at the bending point with a tendency to restore to the planar state. The shape of the flexible frame has two bending points on the center line of the trunk, respectively at the head and tail of the robotic fish.

[0047] When the dielectric elastomer actuator DEA is not driven, under the pulling force applied by the dielectric elastomer actuator DEA, the thin plate body bends in the same direction at the two bending points. The dielectric elastomer actuator DEA shows a folded state, that is, the two wings of the robotic fish fold downward. After the driving voltage is applied, the dielectric elastomer actuator DEA deforms. Specifically, the elastic force decreases and the area expands. Under the action of the pre-tension force, the shape of the thin plate body restores to the planar state. At this time, the folding angle of the dielectric elastomer actuator DEA becomes larger, and the two wings of the robotic fish unfold upward. By repeating this operation, the action of the robotic fish flapping its wings is realized.

[0048] In this embodiment, the PET thin plate (thin plate body) is the trunk of the robotic fish, and its outer shape and dimensions are as Figure 2As shown, its outer shape is a circle cut into a butterfly shape. The areas extending backward on both sides are the side fin parts of the robotic fish, which swing freely along with the vibration of the wings during the swimming of the robotic fish. A hole is reserved in the center of the PET thin plate (thin plate body) as the position for placing the dielectric elastomer actuator DEA2.

[0049] In this embodiment, for the dielectric elastomer actuator DEA2, the dielectric elastomer actuator DEA2 is connected to the thin plate body 1. The dielectric elastomer actuator DEA2 includes an actuator top layer film 21, an actuator bottom layer film 24, and an intermediate layer.

[0050] In this embodiment, the dielectric elastomer actuator DEA adopts a three - layer structure. The actuator top layer film 21 and the actuator bottom layer film 24 are two DE films, and the intermediate layer is a flexible electrode. After putting the DEA with this structure into water, the flexible electrode in the intermediate layer is connected to the positive pole of the driving voltage, and the surrounding water can be used as the flexible electrode of the other pole to connect to the positive terminal. The two outer DEs (the actuator top layer film 21 and the actuator bottom layer film 24) not only play the role of generating deformation but also have the role of separating the positive and negative electrodes. This form of DEA is light in weight, simple in structure, large in deformation amplitude, and few in material types and simple in manufacturing.

[0051] In this embodiment, the internal composition of the dielectric elastomer actuator DEA is as Figure 3 shown. The actuator top layer film 21 and the actuator bottom layer film 24 are two DE films, and the intermediate layer is a flexible electrode composed of carbon powder 22, and carbon paste 23 is applied to increase the contact area between the wire and the electrode to reduce the impedance. After putting the dielectric elastomer actuator DEA with this structure into water, the flexible electrode in the intermediate layer is connected to the positive terminal 34 of the driving voltage, and the surrounding water can be used as the flexible electrode of the other pole to connect to the negative terminal 33.

[0052] In this embodiment, the cable - free micro - robotic fish with flexible drive further includes an on - board drive circuit 3. The on - board drive circuit 3 is mounted on a PET floating board and connected to the trunk of the robotic fish (for example, connected by a cable). The floating board can be supported on the water surface by the action of surface tension, enabling the cable - free micro - robotic fish with flexible drive to float in the water and stabilize the body posture at the same time.

[0053] See Figure 4 and Figure 5, the on-board drive circuit 3 is used to receive and convert energy to drive the DEA. The on-board drive circuit 3 receives and converts energy through the principle of radio transmission, and consists of a spiral coil and a boost circuit. The coil can receive the electromagnetic wave emitted by the transmitter within a range of 20 mm. After the electromagnetic wave is converted by the boost circuit, the system outputs high-voltage direct current. The positive output terminal of the voltage is connected to the flexible electrode of the middle layer of the dielectric elastomer actuator DEA, and the negative output terminal is released into the water to form a DEA drive loop. The circuit selects a flexible printed circuit board (FPC) with light weight and bendability as the substrate. The receiving coil is a PCB coil drawn on the FPC. Compared with the traditional copper wire coil, the PCB coil has higher space utilization rate, lighter weight and lower cost. It can provide continuous energy and control signals without restricting the movement range of the robotic fish.

