Dual-mode micro-robot and preparation method and control method thereof

Abstract

The invention relates to the technical field of robots, and discloses a dual-mode micro-robot and a preparation method and a control method thereof. The double-motion-mode magnetic control micro-robot with the environmental adaptability is integrally designed, assembly is not needed, the manufacturing process is simple, and manufacturing materials are easy to obtain. The motion mode combines a swing advancing mode and a spiral propelling mode, and can adapt to different environments. Oscillating magnetic fields with different frequencies are used for driving the micro-robot, so that the micro-robot can be freely switched between the two modes, coherent motion in a changing environment (from wide to narrow or from narrow to wide) is achieved, the micro-robot does not need to be replaced or a delivery device does not need to be relied on in different scenes, and the working efficiency of the micro-robot is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, and in particular to a dual-mode microrobot and a preparation method and a control method thereof. Background Art

[0002] Microrobots are an important branch of the field of robotics. Their scale can range from centimeters to micro and nanometer levels, and they usually do not require an external power source to be driven. Based on this, microrobots can reach tiny environments that traditional robots cannot enter. They have significant potential application value in microassembly, vascular conduction, targeted drug delivery, gastrointestinal testing, etc., and are gradually changing traditional manufacturing, medicine and other fields.

[0003] Currently, the common microrobot driving methods are divided into cable-driven and cable-free driving. Cable-driven driving uses flexible cables to connect the microrobot to the power supply equipment to provide power for the robot's movement, while cable-free driving provides power sources through external fields, including electric fields, light fields, magnetic fields, etc., which can produce smaller microrobots and reduce the trauma caused to patients during surgery. Combined with the special structural design of the microrobot, the control of the microrobot can be made more precise and efficient. Among them, magnetically controlled microrobots have the advantages of small size, cable-free driving, and harmlessness to organisms. They have important application value in biomedicine, micro-nano manipulation and other fields. Taking biomedical applications as an example, magnetically controlled microrobots can directly enter the lesion site (such as the intestines, blood vessels, etc.), and then complete tasks such as targeted drug delivery and thrombus removal.

[0004] Although the existing magnetically controlled microrobots have various designs, they can usually only achieve a single motion mode. This single motion mode limits their applicable scenarios, resulting in the need to use different magnetically controlled microrobots in different environments, affecting task efficiency. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a dual-mode microrobot and a preparation method thereof, so that the dual-mode microrobot has both a swing forward mode and a spiral propulsion mode, can adapt to different environments, and improve work efficiency;

[0006] The object of the present invention is to provide a control method for the above-mentioned dual-mode microrobot, which realizes the swinging forward and spiral propulsion of the microrobot by controlling the oscillation frequency of the magnetic field.

[0007] In order to solve the above technical problems or at least partially solve the above technical problems, the present invention provides a method for solving the above technical problems or at least partially solving the above technical problems. As a first aspect of the present invention, a dual-mode microrobot is provided, which is integrally formed of a flexible material and includes a column and a threaded portion; the column is divided into a first column and a second column along the axial direction, the length of the first column is greater than the length of the second column, and the first column and the second column have opposite axial magnetic properties;

[0008] The threaded parts are respectively located at two ends of the column and have the same spiral direction and radial magnetism.

[0009] Optionally, the thread of the threaded portion is an external thread. Further optionally, the external thread has a lead of 3 mm, a pitch of 1.5 mm, and an outer contour diameter of the helix of 1.5 mm.

[0010] Optionally, the number of thread lines of the threaded portion is single or double or more.

[0011] Optionally, the ratio of the first column length to the second column length is 2:1.

[0012] As a second aspect of the present invention, a method for preparing the dual-mode microrobot of the present invention is provided, comprising:

[0013] S1. After mixing the curable flexible material and the magnetic material, pouring the mixture into a mold for curing and forming; the mold is 3D printed according to the dual-mode microrobot structure of the present invention;

[0014] S2. According to the magnetization requirements of the dual-mode microrobot described in the present invention, the threaded portion and the column on the solidified microrobot body are magnetized to obtain the dual-mode microrobot.

