Magnetically-driven microminiature bistable paper folding robot, manufacturing method and driving method of magnetically-driven microminiature bistable paper folding robot

Abstract

The invention discloses a magnetically-driven microminiature bistable paper folding robot, a manufacturing method and a driving method of the magnetically-driven microminiature bistable paper folding robot. The paper folding robot comprises a forelimb unit, a body unit and a hind limb unit which are sequentially connected through hinges, and the forelimb unit, the body unit and the hind limb unit are all provided with flexible hinges so that the forelimb unit, the body unit and the hind limb unit can be unfolded or folded; wherein a magnet assembly is arranged on the surface of the body unit, the magnet assembly comprises an oblique magnet close to the forelimb unit and a vertical magnet close to the hind limb unit, and under excitation of a variable magnetic field, the magnet assembly can drive the paper folding robot to achieve conversion of different forms; the manufacturing method has the advantages of low cost and high efficiency by utilizing a 3D printing technology, and is good in practicability; according to the driving method, the robot is allowed to be switched between the unfolded state and the folded state, the environmental adaptability is greatly improved, and the second driving method used for achieving movement of the paper folding robot enables the paper folding robot to have two steady-state movement modes so as to adapt to complex working environments and task requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of micro-robots, and in particular relates to a magnetically driven micro-bi-stable origami robot, a manufacturing method and a driving method thereof. Background Art

[0002] Magnetically driven micro-robots use magnetic fields to achieve movement and have the advantages of contactless drive, low energy consumption and high reliability. In addition, due to their small size and light weight, magnetically driven micro-robots can move freely in complex environments, thereby broadening their application scenarios. They are especially suitable for medical, environmental monitoring, precision manufacturing and other fields. Magnetically driven micro-robots have gradually become a research hotspot.

[0003] At the current stage, magnetically driven micro-robots face multiple design and processing challenges. First, the design of the robot's functional structure needs to find the best balance between load-bearing strength and flexibility to ensure that the robot can still achieve effective movement in an unstructured road environment at a micro scale; second, the processing accuracy is high, and the material limitations and the accuracy of the processing equipment need to be overcome when manufacturing micro-structures; in addition, the control method of the drive system needs to further meet the needs of functional diversity to achieve more efficient dynamic response and motion accuracy.

[0004] In view of this, the present invention aims to propose a magnetically driven miniature bistable origami robot, a manufacturing method and a driving method thereof, explore the technical difficulties in its design, processing and driving aspects, realize a more efficient micro-robot system, and meet the growing market demand, which is of great significance. Summary of the invention

[0005] In order to overcome the technical problems described in the above-mentioned prior art, the purpose of the present invention is to provide a magnetically driven miniature bistable origami robot, a manufacturing method and a driving method thereof.

[0006] In the first aspect, the present invention provides a magnetically driven miniature bistable origami robot, comprising a forelimb unit, a torso unit and a hind limb unit hinged in sequence, wherein the forelimb unit, the torso unit and the hind limb unit are all provided with flexible hinges so as to be able to be flattened or folded; wherein a magnet assembly is provided on the surface of the torso unit, the magnet assembly comprises an oblique magnet close to the forelimb unit and a vertical magnet close to the hind limb unit, and under the excitation of a changing magnetic field, the magnet assembly can drive the origami robot to achieve transformation into different forms.

[0007] As a preferred technical solution, the body unit includes adjacent first and second thick plates, and a first flexible hinge is arranged between the first and second thick plates to achieve flattening or folding. When the origami robot is flattened, the vertical projections of the first and second thick plates in the forward direction are the same hexagon; the forelimb unit includes adjacent third and fourth thick plates, and a second flexible hinge is arranged between the third and fourth thick plates to achieve flattening or folding. When the origami robot is flattened, the vertical projections of the third and fourth thick plates in the forward direction are the same isosceles trapezoid; the hind limb unit includes adjacent fifth and sixth thick plates, and a third flexible hinge is arranged between the fifth and sixth thick plates to achieve flattening or folding. When the origami robot is flattened, the vertical projections of the fifth and sixth thick plates in the forward direction are the same isosceles trapezoid.

