Chain cluster regulation and cargo transportation control method of magnetic-driven micro-nano robots in air environment

Abstract

The application relates to the technical field of micro-nano robots, in particular to a magnetic driving micro-nano robot chain cluster regulation and control method suitable for an air environment. The chain cluster regulation method is as follows: a rotating magnetic field is formed in a vertical plane by applying a vertical direction cosine alternating magnetic field and a horizontal direction sine alternating magnetic field, micro-nano robots are gradually assembled into a long chain cluster, and the length of the chain cluster can be dynamically regulated by adjusting an initial mass, a magnetic field frequency and a strength. The cargo transportation control method is as follows: a magnetic field formed by superimposing an xoy plane fan-shaped oscillating magnetic field and an alternating reverse z-direction direct-current magnetic field is applied, so that the chain cluster body swings in a conical surface and moves forward alternately, a propelling force is applied to the cargo, and therefore controllable transportation and displacement of the cargo are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-nano robots, in particular to a chain cluster regulation and control method of magnetic micro-nano robots in air environment. BACKGROUND

[0002] Micro-nano robots are micro-nano actuators that can achieve precise motion and various complex manipulation tasks in narrow spaces. Among the various driving modes of micro-nano robots, magnetic field driving has become a popular choice among researchers due to its remote maneuverability, flexible control, biocompatibility, and strong driving ability. With the rapid development of micro-nano robot technology, single magnetic micro-nano robots are limited by size, structure, and other factors, and have limited motion and control capabilities, as well as poor propulsion, which cannot continue to meet the needs of various application scenarios. Therefore, researchers have proposed a cluster coordination strategy and designed various magnetic micro-nano robot clusters, which have stronger motion ability and propulsion, as well as the unique feature of adaptive regulation of cluster size, enabling more complex multi-modal collaborative operation tasks.

[0003] Currently, magnetic micro-nano robot clusters are limited by material performance, driving mechanism, and environmental adaptability, and their research scope is still mainly limited to controllable driving in liquid media. In existing technologies, most micro-nano robot clusters rely on van der Waals force, electrostatic force, and hydrophobic / hydrophilic interaction between their surfaces and goods for loading and transporting goods. The above methods are difficult to function without the assistance of liquid media, and have limited loading capacity and poor stability. Therefore, the present application successfully develops a magnetic micro-nano robot chain cluster that can move in air environment and achieve flexible regulation of cluster size, and proposes a "swing-like gait" control method for transporting goods. This method enables the magnetic micro-nano robot chain cluster to achieve flexible propulsion of goods, fully utilizes its structural advantage of high thrust-to-weight ratio, and has broad application potential in human respiratory tract foreign body removal and other complex scenarios that require operation in air environment. SUMMARY

[0004] The present application aims to provide a chain cluster regulation method based on magnetic micro-nano robots in air environment, which can achieve reconfigurable dynamic regulation of the cluster size of magnetic micro-nano robot chain clusters. Further, a "swing-like gait" control method for transporting goods is proposed, which can drive the chain cluster to complete the flexible propulsion of goods simultaneously during the marching process.

[0005] The present application achieves the above-mentioned purpose through the following technical solutions:

[0006] A chain cluster regulation method based on magnetic micro-nano robots in air environment, comprising the following steps:

[0007] S1: applying a vertical direction cosine alternating magnetic field in an air environment, so that the micro-nano robots preliminarily cluster along the vertical direction under the action of the magnetic field, and form multiple short-chain cluster bodies;

[0008] S2: continue to apply a horizontal direction sine alternating magnetic field, which is superimposed with the vertical direction cosine alternating magnetic field in step S1, to form a rotating magnetic field in the vertical plane;

[0009] S3: under the action of the rotating magnetic field, the short-chain cluster bodies of the micro-nano robots roll along the horizontal direction, and gradually assemble into long-chain cluster bodies in the rolling process;

[0010] S4: by adjusting the total mass of the initial micro-nano robots, the frequency and the magnetic field strength of the rotating magnetic field, the length of the magnetic-driven micro-nano robot chain cluster body is dynamically controlled, so as to flexibly adapt to different scales of the working space.