[0015] Optionally, the curable flexible material includes a mixture of polydimethylsiloxane and a curing agent, or Ecoflex material.

[0016] Optionally, S2 includes:

[0017] A magnetization auxiliary template with an "J"-shaped groove is provided. The column of the solidified microrobot is bent 180° at the dividing point between the first column and the second column. At the same time, the threaded portions at both ends of the microrobot and the dividing point of the column are bent 90° respectively and embedded in the "J"-shaped groove of the magnetization auxiliary template. Then, magnetization is performed once radially along the threaded portion, that is, along the axial direction of the column. This can simultaneously meet the different magnetization requirements of the dual-mode microrobot described in the present invention.

[0018] As a third aspect of the present invention, a control method for the dual-mode microrobot of the present invention is provided, comprising:

[0019] The dual-mode microrobot described in the present invention is placed on an oscillating magnetic field platform for driving. The dual-mode microrobot is driven to move forward in a swinging motion mode at a low-frequency oscillating magnetic field frequency, and is driven to move forward in a spiral motion mode at a high-frequency oscillating magnetic field frequency. The turning action of the dual-mode microrobot is completed by controlling the turning direction of the oscillating magnetic field platform.

[0020] Optionally, the frequency of the low-frequency oscillating magnetic field is not higher than 30 Hz, and the frequency of the high-frequency oscillating magnetic field is not lower than 40 Hz.

[0021] The present invention provides a dual-motion mode magnetically controlled microrobot with environmental adaptability, which is an integrated design, does not require assembly, has a simple manufacturing process, and is made of readily available materials. Its motion mode combines a swinging forward mode and a spiral propulsion mode, and can adapt to different environments. The microrobot is driven by oscillating magnetic fields of different frequencies, which enables it to switch freely between the above two modes, thereby achieving coherent motion in a changing environment (from wide to narrow or from narrow to wide), that is, there is no need to replace the microrobot or rely on a delivery device in the face of different scenes, which greatly improves the working efficiency of the microrobot. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0023] Figure 1 Shown is a schematic structural diagram of the dual-mode microrobot of the present invention;

[0024] Figure 2 Shown are schematic diagrams of two forward modes of the dual-mode microrobot of the present invention;

[0025] Figure 3 FIG2 is a schematic diagram of the preparation process of the dual-mode microrobot of the present invention;

[0026] Figure 4 The figure shows the movement experiment of the dual-mode microrobot of the present invention in a transparent tube; (i)-(ii)-(iii)-(iv) respectively represent the states of the microrobot during the movement;

[0027] Reference numerals:

[0028] 1. Cylinder; 11. First cylinder; 12. Second cylinder; 2. Threaded portion. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0031] Microrobots often face complex liquid operating environments in the fields of biomedicine and micro-nano operations. They need to adapt to different environments with different forward motions to achieve higher work efficiency. However, current microrobots usually only have a single forward motion, which makes it difficult to meet the needs of complex and changing working environments. In response to the shortcomings of current microrobots, in the first aspect of the present invention, a dual-mode microrobot is provided, which is integrally formed of a flexible material and includes a column 1 and a threaded portion 2; the column 1 is axially divided into a first column 11 and a second column 12, the length of the first column 11 is greater than the length of the second column 12, and the first column 11 and the second column 12 have opposite axial magnetism;

[0032] The threaded portions 2 are located at both ends of the column 1 and have the same spiral direction and radial magnetism.

[0033] The motion environment of the micro robot provided by the present invention is liquid.

[0034] In certain embodiments of the present invention, the column 1 can have a regular cross-section, such as a circle, square, rectangle, regular polygon, or the like, or an irregular cross-section. In other embodiments of the present invention, the column 1 has a circular cross-section, i.e., a cylindrical shape. In other embodiments of the present invention, the cylindrical shape has a length of 9 mm and a diameter of 1 mm.

