A magnetorheological spherical-like thin film robot and a preparation method and a driving method thereof

Abstract

The application provides a magnetic control spherical thin film robot, a preparation method and a driving method thereof, wherein the magnetic control spherical thin film robot comprises a head and a plurality of movable arms radially distributed around the head, one end of the movable arm close to the head is a leading end, and the other end is a tail end; the movable arm can move in multiple degrees of freedom under the action of an external magnetic field and can be wrapped to the head to completely gather into a hollow sphere. The application is simple to manufacture, has low process requirements, and can complete three action modes of cargo carrying, rolling walking and opening and closing swimming under different external magnetic fields.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic micro-nano robots, in particular to a magnetic spherical film robot and a preparation method and a driving method thereof. BACKGROUND

[0002] Traditional robots cannot be applied to many fine operation fields due to their large size, so micro-nano robots are emerging. Micro-nano robots are usually driven by various ways, including chemical energy (such as H2O2, urea, etc.), external field (light field, ultrasonic wave, magnetic field, etc.), microorganisms or cells (such as sperm). Among them, the robot driven by external magnetic field does not need to design energy device, and the robot movement is driven by controlling external magnetic field, which not only effectively reduces the size of the robot, but also does not harm the human body. The external magnetic field commonly used to drive the movement of the robot includes gradient magnetic field, oscillating magnetic field, uniform magnetic field, etc.

[0003] The targeted drug delivery strategy of micro-nano robots is divided into active drug release and passive drug release. Passive drug release is to move the robot with drug-loaded nanoparticles to the desired position by magnetic driving, wherein the drug release is automatically released under certain conditions (specific temperature, pH value and ion strength). In the case of active drug release, the external magnetic field can not only drive the robot, but also directly trigger the release and loading of the drug. However, in the case of passive drug release, most nanoparticles (≥95%) will accumulate in organs other than target organs, resulting in drug accumulation in non-target organs, thereby causing serious side effects. SUMMARY

[0004] To solve the above technical problems, the present application provides a magnetic spherical film robot, which belongs to the active drug release type and can realize accurate, efficient and rapid point drug release, thereby solving the patient's illness or alleviating pain. Based on the magnetic spherical film robot, a preparation method and a driving method thereof are also provided.

[0005] In one aspect, the present application provides a magnetic spherical film robot, which comprises a head and a plurality of movable arms radially distributed around the head, wherein one end of the movable arm close to the head is the leading end, and the other end is the tail end; the movable arm is wrapped to a hollow sphere under the action of an external magnetic field.

[0006] Further, the movable arm is provided with 4-7.

[0007] Further, the size of the head is smaller than the size of the movable arm.

[0008] Further, the movable arm is made of a flexible member.

[0009] Further, under the action of the external magnetic field, the head and the plurality of active arms can wrap to form a sphere with a diameter of 5mm-15mm for carrying goods.

[0010] In another aspect, the application provides a preparation method of the magnetic control spherical thin film robot, comprising the following steps:

[0011] S1: according to the space limitation of the working environment of the robot, the size of the robot when wrapped as a hollow sphere is designed, and the corresponding two-dimensional size is designed as a reference; then, a corresponding size of a mold is printed by using a high-precision 3D printer;

[0012] S2: the rubber liquid and the magnetic particles are fully mixed and uniformly mixed in a certain proportion to prepare magnetized rubber;

[0013] S3: after fully mixing and uniform mixing, the magnetized rubber is poured into the robot model groove in the pre-prepared mold, and after the magnetized rubber is preliminarily solidified, it is placed in a constant room temperature environment and waits for complete solidification; after complete solidification, the robot is taken out to obtain the connecting body of the head and the active arm;

[0014] S4: the robot model is magnetized in a predetermined magnetization direction by using a magnetization machine to prepare the magnetic control spherical thin film robot.

[0015] Further, in S1, the rubber liquid is polydimethylsiloxane, and the magnetic particles are neodymium iron boron.