[0054] Specifically, the mode in which the on-board drive circuit of the present application receives electrical energy and signals by radio is as Figure 4 shown. The on-board drive circuit 3 includes a receiving coil 32 and a boost circuit 12; the boost circuit 12 includes a transformer 31 and a 10-stage voltage multiplier rectifier circuit 122; among them, after the receiving coil 32 receives radio, it is converted into alternating current of the same frequency through the transformer 31, and after passing through the 10-stage voltage multiplier rectifier circuit 122, 4 kV of direct current is generated. At this time, the dielectric elastomer actuator DEA2 opens its double fins; when there is no voltage in the receiving coil 32, the dielectric elastomer actuator DEA2 contracts, and by cycling in turn, the double fins of the robotic fish can be flapped, and then it can swim forward. In addition, it should be noted that the flapping frequency of the fins can be controlled by the induction current transmission frequency when the receiving coil 32 is powered. Therefore, remote power supply and control of the robotic fish can be realized.

[0055] The cable-free micro robotic fish with flexible drive of the present application has the following advantages:

[0056] 1. The present application uses the structural form of PET and the dielectric elastomer actuator DEA to form a lightweight and micro robotic fish.

[0057] 2. The present application uses the method of radio transmission to remove the external cable of the robotic fish, enabling it to break through the problem of being difficult to combine endurance and activity range.

[0058] 3. The present application uses the method of radio transmission of electrical energy and signals to drive the robotic fish, which simplifies the structural form of the robotic fish and further reduces the mass and volume of the robotic fish.

[0059] In this embodiment, the receiving coil 32 includes a top-layer receiving coil 311, a dielectric-layer receiving coil 312, and a bottom-layer receiving coil 313, where,

[0060] The top receiving coil 311 has 12 turns, the bottom receiving coil 313 has 12 turns, and the dielectric layer receiving coil 312 is used to isolate the top receiving coil 311 and the bottom receiving coil 313.

[0061] In the 10-stage voltage multiplier rectifier circuit, a parallel discharge resistor 124 is used to improve the response speed of the DEA. The on-board drive circuit is as Figure 6 shown. In order to increase the number of turns of the coil, the receiving coil forms a three-layer structure, that is, the top receiving coil has 12 turns, the bottom receiving coil has 12 turns, and the dielectric layer receiving coil is used to isolate the top receiving coil and the bottom receiving coil.

[0062] See Figure 6 and Figure 7 In this embodiment, the wireless transmission circuit 5 includes a transmission coil 51, an MOS transistor 52, a drive board 53, a gate drive IC 54, a crystal oscillator 55, an MCU controller 56, and a buck module 57.

[0063] The supply voltage is supplied to the MCU controller 56 and the drive board 53 through the buck module 57 respectively; the MCU controller 56 sends a control instruction for controlling the frequency to the drive board 53. Through the fixed-frequency signal of the crystal oscillator 55, the gate drive IC 54 drives the MOS transistor 52 to form a control current with a fixed frequency of 400 kHz, which is transmitted to the on-board drive circuit through the transmission coil 51. The structural form of the transmission coil 51 is the same as that of the receiving coil 32, which is divided into three layers, with 8 turns on the bottom layer and 8 turns on the bottom layer, for a total of 16 turns. The transmission circuit diagram is as Figure 7 shown.

[0064] In this embodiment, the present application further includes a power supply for supplying power to the wireless transmission circuit 5.

[0065] The present application has the following advantages:

[0066] 1. The circuit designed by the present invention is small in size and light in weight, and can generate a high voltage of more than 4 kV with only low power consumption, and can be widely applied to the power supply scheme design of DE-driven robots.

[0067] 2. The present invention can simultaneously transmit energy and control signals to the DEA through only a pair of coils, and realize remote control without adding an additional communication module.

[0068] 3. The PCB planar coil drawn on the FPC is used as the receiving coil to increase the number of turns of the coil and the receiving efficiency. The transformer is selected to be light in weight and flat in shape to reduce the volume and weight of the circuit. The voltage multiplier rectifier circuit adopts an adjustable stage design to adjust the output voltage according to actual needs.

