A magnetically controlled snake-scale-like soft actuator and its manufacturing method

Abstract

The present invention discloses a magnetically controlled snake-scale-like soft actuator, comprising a magnetically controlled snake-scale-like soft actuator body and a magnetic field generator. The magnetically controlled snake-scale-like soft actuator body comprises a series of regularly distributed arc-shaped planar shear marks on a magnetic elastomer sheet. The fan-shaped scales formed by the arc-shaped planar shear marks are mixed with magnetic particles. The magnetic particles are magnetized in a first magnetic field so that all the fan-shaped scales of the magnetically controlled snake-scale-like soft actuator body are programmed to obtain a non-uniform magnetic domain distribution, thereby causing out-of-plane warping and expansion deformation along the length direction in a uniform magnetic field. The magnetic field generator is used to apply a second magnetic field to the magnetically controlled snake-scale-like soft actuator body, causing all the fan-shaped scales of the magnetic elastomer sheet to change from a horizontal state to a curved state with out-of-plane warping, while the magnetically controlled snake-scale-like soft actuator body expands and deforms along the length direction. The present invention also discloses a method for manufacturing the magnetically controlled snake-scale-like soft actuator.

Description

Technical Field

[0001] The present application relates to the technical field of soft actuators, and in particular to a magnetically controlled snake-scale-like soft actuator and a manufacturing method thereof. Background Art

[0002] Compared with traditional rigid actuators, soft actuators have good human-computer interaction performance, high deformability and simple structure. They are more adaptable to some special and complex working conditions such as pipes with a certain curvature and biological tissues. They have been a research hotspot in the field of robotics in recent years.

[0003] Common soft actuator actuation methods include air pressure, electroactive, thermally active, and light-responsive. Currently, pneumatic and electric soft actuators are the most widely used. However, because they require constrained components such as airways and wires for driving signal transmission, wireless actuation is difficult to achieve, limiting their potential for further application.

[0004] For applications in enclosed environments, such as biological tissue and small, curved pipes, soft robots require precise control of remote wireless actuation signals for effective motion. Large, rigid robots and wired soft robots struggle to adapt to such demanding environments. Magnetic actuation, with its ability to quickly, remotely, wirelessly, and safely actuate soft actuators made of magnetically active programmable soft materials, coupled with its strong magnetic field penetration, is ideally suited for these specialized applications.

[0005] However, existing soft actuators lack excellent anisotropic friction properties. Therefore, effective motion usually requires the independent activation of multiple actuators, which complicates the structural design and driving mechanism of the soft actuator and increases the difficulty of designing, manufacturing, and driving control of the soft actuator. On the other hand, the current mainstream method for magnetizing soft actuators is to use a fixture to constrain the magnetoelastic robot body into the target three-dimensional shape before magnetizing. However, this method makes it difficult to realize some complex three-dimensional structures, such as those with large out-of-plane buckling deformation, which limits the further application of magnetic soft actuators. Summary of the Invention

[0006] The purpose of this application is to propose a magnetically controlled snake-scale-like magnetic actuator and its manufacturing method, which is inspired by the ancient paper-cutting art and solves the complex problems of soft actuator structure, driving mechanism, control and manufacturing. At the same time, it utilizes its unique anisotropic friction characteristics and expansion and contraction capabilities to enable the magnetically controlled soft actuator to have a certain ability to climb and overcome obstacles.

[0007] The technical solution of the first aspect of the present application provides a magnetically controlled snake-scale-like soft actuator, comprising a magnetically controlled snake-scale-like soft actuator body and a magnetic field generator. The magnetically controlled snake-scale-like soft actuator body is a series of magnetic elastomer sheets with regularly distributed arc-shaped plane shear marks, and the fan-shaped scales formed by the arc-shaped plane shear marks in the magnetic elastomer sheets are mixed with magnetic particles. The magnetic particles are magnetized in a first magnetic field so that all the fan-shaped scales of the magnetically controlled snake-scale-like soft actuator body are programmed to obtain a non-uniform magnetic domain distribution, so that out-of-plane warping and expansion deformation along the length direction will occur in a uniform magnetic field. The magnetic field generator is used to apply a second magnetic field to the magnetically controlled snake-scale-like soft actuator body so that all the fan-shaped scales of the magnetic elastomer sheet change from a horizontal state to a curved state of out-of-plane warping, while the magnetically controlled snake-scale-like soft actuator body expands and deforms along the length direction.

