A micro-nano robot based on a flexible hinge, a driving method and a preparation method

Abstract

The application discloses a micro-nano robot based on a flexible hinge, a driving method and a preparation method, the micro-nano robot comprises a flexible hinge and a bubble capturing structure connected with the flexible hinge, and the flexible hinge comprises a plurality of flexible sections and rigid sections which are alternately connected; when a certain sound field is applied, the flexible sections vibrate and deform, and the rigid sections do not deform; when the sound field is stopped, the flexible sections restore the initial shape; in a liquid environment, the bubble capturing structure is used for capturing bubbles, the bubbles resonate in a sound field environment and drive the bubble capturing structure to move, and the flexible hinge deforms in the sound field environment to capture particles in the liquid, change the moving direction of the micro-nano robot or change the moving speed of the micro-nano robot.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro-nano robots and ultrasonic driving technology, and particularly relates to a micro-nano robot based on a flexible hinge, a driving method and a preparation method. BACKGROUND

[0002] Micro-nano robots, also known as micro-nano motors, are micro-nano functional devices capable of achieving autonomous driving in a low Reynolds number environment. Due to its great potential in the fields of biological engineering, medical technology, chemical detection, drug transportation and the like, it has attracted widespread attention from global researchers and has become one of the research hotspots in recent years. Due to the characteristics of the micro-nano robot itself and the potential working environment, the micro-nano robot is mainly powered by external energy, such as light, electromagnetic field, sound wave, chemical and the like. Among them, the sound driving technology has the advantages of non-contact action, good biocompatibility and high energy utilization rate, and has a broader application prospect in the field of biomedicine. Since the 1990s of the 20th century, how to efficiently and quickly manufacture micro-nano robots has become one of the research hotspots in the related field. At present, the mainstream manufacturing methods include photolithography, electron beam evaporation, electrochemical deposition and 3D printing. With the further development of additive manufacturing technology, the manufacturing precision has broken through to the level of several microns or even lower nanometers. Compared with other manufacturing methods, it has the advantages of fast manufacturing speed, high manufacturing yield and large single batch manufacturing quantity, and shows great research and development potential.

[0003] At present, many research teams have carried out research on tubular micro-nano robots and bubble propulsion type microstructures. The Chinese invention patent with publication number CN111082705A discusses a biocompatible iron-manganese dioxide system micro-nano motor, which combines electrochemical deposition with an ultrasonic field. The outer layer of polyethylene dioxythiophene (PEDOT) and the intermediate layer of Fe are first deposited by electrochemical deposition, and then the inner layer of MnO2 is deposited by electrochemical deposition while introducing an ultrasonic field. The obtained micro-nano motor is a three-layer hollow tubular structure. The structure generates bubbles by catalyzing the decomposition of H2O2 in the liquid by the MnO2 in the inner layer, which propels the motor to move rapidly in the liquid environment. The Chinese invention patent with publication number CN114193428A discusses a micro-nano ultrasonic robot based on bubble propulsion. The robot is made using electrochemical deposition method. The main body is a hollow tubular structure with two open ends, composed of two layers of materials. The outer layer is PEDOT material, which serves as a support. The inner layer is a hydrophobic material that can capture bubbles in the liquid. The robot can move at high speed under the action of the sound field, with a maximum speed of 1000 times the body length per second. The Chinese invention patent with publication number CN117414350A mentions a cell delivery micro robot for cell therapy. The micro-nano robot is composed of a double-layer magnetic elastic hydrogel film, which is an elastic layer and a fixed layer. It can curl or stretch at different temperatures to capture or release drugs, and can move under the action of an external magnetic field to achieve targeted drug delivery.

[0004] The above invention patents have achieved certain functions, but also have some problems. First, the above micro-nano robots have high requirements for the working environment. If certain use conditions are not met, the bubble capture ability and deformation ability will decrease, and even the robot cannot work. Second, the bubble propulsion type micro-nano robots have the problem of uncontrollable movement direction and speed, which limits the actual use effect. Finally, the manufacturing method mentioned in the above invention patents is complicated to operate, the consistency of the finished products is insufficient, and it is difficult to manufacture a large number of micro-nano robots in a short time. SUMMARY

[0005] The purpose of the invention is to overcome the shortcomings of existing micro-nano robots, such as high requirements for working environment, poor capture and deformation ability, and uncontrollable movement direction and speed. The invention provides a micro-nano robot based on flexible hinge, driving method and preparation method.