[0011] Further, the alternating magnetic field used in S1-S4 is generated by passing a positive and negative sine alternating voltage signal output by a signal control box into a three-dimensional Helmholtz coil.

[0012] Further, the control box is powered by 220V alternating current, and through internal power conversion components, control components and drive components, it can output positive and negative sine alternating voltage signals and direct current voltage signals with a frequency of 0-500Hz continuously adjustable and a voltage amplitude of 0-44V continuously adjustable, and is connected with the three-dimensional Helmholtz coil through a specific interface, so as to realize accurate control of magnetic field frequency and magnetic field strength and other magnetic field characteristic parameters. The power conversion component is a switching power supply and a voltage stabilizing module; the control component is a Stm32 single-chip microcomputer, a PS2 handle and a handle signal receiver; and the drive component is a motor drive board, i.e. a servo driver.

[0013] Further, the magnetic micro-nano robot is a large-particle-size ferroferric oxide particle with a size of 10-30μm, which is mostly a polyhedral structure with extremely irregular shape.

[0014] A "swing type imitated gait" cargo transportation control method of a magnetic-driven micro-nano robot chain cluster body in an air environment. Under this control method, the micro-nano robot chain cluster body always maintains a local "point contact" state between one of the two end heads and the base during the marching process, and makes the whole chain cluster body realize left and right alternating swing in a conical surface. When the swing direction is switched, the chain cluster body synchronously switches the end part in contact with the base, so as to continuously advance while swinging left and right, forming a "swing type imitated gait" movement mode. Further, during the swinging process of the chain cluster body, an effective pushing force can be applied to the surrounding cargo, so as to realize controllable transportation and displacement of the cargo.

[0015] Further, the magnetic field working mode of the regulation method is a fan-shaped oscillating magnetic field component in the xoy plane superimposed with a z-direction direct current magnetic field component ; wherein, is used for driving the chain-shaped cluster to realize left-right alternate swinging, is used for lifting one end of the chain-shaped cluster and realizing the switching of the contact end of the chain-shaped cluster with the base by changing the direction when swinging to the limit position in a single direction.

[0016] Further, the fan-shaped oscillating magnetic field component in the xoy plane is formed by superimposing an x-direction cosine alternating magnetic field and a y-direction sine alternating magnetic field; in a complete swinging period, the swinging direction of the chain-shaped cluster is switched by adjusting the angular frequency and phase component of the x-direction and y-direction alternating magnetic fields when swinging to the limit position in a single direction.

[0017] Further, by adjusting the field strength ratio of the fan-shaped oscillating magnetic field component in the xoy plane and the z-direction direct current magnetic field component , the pitch angle between the chain-shaped cluster and the horizontal plane can be controlled; the advancing direction of the chain-shaped cluster and the maximum swinging amplitude are jointly determined by the phase component of the x-direction and y-direction alternating magnetic fields; by adjusting the pitch angle between the chain-shaped cluster and the horizontal plane, the length of the chain-shaped cluster can also be regulated to adapt to different scales of working space.

[0018] A method for removing respiratory tract foreign matter by a chain-shaped cluster, comprising the following steps:

[0019] S1: Releasing the magnetic micro-nano robot to the main trunk area of the simulated tracheal channel through a bronchoscope;

[0020] S2: Applying a rotating magnetic field to make the magnetic micro-nano robot cluster into a chain-shaped cluster and move to the target branch blind end area where the glass beads are located;

[0021] S3: After the chain-shaped cluster reaches the target area, switching the rotating magnetic field to a "swinging type of imitated gait" magnetic field mode and controlling the chain-shaped cluster to return along the original path;

[0022] S4: During the returning process, the chain-shaped cluster synchronously pushes the glass beads to move to the main trunk area, and finally removes the foreign matter from the branch area, thereby realizing the removal of the simulated respiratory tract foreign matter.