[0069] 4. Generate signals using a single MOS excitation circuit and an adjustable - frequency crystal oscillator. The frequency modulation module adjusts the output frequency of the crystal oscillator according to the feedback information from the receiving end. The structures of the transmitting coil and the receiving coil are the same, improving the energy transfer efficiency.

[0070] In this embodiment, the 10 - stage voltage - doubling rectifier circuit further boosts the alternating current through the following formula:

[0071] Where,

[0072] V out is the output voltage of the voltage - doubling rectifier circuit, N is the number of voltage - doubling stages, V in_transformer is the output voltage of the transformer, η is the total efficiency of the transformer and the rectifier circuit, α is the loss coefficient related to the number of stages N, β is the loss coefficient related to capacitor leakage, Cleak is the leakage capacitance, and Ctotal is the total capacitance.

[0073] By adjusting the value of N and considering the losses and capacitance factors in the circuit through the above formula, the output voltage can be set more accurately.

[0074] In this embodiment, the loss coefficient α related to the number of stages N can be obtained through the following formula:

[0075] Assume that the loss power Ploss(N) at different numbers of stages N is measured through experiments. Then the loss coefficient α can be obtained through the fitting formula α = f(N), where f(N) is a function fitted according to the experimental data.

[0076] In this embodiment, the loss coefficient β related to capacitor leakage can be obtained in the following way:

[0077] Assume that the relationship between the capacitor leakage current I leak and the capacitance value C is measured through experiments. Then the loss coefficient β can be obtained through the formula β = k×I leak / C, where k is a constant.

[0078] In this embodiment, the wireless transmitting circuit determines the transmitting power through the following formula:

[0079] Where,

[0080] Pyz is the output power of the dielectric - elastomer - based wireless drive system, Ayz is the voltage of the transmitting coil, Syz is the impedance of the transmitting coil, α is the working angular frequency, Byz is the inductance of the transmitting coil, m is the coupling coefficient, and γyz is the total efficiency of the transmitting circuit.

[0081] In this embodiment, the coupling coefficient is the ratio of the actual mutual inductance M (absolute value) between two inductive elements to its maximum limit value (i.e., the geometric mean of the self-inductances L1 and L2 of the two inductors):

[0082]

[0083] It can be obtained through the following formula:

[0084] Measure self-inductance: Use an LCR meter (an instrument for measuring inductance, capacitance, and resistance) to measure the values of inductors L1 and L2.

[0085] Measure mutual inductance: Use the magnetic field superposition method to measure the linked magnetic flux of the two coils, or calculate the mutual inductance M through the mutual inductance definition formula (where Φ2 is the magnetic flux of the second coil and I1 is the current of the first coil).

[0086] Substitute the measured values of L1, L2, and M into the formula to calculate the coupling coefficient k.

[0087] In this embodiment, driving the dielectric elastomer material requires a voltage of up to more than 4 kV. The traditional wireless power receiving-end circuit structure is complex and usually includes a receiving coil, a rectification module, a voltage regulation module, an inversion module (for converting direct current to alternating current), a transformer (which needs to input alternating current to work), and a voltage multiplier circuit. Such a complex circuit structure is not only large in volume and heavy in weight but also significantly reduces the swimming speed and underwater movement flexibility of the robotic fish.

[0088] However, this application makes full use of the advantage of the low driving power requirement (only in the milliwatt level) of the dielectric elastomer material and innovatively removes the rectification module, voltage regulation module, and inversion module from the receiving end and instead places them at the transmitting end where there are no strict requirements for weight and volume. At the receiving end, we directly input the alternating current induced by the receiving coil into the primary side of the transformer. Through this circuit structure optimization, we have significantly reduced the mass and volume of the robotic fish and remarkably improved its swimming speed, thereby enhancing the swimming performance of the robotic fish.

[0089] In this embodiment, in the traditional control of the double-wing flapping of the robotic fish, usually an additional communication module is required to transmit control signals, and dedicated signal paths are also needed at the transmitting end and the receiving end to achieve instruction transmission. This not only increases the complexity of the circuit structure but also causes the overall volume of the robotic fish to increase and the weight to increase, thus significantly reducing its swimming performance.