[0006] Technical scheme: To solve the above problems, the invention adopts a micro-nano robot based on flexible hinge, which includes a flexible hinge and a bubble capture structure connected to the flexible hinge. The flexible hinge includes a plurality of alternating flexible segments and rigid segments. When a certain sound field is applied, the flexible segments vibrate and deform, and the rigid segments do not deform. When the sound field is stopped, the flexible segments return to their original shape.

[0007] In a liquid environment, the bubble trapping structure is used to trap bubbles, the bubbles resonate in a sound field environment and drive the bubble trapping structure to move, and the flexible hinge deforms in a sound field environment to trap particles in the liquid, change the moving direction of the micro-nano robot, or change the moving speed of the micro-nano robot.

[0008] Further, the flexible hinge is made of a photocured hydrogel material, the stiffness of the flexible section is less than that of the rigid section, and the stiffness of the rigid section is 50-270 MPa.

[0009] Further, the flexible hinge is made of a photocured resin, the elastic modulus of the rigid section is 2300-2700 MPa, and the elastic modulus of the flexible section is 1700-2100 MPa.

[0010] Further, the flexible hinge includes four flexible sections and four rigid sections connected alternately, the flexible hinge forms a closed rectangular frame, the cross section of the flexible section is rectangular, the flexible section is controlled by the frequency of the sound field to deform in two different directions, the cross section of the rigid section is L-shaped, one bubble trapping structure is fixedly connected to each rigid section, and the bubble trapping structures are symmetrically distributed about a center line of the closed rectangular frame, wherein two bubble trapping structures are located on opposite sides of the rectangle, and the other two bubble trapping structures are located on the same side of the rectangle; when the flexible section does not deform, the two bubble trapping structures located on the opposite sides drive in opposite directions and the driving forces cancel each other out, and the two bubble trapping structures located on the same side drive the micro-nano robot to move; when the flexible section deforms, the moving direction of the micro-nano robot changes with the deformation direction of the flexible section.

[0011] Further, the flexible hinge includes a plurality of branched chains, each branched chain includes a flexible section in the middle and rigid sections connected to both ends of the flexible section, the cross section of the flexible section is isosceles trapezoidal, the flexible section is controlled by the frequency of the sound field to deform in the direction of the lower base of the isosceles trapezoid, and the rigid section is provided with a protrusion for connecting to the leg of the isosceles trapezoid; the number of bubble trapping structures is equal to the number of branched chains, each bubble trapping structure is provided with two rigid connecting blocks, the rigid section and the rigid connecting block are connected through a flexible connecting section, each branched chain is connected to two bubble trapping structures at both ends, and the bubble trapping structures and the branched chains form a closed shape; when the flexible section deforms, the length of the branched chain shortens, and the bubble trapping structures move closer to each other to trap particles in the liquid.

[0012] Further, the bubble capturing structure comprises a hollow tube with an open end, and a hydrophobic inner layer arranged on the inner wall of the hollow tube, the hydrophobic inner layer being used for capturing bubbles in a liquid environment.

[0013] Further, the bubble capturing structure comprises a hollow tube with an open end, and a hydrophobic inner layer arranged on the inner wall of the hollow tube, the hydrophobic inner layer being used for capturing bubbles in a liquid environment.

[0014] The application further provides a driving method of the micro-nano robot, a signal generator, a power amplifier and a piezoelectric transducer, the signal generator being used for providing a sinusoidal signal, the power amplifier being used for amplifying the sinusoidal signal provided by the signal generator, and the piezoelectric transducer being used for converting an electric signal into mechanical vibration and then generating an ultrasonic field; the micro-nano robot is placed in a liquid environment, bubbles are captured by the bubble capturing structure, the bubbles resonate in the ultrasonic field and drive the bubble capturing structure to move, the frequency generated by the signal generator and the signal voltage of the power amplifier are changed, the flexible hinge deforms in the ultrasonic field to capture particles in the liquid, change the moving direction of the micro-nano robot or change the moving speed of the micro-nano robot.

