A micro robot and its control method

Abstract

The present invention provides a microrobot and a control method thereof, which relates to the technical field of medical devices. The microrobot comprises a microrobot body and an in vitro control system connected to the microrobot body by signal; the magnetization direction of the microrobot body has an angle α with the radial direction; the angle α is an acute angle; the in vitro control system controls the operation of the microrobot body through a magnetic field. The microrobot provided by the present invention can generate a partial magnetic moment in the forward direction by obliquely magnetizing the microrobot body so that the microrobot body has a magnetization direction with an oblique angle, thereby significantly improving the reaction force of the fluid and increasing the propulsion force of the microrobot body, which is beneficial to improving the movement efficiency of the microrobot and expanding its application range.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a micro robot and a control method thereof. Background Art

[0002] Due to the development demand of precision treatment in the medical field, more and more micro-robots are being developed to achieve precision treatment. Micro-robots, whose scale is generally between microns and millimeters, can achieve a certain degree of complexity of movement, so they can complete the required medical actions in the inner cavity of the human body, such as targeted drug delivery and minimally invasive treatment. Even for smaller-scale micro-robots, micro-assembly operations at the cellular scale can be completed, such as artificial insemination and targeted treatment of cancer cells. The current driving modes of micro-robots are electric field drive, light drive and magnetic field drive. Among them, because the magnetic field is biocompatible, it can penetrate biological tissues and is harmless to human tissues; and the magnetic response process is rapid, and it can quickly generate force and torque, so magnetic field drive is widely used in existing technologies.

[0003] The structural morphology of magnetically driven microrobots varies greatly depending on the application scenario. For magnetically driven microrobots used in minimally invasive interventional atherectomy, when moving in microchannels in a biological body that can be regarded as a low Reynolds number environment, the viscous force on the microrobot is much greater than the inertial force and dominates. Compared with microrobots of other appearance forms, spiral magnetically driven microrobots can provide more sufficient propulsion force and are easier to overcome the resistance in the liquid environment to move and complete the corresponding work. In recent years, many researchers have studied the various mechanisms of spiral microrobots to generate rotational motion and proposed a variety of structural designs for the treatment of vascular diseases. However, the magnetization direction of the existing magnetically driven microrobot is parallel to the magnetic field rotation plane of the magnetic control system. The power of the magnetically driven robot is directly derived from the reaction force of the fluid. The control process is complicated and the motion efficiency is low, which limits the application of microrobots in the medical field. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in order to solve the problem of slow movement of micro-robots in the prior art, the present invention provides a micro-robot, which greatly improves the movement speed of the micro-robot body by obliquely magnetizing the micro-robot body so that it has an oblique magnetization direction, thereby solving the problem of slow movement of micro-robots in the prior art. The technical solution adopted by the present invention to solve its technical problem is:

[0005] A micro-robot, comprising a micro-robot body, and an in vitro control system connected to the micro-robot body by signals;

[0006] There is an angle α between the magnetization direction of the micro robot body and the radial direction;

[0007] The angle α is an acute angle;

[0008] The in vitro control system controls the operation of the micro-robot body by applying an external rotating magnetic field along the axis of the micro-robot body.

[0009] Optionally, the angle α has a value range of: 0°<α≤45°.

[0010] Optionally, the angle α has a value range of: 15°≤α≤45°.

[0011] Optionally, the microrobot body is obtained by 3D printing using a photocurable resin doped with magnetic powder.

[0012] Another object of the present invention is to provide a control method for the microrobot as described above, comprising the following steps:

[0013] S1: The microrobot body is magnetized obliquely, and the angle α between the magnetization direction and the radial direction;

[0014] S2: Using a magnetic field to control the operation of the microrobot body through an in vitro control system; the direction of the magnetic field is the same as the axial direction of the microrobot body.

[0015] Optionally, obliquely magnetizing the microrobot body includes: placing the microrobot body on a magnetizing platform, and magnetizing the microrobot body on the magnetizing platform using a magnetizer.

[0016] Optionally, the magnetization platform includes at least one inclined support plate and a clamp matched with the support plate; the support plate and the clamp together form a plurality of mounting grooves suitable for placing the micro robot body.

[0017] Optionally, the angle between the direction of the magnetic field generated by the magnetizer and the support plate is an acute angle.

[0018] Optionally, the extracorporeal control system comprises three pairs of orthogonally placed Helmholtz coils.

[0019] Optionally, the magnetic field strength of each pair of Helmholtz coils in the middle area is not less than 8 mT.