[0023] The beneficial effects of the present application are:

[0024] ​A magnetic-driven micro / nano robot chain cluster capable of stable assembly and controllable movement in air environment is developed by applying a combined magnetic field in air environment, and a flexible regulation method for the cluster size of the chain cluster is proposed. Meanwhile, a "swing type imitated gait" cargo transportation control method based on the magnetic-driven micro / nano robot chain cluster is proposed, which can realize the synchronous pushing transportation of cargo during the movement of the chain cluster, and adapt to the cargo transportation demand in different scale workspaces. Compared with the traditional micro / nano robot cluster, the present application overcomes the technical bottlenecks of the existing micro / nano robot cluster, such as high dependence on liquid medium, limited cargo transportation capacity and difficulty in realizing stable movement and control in air environment, and shows excellent application prospect and practical value in the removal of foreign bodies in human respiratory tract and other complex scenarios requiring operation in air environment. BRIEF DESCRIPTION OF DRAWINGS

[0025] The present application will be further described in detail below in combination with the drawings and specific implementation methods.

[0026] Figure 1 An overall schematic diagram of the micro / nano robot cluster into a chain cluster in air environment and transporting cargo;

[0027] Figure 2 A scanning electron microscope image of the micro / nano robot and its hysteresis loop diagram;

[0028] Figure 3 A schematic diagram of the micro / nano robot cluster into a chain cluster in air environment and its time sequence snapshot diagram;

[0029] Figure 4 A data diagram of the length change of the chain cluster of the micro / nano robot under different mass and magnetic field parameters;

[0030] Figure 5 A schematic diagram of the "swing type imitated gait" movement mode of the magnetic-driven micro / nano robot chain cluster along the positive x direction and its magnetic field working mechanism and a time sequence snapshot diagram;

[0031] Figure 6 A pitch angle schematic diagram of the magnetic-driven micro / nano robot chain cluster and a data diagram of the length change of the cluster under different pitch angle conditions;

[0032] Figure 7 A time sequence snapshot diagram of the cargo transportation trajectory of the magnetic-driven micro / nano robot chain cluster and a mechanical analysis diagram between the cargo and the cluster;

[0033] Figure 8 A time sequence snapshot diagram of the flexibility verification of the cargo transportation of the magnetic-driven micro / nano robot chain cluster and a time sequence snapshot diagram of the transportation capacity verification of the chain cluster in a narrow pipeline;

[0034] Figure 9A time sequence snapshot of the magnetic-driven micro-nano robot chain cluster body removing foreign matter in a simulated tracheal channel. DETAILED DESCRIPTION

[0035] The application will be further described in detail below with reference to the accompanying drawings.

[0036] The scanning electron microscope image of the magnetic micro-nano robot is as shown in the figure. Figure 2 A to Figure 2 As shown in B, it is a ferroferric oxide particle with an irregular polyhedral structure, and the particle size is in the range of 10-30 μm. Figure 2 As can be seen from C, it has a high saturation magnetization of 64.09 emu / g, showing excellent magnetic performance. Since the application does not involve the shape effect analysis of the magnetic micro-nano robot, the specific shape is not the focus of the application. In order to intuitively indicate the magnetic micro-nano robot in the chain cluster regulation and cargo transportation control method, all schematic diagrams in the specification are directly indicated by the spherical structure.

[0037] As shown in the figure, Figure 1 The application successfully realizes the assembly of the chain cluster of the magnetic micro-nano robot by applying a rotating magnetic field in the vertical plane in the air environment. Further, for the chain cluster, a "swing type emulating gait" cargo transportation control method is proposed, which synchronously applies a pushing force to the front cargo during the marching process, so as to realize the flexible transportation of the cargo.

[0038] A kind of chain cluster regulation method based on magnetic micro-nano robot in air environment is described in detail:

[0039] As shown in the figure, Figure 3 First, a cosine alternating voltage signal is applied to the z-direction coil of the three-dimensional Helmholtz coil device to generate a cosine alternating magnetic field in the vertical direction, and the magnetic micro-nano robot is driven to be affected by the magnetic dipole interaction force in the air environment along the vertical direction to preliminarily cluster, forming multiple short chain cluster bodies. Subsequently, a sine alternating voltage signal is applied to the x-direction coil to further generate a sine alternating magnetic field in the horizontal direction, which is coupled with the z-direction magnetic field to form a rotating magnetic field rotating clockwise in the vertical plane. Under the action of the rotating magnetic field, the short chain cluster body is driven to roll along the horizontal direction by the magnetic torque, and gradually assembles into a long chain cluster body during the marching process due to the magnetic mutual attraction force between them, until the cluster size tends to be stable.