[0090] This application proposes an innovative control method that couples the energy signal with the frequency control signal. Through only a pair of transmitting and receiving coils, the synchronous transmission of energy and control signals can be achieved, successfully realizing the multiplexing of the signal transmission channel. With this method, without adding an additional signal transmission module, the transmitting end can non-contactedly control the swing frequency of the two wings of the robotic fish. This improvement effectively reduces the weight and volume of the robotic fish, significantly enhancing its swimming performance and making the robotic fish more flexible and efficient in the underwater environment.

[0091] Although the present invention has been described in detail with general descriptions and specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A flexible-driven cable-free micro robotic fish, characterized in that, The flexible-drive cableless micro robotic fish includes: A thin plate body (1), the thin plate body (1) is in a butterfly shape, and a DEA mounting hole is provided in the middle of the thin plate body (1); A dielectric elastomer actuator DEA (2), the dielectric elastomer actuator DEA (2) is installed in the DEA mounting hole, and the dielectric elastomer actuator DEA (2) includes an actuator top layer film (21), an actuator bottom layer film (24) and an intermediate layer; A floating plate, on which an on-board drive circuit (3) is provided, the positive terminal (34) of the on-board drive circuit (3) is connected to the intermediate layer, and the negative terminal (33) extends into the water; wherein, The actuator top layer film (21) is a dielectric elastomer DE film, the actuator bottom layer film (24) is a dielectric elastomer DE film, and the intermediate layer is a flexible electrode composed of carbon powder (22) and coated with carbon paste (23); When in water, the flexible electrode in the middle layer of the dielectric elastomer actuator DEA is connected to the positive terminal of the drive voltage, and the surrounding water serves as the flexible electrode connected to the negative terminal; The on-board drive circuit is used to obtain radio waves, generate a square wave voltage with an amplitude of 4 kV according to the radio waves, so as to drive the dielectric elastomer actuator DEA (2) to act.

2. The flexible-drive cable-free micro robotic fish according to claim 1, characterized in that, The on-board drive circuit (3) includes a receiving coil (32) and a boosting circuit (12); the boosting circuit (12) includes a transformer (31) and a 10-stage voltage multiplier rectifier circuit (122); wherein, After the receiving coil (32) receives radio waves, it is converted into alternating current with the same frequency through the transformer (31), and passes through the 10-stage voltage multiplier rectifier circuit (122) to generate 4 kV of direct current.

3. The flexible-drive cable-free micro robotic fish according to claim 2, characterized in that, The on-board drive circuit further includes a discharge resistor (124), and the discharge resistor (124) is connected in parallel with the 10-stage voltage multiplier rectifier circuit.

4. The cable-free micro robotic fish with flexible drive according to claim 3, characterized in that, The on-board drive circuit (3) further includes a PET floating plate, and the receiving coil (32), the discharge resistor (124) and the boosting circuit (12) are arranged on the PET floating plate.

5. The flexible-drive cable-free micro robotic fish according to claim 4, characterized in that, The flexible-drive cableless micro robotic fish further includes a wireless transmission circuit (2), and the wireless transmission circuit is used to provide electromagnetic waves for the on-board drive circuit (3).

6. The cable-free micro robotic fish with flexible drive according to claim 5, wherein, The flexible-drive cableless micro robotic fish further includes a power supply, and the power supply is used to supply power to the wireless transmission circuit (2).

7. The flexible-drive cable-free micro robotic fish according to claim 3, wherein, The receiving coil (32) includes a top layer receiving coil (311), a dielectric layer receiving coil (312) and a bottom layer receiving coil (313), wherein, The top layer receiving coil (311) has 12 turns, the bottom layer receiving coil (313) has 12 turns, and the dielectric layer receiving coil (312) is used to isolate the top layer receiving coil (311) and the bottom layer receiving coil (313).

8. The flexible-drive cable-free micro robotic fish according to claim 7, wherein The 10-stage voltage multiplier rectifier circuit further boosts the alternating current through the following formula: Among them, V out is the output voltage of the voltage-doubling rectifier circuit, N is the number of voltage-doubling stages, V in_transformer is the output voltage of the transformer, η is the total efficiency of the transformer and the rectifier circuit, α is the loss coefficient related to the number of stages N, β is the loss coefficient related to the capacitor leakage, C leak is the leakage capacitance, C total is the total capacitance.

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