[0020] The beneficial effects of the present invention are:

[0021] The microrobot provided by the present invention can generate a partial magnetic moment in the forward direction by obliquely magnetizing the microrobot body so that it has a magnetization direction with an oblique angle, thereby significantly improving the reaction force of the fluid and increasing the propulsion force of the microrobot body, which is beneficial to improving the movement efficiency of the microrobot; at the same time, by setting different magnetization directions, the coupling of the microrobot's pulverization function module and the magnetic drive module is realized, so that the dirt or biofilm in the pipeline can be effectively removed, and the space occupied by the permanent magnet in the traditional magnetic microrobot is saved, which helps to reduce the size and movement time of the microrobot; in addition, by controlling the magnetic field strength, the travel speed and pulverization intensity of the microrobot can be adjusted at the same time to meet different application requirements and expand its application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0023] Figure 1 It is a simplified structural diagram of the micro robot body in the present invention;

[0024] Figure 2 is a simulation schematic diagram of a three-dimensional Helmholtz coil system in the present invention;

[0025] Figure 3 is a schematic structural diagram of a three-dimensional Helmholtz coil system in the present invention;

[0026] Figure 4 It is a schematic diagram of the assembly of the magnetization platform in the present invention;

[0027] Figure 5 This is a physical picture of the magnetization platform in the present invention;

[0028] Figure 6 This is a physical diagram of the magnetization instrument in the present invention;

[0029] Figure 7 This is a schematic diagram of the oblique magnetization principle of the micro robot body in the present invention;

[0030] Figure 8 Schematic diagram of a magnetic field in which the angle α between the magnetization direction and the radial direction of the microrobot body of the present invention is 45°;

[0031] Fig. 9 Schematic diagram of a magnetic field in which the angle α between the magnetization direction and the radial direction of the microrobot body of the present invention is 30°;

[0032] Fig.10 is a schematic diagram of a magnetic field in which the angle α between the magnetization direction and the radial direction of the microrobot body of the present invention is 15°;

[0033] Fig.11 is a schematic diagram of a magnetic field in which the angle α between the magnetization direction and the radial direction of the microrobot body of the present invention is 0°;

[0034] Fig.12 It is a schematic diagram of the magnetic control method of the micro robot body in the present invention;

[0035] Fig.13 It is a 2D schematic diagram of the force analysis of the micro robot body in the present invention;

[0036] Fig.14 It is a 3D schematic diagram of the force analysis of the micro robot body in the present invention;

[0037] Fig.15 It is a schematic diagram of force analysis of the speed enhancement principle of the micro robot body in the present invention;

[0038] Fig.16 It is a schematic diagram summarizing the movement speed of a micro robot body with a diameter of 4 mm in the present invention in a 5 mm pipe under the action of different gradient magnetic fields and α of 0°-75°;

[0039] Fig.17 This is a schematic diagram of the movement of a micro robot body with a diameter of 4 mm in the present invention in a 5 mm pipe under the action of a magnetic field with an α of 45°;

[0040] Fig.18 This is a schematic diagram of the movement of a micro robot body with a diameter of 4 mm in the present invention in a 5 mm pipe under the action of a magnetic field with an α of 30°;

[0041] Fig.19 This is a schematic diagram of the movement of a micro robot body with a diameter of 4 mm in the present invention in a 5 mm pipe under the action of a magnetic field with an α of 15°;

[0042] Fig. 20 This is a schematic diagram of the movement of a micro robot body with a diameter of 4 mm in the present invention in a 5 mm pipe under the action of a magnetic field with an α of 0°;

[0043] Fig.21 It is a schematic diagram summarizing the movement speed of a micro robot body with a diameter of 4 mm in the present invention in a 5 mm pipe under the action of a magnetic field with an α of 0°-45°;

[0044] Fig. 22 It is a schematic diagram summarizing the movement speed of a micro robot body with a diameter of 3 mm in the present invention in a 4 mm pipe under the action of different gradient magnetic fields and when α is 0°-75°;

[0045] Fig.23 It is a schematic diagram summarizing the movement speed of a micro robot body with a diameter of 5 mm in the present invention in a 6 mm pipe when α is 0°-75° and under the action of different gradient magnetic fields.