[0040] Further, the length of the chain cluster body is controlled by changing the initial mass m of the magnetic micro-nano robot and the frequency f and field strength B of the rotating magnetic field to flexibly adapt to different scales of the working space.

[0041] As shown in the figure, Figure 4As shown in A, under the condition of magnetic field strength B = 15 mT, frequency f = 1 Hz, the average length of the chain-like cluster increases with the increase of the initial mass m of the magnetic micro-nano robot. As the curve tends to be flat, it can be seen that the effect of the initial mass m on the length of the cluster gradually weakens. This is due to the limitation of the rotating magnetic field strength B and the frequency f on the assembly ability of the cluster, so that the cluster ability of the magnetic micro-nano robot in a certain cluster area tends to be saturated.

[0042] As shown in Figure 4 As shown in B, under the condition of magnetic field strength B = 15 mT, initial mass m = 3 mg, the average length of the chain-like cluster decreases with the increase of the rotating magnetic field frequency f. At an extremely low magnetic field frequency of 0.1 Hz, the average length of the chain-like cluster can reach 4.31 mm, while at 60 Hz it is only 1.04 mm. This phenomenon is due to the fact that the centrifugal force between the magnetic micro-nano robots is intensified at high frequency, resulting in a decrease in the stability of the original long chain structure, separation and shortening.

[0043] As shown in Figure 4 As shown in C, under the condition of magnetic field frequency f = 1 Hz, initial mass m = 3 mg, the average length of the chain-like cluster increases with the increase of the rotating magnetic field strength B. This is because the high magnetic field strength enhances the magnetic mutual attraction between short chains, promoting their assembly into long chain structures.

[0044] Further, a "swing type imitative gait" cargo transportation control method based on a chain-like cluster of magnetic driving micro-nano robots is described in detail:

[0045] Taking the case where the chain-like cluster of magnetic driving micro-nano robots travels in the positive x direction as an example, combined with Figure 5 The control method is described. As shown in Figure 5 B and Figure 5 C, the magnetic field mode of the control method is formed by superimposing the fan-shaped oscillating magnetic field component in the xoy plane and the direct current magnetic field component in the z direction. Specifically, the motion behavior of the chain-like cluster traveling in the positive x direction and the magnetic field working mechanism under the control method can be decomposed into the following steps:

[0046] S1: In the initial state, the fan-shaped oscillating magnetic field component in the xoy plane and the direct current magnetic field component in the z direction together constitute a diagonal magnetic field total vector in the three-dimensional Cartesian coordinate system. The chain-like cluster is tilted at one end under the action of the magnetic torque and tends to align with the direction of the magnetic field total vector. Subsequently, It rotates counterclockwise around the origin, making the chain-like cluster swing counterclockwise around the contact point between it and the base in a conical surface, corresponding to steps ① and ② in the figure;

[0047] S2: After the chain-like cluster swings counterclockwise to its extreme position, control the z-axis DC magnetic field component. The instantaneous reversal causes the contact end with the substrate to switch under the action of instantaneous magnetic torque. Due to the change in the landing point, the chain-like cluster moves forward as a whole, corresponding to step ③ in the figure;

[0048] S3: Control The rotation direction changes from counterclockwise to clockwise, and the chain cluster continues to swing clockwise around its contact point with the base under the action of magnetic torque, corresponding to steps ④ and ⑤ in the figure.

[0049] S4: After the chain-like cluster swings clockwise to its extreme position, control the z-axis DC magnetic field component. Instantaneous reversal achieves the switching of the contact end between the cluster body and the substrate, corresponding to step ⑥ in the diagram. Simultaneously, The rotation direction is switched again, and the above cycle is repeated.