[0015] The application further provides a preparation method of the micro-nano robot, a computer and a light-curing 3D printer, the computer being connected with the light-curing 3D printer through a data line, and comprising the following steps.

[0016] Step 1, a three-dimensional model of the micro-nano robot is established by using modeling software, and the three-dimensional model file is saved in a file format recognizable by slicing software;

[0017] Step 2, the three-dimensional model file is imported into the slicing software for slicing processing, and a printing file recognizable by the light-curing 3D printer is generated;

[0018] Step 3, the printing file is sent to the light-curing 3D printer and printing is performed;

[0019] Step 4, after the printing is completed, the printing platform is taken out and placed in a cleaning tank for cleaning;

[0020] Step 5, the micro-nano robot is taken off from the platform by using ultrasonic waves.

[0021] Further, the step 3 selects the photosensitive material to print, and in the printing process, the photocuring 3D printer changes the illumination intensity and illumination time of the curing light to make a material solidify into a structure with different mechanical properties, thereby realizing the deformable function, and the illumination time of the flexible section is less than that of the rigid section.

[0022] Advantages: Compared with the prior art, the present application has the following advantages: (1) Compared with temperature control / chemical control deformable micro-nano robots, the present application only needs ultrasonic waves for control, reducing the requirements for the working environment and expanding the use range of micro-nano robots; (2) Through the design of flexible hinges and the combination of sound field changes, the motion direction and speed of the micro-nano robot are controlled, improving the controllability of the micro-nano robot; (3) The combination of flexible hinges and bubble resonance driving realizes the capture and transportation of micro-particles, which can be applied to the fields of drug delivery, chemical detection, environmental detection, etc., further expanding the application field of micro-nano robots; (4) The flexible hinge has a simple structure, a fast response speed to sound waves, and can quickly return to the original state after ultrasonic waves stop, having good usability, applicability and reusability; (5) Through the light-curing 3D printing technology, a considerable number of micro-nano robots can be printed in a short time, and the printed micro-nano robots have good consistency and high precision, compared with traditional micro-nano robot manufacturing technology, the printing cost is low, the printing efficiency is high, and the operation is simple. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the overall structure and deformation schematic diagram of the micro-nano robot of example one;

[0024] Figure 2 It is the working schematic diagram of the micro-nano robot of example one;

[0025] Figure 3 It is the structure and deformation schematic diagram of the bidirectional deformation flexible hinge;

[0026] Figure 4 It is the two-direction deformation schematic diagram of the bidirectional deformation flexible hinge;

[0027] Figure 5 It is the driving system structure schematic diagram;

[0028] Figure 6 It is the overall structure and deformation schematic diagram of the micro-nano robot of example two;

[0029] Figure 7 It is the structure and deformation schematic diagram of the unidirectional deformation flexible hinge;

[0030] Figure 8 It is the working schematic diagram of the micro-nano robot of example two;

[0031] Figure 9 Structure diagram of micro-nanorobot in Example 1;

[0032] Figure 10 Flow chart of micro-nanorobot preparation method;

[0033] Figure 11 Structure diagram of micro-nanorobot preparation process;

[0034] In the figure, 1 is a rigid part, 2 is a flexible part, 3 is a bidirectional deformation flexible hinge, 4 is a unidirectional deformation flexible hinge, 5 is the inner layer of the bubble trapping structure, 6 is the trapped bubble, 7 is a closed rectangular frame, 8 is a bubble trapping structure, 9 is a computer, 10 is a light-cured 3D printer, 11 is an array of micro-nanorobots, 12 is a printing platform carrying micro-nanorobot particles, 13 is a water inlet, 14 is a signal generator, 15 is a power amplifier, 16 is a piezoelectric transducer, 17 is a branched chain, 18 is a target particle, and 19 is a rigid wing. DETAILED DESCRIPTION