[0046] In the figure: 1-head; 2-body; 3-tail. DETAILED DESCRIPTION

[0047] The present invention is now further described in detail. The embodiments described below are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0049] In order to solve the problem of slow movement of a microrobot in the prior art, the present invention provides a microrobot, which includes a microrobot body and an in vitro control system connected to the microrobot body by signal; wherein the magnetization direction of the microrobot body has an angle α with the radial direction; it should be noted that the radial direction here refers to the radial direction of the microrobot body, that is, the direction perpendicular to the axis of the microrobot body; and the angle α is an acute angle; at this time, the angle between the magnetization direction and the axis of the microrobot body is 90°-α; the in vitro control system controls the operation of the microrobot body by applying an external rotating uniform magnetic field along the axis of the microrobot body, so that the magnetization direction of the microrobot is not parallel to the magnetic field rotation plane of the magnetic control system, thereby generating a partial magnetic moment in the forward direction of the microrobot body, significantly improving the reaction force of the fluid and increasing the propulsion force of the microrobot body.

[0050] Existing spiral magnetically driven microrobots usually consist of two parts: a spiral and a permanent magnet. The permanent magnet is usually a cylindrical permanent magnet or an annular permanent magnet, which is embedded in the center of the spiral. The magnetization plane of the embedded permanent magnet is parallel to the axial direction of the spiral, that is, the magnetic moment direction of the permanent magnet (the normal to the magnetization plane) is parallel to the magnetic field rotation direction of the external magnetic control system, and is driven by an external biaxial rotating magnetic field to achieve rotational motion and forward motion. In other words, the magnetization direction of the existing magnetically driven microrobot is parallel to the magnetic field rotation plane of the magnetic control system, and the forward power of the magnetically driven robot is directly derived from the reaction force of the fluid. The control process is complicated and the motion efficiency is low, which limits the application of microrobots in the medical field.

[0051] The microrobot provided by the present invention can generate a partial magnetic moment in the forward direction by obliquely magnetizing the microrobot body so that it has a magnetization direction with an oblique angle, thereby significantly improving the reaction force of the fluid and increasing the propulsion force of the microrobot body, which is beneficial to improving the movement efficiency of the microrobot.

[0052] At the same time, for a microrobot equipped with a pulverizing function, the pulverizing function module of the microrobot is coupled with the magnetic drive module by setting different magnetization directions, thereby effectively removing dirt or biofilm in the pipeline and saving the space occupied by the permanent magnet in the traditional magnetic microrobot, which helps to reduce the size and movement time of the microrobot; in addition, by controlling the magnetic field strength, the travel speed and pulverizing intensity of the microrobot can be adjusted simultaneously to meet different application requirements and expand its application range.

[0053] See also Figure 8-Figure 11 As shown, the preferred value range of the angle α of the present invention is: 0°<α≤45°; the angle within this range can achieve a larger dynamic diameter, thereby increasing the propulsion force of the micro robot.

[0054] Furthermore, in order to increase the movement speed of the micro robot, the preferred value range of the angle α of the present invention is: 15°≤α≤45°.

[0055] In order to make the prepared micro robot body more flexible and efficient, the present invention preferably uses a photocurable resin doped with magnetic powder to obtain a prototype through 3D printing, and then magnetizes the prototype.

[0056] The photocurable resin doped with magnetic powder of the present invention can be selected from the corresponding existing technology; specifically, the present invention preferably uses neodymium iron boron magnetic powder as the magnetic powder; the photocurable resin is preferably one or more of epoxy (meth) acrylate resin, polyester (meth) acrylate resin, polyurethane (meth) acrylate resin, and (meth) acrylate monomer; and further preferably, the particle size of the magnetic powder is 1-10μm; and the percentage of the magnetic powder in the total mass of the photocurable resin is preferably 15%.

[0057] Another object of the present invention is to provide a control method for the microrobot as described above, comprising the following steps:

[0058] S1: The microrobot body is magnetized obliquely, and the angle α between the magnetization direction and the radial direction;

[0059] S2: Using a magnetic field to control the operation of the microrobot body through an in vitro control system; the direction of the magnetic field is the same as the axial direction of the microrobot body.

[0060] The present invention preferably performs oblique magnetization on the microrobot body, including: placing the microrobot body on a magnetization platform, and magnetizing the microrobot body on the magnetization platform using a magnetizer.

[0061] Traditional magnetizers only have one magnetization direction (horizontal or vertical). In order to meet the requirements of the oblique magnetization angle of this product, Figure 4-5As shown, the preferred magnetization platform of the present invention includes at least one inclined support plate and a clamp matched with the support plate; the support plate and the clamp together form a plurality of mounting grooves suitable for placing the micro robot body.