[0008] In any of the above technical solutions, further, the magnetically controlled snake-scale-like soft actuator body includes at least four groups of fan-shaped scales arranged along the length direction, and all fan-shaped scales are warped out of the plane in the same direction in the second magnetic field, similar to the warping state of the scales on the surface of snake skin.

[0009] In any of the above technical solutions, further, the first magnetic field is a pulsed magnetic field, and the second magnetic field is a uniform magnetic field.

[0010] In any of the above technical solutions, further, when a second magnetic field is applied, the magnetically controlled snake-scale-like soft actuator expands and deforms, and the backward friction coefficient becomes greater than the forward friction coefficient, resulting in forward expansion motion. When the magnetic field is removed, the magnetically controlled snake-scale-like soft actuator recovers its deformation, and can continue its forward contraction and crawling motion, mimicking the snake-like scales, due to its own contraction and the anisotropic friction coefficient.

[0011] In any of the above technical solutions, further, the magnetically controlled snake-scale-like soft actuator body is made of soft materials, 3D printing and laser cutting technology;

[0012] The soft material can use a silicone-based elastic material as the matrix material, and then add Ruthenium-iron-boron magnetic particles to the matrix material with a content of 1-80wt%. The silicone-based elastic material with added Ruthenium-iron-boron magnetic particles is used to 3D print and laser cut magnetic elastomer sheets to make a magnetically controlled snake-scale-like soft actuator body.

[0013] The technical solution of the second aspect of the present application is: providing a method for manufacturing a magnetically controlled snake-scale-like soft actuator with a paper-cutting-inspired design, the method comprising: step 1, using magnetically active programmable soft materials and 3D printing technology to make a magnetic elastomer sheet and solidifying it at high temperature; step 2, using laser cutting technology to cut a series of regularly distributed arc-shaped plane cuts on the solidified magnetic elastomer sheet, and retaining a certain length at the left and right ends as clamped parts; step 3, clamping the cut magnetic elastomer sheet on a uniaxial stretching device and stretching it a certain distance along its length direction, and the fan-shaped scales on the sheet will warp outward due to the out-of-plane buckling force generated by the stretching; step 4, placing the stretched and deformed magnetic elastomer sheet under a first magnetic field and magnetizing it to saturation; step 5, removing the magnetic elastomer sheet from the uniaxial stretching device, and cutting the magnetic elastomer sheet to make the magnetically controlled snake-scale-like soft actuator body.

[0014] In any of the above technical solutions, further, in step 1, the 3D printing technology adopts ink direct writing 3D printing technology of flexible composite material ink, wherein the extrusion pressure is 100-300kPa, the moving speed is 15-40mm / s, and the filling density is 90%.

[0015] In any of the above technical solutions, further, in step 2, the radius of the arc-shaped plane shear mark is set to 3.5 mm, the arc length is 6.5 mm, the thickness of the shear mark is 0.2 mm, the distance between adjacent arcs in the same row is 2 mm, the adjacent distance in the same column is 4 mm, the distance between the centers of adjacent staggered arcs is 4 mm x 2 mm, and the thickness of the elastomer mesh sheet is 0.5 mm.

[0016] In any of the above technical solutions, further, in step 3, the existing uniaxial stretching device is used to stretch the magnetic elastomer sheet after cutting, and the total stretching length is 8 mm. The clamping areas are located at the left and right ends of the corresponding magnetic elastomer sheet, and the lengths are both about 5 mm. The clamping areas at the left and right ends cover the entire edge of the magnetic elastomer sheet. After the stretching process is completed, the obtained tensile strain is stably maintained by a fixing device.