[0016] In another aspect, the application provides a driving method of the magnetic control spherical thin film robot, and the steps for realizing the goods carrying action are:

[0017] When wrapping goods, the robot is controlled to move to the vicinity of the target goods by an external magnetic field, and the active arm of the robot is aligned with the goods, an external magnetic field with a uniform direction pointing to the goods is generated around the robot, and the magnetic field strength is gradually increased until the robot completely wraps the goods;

[0018] When unloading the goods, the magnetic field strength is gradually weakened to make the robot reach a semi-wrapping state and release the goods.

[0019] Further, the steps for realizing the rolling walking action are:

[0020] An external rotating magnetic field with a uniform direction perpendicular to the downward direction of the head is generated around the robot; the magnetic field strength is gradually increased until the robot reaches a completely wrapped state;

[0021] The magnetic field strength is kept unchanged, and the direction of the external magnetic field is gradually rotated to the target direction to ensure that the axial downward field strength component remains unchanged.

[0022] Further, the steps for realizing the opening and closing swimming action are:

[0023] A uniform and external magnetic field is generated around the robot, which is perpendicular to the head, gradually increasing the magnetic field strength, so that the robot reaches a semi-wrapped state; continue to enhance the magnetic field strength until the robot reaches a fully wrapped state; the applied magnetic field strength is a cycle, and the robot completes two stages of action in each cycle.

[0024] Compared with the prior art, the beneficial effects of the present application are:

[0025] The robot has the function of carrying powder cargo, and can work in various working conditions, and can realize directional motion in liquid environment and on solid surface; and can be processed to micro-nanometer level, so as to be applied to medical field, and realize targeted drug delivery and foreign matter removal. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Figure 1 The semi-wrapped state and structure of the magnetically controlled spherical thin film robot of the embodiment of the present application are shown in the schematic diagram.

[0028] Figure 2 The fully wrapped state of the magnetically controlled spherical thin film robot of the embodiment of the present application is shown in the schematic diagram.

[0029] Figure 3 The magnetization direction of the magnetically controlled spherical thin film robot of the embodiment of the present application when the movable arm is in the flattened state is shown in the schematic diagram.

[0030] Figure 4 The magnetization direction of the magnetically controlled spherical thin film robot of the embodiment of the present application when the head is in the flattened state is shown in the schematic diagram.

[0031] Figure 5 The magnetization direction of the magnetically controlled spherical thin film robot of the embodiment of the present application is shown in the schematic diagram.

[0032] Figure 6 The preparation mold structure of the magnetically controlled spherical thin film robot of the embodiment of the present application is shown in the schematic diagram.

[0033] Explanation of reference signs:

[0034] 1: head; 2: movable arm. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0037] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, "a plurality of" means two or more, unless otherwise specifically limited. In addition, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] As shown in Figure 1 and Figure 2 The present application proposes a magnetically controlled spherical thin film robot. The robot has multiple motion modes and targeted drug release functions, and can complete cargo transportation under the driving of an external magnetic field. The present application aims to solve the problems of targeted drug delivery and foreign body removal in the medical field. The proposed magnetically controlled spherical thin film robot can be driven by an external magnetic field to transport cargo, especially micro-powder cargo. In addition, the magnetically controlled spherical thin film robot can also be used for in-vivo foreign body removal for patients who have swallowed foreign bodies.

[0039] As shown in Figure 1As shown, the main body of the magnetically controlled spherical thin film robot includes a head 1 and a plurality of movable arms 2 radially distributed around the head 1. The movable arms 2 have a first end near the head 1 and a second end away from the head 1. The movable arms 2 are wrapped around the head 1 to form a hollow sphere under the action of an external magnetic field. The movable arms 2 are provided with 4-7 arms, and the movable arms 2 and the head 1 are made of flexible members.

[0040] In this embodiment, the movable arms 2 are preferably provided with 5 arms, which are radially arranged around the robot head 1 and have the same structure. The movable arms 2 of the robot are connected together through the head 1, and the size of the robot head 1 is obviously smaller than the size of the movable arms 2.