[0008] As a preferred technical solution, a fourth flexible hinge is provided between the first thick plate and the third thick plate for connection, a fifth flexible hinge is provided between the second thick plate and the fourth thick plate for connection, a sixth flexible hinge is provided between the first thick plate and the fifth thick plate for connection, and a seventh flexible hinge is provided between the second thick plate and the sixth thick plate for connection. When the origami robot is fully folded, the origami robot forms a hexagonal prism.

[0009] As a preferred technical solution, a first protrusion is provided on one side of the first thick plate in the thickness direction, a second protrusion is provided on one side of the second thick plate in the thickness direction, and the first flexible hinge is provided between the first protrusion and the second protrusion; a third protrusion is provided on one side of the first thick plate in the thickness direction, a fourth protrusion is provided on one side of the third thick plate in the thickness direction, and the fourth flexible hinge between the first thick plate and the third thick plate is provided between the third protrusion and the fourth protrusion; a fifth protrusion is also provided on one side of the first thick plate in the thickness direction, a sixth protrusion is provided on one side of the fifth thick plate in the thickness direction, and the sixth flexible hinge between the first thick plate and the fifth thick plate is provided between the fifth protrusion and the sixth protrusion, so that when the origami robot is fully folded, the origami robot has a certain storage space inside.

[0010] As a preferred technical solution, the first thick plate, the second thick plate, the third thick plate, the fourth thick plate, the fifth thick plate and the sixth thick plate are all made of polylactic acid material through 3D printing technology.

[0011] As a preferred technical solution, the first thick plate and the second thick plate are both configured with at least one inclined magnet and at least one vertical magnet, wherein the magnet assembly is axially symmetrically distributed about the first flexible hinge; the spatial angles between the vertical magnet, the inclined magnet and the first flexible hinge are 90° and 30°, respectively.

[0012] As a preferred technical solution, the oblique magnets and the vertical magnets are both made of strong NdFeB magnets produced by a zinc-nickel alloy electroplating process.

[0013] In a second aspect, the present invention further provides a method for manufacturing the above-mentioned magnetically driven miniature bistable origami robot, comprising the following steps:

[0014] The thick plates and elastic receiving grooves are made of polylactic acid material and polyurethane material through 3D printing technology;

[0015] Place each thick plate into the elastic receiving groove, and set a flexible hinge at the corresponding connection of each thick plate;

[0016] The silicone film is attached to the surface of each thick plate through polylactic acid;

[0017] Place each thick plate structure in a folded state into an elastic card slot and let it stand for 24 hours;

[0018] Use all-purpose glue to stick the magnet assembly to the corresponding surfaces of the first thick plate and the second thick plate according to the design plan, so that the magnetization direction of the magnet assembly points from the inside of the robot to the outer edge of the robot.

[0019] In a third aspect, the present invention further provides a driving method, including a first driving method for the origami robot to achieve different form transformations, which includes:

[0020] When the origami robot is placed with the magnet assembly facing upward, that is, the origami robot is flattened, an electromagnet is arranged below the working plane of the origami robot, and a pulse current is passed through the electromagnet to excite a magnetic field with a downward convergence direction directly below the origami robot, so that the origami robot obtains a closing torque and switches from a flattened state to a folded state;

[0021] When the origami robot is folded, a reverse pulse current is passed through the electromagnet to excite an upward-diverging magnetic field directly below the origami robot. The origami robot obtains an unfolding torque and switches from a folded state to an unfolded state.

[0022] As a preferred technical solution, this driving method also includes a second driving method for the origami robot to achieve movement. The origami robot includes two steady-state movement modes.