[0035] Example 1

[0036] As shown in Figure 1 and Figure 2 , a flexible hinge-based micro-nanorobot in this embodiment includes four bubble trapping structures 8 and a closed rectangular frame 7 surrounded by a bidirectional deformation flexible hinge 3. The bidirectional deformation flexible hinge 3 includes four flexible segments 2 and four rigid segments 1 connected alternately. The Young's modulus of the flexible segment is lower than that of the rigid segment, and the flexible segment is more flexible and elastic. In the manufacturing process, by setting different light exposure time and light intensity, the same material will have different mechanical properties after curing, forming different parts. Light-cured hydrogel or light-cured resin material can be used. When hydrogel material is used, the rigidity of the rigid segment after curing is 50-270 MPa, and the rigidity of the flexible segment 2 is less than that of the rigid segment 1. When light-cured resin material is used, the elastic modulus of the rigid segment 1 is 2300-2700 MPa, and the elastic modulus of the flexible segment 2 is 1700-2100 MPa. The flexible hinge is placed in a liquid environment and a specific acoustic field is applied. The flexible segment in the hinge will vibrate and deform, and at the same time a rotating moment is given to the two sides of the rigid segment, i.e. the acoustic-induced deformation phenomenon occurs. When the hinge material is hydrogel, an external acoustic field with a frequency of 6.5 kHz-20 kHz and a voltage amplitude of 20 Vpp-45 Vpp is applied; when the material is resin, an external acoustic field with a frequency of 18 kHz-25 kHz and a voltage amplitude of 20 Vpp-45 Vpp is applied. The entire micro-nanorobot will deform, and after stopping the application of the acoustic field, the flexible hinge can recover to the initial shape, having good reusability.

[0037] As shown in Figure 3 and Figure 4As shown, the flexible segment 2 has a rectangular cross-section and the ability to deform in two directions. By changing the frequency of the ultrasonic sound field, the distribution of the acoustic flow field in the sound field is changed, thereby controlling the deformation of the hinge in different directions. The rigid segment 1 has an L-shaped cross-section, and a bubble trapping structure 8 is fixedly connected to each rigid segment 1. The bubble trapping structures 8 are symmetrically distributed about one centerline of the closed rectangular frame 7, with two bubble trapping structures 8 located on opposite sides of the rectangle and the other two located on the same side of the rectangle.

[0038] The bubble trapping structure 8 includes a hollow tube with one end open and a hydrophobic inner layer 5 disposed on the inner wall of the hollow tube. The interior of the hollow tube is a blind hole structure with a single-end opening. A constriction structure is provided at one end of the hollow tube opening. The hydrophobic inner layer 5 is used to trap bubbles 6 in a liquid environment. The bubbles 6 can resonate in the acoustic field environment, driving the entire micro-nano robot to move at high speed.

[0039] When the flexible segment 2 is not deformed, the two bubble trapping structures 8 located on opposite sides drive in opposite directions and their driving forces cancel each other out. The two bubble trapping structures 8 located on the same side drive the micro-nano robot to move in a straight line. When the flexible segment 2 is deformed, the direction of motion of the micro-nano robot changes with the direction of deformation of the flexible segment 2. The flexible segment 2 can deform in a clockwise or counterclockwise direction under a specific frequency sound field, thereby changing the direction of motion of the micro-nano robot.

[0040] like Figure 5 As shown, driving micro-nano robots requires the use of a signal generator 14, a power amplifier 15, and a piezoelectric transducer 16. The signal generator 14 is used to generate a sine wave of 1kHz-10MHz, the power amplifier 15 is used to control the signal voltage between 10-60V, and the piezoelectric transducer 16 is used to convert the electrical signal into mechanical vibration, thereby generating an ultrasonic field.