[0062] Furthermore, in the present invention, the angle between the direction of the magnetic field generated by the magnetizer and the support plate is preferably an acute angle.

[0063] See also Figure 6 , Figure 7 As shown, the present invention preferably uses a MI-12100 magnetizer to actively control the microrobot body. An external rotating uniform magnetic field is applied along the axis of the microrobot to induce a rotating motion.

[0064] Based on the characteristics of the Helmholtz coil in generating a magnetic field, which has a simple principle, accurate precision and convenient control, the present invention preferably uses an in vitro control system including three pairs of orthogonally placed Helmholtz coils; a magnetic control system using three groups of orthogonally placed Helmholtz coils provides a uniformly rotating magnetic field, which is the power source of the microrobot body. Each pair of coils consists of two coaxially placed circular coils, and the parameters of the coils and the internal wires need to be the same. When the spacing between the two coils is equal to the radius of the coils and currents of equal magnitude are passed through them in the same direction, a uniform magnetic field can be generated in the central area of ​​the pair of coils. If two pairs of Helmholtz coils are placed orthogonally and sinusoidal alternating currents with a phase difference of 90° are passed through them respectively, a uniform rotating magnetic field of a certain frequency can be generated in the orthogonal plane. Therefore, in order to realize the free movement of the microrobot in three-dimensional space, that is, to generate a rotating magnetic field that rotates around any vector direction in three-dimensional space, the present invention preferably places it orthogonally, see. Figure 2 , Figure 3 As shown, a uniform rotating magnetic field with adjustable direction and magnitude is generated by three pairs of orthogonally placed Helmholtz coils.

[0065] Considering the dimensions of the existing microrobot and the size of the pipeline required for motion control, the present invention preferably sets the operable space in the middle position surrounded by the three pairs of Helmholtz coils to a spherical range of Φ60mm; and preferably, the magnetic field strength of each pair of the Helmholtz coils in the middle area is not less than 8mT; then, considering that the Helmholtz coil is affected by the resistance of its own wire, a large amount of heat will be generated if it continues to run for a certain period of time under a large input current, so the input current should not be greater than 5A. According to the above requirements, the design parameters of the coil are shown in Table 1:

[0066] Table 1

[0067]

[0068] The control method of the micro robot provided by the present invention first places the micro robot body on a magnetizing platform, and then places the magnetizing platform in a magnetizing instrument for oblique magnetization, such as Fig.12 As shown in the figure, the principle is that the magnetizing instrument generates a vertical magnetic field, and the microrobot body is placed on an inclined plane, so that the microrobot body has a magnetism with an inclined angle α, and a partial magnetic moment will be generated in the forward direction; in the magnetic control system of the three-dimensional Helmholtz coil, a rotating magnetic field is generated on the YZ-axis Helmholtz coil, the rotating plane is YZ, the normal is X, and a gradient field is generated on the X-axis Helmholtz coil, with a direction of X; under the action of the gradient field and the partial magnetic moment, the reaction force of the fluid can be significantly improved, the propulsion force of the microrobot body can be increased, and the movement efficiency of the microrobot can be improved ( Figure 13-15 ); finally, the operation of the microrobot body is controlled by the magnetic control system of the three-dimensional Helmholtz coil through the in vitro control system; during the operation of the microrobot body, the state and performance of the microrobot body can be continuously monitored, and adjustments and optimizations can be made as needed to achieve the desired operation effect.

[0069] Since the resistance has a great influence on the operation of the microrobot during its operation, in addition to compact design and safety, motion resistance is also an important factor to be considered. Figure 1 As shown, the present invention further preferably comprises a microrobot body including a head 1, a body 2 and a tail 3 connected in sequence; wherein the head 1 and the tail 3 are both conical structures, specifically, the tips of the conical structures of the head 1 and the tail 3 extend away from the body 2; the body 2 comprises a spiral structure.

[0070] The microrobot body is provided with large-angle drill bits at both ends of the structure and a spiral structure in the middle of the structure, which can reduce the resistance during rotation on the one hand and realize forward movement and grinding action at the same time on the other hand, which helps to provide a variety of grinding methods; at the same time, the sturdy design ensures the structural strength and enhances the grinding ability.

[0071] Furthermore, the preferred spiral structure of the present invention includes two spiral lines, and the two spiral lines are respectively connected to the head 1 and the tail 3, so that the micro robot body can change the movement direction more quickly by adjusting the direction of the magnetic field.