[0023] First steady-state movement: When the origami robot is deforming back and forth within a small range of folding angles, three electromagnetic coils that are orthogonal to each other are used to excite an alternating divergent magnetic field obliquely above the origami robot's forward direction. The origami robot is simultaneously coupled by the magnetic torque and the magnetic gradient force. The magnetic torque causes the origami robot to fold and unfold back and forth, and the magnetic gradient force causes the pressure exerted on the ground by the forelimb unit and the hindlimb unit to be unevenly distributed, so that the robot crawls forward under the drive of the composite magnetic field;

[0024] Second steady-state movement: When the origami robot is fully folded, it maintains a closed magnetic moment and uses three electromagnetic coils that are orthogonal to each other to excite a rotating magnetic field in the forward direction of the origami robot. The fully folded origami robot rolls forward driven by the rotating magnetic field.

[0025] In summary, the present invention has the following technical effects:

[0026] The present invention discloses a magnetically driven miniature bistable origami robot, a manufacturing method and a driving method thereof. The origami robot comprises a forelimb unit, a body unit and a hindlimb unit which are hinged in sequence, and the forelimb unit, the body unit and the hindlimb unit are all provided with flexible hinges so as to be able to be flattened or folded; wherein, a magnet assembly is provided on the surface of the body unit, and the magnet assembly comprises an oblique magnet close to the forelimb unit and a vertical magnet close to the hindlimb unit, and under the excitation of a changing magnetic field, the magnet assembly can drive the origami robot to achieve transformation into different forms; the manufacturing method utilizes 3D printing technology to print and manufacture each thick plate and connect them, and by attaching a silicone film to the surface of each thick plate as a flexible hinge, the manufacturing method has the advantages of high printing accuracy, overcoming material limitations, low cost, good practicality and high efficiency; the driving method comprises a first driving method for the origami robot to achieve transformation into different forms, and a second driving method for the origami robot to achieve movement, allowing the robot to switch between flattened and folded states, greatly improving environmental adaptability, wherein the second driving method enables the origami robot to have two steady-state movement modes: crawling and rolling, so as to adapt to complex working environments and task requirements. Therefore, compared with the existing micro-robot technology, the magnetically driven micro-bistable origami robot, the manufacturing method and the driving method thereof provided by the present invention have obvious technical advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1is a schematic diagram of the flattened structure of the origami robot according to an embodiment of the present invention;

[0029] Figure 2 is a structural schematic diagram of the origami robot according to an embodiment of the present invention when it is flattened at another angle;

[0030] Figure 3 is a schematic diagram of the structure of the origami robot according to an embodiment of the present invention when it is folded in a small range;

[0031] Figure 4 is a schematic diagram of the structure of the origami robot according to an embodiment of the present invention when it is fully folded;

[0032] Figure 5 is a flow chart of a method for making an origami robot according to an embodiment of the present invention;

[0033] Figure 6 is a process schematic diagram of a first driving method for an origami robot according to an embodiment of the present invention;

[0034] Figure 7 is a process schematic diagram of a second driving method for an origami robot according to an embodiment of the present invention;

[0035] The meanings of the reference numerals are as follows:

[0036] 1-body unit, 11-first thick plate, 12-second thick plate;

[0037] 2-forelimb unit, 21-third thick plate, 22-fourth thick plate;

[0038] 3-hind limb unit, 31-fifth thick plate, 32-sixth thick plate;

[0039] 41 - first flexible hinge, 42 - second flexible hinge, 43 - third flexible hinge, 44 - fourth flexible hinge, 45 - fifth flexible hinge, 46 - sixth flexible hinge, 47 - seventh flexible hinge;

[0040] 51- oblique magnet, 52- vertical magnet;

[0041] 61 - first bump, 62 - second bump, 63 - third bump, 64 - fourth bump, 65 - fifth bump, 66 - sixth bump. DETAILED DESCRIPTION

[0042] The following will be combined with the accompanying drawings in this embodiment to clearly and completely describe the technical solution in this embodiment. The present embodiment described herein is only for illustrative purposes and is not intended to limit the scope of protection of the present invention. Therefore, it should be understood that various modifications and changes can be made to this embodiment without departing from the scope of protection of the present invention.