[0050] Because the chain-like aggregate continuously oscillates in a conical motion during movement, maintaining an inclined posture with one end raised and the other in contact with the base, and the switching pattern of its contact ends is similar to the alternating process of human walking, the control method is called the "oscillating gait-mimicking" cargo transportation control method. Figure 5 As shown in Figure A.

[0051] like Figure 5 As shown in Figure B, the magnetic field components are defined. Let the angle between its rotational limit position and the center line of its fan-shaped oscillation region be the swing angle α. Then, the maximum swing angle of the chain-like cluster in the same direction in a single swing is 2α. Further, define... The angle between the centerline of the sector-shaped oscillation region and the positive x-axis is the travel angle θ, which determines the travel direction of the chain-like cluster. Figure 5 Taking the case shown as an example, when the travel angle θ = 3π / 2, the chain-like cluster moves along the positive x-direction, meaning that the angle between its travel direction and the positive x-axis always has a phase difference of 3π / 2 from the travel angle θ. The magnetic field working mechanism of the control method can be expressed in the following mathematical form:

[0052]

[0053] Where T is the time it takes for the chain-like cluster to complete one complete oscillation, i.e., the oscillation period; t is the working time of the magnetic field; B xy The xoy plane sector-shaped oscillating magnetic field component magnetic field strength mode, B z Z-direction DC magnetic field component The magnetic field strength modulus; f is The rotational frequency of the magnetic field is B, which is the magnetic field frequency; B is the total magnetic field vector. The magnetic field strength modulus, i.e., the magnetic field strength; and These represent unit vectors in the positive x, y, and z directions, respectively. Alternating magnetic field from x to cosine With the y-direction sinusoidal alternating magnetic field This is achieved through superposition, by adjusting the angular frequency and phase components of the alternating magnetic fields in the x and y directions. This can be achieved Switching the direction of rotation. Further, by adjusting... The value of the travel angle θ can be used to flexibly change the travel direction of the chain-like cluster.

[0054] In addition, the total magnetic field vector is defined. The angle between the xoy plane and the xoy plane is the pitch angle β, such as Figure 6 As shown in Figure A. Experimental results show that the length of the chain-like cluster can be controlled by adjusting the pitch angle β to adapt to workspaces of different scales. For example... Figure 6 As shown in Figure B, under the conditions of initial mass m = 3 mg, magnetic field strength B = 15 mT, magnetic field frequency f = 1 Hz, and swing angle α = 45°, the average length of the chain-like cluster decreases with the increase of pitch angle β. This may be because the increase of pitch angle β leads to an increase in the instantaneous angular acceleration of the chain-like cluster during the switching process at the end in contact with the substrate, which intensifies the instantaneous centrifugal force between the micro-nano robots, destroys the stability of the originally long chain structure, and causes it to separate and shorten.

[0055] Furthermore, the chain-like aggregate can exert an effective pushing force on surrounding goods during its oscillation, thereby achieving controllable transport and displacement of the goods. Using 1mm diameter glass beads as the goods, the pushing and transporting effect of the chain-like aggregate on the goods is analyzed. Figure 7 The experimental results for A show that the trajectory of the glass beads propelled by the chain-like aggregate is wavy, not straight. This is because the chain-like aggregate exerts a pushing force on the glass beads during its oscillation, and the direction of its oscillation continuously changes. Figure 7 As shown in Figure B, the forces acting on the glass bead include the normal impact force Fn and the tangential force Ft exerted by the chain-like cluster, the frictional force Ff and the supporting force Fs provided by the substrate, and gravity G. Simultaneously, the tangential force also generates a tangential torque M relative to the center of mass of the glass bead, driving it to rotate.

[0056] The flexibility of cargo transportation in chain-like clusters was verified. For example... Figure 8 As shown in Figure A, the chain-like aggregate can transport glass beads with a diameter of 1 mm from the starting area in the lower left corner of the maze passage to the target area in the lower right corner in a short time, and has the ability to perform cargo transportation along paths such as "direct turns" and "continuous U-shaped turns". Furthermore, the cargo transportation capability of the chain-like aggregate in extremely narrow passages is verified.Figure 8 As shown in FIG. 8B, under the specific parameter conditions of magnetic field strength B = 12 mT, magnetic field frequency f = 0.4 Hz, swing angle a = 69°, and pitch angle b = 12°, the chain-like cluster can effectively transport glass beads with a diameter of 1 mm in a pipeline with a diameter of 3 mm.