[0041] The driving method of the micro-nano robot in this embodiment is specifically: for the hydrogel-based flexible hinge, the signal generator 14 generates an acoustic field with a frequency of 6.5 kHz-20 kHz and a voltage amplitude of 20 Vpp-45 Vpp in a liquid environment, and for the resin-based flexible hinge, the signal generator 14 generates an acoustic field with a frequency of 18 kHz-25 kHz and a voltage amplitude of 20 Vpp-45 Vpp in a liquid environment, so that the four flexible segments 2 simultaneously deform clockwise or counterclockwise, the frames on both sides move towards the middle, the opening direction of the bubble trapping structure 8 changes, and the resulting resultant force will push the micro-nano robot to move at high speed in a new direction. Within a given acoustic field range, there is a critical frequency value. When the frequency of the acoustic field exceeds the critical value, the direction of the excited acoustic flow field will change, and in turn the direction of the flexible hinge deformation will change. The critical value is affected by various factors and will change within a certain range. Under normal circumstances, the critical value of the hydrogel material is between 11 kHz and 14 kHz, and the critical value of the resin material is between 20 kHz and 23 kHz. The micro-nano robot has the advantages of rapid response and good multiplicity. By controlling the frequency of the driving acoustic field to quickly switch on both sides of the critical value, the micro-nano robot can be driven to move at high speed along a complex trajectory, greatly improving the motion and control of the acoustic-controlled micro-nano robot.

[0042] Embodiment Two

[0043] As shown in Figure 6 , a micro-nano robot based on a flexible hinge in this embodiment includes four bubble trapping structures 8 and a one-way deformation flexible hinge 4. The one-way deformation flexible hinge 4 includes four branches 17, and each branch 17 includes a flexible segment 2 located in the middle and a rigid segment 1 connected to both ends of the flexible segment 2. As shown in Figure 7 , the cross section of the flexible segment 2 is isosceles trapezoidal, and the rigid segment 1 is provided with a protrusion for connecting with the waist of the isosceles trapezoid. The design of the isosceles trapezoidal flexible segment 2 makes the contraction degree of the long side of the flexible segment exceed that of the short side in the acoustic field, resulting in the deflection of the branch to one side of the long side, thereby realizing the directional control of the hinge movement.

[0044] The bubble trapping structure 8 is provided with two rigid connecting blocks, and the rigid segment 1 is connected to the rigid connecting blocks through a flexible connecting segment. Each branch 17 is connected to two bubble trapping structures 8 at both ends, and the bubble trapping structures 8 and the branches 17 form a closed shape. When the flexible segment 2 deforms, the branch 17 deforms and folds, and the bubble trapping structures 8 approach each other to trap particles in the liquid.

[0045] As shown in Figure 8As shown, the driving method of the micro-nano robot in this embodiment is as follows: In the first stage, a sound field with a driving voltage of 30V and a frequency of 30kHz is used to drive the micro-nano robot to approach the target particle 18; in the second stage, the voltage of the driving sound field is reduced to between 10V and 15V, and the micro-nano robot is controlled to slowly approach the target particle 18 and move to a suitable position so that the target particle 18 is located in the middle of the micro-nano robot; in the third stage, for the hydrogel-based flexible hinge, a sound field with a frequency of 6.5kHz-20kHz and a voltage of 45V is applied, and for the resin-based flexible hinge, a sound field with a frequency of 18kHz-25kHz and a voltage of 45V is applied, so that the micro-nano robot deforms and clamps the target particle 18; after successfully capturing the target particle, while maintaining a high voltage, the frequency is adjusted within the sound field frequency range that the flexible hinge can deform until the bubble resonates, driving the particle to move at high speed.