[0043] In the description of the present invention, unless otherwise clearly specified and limited, the term "and / or" includes any and all combinations of one or more associated listed items. Unless otherwise specified or explained, the terms "connection", "fixed", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] Further, in the description of the present invention, it should be understood that the directional words described in the present embodiment are described at the angles shown in the accompanying drawings and should not be understood as limiting the present embodiment. It should also be understood that in the context, when it is mentioned that an element or feature is connected to another element (one or more), it can not only be directly connected to the other (one or more) elements, but also indirectly connected to the other (one or more) elements through an intermediate element.

[0045] Before introducing the technical solution of the present invention, it is necessary to explain the background of the invention of the present invention. It is common that magnetically driven micro-robots use magnetic fields to achieve movement, which has the advantages of contactless drive, low energy consumption and high reliability. In addition, magnetically driven micro-robots can move freely in complex environments due to their small size and light weight, thereby broadening their application scenarios. They are particularly suitable for medical, environmental monitoring and precision manufacturing and other fields. Magnetic driven micro-robots have gradually become a hot topic of research. At present, magnetically driven micro-robots face multiple design and processing challenges. First, the design of the robot's functional structure needs to find the best balance between bearing strength and flexibility to ensure that the robot can still achieve effective movement in an unstructured road environment at a micro scale; secondly, the processing accuracy requirements are high, and the material limitations and the accuracy of the processing equipment need to be overcome when manufacturing micro-structures; in addition, the control method of the drive system needs to further meet the needs of functional diversity to achieve more efficient dynamic response and motion accuracy. To this end, the present invention aims to propose a magnetically driven micro-sized bistable origami robot, a manufacturing method and a driving method thereof.

[0046] First, see Figures 1 to 4The exemplary embodiment of the present invention provides a magnetically driven miniature bistable origami robot, which includes a forelimb unit 32, a body unit 1 and a hindlimb unit connected in sequence by hinges, wherein the forelimb unit 32, the body unit 1 and the hindlimb unit are all provided with flexible hinges so as to be able to be flattened or folded; wherein the body unit 1 is provided with a magnet assembly on its surface, wherein the magnet assembly includes an oblique magnet 51 close to the forelimb unit 32 and a vertical magnet 52 close to the hindlimb unit, and under the excitation of a changing magnetic field, the magnet assembly can drive the origami robot to achieve conversion to different forms. It should be noted that this origami robot adopts thick plate origami technology, which combines traditional origami with modern engineering, and is a structure that uses engineering plates as folding panels. Unlike ordinary origami, thick plate origami considers the influence of material thickness on the folding form and is applied to machinery, construction and other fields.

[0047] The following is a description of the various components of this origami robot:

[0048] See also Figures 1 to 4 The body unit 1 includes an adjacent first thick plate 11 and a second thick plate 12, and a first flexible hinge 41 is arranged between the first thick plate 11 and the second thick plate 12 to achieve flattening or folding; the forelimb unit 32 includes an adjacent third thick plate 21 and a fourth thick plate 22, and a second flexible hinge 42 is arranged between the third thick plate 21 and the fourth thick plate 22 to achieve flattening or folding; the hind limb unit includes an adjacent fifth thick plate 31 and a sixth thick plate 32, and a third flexible hinge 43 is arranged between the fifth thick plate 31 and the sixth thick plate 32 to achieve flattening or folding; wherein, when the origami robot is flattened, the vertical projections of the first thick plate 11 and the second thick plate 12 in the forward direction are the same hexagon, the vertical projections of the third thick plate 21 and the fourth thick plate 22 in the forward direction are the same isosceles trapezoid, and the vertical projections of the fifth thick plate 31 and the sixth thick plate 32 in the forward direction are the same isosceles trapezoid.