[0035] In some embodiments of the present invention, the ratio of the length of the first column 11 to the length of the second column 12 is 2:1.

[0036] In certain embodiments of the present invention, the threaded portion 2 may be a cylindrical thread or a conical thread according to its parent shape, and may be a triangular thread, a trapezoidal thread, a sawtooth thread, a rectangular thread, a dome thread, or any combination thereof according to its thread profile (cross-sectional shape). In other embodiments of the present invention, the threaded portion 2 may be a conical thread according to its parent shape, and a rectangular thread according to its thread profile.

[0037] In certain embodiments of the present invention, the thread of the threaded portion 2 is an external thread. Compared to an internal thread, an external thread is less affected by drainage during the spiral motion of the spiral portion. In other embodiments of the present invention, the external thread has a lead of 3 mm, a pitch of 1.5 mm, and an outer contour diameter of the helix of 1.5 mm.

[0038] In certain embodiments of the present invention, the thread of the threaded portion 2 can be left-handed or right-handed, with right-handed threads typically being preferred. The thread of the threaded portion 2 can have a single or double thread, with double-thread threads offering the best motion efficiency. In other embodiments of the present invention, the threaded portion 2 is a right-handed, double-thread thread.

[0039] See also Figure 1 Schematic diagram of the dual-mode microrobot structure of the present invention. In this example, it includes a cylinder 1 with a circular cross-section and conical threaded portions 2 located at both ends of the cylinder 1; the cylinder 1 is divided into two regions, a first cylinder 11 and a second cylinder 12, and the length ratio of the two regions is 2:1; the threaded portions 2 are all right-handed double-thread threads.

[0040] Under the high-frequency oscillating magnetic field perpendicular to the long axis of the microrobot, the swing speed of the first column 11 and the second column 12 of the column 1 cannot keep up with the change of the magnetic field direction, and cannot produce effective swing, and is in a state of out of step, which has no effect on the movement of the microrobot; while the spiral part 2 can drive the entire microrobot to rotate continuously around the axis under the high-frequency oscillating magnetic field. At this time, the propulsion force of the microrobot comes from the spiral propulsion generated by the interaction between the spiral part 2 and the surrounding liquid, such as Figure 2 -As shown in A;

[0041] Under a low-frequency oscillating magnetic field perpendicular to the long axis of the microrobot, the spiral portion 2 will produce a random alternating motion of clockwise and counterclockwise rotation, and cannot produce continuous rotation around the axis, which has no effect on the movement of the microrobot; and the first column 11 and the second column 12 of the column 1 have opposite axial magnetism, which will produce alternating C-shaped and anti-C-shaped deformations, and the length of the first column 11 is greater than the length of the second column 12. At this time, the propulsion force of the microrobot comes from the deformation similar to "fish swimming" produced by the column 1 driving the entire microrobot, and the forward direction is toward one end of the first column 11, as shown in FIG. Figure 2 -B.

[0042] In a second aspect of the present invention, a method for preparing the dual-mode microrobot of the present invention is provided, comprising:

[0043] S1. After mixing the curable flexible material and the magnetic material, pouring the mixture into a mold for curing and forming; the mold is 3D printed according to the dual-mode microrobot structure of the present invention;

[0044] S2. According to the magnetization requirements of the dual-mode microrobot described in the present invention, the threaded portion and the column on the solidified microrobot body are magnetized to obtain the dual-mode microrobot.

[0045] In certain embodiments of the present invention, the curable flexible material can also be a biocompatible material, such as a mixture of polydimethylsiloxane and a curing agent, or Ecoflex material. The curing agent used in polydimethylsiloxane can be selected from silane coupling agents. Ecoflex, after mixing the two components, cures at room temperature, thus eliminating the need for a curing agent.

[0046] In certain embodiments of the present invention, the magnetic material includes but is not limited to neodymium iron boron and ferrosoferric oxide, and any magnetic material with relatively strong residual magnetic strength may be used.