[0041] One end of the movable arm 2 is arc-shaped and connected to the head 1, which is called the first end, and the other end is called the second end. Under the action of an external magnetic field, the head 1 and the 5 movable arms 2 can be wrapped to form a hollow sphere with a diameter of 5-15 mm for carrying goods.

[0042] In this embodiment, the length of the movable arm 2 is preferably 7.12 mm, and the thickness is preferably 0.1 mm. The diameter of the head 1 is preferably 0.5 mm, and the thickness is preferably 0.1 mm, which serves to connect the 5 movable arms 2. When the magnetically controlled spherical thin film robot is unfolded in a two-dimensional plane, the length from the center of the head 1 to the end of the movable arm 2 is 7.62 mm.

[0043] In order to enable the robot to complete various action modes, the movable arms 2 and the head 1 of the robot have different magnetization directions in different directions, as shown. Figures 3 to 5 The specific magnetization method is as follows: first, the robot is completely wrapped and fixed on the spherical mold to ensure that the thin film robot is as close as possible to the mold. Then, an external magnetic field is applied vertically downward to the head 1 for magnetization, as shown. Figure 5

[0044] When unfolded into a plane, the specific magnetization directions of the movable arms 2 are as follows: taking the vertical downward magnetization direction of the first end of the movable arm 2 as the reference direction, rotating clockwise, and the rotation angle increases with the increase of the distance from the first end of the movable arm 2. Finally, the first end, the midpoint and the end of the movable arm 2 form vertical downward, horizontal left and vertical upward magnetization directions, respectively, as shown. Figure 3 The magnetization direction of the head 1 on the two-dimensional plane is as follows: taking the center of the head 1 as the reference point and the direction perpendicular to the head 1 as the reference direction, the magnetization directions of other parts of the head gradually tilt outward, and the tilt angle increases with the increase of the distance from the reference point, forming an oblique downward magnetization direction, as shown. Figure 4 ​The five movable arms 2 of the robot can realize multi-degree-of-freedom movement and can be bent and closed into a sphere under the action of an external magnetic field, as shown in Figure 2

[0045] The specific manufacturing method of the magnetic control spherical thin film robot is as follows:

[0046] S1: According to the space limitation of the working environment of the robot, the size of the robot when wrapped as a sphere is designed, and the corresponding two-dimensional size is designed as a reference. Then, a corresponding size of a mold is printed by using a high-precision 3D printer, and the depth of the groove of the mold is 0.1mm, as shown in Figure 6

[0047] S2: The rubber liquid and the magnetic particles are mixed in a ratio of 1:0.15, and are fully mixed and uniform, to obtain the magnetized rubber (MR). Here, the rubber liquid and the magnetic particles refer to polydimethylsiloxane (PDMS) and neodymium iron boron (NdFeB), respectively. PDMS has good thermal stability, chemical inertness and excellent flexibility. More importantly, PDMS has good biocompatibility and is not easy to cause biological immune rejection. NdFeB has strong magnetic performance and can generate a stronger magnetic field than other magnetic materials under the same volume. In addition, NdFeB also has excellent magnetic stability and can maintain stable magnetic performance under extreme conditions such as high temperature.

[0048] S3: After being fully mixed and uniform, the magnetized rubber (MR) is poured into the robot model groove in the pre-prepared mold. After the MR is preliminarily solidified, it is placed in a constant room temperature environment and waits for complete solidification. After complete solidification, the robot is taken out, and the connection body of the head 1 and the movable arm 2 is obtained, and thus the thin film robot body is obtained. After the PDMS in the MR is solidified, it has an elastic modulus of 3.9Mpa, which provides good flexibility for the robot and provides the feasibility of realizing multi-degree-of-freedom movement for the robot.

[0049] S4: After the robot body is completely manufactured, the robot model is magnetized in the predetermined magnetizing direction described above by using a magnetizing machine, so as to obtain the magnetic control spherical thin film robot.