[0049] Based on the structures of the forelimb unit 32, the body unit 1 and the hindlimb unit, in order to realize the flexible connection between the three, please refer to Figures 1 to 4As a preferred technical solution, a fourth flexible hinge 44 is provided between the first thick plate 11 and the third thick plate 21 for connection, a fifth flexible hinge 45 is provided between the second thick plate 12 and the fourth thick plate 22 for connection, a sixth flexible hinge 46 is provided between the first thick plate 11 and the fifth thick plate 31 for connection, and a seventh flexible hinge 47 is provided between the second thick plate 12 and the sixth thick plate 32 for connection. Therefore, when the origami robot is fully folded, the folding path is that the first thick plate 11 and the second thick plate 12 are folded along the first flexible hinge 41 to realize the folding of the body unit 1, driving the third thick plate 21 and the fourth thick plate 22 to fold toward the body unit 1 through the second, fourth and fifth flexible hinges to realize the folding of the forelimb unit 32, and the folding action of the hind limb unit is the same as the forelimb unit 32, so that the origami robot can form a hexagonal prism when it is fully folded, providing a structural basis for the subsequent movement mode of the origami robot.

[0050] Furthermore, in order to ensure that the origami robot has a certain storage space inside when it is fully folded, please refer to Figures 1 to 4 As a preferred technical solution, a first protrusion 61 is provided on one side of the first thick plate 11 in the thickness direction, a second protrusion 62 is provided on one side of the second thick plate 12 in the thickness direction, and a first flexible hinge 41 is provided between the first protrusion 61 and the second protrusion 62; a third protrusion 63 is provided on one side of the first thick plate 11 in the thickness direction, a fourth protrusion 64 is provided on one side of the third thick plate 21 in the thickness direction, and a fourth flexible hinge between the first thick plate 11 and the third thick plate 21 is provided between the third protrusion 63 and the fourth protrusion 64; the first thick plate 11 A fifth protrusion 65 is also provided on one side in the thickness direction, a sixth protrusion 66 is provided on one side of the fifth thick plate 31 in the thickness direction, and a sixth flexible hinge between the first thick plate 11 and the fifth thick plate 31 is provided between the fifth protrusion 65 and the sixth protrusion 66. When the origami robot is fully folded, the origami robot in the shape of a hexagonal prism has a certain thickness through the above-mentioned protrusions, and has a storage space formed by the protrusion enclosure inside, so that the origami robot can carry some goods when fully folded to carry out clamping and carrying work. For example, in this embodiment, the thickness of each thick plate is 1mm, the thickness of the first protrusion 61 and the second protrusion 62 is 3mm, the thickness of the third protrusion 63, the fourth protrusion 64, the fifth protrusion 65, and the sixth protrusion 66 is 2mm, and the thickness of the origami robot when fully folded is determined by the first thick plate 11, the second thick plate 12, the first protrusion 61 and the second protrusion 62, that is, a hexagonal prism with a thickness of 8mm is formed. In addition, it should be noted that when the origami robot is fully folded, the first protrusion 61 and the second protrusion 62 overlap correspondingly, the third protrusion 63 and the fourth protrusion 64 overlap correspondingly, and the fifth protrusion 65 and the sixth protrusion 66 overlap correspondingly.

[0051] As a preferred technical solution, the first thick plate 11, the second thick plate 12, the third thick plate 21, the fourth thick plate 22, the fifth thick plate 31 and the sixth thick plate 32 are all made of polylactic acid material by 3D printing technology. It should be understood that polylactic acid material has a lower melting point, usually between 180°C and 220°C, and is easier to process and print than many other 3D printing materials; in addition, polylactic acid material has high printing accuracy and good surface flatness, which is suitable for printing objects with delicate details.

[0052] As for the magnet assembly of this origami robot, as a preferred technical solution, the first thick plate 11 and the second thick plate 12 are both configured with at least one oblique magnet 51 and at least one vertical magnet 52, wherein the magnet assembly is axially symmetrically distributed about the first flexible hinge 41; the spatial angles between the oblique magnet 51, the vertical magnet 52 and the first flexible hinge 41 are 90° and 30° respectively. As a preferred technical solution, the oblique magnet 51 and the vertical magnet 52 are both made of strong neodymium iron boron magnets made by zinc-nickel alloy electroplating process.