[0017] In any of the above technical solutions, further, in step 4, the stretched magnetic elastomer sheet and the uniaxial stretching device are placed inside the magnetizing coil of the magnetizer, the voltage of the magnetizer is set to 1200V, and the magnetic field size inside the corresponding magnetizing coil is 1-4T, preferably 3T. The magnetic field is instantly released in a short time to complete the magnetization programming process of the magnetic elastomer sheet.

[0018] The beneficial effects of this application are:

[0019] The technical solution in this application provides a magnetically controlled snake-scale-like soft actuator. Through a design inspired by paper-cutting, the magnetic elastomer sheet obtains excellent local out-of-plane buckling deformation ability at the shear mark when it is pulled. Through the magnetization programming method, the magnetic particles in the magnetically controlled snake-scale-like soft actuator body are magnetized using a first magnetic field to obtain a non-uniform magnetic domain distribution when all the arc-shaped scales of the magnetically controlled snake-scale-like soft actuator are buckled out-of-plane and stretched along the length direction. This allows all the arc-shaped scales to have the property of warping outwards under the action of a second magnetic field, while the magnetically controlled snake-scale-like soft actuator body expands and deforms along the length direction, and can quickly shrink and return to its initial horizontal state when the magnetic field is removed. Furthermore, by warping all the circular arc-shaped scales of the magnetically controlled snake-scale-like soft actuator outward in the same direction in the second magnetic field, the backward friction coefficient of the magnetically controlled snake-scale-like soft actuator body becomes greater than the forward friction coefficient, causing the magnetically controlled snake-scale-like soft actuator body to expand and deform forward. Furthermore, after the second magnetic field is removed, the magnetically controlled snake-scale-like soft actuator body can continue to move forward due to the deformation process of the body contracting and the scales flattening, similar to the crawling motion mode of snake-driven skin scales. Compared with existing magnetically controlled soft robots, the proposed paper-cutting-inspired magnetically controlled snake-scale-like soft actuator has a new structure and drive mode, and also has a certain ability to climb and overcome obstacles, which is conducive to the further application of magnetically controlled soft robots in fields such as biomedicine and pipelines.

[0020] The present application also provides a method for manufacturing a magnetically controlled snake-scale-like soft actuator. This method is inspired by the ancient art of paper-cutting. By combining paper-cutting design and mechanical stretching-guided out-of-plane buckling deformation technology, a complex three-dimensional structure that is difficult to obtain by traditional mold manufacturing is achieved, which greatly reduces the manufacturing difficulty of the magnetically controlled snake-scale-like soft actuator and can well inspire the manufacture of other types of bionic soft robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The advantages of the above and / or additional aspects of the present application will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 is a schematic diagram of a magnetically controlled snake-scale-like soft actuator according to an embodiment of the present application;

[0023] Figure 2 is a schematic diagram of force analysis of a magnetically controlled snake-scale-like soft actuator during motion according to an embodiment of the present application;

[0024] Figure 3 is a schematic flow chart of a method for manufacturing a magnetically controlled snake-scale-like soft actuator according to one embodiment of the present application;

[0025] Figure 4This is a schematic diagram of the design dimensions of a magnetic elastomer sheet having a series of regularly distributed arc-shaped planar shear marks according to one embodiment of the present application;

[0026] Figure 5 is a schematic diagram of a uniaxial stretching device according to one embodiment of the present application;

[0027] Figure 6 is a schematic diagram of a crawling process of a magnetically controlled snake-scale-like soft actuator according to an embodiment of the present application;

[0028] Figure 7 This is a schematic diagram of the climbing process of the magnetically controlled snake-scale-like soft actuator according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0031] Example 1:

[0032] like Figure 1 As shown, this embodiment provides a magnetically controlled snake-scale-like soft actuator, which is inspired by paper-cutting and includes: a magnetically controlled snake-scale-like soft actuator body and a magnetic field generator (not shown); wherein the magnetically controlled snake-scale-like soft actuator body serves as an integrated flexible actuator that can crawl forward sustainably, and the magnetic field generator is used to apply an external remote-driven magnetic field to the magnetically controlled snake-scale-like soft actuator body, so that the magnetically controlled snake-scale-like soft actuator body imitates the snake-driven skin scales to crawl forward under the synergistic action of magnetic force and friction force.

