Preparation method of magnetic robot with core-shell structure

Abstract

The invention discloses a preparation method of a magnetic robot with a core-shell structure, and belongs to the technical field of magnetic robot preparation. The problems that an existing magnetic drive micro-robot raw material has biological toxic and side effects, the preparation process is complex, and the cost is high are solved. Comprising the following steps: uniformly mixing a gelatin solution and a calcium chloride solution according to a ratio of 3: 1, and then uniformly mixing with ferroferric oxide particles with the particle size of 20nm according to a mass fraction of 5-10% to obtain a magnetic mixed solution; dropping the magnetic mixed liquid into a culture dish of liquid paraffin oil, and cooling to form gelatin balls with magnetic particles; after cleaning, soaking in a sodium alginate solution for at least 10 seconds, and then taking out to form a calcium alginate shell; obtaining an initial magnetic robot with a core-shell structure; heating to melt the gelatin balls, enabling the magnetic particles in the gelatin balls to realize chain-shaped directional assembly in an adjustable uniform magnetic field, and cooling and shaping to obtain the final magnetic robot with a core-shell structure. The preparation method is used for preparing the magnetic robot.

Description

Technical Field

[0001] The invention relates to a method for preparing a core-shell structure magnetic robot, and belongs to the technical field of magnetic robot preparation. Background Art

[0002] Due to their tiny structure and controllable navigation capabilities, microrobots can complete designated tasks outside or inside cells and have shown great application potential in many fields, including targeted drug delivery, minimally invasive surgery, and environmental purification.

[0003] There are many ways to drive microrobots, such as magnetic field, electric field, light field, chemical, biological drive, etc., each with its own advantages and disadvantages. By comparison, it can be found that magnetic field drive has higher biocompatibility, faster response speed and control accuracy, and non-contact remote operation compared to other drive methods, so magnetic field drive has become the mainstream drive method for microrobots.

[0004] The existing methods for preparing magnetic field-driven microrobots face the following problems: the materials used for preparing them have biological toxicity, the equipment and process for preparing them are complex and costly. In addition, the existing magnetic drive system cannot generate a high-frequency and high-intensity magnetic field in a relatively large working space, which is not conducive to improving the movement ability of microrobots in practical applications. Summary of the invention

[0005] In view of the problems that the raw materials of existing magnetically driven micro-robots have biological toxic side effects, and the preparation process is complicated and costly, the present invention provides a method for preparing a core-shell structured magnetic robot.

[0006] A method for preparing a core-shell structure magnetic robot of the present invention comprises:

[0007] The gelatin solution and the calcium chloride solution are uniformly mixed in a ratio of 3:1, and then uniformly mixed with ferroferric oxide particles with a particle size of 20 nm in a ratio of 5% to 10% by mass to obtain a magnetic mixed solution;

[0008] The magnetic mixed liquid droplets are cooled in a culture dish containing 4 degrees Celsius liquid paraffin oil to form gelatin balls with magnetic particles; the paraffin oil on the surface of the gelatin balls is cleaned, and then the balls are immersed in a sodium alginate solution for at least 10 seconds and then taken out to form a calcium alginate shell; an initial magnetic robot with a core-shell structure is obtained;

[0009] The initial magnetic robot is heated to melt its gelatin balls, and the magnetic particles therein are assembled in a chain-like manner in an adjustable uniform magnetic field. The robot is then cooled and shaped to obtain a final magnetic robot with a core-shell structure.

[0010] According to the method for preparing the core-shell structure magnetic robot of the present invention, the method for preparing the gelatin solution is:

[0011] The gelatin particles were mixed with deionized water and stirred in a magnetic stirrer at 45 degrees Celsius until completely melted to obtain a 10% wt gelatin solution.