[0053] Second, see Figure 5 The present invention also provides a method for manufacturing the above-mentioned magnetically driven miniature bistable origami robot, comprising the following steps:

[0054] Step 1: using polylactic acid material and polyurethane material to respectively manufacture each thick plate and elastic receiving groove through 3D printing technology;

[0055] Specifically, a hot-melt 3D printer is used to heat the polylactic acid filament to 225°C, and after the filament is melted, each thick plate is printed layer by layer through an extruder. Then, a hot-melt 3D printer is also used to melt the thermoplastic polyurethane elastomer filament, and it is printed layer by layer through an extruder to produce an elastic receiving groove with the same shape as the origami robot when it is completely flattened.

[0056] Step 2: Place each thick plate into the elastic receiving groove, and set a flexible hinge at the corresponding connection of each thick plate;

[0057] Specifically, the printed thick plates are placed into the elastic receiving groove in turn so that the lower surfaces of the thick plates are in the same horizontal plane, wherein the edge contour inside the elastic receiving groove is slightly smaller than the shape of the origami robot when it is completely flattened, ensuring that the elastic receiving groove and the edges of the thick plates can fit completely and tightly, and flexible hinges are set at the corresponding connections of the thick plates. The flexible hinges are in the form of thin layers and can be made of rubber materials, such as TPU rubber.

[0058] Step 3, attaching the silicone film to the surface of each thick plate through polylactic acid;

[0059] Specifically, use a cutter to cut the silicone film into a shape that can fit the surface of each thick plate, use a brush to evenly apply a proper amount of silicone mucus near the hinges between adjacent thick plates, and then use tweezers to stick the cut silicone film to the surface of each thick plate. In order to ensure that the silicone mucus is firmly bonded, it is necessary to apply a proper amount of force to press the film to remove the air between the silicone mucus and the silicone film.

[0060] Use an air gun to blow air evenly for about 15 minutes at a distance of 20 cm from the surface of the silicone film at a temperature of 25°C, so that the silicone mucus solidifies at a faster speed and can adhere well to the polylactic acid and silicone film. It should be understood that polymer colloids generally take a long time to solidify. The longer the curing time, the better the adhesion effect and the better the effect of bearing complex stress;

[0061] Since the colloid has a certain fluidity, long-term static curing will cause the silicone to fill all the gaps between the thick plates. After the colloid is completely solidified, a cutter is needed to cut the origami robot out of the elastic holding groove as a whole. After that, a cutter is still needed to cut open the non-hinge parts of the sides of the adjacent thick plates to remove excess colloid, so as to facilitate folding the entire origami structure.

[0062] Step 4, placing each thick plate structure in a folded state into an elastic card slot and leaving it to stand for 24 hours;

[0063] Long-term folding can make the silicone film at the flexible hinge form effective prestressed creases, making it easier to guide the thick plate origami structure to the target folding path.

[0064] Step 5: Use all-purpose glue to stick the magnet assembly to the corresponding surfaces of the first thick plate and the second thick plate according to the design plan, so that the magnetization direction of the magnet assembly points from the inside of the robot to the outer edge of the robot.

[0065] In a third aspect, the present invention further provides a driving method, see Figure 6 , including a first driving method for the origami robot to achieve different form transformations, which includes:

[0066] When the origami robot is placed with the side provided with the magnet assembly facing upward, that is, when it is flattened, an electromagnet is set below the working plane of the origami robot, and a pulse current is passed through the electromagnet to excite a magnetic field with a downward convergence direction directly below the origami robot. The origami robot obtains a closing torque and can switch from a flattened state to a folded state; when the origami robot is folded, a reverse pulse current is passed through the electromagnet to excite a magnetic field with an upward divergence direction directly below the origami robot. The origami robot obtains an unfolding torque and can switch from a folded state to a flattened state.