[0057] Further, the ability of the chain-like cluster to remove foreign matter in a simulated airway passage was verified, as shown in FIG. 8C. Figure 9 The foreign matter was a glass bead with a diameter of 1 mm, and the simulated airway passage was a 3D printed model constructed based on human segmental bronchial CT scan data. To ensure the experimental effect, the outlets of the passage were closed. Specifically, the method for removing respiratory tract foreign matter by the chain-like cluster included the following steps:

[0058] S1: releasing the magnetic micro-nano robot into the main stem region of the simulated airway passage through a bronchoscope;

[0059] S2: applying a rotating magnetic field to make the magnetic micro-nano robot cluster into a chain-like cluster and move to the target blind end region of the glass bead;

[0060] S3: after the chain-like cluster reaches the target region, switching the rotating magnetic field to a "swing-like gait" magnetic field mode and controlling the chain-like cluster to return along the original path;

[0061] S4: during the return process, the chain-like cluster synchronously pushes the glass bead to move towards the main stem region, finally removing the foreign matter from the branch region, and achieving the removal of the simulated respiratory tract foreign matter.

[0062] Among them, step S2 adopts a rotating magnetic field instead of a "swing-like gait" magnetic field mode, because the disturbance of the chain-like cluster to the glass bead is minimal under the rotating magnetic field, which can effectively prevent the glass bead from being pushed deeper into the blind end, thereby ensuring the smooth removal of the glass bead subsequently.

[0063] In summary, the present application develops a magnetic-driven micro-nano robot chain-like cluster suitable for air environment, and further proposes a cluster size regulation method and a "swing-like gait" cargo transportation control method for the cluster. Among them, the "swing-like gait" cargo transportation control method can make the chain-like cluster synchronously push the target cargo during the marching process, thereby realizing the controllable transportation of the cargo. In addition, by adjusting the initial total mass m of the micro-nano robot, the magnetic field frequency f, the magnetic field strength B, and the pitch angle b, not only the dynamic regulation of the length of the chain-like cluster can be realized, but also the contact effect between the chain-like cluster and the cargo can be adjusted, thereby adapting to the cargo transportation demand in different scale spaces. The present application has broad application prospects in the removal of human respiratory tract foreign matter and other complex scenarios requiring operation in air environment.

Claims

1. A method for controlling cargo transportation of a magnetically driven micro / nano robot in an air environment, characterized in that, The motion behavior of the chain-like cluster body moving along the positive x direction under the control method and the corresponding magnetic field working mechanism include the following steps: S1: in the initial state, the xoy plane sector oscillation magnetic field component and the z direction DC magnetic field component together constitute the oblique magnetic field total vector in the three-dimensional Cartesian coordinate system , the chain cluster body is warped at one end under the action of the magnetic torque and tends to align with the direction of the total magnetic field vector; subsequently, rotate counterclockwise around the origin, so that the chain cluster body swings counterclockwise around the contact point of the base in a conical surface; S2: when the chain cluster swings to the limit position in the counterclockwise direction, control the z-direction DC magnetic field component Instantaneous reversal, which switches the contact end with the base under the action of instantaneous magnetic torque; due to the change of landing position, the chain cluster as a whole realizes forward movement; S3: control The rotation direction of the chain-like cluster is switched from counterclockwise to clockwise, and the chain-like cluster continues to swing clockwise around the contact point with the base under the action of the magnetic torque. S4: When the chain cluster body swings clockwise to the limit position, control the z-direction DC magnetic field component Instantaneous reverse, realize the switching of the contact end of the cluster body and the base, The rotation direction is switched again, and the steps S1 to S4 are repeated to circulate the process. 2.The cargo transportation control method of the magnetic-driven micro-nano robot in air environment according to claim 1, characterized in that: During the swinging process of the chain-like cluster body, an effective pushing force is applied to the surrounding goods to achieve controllable transportation and displacement of the goods. 3.The cargo transportation control method of the magnetic-driven micro-nano robot in air environment according to claim 1, characterized in that: xoy plane sectorial oscillating magnetic field component Formed by superimposition of x-direction cosine alternating magnetic field and y-direction sine alternating magnetic field; in a complete oscillation period, the switching of the oscillation direction of the chain cluster body is realized by adjusting the angular frequency and phase component of the x-direction and y-direction alternating magnetic field when oscillating to the limit position in the same direction for a single time. 4.The cargo transportation control method of the magnetic-driven micro-nano robot in air environment according to claim 1, characterized in that: By adjusting the field strength ratio of the xoy plane sectorial oscillating magnetic field component to the z-direction direct current magnetic field component , the pitch angle between the chain-like cluster and the horizontal plane can be controlled; the traveling direction of the chain-like cluster and the maximum swing amplitude are jointly determined by the phase components of the x-direction and y-direction alternating magnetic fields.