[0012] According to the method for preparing the core-shell structure magnetic robot of the present invention, the method for preparing the calcium chloride solution is as follows:

[0013] Anhydrous calcium chloride particles were mixed with deionized water, and stirred in a magnetic stirrer at room temperature until completely melted to obtain a 1%wt calcium chloride solution.

[0014] According to the method for preparing the core-shell structure magnetic robot of the present invention, a needle is used to extract the magnetic mixed liquid, and an extrusion method is used to obtain droplets of the magnetic mixed liquid.

[0015] According to the method for preparing the core-shell structure magnetic robot of the present invention, the gelatin balls are repeatedly cleaned with water and anhydrous ethanol to remove the paraffin oil on the surface of the gelatin balls.

[0016] According to the method for preparing the core-shell structure magnetic robot of the present invention, the method for preparing the sodium alginate solution is as follows:

[0017] Sodium alginate powder was mixed with deionized water, and stirred in a magnetic stirrer at 40 degrees Celsius until completely melted to obtain a 2%wt sodium alginate solution.

[0018] According to the preparation method of the core-shell structure magnetic robot of the present invention, the adjustable uniform magnetic field is provided by a magnetic field generating device; the magnetic field generating device adjusts the distance between two cylindrical permanent magnets to achieve regulation of the magnetic field intensity of the adjustable uniform magnetic field; and the melted gelatin balls are cooled and shaped by a correspondingly arranged cooling unit to obtain the final magnetic robot with a core-shell structure.

[0019] According to the method for preparing a core-shell structure magnetic robot of the present invention, the magnetic field generating device comprises two positioning base plates, two permanent magnet mounting units and a magnetic robot placement bracket.

[0020] The two positioning base plates are provided with slideways along the length direction respectively and are placed opposite to each other; the magnetic robot placement bracket is bridged between the two positioning base plates and connected to the corresponding positions of the middle sections of the two positioning base plates; the two permanent magnet installation units are bridged between the two positioning base plates and are arranged on both sides of the magnetic robot placement bracket; the permanent magnet installation units are slidably connected to the two positioning base plates;

[0021] A culture dish is placed in the middle of the magnetic robot placement bracket for placing the magnetic robot; a cooling unit is arranged below the corresponding position of the culture dish.

[0022] According to the method for preparing a core-shell structure magnetic robot of the present invention, the permanent magnet installation unit comprises a base, a top cover, an inner baffle and an outer baffle.

[0023] The two bottom ends of the base are slidably connected to the two positioning base plates and fixed by screws and nuts; the top cover is fixed to the base by screws and nuts, and a cavity is formed between the top cover and the base, and the inner baffle plate and the outer baffle plate form a packaging structure in the cavity for packaging the cylindrical permanent magnet.

[0024] According to the preparation method of the core-shell structure magnetic robot of the present invention, the magnetic robot placement bracket has a structure with high ends and low middle along the bridging direction, the middle low section is used to place the culture dish, and the high ends are used to form a limit for the culture dish; the lower part of the middle low section serves as a cooling unit for placing a cooling component to cool and shape the gelatin balls of the magnetic robot in a melted state; the height of the middle low section makes the magnetic robot in the culture dish between two cylindrical permanent magnets.

[0025] Beneficial effects of the present invention: The magnetic robot of the method of the present invention is prepared based on biocompatible and degradable hydrogel materials, and has a core-shell structure. The directional assembly of magnetic particles inside the robot is completed by applying a directional magnetic field externally, that is, the magnetic particles are assembled into a chain structure by adjusting the adjustable magnetic field, so that the maximum movement speed of the robot can be flexibly controlled.

[0026] The method of the present invention utilizes the inherent properties of calcium alginate and gelatin hydrogel to prepare a robot with a core-shell structure and magnetic particles inside; the direction of the magnetic particles in the core of the robot is controlled by an external magnetic field to obtain a chain structure of the magnetic particles; and according to the requirements for the robot's motion performance, external magnetic fields of different intensities are used to achieve flexible regulation of the robot's maximum motion speed.