[0067] This driving method also includes a second driving method for the origami robot to move. Figure 7, the origami robot includes the following two steady-state movement modes:

[0068] First steady-state movement: When the origami robot deforms back and forth within a small range of folding angles, three electromagnetic coils that are orthogonal to each other are used to excite alternating divergent magnetic fields diagonally above the origami robot's forward direction. The origami robot is simultaneously affected by the coupling of magnetic torque and magnetic gradient force. The magnetic torque causes the origami robot to fold and unfold back and forth, and the magnetic gradient force causes the pressure exerted on the ground by the forelimb unit and the hindlimb unit to be unevenly distributed, so that the robot crawls forward driven by the composite magnetic field. For example, in this embodiment, the basic amplitude of the current is set to 5A, and the amplitude coefficient is set to 0.995, 0.0705, and 0.0705, with the same phase and a frequency of 3Hz, so as to excite an alternating and reciprocating divergent magnetic field obliquely above the forward direction of the origami robot. Specifically, when folding, the magnetic gradient force exerted on the oblique magnet close to the forelimb unit is greater than the magnetic gradient force exerted on the vertical magnet close to the hind limb unit, so that the forelimb unit is heavier than the hind limb unit, which in turn results in a large friction force on the forelimb unit and a small friction force on the hind limb unit; when unfolding, the magnetic gradient force exerted on the oblique magnet close to the forelimb unit is greater than the magnetic gradient force exerted on the vertical magnet close to the hind limb unit, and the forelimb unit is lighter than the hind limb unit, which in turn results in a small friction force on the forelimb unit and a large friction force on the hind limb unit. Finally, the origami robot crawls forward driven by the composite magnetic field.

[0069] Second steady-state movement: When the origami robot is fully folded, it takes on an approximate ellipsoid shape, maintains a closed magnetic moment, and uses three electromagnetic coils that are orthogonal to each other in the forward direction of the origami robot to excite a rotating magnetic field, and the fully folded origami robot rolls forward under the drive of the rotating magnetic field. For example, in this embodiment, three sinusoidal currents are input into the electromagnetic device, the basic amplitude of the current is set to 5A, the amplitude coefficients are set to 0.4729, 0.9424, and 0.9424, respectively, the phases are set to 48.6158°, 277.2°, and 180°, respectively, and the frequency is 1Hz, so as to excite a rotating magnetic field in the forward direction of the origami robot, and the robot has the ability to roll in the rotating magnetic field.

[0070] In summary, this driving method includes a first driving method for the origami robot to achieve different form transformations, and a second driving method for the origami robot to achieve movement, allowing the robot to switch between flattened and folded states, greatly improving environmental adaptability. Among them, the second driving method enables the origami robot to have two steady-state movement modes: crawling and rolling, so as to adapt to complex working environments and task requirements.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetically driven miniature bistable origami robot, characterized in that: It includes a forelimb unit, a body unit and a hind limb unit which are hinged in sequence, wherein the forelimb unit, the body unit and the hind limb unit are all configured with flexible hinges so as to be able to be flattened or folded; wherein, a magnet assembly is configured on the surface of the body unit, and the magnet assembly includes an oblique magnet close to the forelimb unit and a vertical magnet close to the hind limb unit, and under the excitation of a changing magnetic field, the magnet assembly can drive the origami robot to achieve different form transformations and movements.

2. The origami robot according to claim 1, characterized in that: The body unit includes adjacent first and second thick plates, and a first flexible hinge is arranged between the first and second thick plates to achieve flattening or folding. When the origami robot is flattened, the vertical projections of the first and second thick plates in the forward direction are the same hexagon; the forelimb unit includes adjacent third and fourth thick plates, and a second flexible hinge is arranged between the third and fourth thick plates to achieve flattening or folding. When the origami robot is flattened, the vertical projections of the third and fourth thick plates in the forward direction are the same isosceles trapezoid; the hindlimb unit includes adjacent fifth and sixth thick plates, and a third flexible hinge is arranged between the fifth and sixth thick plates to achieve flattening or folding. When the origami robot is flattened, the vertical projections of the fifth and sixth thick plates in the forward direction are the same isosceles trapezoid.

3. The origami robot according to claim 2, characterized in that: A fourth flexible hinge is provided between the first thick plate and the third thick plate for connection, a fifth flexible hinge is provided between the second thick plate and the fourth thick plate for connection, a sixth flexible hinge is provided between the first thick plate and the fifth thick plate for connection, and a seventh flexible hinge is provided between the second thick plate and the sixth thick plate for connection. When the origami robot is fully folded, the origami robot forms a hexagonal prism.