[0050] The magnetic control spherical thin film robot can be wirelessly driven and controlled by a three-dimensional Helmholtz coil. The three-dimensional Helmholtz coil can independently generate a magnetic field in the X, Y and Z axes, that is, each group of Helmholtz coils can independently drive the magnetic field in one axial direction. When two or more groups of Helmholtz coils are simultaneously enabled, a magnetic field in any direction can be generated in a two-dimensional or three-dimensional plane, so that the thin film robot can move in multiple directions.​​

[0051] The robot can realize different multi-degree-of-freedom actions under the action of different external magnetic fields. Under the driving of different external magnetic fields, the robot can complete three action modes of cargo carrying, rolling walking and opening and closing swimming. The method for driving the thin film robot to complete different actions is as follows:

[0052] The specific driving method for driving the magnetic control type spherical thin film robot to complete the "cargo carrying" action is as follows: first, the robot is controlled to move to the vicinity of the target cargo by an external magnetic field, and the five movable arms 2 of the robot are aligned with the cargo. Then, an external magnetic field uniform in direction and pointing to the cargo is generated around the robot, and the magnetic field strength is gradually increased until the thin film robot completely wraps the cargo, and the cargo loading action is completed. Conversely, the magnetic field strength is gradually weakened, and the robot reaches a semi-wrapped state, so that the cargo can be released, and the cargo unloading action is completed.

[0053] The specific driving method for driving the magnetic control type spherical thin film robot to complete the "rolling walking" action is as follows: first, an external rotating magnetic field uniform in direction and perpendicular to the head downward is generated around the robot, and then the magnetic field strength is gradually increased until the thin film robot reaches a completely wrapped state. Next, the magnetic field strength is kept unchanged, and the direction of the external magnetic field is gradually rotated to the target direction. At the same time, it is necessary to ensure that the axial field strength component remains unchanged, so as to ensure that the state of the robot tightly wrapped is not changed, and the rolling walking action of the robot is realized.

[0054] The specific driving method for driving the magnetic control type spherical thin film robot to complete the "opening and closing swimming" action is as follows: first, an external magnetic field uniform in direction and perpendicular to the head is generated around the robot, and the magnetic field strength is gradually increased to make the robot reach a semi-wrapped state, which is the first stage action. Then, the magnetic field strength is continuously increased until the robot reaches a completely wrapped state, which is the second stage action. The applied magnetic field strength is one cycle, and the robot completes two stage actions in each cycle, and thus the opening and closing swimming action of the robot is realized. If the robot needs to complete a turning action, the direction of the external magnetic field is gradually rotated to the target moving direction while the size of the external magnetic field is changed, and the robot can complete the turning.

[0055] The magnetic control type spherical thin film robot proposed in the application is a flexible robot, and the material has good biocompatibility and is not easy to cause biological immune rejection and damage to the organism. In addition, the proposed magnetic control type spherical thin film robot does not need to design an energy device in the body, which greatly reduces the size of the robot. When performing targeted drug delivery, it is not limited to block-shaped drugs, and under a certain external magnetic field, powder-shaped drugs can be transported.

[0056] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A magnetically controlled spheroid-like thin film robot, characterized by, The application relates to a magnetically-controllable spherical thin film robot, which comprises a head (1) and a plurality of active arms (2) radially distributed around the head (1), wherein one end of the active arms (2) close to the head (1) is a first end, and the other end is a second end; under the action of an external magnetic field, the active arms (2) are wrapped to a hollow sphere around the head (1); when the active arms (2) are unfolded into a plane, the specific magnetization directions of the active arms (2) are as follows: taking the magnetization direction of the first end of the active arms (2) vertically downward as a reference direction, the magnetization direction is rotated clockwise, and the rotation angle is increased with the increase of the distance from the first end of the active arms (2); finally, the magnetization directions of the first end, the midpoint and the second end of the active arms (2) are vertically downward, horizontally leftward and vertically upward respectively; the magnetization direction of the head (1) on a two-dimensional plane is as follows: taking the center of the head (1) as a reference point, and taking the direction perpendicular to the head (1) downward as a reference direction, the magnetization directions of other parts of the head (1) are gradually inclined outward, the inclination angle is increased with the increase of the distance from the reference point, and the magnetization direction is formed to be obliquely downward.