[0046] Example 3

[0047] like Figure 9 As shown, this embodiment of a micro / nano robot based on a flexible hinge includes a bubble-capturing structure 8 and rigid winglets 19 symmetrically mounted on both sides of the bubble-capturing structure 8 with the axis of symmetry as the axis of symmetry. A unidirectional deformable flexible hinge 4 is also present. The rigid winglets 19 are trapezoidal and enhance the stability of the micro / nano robot's movement. A rigid connecting block is provided on the bubble-capturing structure 8. One end of the rigid winglet 19 is connected to the upper rigid connecting block of the bubble-capturing structure 8 via a flexible connecting section, which allows for bidirectional deformation. The flexible hinge includes three alternately connected flexible segments 2 and two rigid segments 1. The cross-section of the flexible segments 2 is an isosceles trapezoid, and the rigid segments 1 have protrusions for connecting to the waist of the isosceles trapezoid. The two flexible segments 2 at both ends are connected to the lower rigid connecting block of the bubble-capturing structure 8 and the tail of the rigid winglet 19, respectively. By controlling the deformation of the flexible segments 2, the angle between the rigid winglet 19 and the axis of the bubble-capturing structure 8 is changed, thereby altering the resistance of the micro / nano robot's movement in the liquid environment and achieving speed control of the micro / nano robot.

[0048] The driving method of the micro-nano robot in this embodiment is as follows: for hydrogel-based flexible hinges, a frequency of 6.5kHz-20kHz is applied, and for resin-based flexible hinges, a frequency of 18kHz-25kHz is applied to cause the flexible hinges to deform. By controlling the driving voltage to vary between 22.5V and 45V, the angle between the rigid wing 19 and the central axis of the bubble trapping structure 8 can be controlled to vary between 30° and 45°, generating different levels of resistance, thereby controlling the micro-nano robot to move at different speeds.

[0049] Example 4

[0050] like Figure 10 andFigure 11 As shown, the application also provides a preparation method of the micro-nano robot, provides a computer 9 and a light-curing 3D printer 10, the computer 9 is connected with the light-curing 3D printer 10 through a data line to realize file transmission, and the light-curing 3D printer 10 is controlled through the computer 9, and the method comprises the following steps:

[0051] Step 1: according to the structure design of the micro-nano robot, a modeling software in the computer 9 is used to establish a three-dimensional model of the micro-nano robot, and a model of a single micro-nano robot is used as a basis to generate a micro-nano robot array 11, a printing platform 12 is arranged below the micro-nano robot array 11, a water gap 13 is added on the array, and a three-dimensional model file is saved in a file format recognizable by slicing software.

[0052] Step 2: the three-dimensional model file is imported into the slicing software, and the modeling file is processed, for example, the printing position is adjusted, the defects of the modeling file are repaired, and the support part is added according to the structure of the micro-nano robot, and the like. After the file processing is completed, the slicing processing is performed to generate a printing file which can be recognized by the 3D printer.

[0053] Step 3: the printing file is opened in the light-curing 3D printer 10, and the printing parameters are set to ensure that different parts of the micro-nano robot have different mechanical properties and can realize the deformation function. The hardware part of the light-curing printer is checked and leveled to ensure that the precision of the printer can meet the needs of printing the micro-nano robot. The light-curing printing platform is installed in the printing liquid tank, the photosensitive material is added in the printing liquid tank, and the printing is started. The photosensitive material can be selected from light-curing resin and light-curing hydrogel, if the light-curing hydrogel is selected, the light-curing agent also needs to be added, for example, the light-curing agent Darocur 1173 needs to be added in a ratio of 5:1 to the hydrogel material PEGDA700 to ensure that the material can be successfully cured. In the printing process, the light-curing 3D printer 10 changes the light intensity and irradiation time of the curing light to make a material solidify into a structure with different mechanical properties, thereby realizing the deformable function. In order to obtain the expected flexible hinge, the irradiation time of the flexible section is less than that of the rigid section, and the specific parameter settings are as follows: the light intensity of the hydrogel material is set to 30 mw / cm 2 , the irradiation time of the flexible section is set to 50 ms-200 ms, and the irradiation time of the rigid section is set to 200 ms-300 ms; the light intensity of the resin material is set to 35 mw / cm 2 , the irradiation time of the flexible section is set to 500 ms-800 ms, and the irradiation time of the rigid section is set to 800 ms-1 s.

[0054] Step 4, after printing, the printing platform 12 is taken out of the light curing liquid tank, and the printing platform 12 is placed in a cleaning tank filled with cleaning reagent to wash off the light curing material remaining on the micro-nano robot array and the platform. In order to avoid the micro-nano robot from falling off the printing platform 12, the cleaning is gently stirred in the liquid. Different cleaning solvents are selected according to the type of light curing material. When the material is photosensitive resin, anhydrous ethanol is used for cleaning; when the material is hydrogel, isopropyl alcohol is used for cleaning.