[0027] The robot prepared by the method of the present invention is biodegradable, has low cost, simple process and is suitable for mass preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flow chart of the method for preparing the core-shell structure magnetic robot of the present invention;

[0029] Figure 2 is a schematic diagram of a gelatin ball;

[0030] Figure 3 is a schematic diagram of the formation of a calcium alginate shell;

[0031] Figure 4 This is a schematic diagram of the initial magnetic robot;

[0032] Figure 5 This is a schematic diagram of the initial magnetic robot after heating;

[0033] Figure 6 This is a schematic diagram of the final magnetic robot with a core-shell structure;

[0034] Figure 7 is a schematic diagram of a magnetic field generating device;

[0035] Figure 8 This is a schematic diagram of the preparation process of the initial magnetic robot with a core-shell structure;

[0036] Fig. 9 This is a schematic diagram of the directional assembly process of magnetic particles inside the initial magnetic robot. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0039] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0040] Specific implementation method 1. Combination Figures 1 to 9 As shown, the present invention provides a method for preparing a core-shell structure magnetic robot, comprising:

[0041] The gelatin solution and the calcium chloride solution are uniformly mixed in a ratio of 3:1, and then uniformly mixed with ferroferric oxide particles with a particle size of 20 nm in a ratio of 5% to 10% by mass to obtain a magnetic mixed solution;

[0042] Combination Figure 2 , Figure 3 and Figure 8 As shown, the magnetic mixed liquid droplets are cooled in a culture dish containing 4 degrees Celsius liquid paraffin oil, and left to stand for a while to form gelatin balls with magnetic particles; after cleaning the paraffin oil on the surface of the gelatin balls, they are placed in a sodium alginate solution and soaked for at least 10 seconds and then taken out to form a calcium alginate shell; an initial magnetic robot with a core-shell structure is obtained; the sodium alginate solution is a 2%wt sodium alginate solution;

[0043] Combination Figures 4 to 6 and Fig. 9As shown, the initial magnetic robot is heated to melt all the gelatin balls at its core, and the magnetic particles therein are assembled in a chain-like manner in an adjustable uniform magnetic field. The robot is then cooled and shaped until the gelatin at the core is completely solidified. The solidification of the core gelatin shapes the assembly of the magnetic particles, and finally a final magnetic robot with a core-shell structure is obtained.

[0044] This embodiment utilizes the inherent characteristics of calcium alginate and gelatin hydrogel to complete the preparation of a robot with a core-shell structure. Heating the robot can melt the core gelatin, and then placing the robot in an adjustable magnetic field generating device can complete the chain-shaped directional assembly of the robot's core magnetic particles and the re-cooling and shaping of the robot.

[0045] Further, the preparation method of the gelatin solution is:

[0046] The gelatin particles were mixed with deionized water and stirred in a magnetic stirrer at 45 degrees Celsius until completely melted to obtain a 10% wt gelatin solution.

[0047] The preparation method of calcium chloride solution is:

[0048] Anhydrous calcium chloride particles were mixed with deionized water, and stirred in a magnetic stirrer at room temperature until completely melted to obtain a 1%wt calcium chloride solution.

[0049] In this embodiment, a needle is used to extract the magnetic mixed liquid, and a simple extrusion method is used to obtain droplets of the magnetic mixed liquid, which are then dropped into a culture dish containing liquid paraffin at 4 degrees Celsius. After the droplets are cooled, gelatin balls with magnetic particles are formed.

[0050] A simple extrusion method can prepare a large number of gelatin spheres in a short period of time, and shell preparation and directed assembly of magnetic particles can be performed on a large number of robots simultaneously.

[0051] Use tweezers to take the gelatin ball out of the liquid paraffin, and wash the gelatin ball repeatedly with water and anhydrous ethanol to remove the paraffin oil on the surface of the gelatin ball.