[0072] Furthermore, in order to further expand the scope of use of the microrobot, the present invention preferably forms a drug-carrying space between the head 1, the tail 3 and the two spiral lines; for example, the drug-carrying cavity can carry litholytic drugs, so that the litholytic drugs can be transported to the vicinity of the stone by the microrobot for release.

[0073] Specifically, in the present invention, the outer diameter of the body 2 is preferably in the range of 1 mm to 5 mm; the length of the micro robot body is preferably in the range of 2.5 mm to 12.5 mm.

[0074] In order to highlight the advantages of the technical solution provided by the present invention, the motion examples of the present invention are described in detail below.

[0075] Exercise Example 1:

[0076] A uniform rotating magnetic field in the same direction as the pipeline was applied, and a unidirectional axial advancement method was used to measure the dynamic diameters of the 3mm, 4mm, and 5mm microrobot bodies when the angle α between the magnetization direction and the radial direction was 45°, 30°, 15°, and 0°, respectively. The test results are shown in the following table:

[0077] Table 2

[0078]

[0079] According to the test results, the obliquely magnetized microrobot undergoes conical pendulum when exposed to a magnetic field with the same direction as the axis of the microrobot body. When the angle α is in the range of 0° to 45°, the dynamic diameter of the microrobot body increases, and its speed also increases accordingly as the angle α increases. This proves from the fluid mechanics level of the robot that oblique magnetization helps to increase the movement speed of the microrobot.

[0080] Exercise Example 2:

[0081] The example experiment measured the speed of a robot with a diameter of 4mm and an angle α between the magnetization direction and the radial direction of 0°-75° along a predetermined path. The experiment used a tube with a diameter of 5mm, in which the fluid in the tube used simulated blood (a mixture of glycerol and water in a ratio of 4:6) to achieve a similar effect to blood. This motion example experiment measured the forward speed of the microrobot body at various magnetization angles under different magnetic field gradients based on the contribution ratio of the Taguchi optimization method: the angle accounted for 95.46% and the gradient accounted for 4.54%. Each group of experiments was repeated 5 times, and the final speed was averaged. The experimental results are shown in the figure below. Fig.16 And the following table shows.

[0082] Table 3

[0083] 75° 60° 45° 30° 15° 0° -0.04T / m 0.66 13.04 10.06 23.08 19.98 5.61 -0.02T / m 2.11 13.83 9.64 25.03 19.32 7.29 0 1.60 12.37 10.14 26.57 19.53 6.45 0.02T / m 1.09 8.34 11.27 25.03 20.90 6.72 0.04T / m 1.73 5.61 10.99 26.82 18.62 7.60

[0084] The experimental results show that when the angle α between the magnetization direction and the radial direction is 15°-45°, the movement speed of the microrobot is significantly improved, with a maximum speed of 26.57 mm / s, which is 290% higher than the maximum speed of 6.73 mm / s of the microrobot with an angle α of 0°; the average speed of the microrobot with an angle α of 15° is 192.13% higher than the average speed of the traditional radial magnetized robot, the average speed of the microrobot with an angle α of 30° is 275.79% higher than the average speed of the traditional radial magnetized robot, the average speed of the microrobot with an angle α of 45° is 54.73% higher than the average speed of the traditional radial magnetized robot, and the average speed of the microrobot with a diameter of 4 mm and an angle α of 60° is 97.06% higher than the average speed of the traditional radial magnetized robot.

[0085] in, Figure 17-20 The microrobot body of the present invention adopts a unidirectional axial forward mode under the action of a uniform rotating magnetic field in the same direction as the pipeline. The motion schematic diagram when the angle α between the magnetization direction and the radial direction is 45°, 30°, 15° and 0° is selected respectively. The robot body is divided into four groups according to the different magnetization angles. Each group of experiments is repeated 5 times. The speed is finally averaged. The experimental results are integrated into the following Fig.21 Line chart with error bars shown; Fig.21 It can be seen that the movement speed of the microrobots with an angle α of 15°-45° has been significantly improved, with average speeds of 19.53mm / s, 26.57mm / s, and 10.14mm / s respectively; compared with the average speed of 6.45mm / s of the traditional radial magnetized robot, the average speed of the microrobots with an angle α of 15° between the magnetization direction and the radial direction increased by 202.79%, the average speed of the microrobots with an angle α of 30° increased by 311.94%, and the average speed of the microrobots with an angle α of 45° increased by 57.21%.