[0047] In certain embodiments of the present invention, the mass ratio of the polydimethylsiloxane or Ecoflex material to the magnetic material is 1:(0.8-1.2), for example 1:1. A mass ratio lower than this will reduce the magnetism of the microrobot, and a mass ratio higher than this will disperse the polydimethylsiloxane or Ecoflex material, making the microrobot structure easily destroyed.

[0048] In certain embodiments of the present invention, S2 comprises:

[0049] Provide a magnetization auxiliary template with a "J" shaped groove, the shape of the groove can refer to Figure 3 The groove shape of the "magnetization" step in the process flow is to bend the column 1 of the solidified microrobot 180° at the dividing point between the first column 11 and the second column 12, and at the same time, the threaded parts 2 at both ends of the microrobot and the dividing point of the column 1 are bent 90° respectively, and embedded in the "J"-shaped groove of the magnetization auxiliary template, and then magnetize once along the radial direction of the threaded part 2, that is, along the axial direction of the column 1, so that the different magnetization requirements of the dual-mode microrobot described in the present invention can be met at the same time, the magnetization efficiency is higher, and the overall preparation time of the microrobot is reduced.

[0050] In a third aspect of the present invention, a control method for the dual-mode microrobot according to the present invention is further provided, comprising:

[0051] The dual-mode microrobot described in the present invention is placed on an oscillating magnetic field platform for driving. The dual-mode microrobot is driven to move forward in a swinging motion mode at a low-frequency oscillating magnetic field frequency, and is driven to move forward in a spiral motion mode at a high-frequency oscillating magnetic field frequency. The turning action of the dual-mode microrobot is completed by controlling the turning direction of the oscillating magnetic field platform.

[0052] In certain embodiments of the present invention, the frequency of the low-frequency oscillating magnetic field is not higher than 30 Hz. Furthermore, the frequency of the low-frequency oscillating magnetic field is 1-30 Hz, for example, 1 Hz, 5 Hz, 10 Hz, 15 Hz, 20 Hz, 25 Hz, 30 Hz.

[0053] In certain embodiments of the present invention, the frequency of the high-frequency oscillating magnetic field is not less than 40 Hz. Furthermore, the frequency of the high-frequency oscillating magnetic field is 40-75 Hz, for example, 40 Hz, 45 Hz, 50 Hz, 55 Hz, 60 Hz, 65 Hz, or 70 Hz.

[0054] The dual-mode microrobot provided by the present invention can be driven by a low-frequency oscillating magnetic field for rapid swinging motion in a wide liquid environment. In a narrower liquid environment, it can be driven by a high-frequency oscillating magnetic field for slow, spiral propulsion through a narrow area, minimizing impact on the surrounding environment. When steering is required, the robot can coordinate with the rotating platform below the oscillating magnetic field platform to perform actions such as cornering and branch selection.

[0055] The experimental methods in the following examples, unless otherwise specified, are conventional methods, and the experimental materials used in the following examples, unless otherwise specified, were purchased from commercial sources. In the specific embodiments of the present invention, unless otherwise specified, the experimental environment and parameter conditions of each group in the specific example tests remained consistent, except for the differences clearly stated.

[0056] The following further describes a dual-mode sensor and a method for preparing the same provided by the present invention.

[0057] Example 1:

[0058] Step 1: Evenly mix polydimethylsiloxane, silane coupling agent, and neodymium iron boron powder according to a mass ratio of 10:1:10, place them in a vacuum box for vacuum degassing for 20 minutes, and then pour them into the mold obtained by 3D printing.

[0059] Step 2: Place the mold obtained in step 1 in an electric heating box and heat it at 85° C. for 2.5 hours to solidify the mixture in step 1.

[0060] Step 3: Soak the mold obtained in step 2 in acetone for 5 hours. After the mold becomes brittle, peel it off to obtain the internal molding structure.

[0061] Step 4: Cut off the excess part of the gate to obtain the main body of the microrobot.

[0062] Step 5: Place the microrobot on the “J” shaped magnetization auxiliary template for magnetization. Figure 1 The magnetization state shown. See the process flow chart Figure 3.