[0052] The preparation method of sodium alginate solution is as follows:

[0053] Sodium alginate powder was mixed with deionized water, and stirred in a magnetic stirrer at 40 degrees Celsius until completely melted to obtain a 2%wt sodium alginate solution.

[0054] Going a step further, combined Figure 7 As shown, the adjustable uniform magnetic field is provided by a magnetic field generating device; the magnetic field generating device adjusts the distance between two cylindrical permanent magnets to achieve magnetic field intensity regulation of the adjustable uniform magnetic field; and the melted gelatin balls are cooled and shaped by a correspondingly arranged cooling unit to obtain a final magnetic robot with a core-shell structure.

[0055] The magnetic field generating device comprises two positioning base plates 1-1, two permanent magnet mounting units 1-3 and a magnetic robot placement bracket 1-2.

[0056] The two positioning base plates 1-1 are provided with slideways along the length direction respectively and are placed opposite to each other; the magnetic robot placement bracket 1-2 is bridged between the two positioning base plates 1-1 and connected to the corresponding positions of the middle sections of the two positioning base plates 1-1; the two permanent magnet installation units 1-3 are bridged between the two positioning base plates 1-1 and are arranged on both sides of the magnetic robot placement bracket 1-2; the permanent magnet installation units 1-3 are slidably connected to the two positioning base plates 1-1;

[0057] A culture dish is placed in the middle section of the magnetic robot placement bracket 1-2 for placing the magnetic robot; a cooling unit is arranged below the corresponding position of the culture dish.

[0058] The permanent magnet installation unit 1-3 includes a base 1-31, a top cover 1-32, an inner baffle 1-33 and an outer baffle 1-34.

[0059] The two bottom ends of the base 1-31 are slidably connected to the two positioning base plates 1-1 and fixed by screws and nuts; the top cover 1-32 is fixed to the base 1-31 by screws and nuts, and a cavity is formed between the top cover 1-32 and the base 1-31, and the inner baffle plate 1-33 and the outer baffle plate 1-34 form a packaging structure in the cavity for encapsulating cylindrical permanent magnets.

[0060] The positioning base plate 1-1 is provided with a mounting positioning hole for connecting and fixing with the base 1-31 through screws and nuts; the base 1-31 can slide along the positioning base plate 1-1, so that the relative position of the permanent magnet can be adjusted to a desired distance, thereby achieving adjustable magnetic field strength. The inner baffle plate 1-33 and the outer baffle plate 1-34 can be connected through a screw and nut structure.

[0061] The magnetic robot placement bracket 1-2 has a structure with high ends and a low middle along the bridging direction. The low middle section is used to place the culture dish, and the high ends are used to limit the culture dish. The lower part of the middle low section serves as a cooling unit for placing cooling parts to cool and shape the gelatin balls of the magnetic robot in a melted state. The height of the middle low section makes the magnetic robot in the culture dish between two cylindrical permanent magnets.

[0062] The cooling element may be an ice cube, which cools the robot and thereby realizes the finalization of the directional assembly of the magnetic particles.

[0063] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A method for preparing a core-shell structure magnetic robot, characterized in that: include: The gelatin solution and the calcium chloride solution are uniformly mixed in a ratio of 3:1, and then uniformly mixed with ferroferric oxide particles with a particle size of 20 nm in a ratio of 5% to 10% by mass to obtain a magnetic mixed solution; The magnetic mixed liquid droplets are cooled in a culture dish containing 4 degrees Celsius liquid paraffin oil to form gelatin balls with magnetic particles; the paraffin oil on the surface of the gelatin balls is cleaned, and then the balls are immersed in a sodium alginate solution for at least 10 seconds and then taken out to form a calcium alginate shell; an initial magnetic robot with a core-shell structure is obtained; The initial magnetic robot is heated to melt its gelatin balls, and the magnetic particles therein are assembled in a chain-like manner in an adjustable uniform magnetic field. The robot is then cooled and shaped to obtain a final magnetic robot with a core-shell structure.