[0086] Exercise Example 3:

[0087] A uniform rotating magnetic field in the same direction as the pipeline was applied, and a unidirectional axial advancement method was adopted. A 3mm diameter microrobot with an angle α between the magnetization direction and the radial direction of 0°-75° was selected to advance axially in a 4mm pipeline. The advancement speed of the microrobot body at various magnetization angles under different magnetic field gradients was measured, as shown in the following figure. Fig. 22As shown, the movement speed of the microrobot with an angle α of 15°-45° has been significantly improved, with a maximum speed of 18.14 mm / s, which is 91% higher than the maximum speed of 9.48 mm / s of the microrobot with an angle α of 0°; the average speed of the 3mm diameter microrobot with an angle α of 15° is 36.08% higher than the average speed of the traditional radial magnetized robot, the average speed of the 3mm diameter microrobot with an angle α of 30° is 36.08% higher than the average speed of the traditional radial magnetized robot, and the average speed of the 3mm diameter microrobot with an angle α of 45° is 83.9% higher than the average speed of the traditional radial magnetized robot.

[0088] Exercise Example 4:

[0089] A uniform rotating magnetic field in the same direction as the pipeline was applied, and a unidirectional axial advancement method was adopted. A 5mm diameter microrobot with an angle α between the magnetization direction and the radial direction of 0°-75° was selected to advance axially in a 6mm pipeline. The advancement speed of the microrobot body at various magnetization angles under different magnetic field gradients was measured, as shown in the following figure. Fig.23 As shown, when the angle α is 15°-45°, the movement speed of the micro robot is significantly improved.

[0090] According to the above-mentioned motion example results, the microrobot provided by the present invention has a magnetic direction at an oblique angle after the microrobot body is obliquely magnetized at an angle of 15°≤α≤75°. Compared with the traditional radially magnetized robot, the movement speed is significantly improved, and the larger the size of the microrobot body, the faster the movement speed. It can be seen that the microrobot of the present invention takes less time and is more efficient when performing the same forward task, and has a wide range of applications; secondly, the microrobot with a customized magnetization angle advances axially in the pipeline, and its movement path is predetermined, which can be controlled and navigated more accurately, which increases the safety of the microrobot during medical treatment, detection or other applications, and can better avoid damage to the surrounding environment or human body; therefore, the appropriate microrobot magnetization angle and size can be selected according to actual conditions to work efficiently and safely.

[0091] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A micro robot, characterized in that: It includes a micro-robot body and an in vitro control system connected to the micro-robot body by signal; There is an angle α between the magnetization direction of the micro robot body and the radial direction; The angle α is an acute angle; The in vitro control system controls the operation of the micro-robot body by applying an external rotating magnetic field along the radial direction of the micro-robot body; The value range of the angle α is: 0°<α≤45°; The microrobot body comprises a head (1), a body (2) and a tail (3) which are connected in sequence; the head (1) and the tail (3) are both conical structures; the tips of the conical structures of the head (1) and the tail (3) extend in a direction away from the body (2); the body (2) comprises a spiral structure; By obliquely magnetizing the microrobot body, an angle α is formed between the magnetization direction of the microrobot body and the radial direction; Obliquely magnetizing the microrobot body includes: placing the microrobot body on a magnetizing platform, and magnetizing the microrobot body on the magnetizing platform using a magnetizer; The magnetization platform includes at least one inclined support plate and a fixture matched with the support plate; the support plate and the fixture are combined to form a plurality of mounting grooves suitable for placing the micro robot body; The angle between the direction of the magnetic field generated by the magnetizer and the support plate is an acute angle.

2. The microrobot according to claim 1, characterized in that: The value range of the angle α is: 15°≤α≤45°.

3. The microrobot according to claim 1 or 2, characterized in that: The microrobot body is obtained by 3D printing using a photocurable resin doped with magnetic powder.

4. A control method for a microrobot as claimed in any one of claims 1 to 3, characterized in that: The steps include: S1: The microrobot body is magnetized obliquely, and the angle α between the magnetization direction and the radial direction; S2: Using a magnetic field to control the operation of the microrobot body through an in vitro control system; the direction of the magnetic field is the same as the axial direction of the microrobot body.

5. The microrobot control method according to claim 4, characterized in that: The extracorporeal control system includes three pairs of orthogonally placed Helmholtz coils.

6. The microrobot control method according to claim 5, characterized in that: The magnetic field strength of each pair of the Helmholtz coils in the middle region is not less than 8 mT.

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