[0063] Example 2:

[0064] The microrobot prepared in Example 1 was placed in a transparent tube containing a mixture of glycerol and water in a volume ratio of 3:2, simulating a blood environment, and the microrobot was driven using a rotatable oscillating magnetic field platform.

[0065] When the dual motion mode microrobot is in a wider area, it can move forward in a swing motion mode under a low-frequency oscillating magnetic field (oscillation frequency is less than 10 Hz), such as Figure 4 (i) As shown; in a relatively small area, the magnetic field oscillation frequency is increased, and it can move forward in a spiral motion mode under a high-frequency oscillating magnetic field (oscillation frequency is higher than 45Hz), as shown in FIG. Figure 4 (ii) In addition, the movement direction of the dual-motion mode microrobot is always perpendicular to the magnetic field oscillation direction, so the dual-motion mode microrobot can cooperate with the rotating platform under the oscillating magnetic field platform to turn and complete the behaviors of turning, branch selection, etc., as shown in Figure 4 As shown in (iii) and (iv).

[0066] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0067] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and actual applications are not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, any method and embodiment similar to the technical solution without creative design shall fall within the scope of protection of the present invention.

Claims

1. A dual-mode microrobot, characterized in that: It is formed in one piece from a flexible material and comprises a column and a threaded portion; the column is divided into a first column and a second column along the axial direction, the length of the first column is greater than the length of the second column, and the first column and the second column have opposite axial magnetic properties; The threaded parts are respectively located at two ends of the column and have the same spiral direction and radial magnetism.

2. The dual-mode microrobot according to claim 1, characterized in that: The thread of the threaded portion is an external thread.

3. The dual-mode microrobot according to claim 2, characterized in that: The lead of the external thread is 3 mm, the pitch is 1.5 mm, and the outer contour diameter of the helix is ​​1.5 mm.

4. The dual-mode microrobot according to any one of claims 1 to 3, characterized in that: The number of thread lines of the threaded portion is single or double or more.

5. The dual-mode microrobot according to claim 1, characterized in that: The ratio of the first column length to the second column length is 2:

1.

6. A method for preparing a dual-mode microrobot as claimed in claim 1, characterized in that: include: S1. After mixing the curable flexible material and the magnetic material, pouring them into a mold for curing and forming; the mold is formed by 3D printing according to the dual-mode microrobot structure of claim 1; S2. According to the magnetization requirements of the dual-mode microrobot described in claim 1, the threaded portion and the column on the solidified microrobot body are magnetized to obtain the dual-mode microrobot.

7. The preparation method according to claim 6, characterized in that The curable flexible material includes a mixture of polydimethylsiloxane and a curing agent, or an Ecoflex material.

8. The preparation method according to claim 6, wherein S2 include: A magnetization auxiliary template with an "J"-shaped groove is provided, and the column of the solidified microrobot is bent 180° at the dividing point between the first column and the second column. At the same time, the threaded portions at both ends of the microrobot and the dividing point of the column are bent 90° respectively, and embedded in the "J"-shaped groove of the magnetization auxiliary template. Then, magnetization is performed once radially along the threaded portion, that is, along the axial direction of the column, so that the different magnetization requirements of the dual-mode microrobot described in claim 1 can be simultaneously met.

9. A control method for a dual-mode microrobot as claimed in claim 1, characterized in that: include: The dual-mode microrobot described in claim 1 is placed on an oscillating magnetic field platform for driving. The dual-mode microrobot is driven to move forward in a swinging motion mode at a low-frequency oscillating magnetic field frequency, and is driven to move forward in a spiral motion mode at a high-frequency oscillating magnetic field frequency. The turning action of the dual-mode microrobot is completed by controlling the turning direction of the oscillating magnetic field platform.

10. The control method according to claim 9, characterized in that: The frequency of the low-frequency oscillating magnetic field is not higher than 30 Hz, and the frequency of the high-frequency oscillating magnetic field is not lower than 40 Hz.

Images