2. The method for preparing a core-shell structure magnetic robot according to claim 1, characterized in that: The preparation method of the gelatin solution is: The gelatin particles were mixed with deionized water and stirred in a magnetic stirrer at 45 degrees Celsius until completely melted to obtain a 10% wt gelatin solution.

3. The method for preparing a core-shell structure magnetic robot according to claim 1, characterized in that: The preparation method of calcium chloride solution is: Anhydrous calcium chloride particles were mixed with deionized water, and stirred in a magnetic stirrer at room temperature until completely melted to obtain a 1%wt calcium chloride solution.

4. The method for preparing a core-shell structure magnetic robot according to claim 1, characterized in that: The magnetic mixed liquid is extracted by a needle tube, and the magnetic mixed liquid droplets are obtained by an extrusion method.

5. The method for preparing a core-shell structure magnetic robot according to claim 1, characterized in that: The gelatin balls were repeatedly washed with water and anhydrous ethanol to remove the paraffin oil on the surface of the gelatin balls.

6. The method for preparing a core-shell structure magnetic robot according to claim 1, characterized in that: The preparation method of sodium alginate solution is as follows: Sodium alginate powder was mixed with deionized water, and stirred in a magnetic stirrer at 40 degrees Celsius until completely melted to obtain a 2%wt sodium alginate solution.

7. The method for preparing a core-shell structure magnetic robot according to claim 1, characterized in that: The adjustable uniform magnetic field is provided by a magnetic field generating device; the magnetic field generating device adjusts the distance between two cylindrical permanent magnets to achieve magnetic field intensity regulation of the adjustable uniform magnetic field; and the melted gelatin balls are cooled and shaped by a correspondingly arranged cooling unit to obtain a final magnetic robot with a core-shell structure.

8. The method for preparing a core-shell structure magnetic robot according to claim 7, characterized in that: The magnetic field generating device comprises two positioning base plates (1-1), two permanent magnet mounting units (1-3) and a magnetic robot placement bracket (1-2). The two positioning base plates (1-1) are respectively provided with slideways along the length direction and are placed opposite to each other; the magnetic robot placement bracket (1-2) is bridged between the two positioning base plates (1-1) and connected to corresponding positions of the middle sections of the two positioning base plates (1-1); the two permanent magnet installation units (1-3) are bridged between the two positioning base plates (1-1) and are arranged on both sides of the magnetic robot placement bracket (1-2); the permanent magnet installation units (1-3) are slidably connected to the two positioning base plates (1-1); A culture dish is placed in the middle of the magnetic robot placement bracket (1-2) for placing the magnetic robot; a cooling unit is arranged below the corresponding position of the culture dish.

9. The method for preparing a core-shell structure magnetic robot according to claim 8, characterized in that: The permanent magnet mounting unit (1-3) comprises a base (1-31), a top cover (1-32), an inner baffle (1-33) and an outer baffle (1-34), The two bottom ends of the base (1-31) are slidably connected to the two positioning base plates (1-1) correspondingly and are fixed by screws and nuts; the top cover (1-32) is fixed to the base (1-31) by screws and nuts, and a cavity is formed between the top cover (1-32) and the base (1-31); the inner baffle plate (1-33) and the outer baffle plate (1-34) form a packaging structure in the cavity for packaging a cylindrical permanent magnet.

10. The method for preparing a core-shell structure magnetic robot according to claim 9, characterized in that: The magnetic robot placement bracket (1-2) has a structure with high ends and a low middle along the bridging direction, wherein the low middle section is used to place a culture dish, and the high ends are used to limit the culture dish; the lower part of the low middle section serves as a cooling unit for placing a cooling component to cool and shape the gelatin balls of the magnetic robot in a melted state; and the height of the low middle section enables the magnetic robot in the culture dish to be located between two cylindrical permanent magnets.

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