[0055] Step 5, the cleaned printing platform is placed in pure water, a micro ultrasonic generator is placed close to the micro-nano robot array, and the generator is started to generate impact force. The ultrasonic waves generated can excite the jet flow in the liquid environment, and generate enough impact force to make the micro-nano robot fall off the platform, without causing damage to the structure of the robot.

Claims

1. A flexible-hinge-based micro / nano robot, characterized by, The flexible hinge includes several branches (17), the branch (17) includes a flexible section (2) in the middle, a rigid section (1) connected to both ends of the flexible section (2), the cross section of the flexible section (2) is isosceles trapezoidal, the flexible section (2) is controlled by the frequency of the sound field to deform to the lower base of the isosceles trapezoidal, and the rigid section (1) is provided with a protrusion for connecting with the waist of the isosceles trapezoidal; the number of bubble capturing structures (8) is equal to the number of branches; the bubble capturing structure (8) is provided with two rigid connecting blocks, the rigid section (1) is connected with the rigid connecting blocks through a flexible connecting section, each branch (17) is connected with one bubble capturing structure (8) at both ends, respectively, the bubble capturing structure (8) and the branch form a closed shape, when a certain sound field is applied, the flexible section (2) vibrates and deforms, the rigid section (1) does not deform, when the sound field stops being applied, the flexible section (2) restores the original shape; in a liquid environment, the bubble capturing structure (8) is used for capturing bubbles, the bubbles resonate in the sound field environment and drive the bubble capturing structure (8) to move; when the flexible section (2) deforms, the length of the branch (17) is shortened, and the bubble capturing structures (8) are close to each other to capture particles in the liquid. Or including a bubble capturing structure (8) and a rigid wing (19) and a flexible hinge symmetrically installed on both sides of the bubble capturing structure (8) with the axis of the bubble capturing structure (8) as the symmetry axis, one end of the rigid wing (19) is connected with the upper part of the bubble capturing structure (8) through a flexible connecting section, the flexible hinge includes three flexible sections (2) and two rigid sections (1) connected alternately, the cross section of the flexible section (2) is isosceles trapezoidal, the flexible section (2) is controlled by the frequency of the sound field to deform to the lower base of the isosceles trapezoidal, and the rigid section (1) is provided with a protrusion for connecting with the waist of the isosceles trapezoidal; the two flexible sections (2) at both ends are connected with the lower part of the bubble capturing structure (8) and the rigid wing (19), respectively; when a certain sound field is applied, the flexible section (2) vibrates and deforms, the rigid section (1) does not deform, when the sound field stops being applied, the flexible section (2) restores the original shape; in a liquid environment, the bubble capturing structure (8) is used for capturing bubbles, the bubbles resonate in the sound field environment and drive the bubble capturing structure (8) to move; by controlling the deformation of the flexible section (2), the angle between the rigid wing (19) and the axis of the bubble capturing structure (8) is changed, so that the resistance of the micro-nano robot moving in the liquid environment is changed, and the control of the moving speed of the micro-nano robot is realized.

2. The flexure-based micro / nano robot of claim 1, wherein, The flexible hinge is made of photocured hydrogel material, the rigidity of the flexible section (2) is smaller than that of the rigid section (1), and the rigidity of the rigid section (1) is 50-270 MPa.

3. The flexure-based micro / nano robot of claim 1, wherein, The flexible hinge is made of photocured resin, the elastic modulus of the rigid section (1) is 2300-2700 MPa, and the elastic modulus of the flexible section (2) is 1700-2100 MPa.

4. The flexure-based micro / nano robot of claim 1, wherein, The bubble trapping structure (8) comprises a hollow tube open at one end, a hydrophobic inner layer (5) arranged on the inner wall of the hollow tube, the hydrophobic inner layer (5) being used for trapping bubbles (6) in a liquid environment.

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