5. The cargo transportation control method of the magnetic-driven micro-nano robot in air environment according to claim 4, characterized in that: By adjusting the pitch angle between the chain-like cluster body and the horizontal plane, the length of the chain-like cluster body can also be controlled to adapt to different scales of the working space. 6.A method for regulating a chain-like cluster of magnetic micro / nano robots in an air environment, characterized in that, The goods transportation control method for the magnetic-driven micro-nano robot in the air environment of claim 1 comprises the following steps: S1: In the air environment, a vertical direction cosine alternating magnetic field is applied to make the micro-nano robot preliminarily cluster in the vertical direction under the action of the magnetic field, forming multiple short chain-like cluster bodies; S2: Continue to apply a horizontal direction sine alternating magnetic field, which is superimposed with the vertical direction cosine alternating magnetic field in step S1, to form a rotating magnetic field in the vertical plane; S3: Under the action of the rotating magnetic field, the short chain-like cluster body of the micro-nano robot rolls along the horizontal direction, and gradually assembles into a long chain-like cluster body during the rolling process; S4: By adjusting the total mass of the initial micro-nano robot, the frequency and the magnetic field strength of the rotating magnetic field, the length of the magnetic-driven micro-nano robot chain-like cluster body is dynamically controlled, so as to flexibly adapt to different scales of the working space; In the chain-like cluster control method based on the magnetic micro-nano robot in the air environment, the alternating magnetic field used in S1-S4 is generated by passing a positive sine alternating voltage signal output by a signal control box into a three-dimensional Helmholtz coil; The control box is powered by 220V alternating current, and through internal power conversion components, control components and drive components, it can output positive sine alternating voltage signals and direct current voltage signals with continuously adjustable frequency in the range of 0 to 500 Hz and continuously adjustable voltage amplitude in the range of 0 to 44 V, and through a specific interface, it is connected with the three-dimensional Helmholtz coil to realize accurate control of magnetic field characteristics such as magnetic field frequency and magnetic field strength; The magnetic micro-nano robot is a large-particle-size ferroferric oxide particle in the range of 10μm-30μm, mostly irregular polyhedral structure.

7. A method of removing respiratory tract foreign bodies by a chain cluster, characterized in that, The method comprises the following steps: S1: Release the magnetic micro-nano robot to the main trunk area of the simulated airway channel through a bronchoscope; S2: Apply a rotating magnetic field to make the magnetic micro-nano robot cluster into a chain-like cluster body and move to the target branch blind end area where the glass beads are located; S3: After the chain-like cluster body reaches the target area, switch the rotating magnetic field to a "swing type imitated gait" magnetic field mode and control the chain-like cluster body to return along the original path; apply the goods transportation control method of the magnetic-driven micro-nano robot in the air environment of claim 1; S4: During the return process, the chain-like cluster body synchronously pushes the glass beads to move to the main trunk area, finally removes the foreign matter from the branch area, and realizes the removal of the simulated respiratory tract foreign matter.

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