4. The origami robot according to claim 3, characterized in that: A first protrusion is provided on one side of the first thick plate in the thickness direction, a second protrusion is provided on one side of the second thick plate in the thickness direction, and the first flexible hinge is provided between the first protrusion and the second protrusion; a third protrusion is provided on one side of the first thick plate in the thickness direction, a fourth protrusion is provided on one side of the third thick plate in the thickness direction, and the fourth flexible hinge between the first thick plate and the third thick plate is provided between the third protrusion and the fourth protrusion; a fifth protrusion is also provided on one side of the first thick plate in the thickness direction, a sixth protrusion is provided on one side of the fifth thick plate in the thickness direction, and the sixth flexible hinge between the first thick plate and the fifth thick plate is provided between the fifth protrusion and the sixth protrusion, so that when the origami robot is fully folded, the origami robot has a certain storage space inside.

5. The origami robot according to claim 4, characterized in that: The first thick plate, the second thick plate, the third thick plate, the fourth thick plate, the fifth thick plate and the sixth thick plate are all made of polylactic acid material through 3D printing technology.

6. The origami robot according to claim 5, characterized in that: The first thick plate and the second thick plate are both configured with at least one oblique magnet and at least one vertical magnet, wherein the magnet assembly is axially symmetrically distributed about the first flexible hinge, and the spatial angles between the vertical magnet, the oblique magnet and the first flexible hinge are 90° and 30°, respectively.

7. The origami robot according to claim 6, characterized in that: The oblique magnet and the vertical magnet are both made of NdFeB strong magnets produced by zinc-nickel alloy electroplating process.

8. A method for making an origami robot according to any one of claims 1 to 7, characterized in that: include: The thick plates and elastic receiving grooves are made of polylactic acid material and polyurethane material through 3D printing technology; Place each thick plate into the elastic receiving groove, and set a flexible hinge at the corresponding connection of each thick plate; The silicone film is attached to the surface of each thick plate through polylactic acid; Place each thick plate structure in a folded state into an elastic card slot and let it stand for 24 hours; Use all-purpose glue to stick the magnet assembly to the corresponding surfaces of the first thick plate and the second thick plate according to the design plan, so that the magnetization direction of the magnet assembly points from the inside of the robot to the outer edge of the robot.

9. A driving method for the origami robot according to any one of claims 1 to 7, characterized in that: A first driving method for an origami robot to achieve different form transformations includes: When the origami robot is placed with the magnet assembly facing upward, that is, the origami robot is flattened, an electromagnet is arranged below the working plane of the origami robot, and a pulse current is passed through the electromagnet to excite a magnetic field with a downward convergence direction directly below the origami robot, so that the origami robot obtains a closing torque and switches from a flattened state to a folded state; When the origami robot is folded, a reverse pulse current is passed through the electromagnet to excite an upward-diverging magnetic field directly below the origami robot. The origami robot obtains an unfolding torque and switches from a folded state to an unfolded state.

10. The driving method according to claim 9, characterized in that: The driving method also includes a second driving method for the origami robot to achieve movement. The origami robot includes two steady-state movement modes. First steady-state movement: When the origami robot is deforming back and forth within a small range of folding angles, three electromagnetic coils that are orthogonal to each other are used to excite an alternating divergent magnetic field obliquely above the origami robot's forward direction. The origami robot is simultaneously coupled by the magnetic torque and the magnetic gradient force. The magnetic torque causes the origami robot to fold and unfold back and forth, and the magnetic gradient force causes the pressure exerted on the ground by the forelimb unit and the hindlimb unit to be unevenly distributed, so that the robot crawls forward under the drive of the composite magnetic field; Second steady-state movement: When the origami robot is fully folded, it maintains a closed magnetic moment and uses three electromagnetic coils that are orthogonal to each other to excite a rotating magnetic field in the forward direction of the origami robot. The fully folded origami robot rolls forward driven by the rotating magnetic field.

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