2. The magnetorheological spheroid film robot of claim 1, wherein, The active arms (2) are provided with 4-7 active arms.

3. The magnetorheological clastic spherical thin-film robot according to claim 1, wherein, The size of the head (1) is smaller than the size of the active arms (2).

4. The magnetorheological clastic spherical thin-film robot according to claim 1, characterized in that, The active arms (2) are made of flexible members.

5. The magnetorheological clastic spherical thin-film robot according to claim 1, wherein, Under the action of an external magnetic field, the head (1) and the plurality of active arms (2) can be wrapped to form a sphere with a diameter of 5mm-15mm, which is used for carrying goods.

6. A method for manufacturing a magnetically controlled spheroid-like thin film robot, for manufacturing the magnetically controlled spheroid-like thin film robot according to any one of claims 1 to 5, characterized in that, The application further discloses a method for manufacturing the magnetically-controllable spherical thin film robot. S1: according to the space limitation of the working environment of the robot, the size of the robot when wrapped into a hollow sphere is designed, and the corresponding two-dimensional size is designed by taking the size as a reference; then, a corresponding mold is printed by using a high-precision 3D printer; S2: the rubber liquid and the magnetic particles are fully mixed and uniformly mixed at a certain ratio to prepare magnetized rubber; S3: after being fully mixed and uniformly mixed, the magnetized rubber is poured into the robot model groove in the pre-prepared mold, and after the magnetized rubber is preliminarily solidified, the robot is placed in a constant room temperature environment and waits for complete solidification; after complete solidification, the robot is taken out to obtain the connection body of the head (1) and the active arms (2); S4: the robot model is magnetized in a predetermined magnetization direction by using a magnetizing machine to prepare the magnetically-controllable spherical thin film robot.

7. The method of claim 6, wherein the magnetic control spherical thin film robot is prepared by the steps of: forming a plurality of magnetic control spherical thin film robots on a substrate; and separating the plurality of magnetic control spherical thin film robots from the substrate. In S2, the rubber liquid is polydimethylsiloxane, and the magnetic particles are neodymium iron boron.

8. A driving method of a magnetically controlled spherical thin film robot, for driving the magnetically controlled spherical thin film robot according to any one of claims 1 to 5, characterized by, The steps for realizing the goods carrying action are as follows: When the goods are wrapped, the robot is controlled to move to the vicinity of the target goods by an external magnetic field, the active arms (2) of the robot are aligned with the goods, an external magnetic field which is uniform and has a direction pointing to the goods is generated around the robot, and the magnetic field strength is gradually increased until the robot completely wraps the goods; When the goods are unloaded, the magnetic field strength is gradually weakened, the robot reaches a semi-wrapped state, and the goods are released.

9. The driving method of the magnetron spherical thin film robot according to claim 8, wherein The steps for realizing the rolling walking action are as follows: An external rotating magnetic field which is uniform and has a direction perpendicular to the downward direction of the head (1) is generated around the robot; the magnetic field strength is gradually increased until the robot reaches a completely wrapped state; The magnetic field strength is kept unchanged, and the direction of the external magnetic field is gradually rotated to a target direction, so that the axial downward field strength component is kept unchanged.

10. The driving method of the magnetron-type spherical thin film robot according to claim 8, wherein The step of realizing the opening and closing movement is: A uniform and directional external magnetic field perpendicular to the head (1) is generated around the robot, and the magnetic field strength is gradually increased so that the robot reaches a semi-wrapped state; Continue to increase the magnetic field strength until the robot reaches a fully wrapped state; the applied magnetic field strength is a cycle, and the robot completes two stage actions in each cycle.

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