[0033] In this embodiment, the main body of the magnetically controlled snake-scale-like soft actuator is a magnetic elastic thin sheet having a series of regularly distributed arc-shaped plane shear marks, and magnetic particles are mixed into the thin sheet.

[0034] The magnetic particles are magnetized in a first magnetic field so that all the fan-shaped scales of the magnetically controlled snake-scale-like soft actuator body are programmed to obtain a non-uniform magnetic domain distribution, thereby causing out-of-plane warping and elongation along the length direction of the soft actuator body in a uniform magnetic field.

[0035] Specifically, the magnetically controlled snake-scale-like soft actuator body is made of soft materials, 3D printing and laser cutting technology.

[0036] The soft material can be made of a silicone-based elastic material as the base material, and then Ru-Fe-B magnetic particles are added to the base material at a content of 1-80wt%. The silicone-based elastic material with added magnetic particles can then be used for 3D printing and laser cutting of magnetic elastomer sheets.

[0037] Since magnetic particles are provided in the fan-shaped scales in the magnetically controlled snake-scale-like soft actuator body, a first magnetic field programming method can be adopted so that when a second magnetic field is applied, the magnetically controlled snake-scale-like soft actuator body can produce expansion deformation and bending deformation under the action of the fan-shaped scales. Since the backward friction coefficient of the magnetically controlled snake-scale-like soft actuator body after deformation is greater than the forward friction coefficient, the magnetically controlled snake-scale-like soft actuator body will undergo forward expansion deformation movement; when the magnetic field is removed, during the process of the magnetically controlled snake-scale-like soft actuator body recovering its deformation, the magnetically controlled snake-scale-like soft actuator body can imitate the snake-driven scales to continue to shrink and crawl forward under the action of its own contraction and anisotropic friction coefficient.

[0038] Preferably, this embodiment also demonstrates a method for realizing a magnetically controlled snake-scale-like soft actuator body, wherein the magnetically controlled snake-scale-like soft actuator body comprises at least four groups of fan-shaped scales distributed along the length direction in a certain regular pattern, and all fan-shaped scales are warped out of plane in the same direction.

[0039] Specifically, in the process of manufacturing the magnetically controlled snake-scale-like soft actuator body, first, a stretchable magnetic elastomer sheet is 3D printed, and then 5 rows and 8 columns of identically sized arc-shaped plane cuts are cut on the magnetic elastomer sheet using a carbon dioxide laser cutting machine to obtain the required fan-shaped scales.

[0040] In this embodiment, the radius of the arc-shaped plane shear mark is set to 3.5 mm, the arc length is 6.5 mm, the thickness of the shear mark is 0.2 mm, the distance between adjacent arcs in the same row is 2 mm, the adjacent distance in the same column is 4 mm, the distance between the centers of adjacent staggered arcs is 4 mm x 2 mm, and the thickness of the elastomer mesh sheet is 0.5 mm.

[0041] Next, the left and right ends of the cut magnetoelastic sheet are clamped on a uniaxial stretching device and then stretched outward by 4 mm. Due to the out-of-plane buckling stress generated by the stretching at the shear mark, all the fan-shaped scales in the magnetoelastic sheet change from a horizontal state to an out-of-plane warped state, similar to the outward splay of snake skin scales. The stretched and deformed magnetoelastic sheet is then placed in a first magnetic field and magnetized until magnetic saturation occurs.

[0042] Finally, the magnetic elastomer sheet is removed from the uniaxial stretching apparatus. Due to the release of the tensile strain constraint, the magnetic elastomer sheet will return to a flattened state. In order for the manufactured magnetically controlled snake-like soft actuator to be able to imitate a snake's forward crawling under the synergistic action of magnetic force and friction, the magnetically controlled snake-like soft actuator body needs to have an anisotropic friction coefficient on the ground. Therefore, the portion of the magnetic elastomer sheet without fan-shaped scales and the edge portion where the buckling deformation is unstable due to boundary effects are removed. The remaining portion of approximately three rows and four columns of fan-shaped scales of the same size is used as the magnetically controlled snake-like soft actuator body.

[0043] When an external magnetic field is applied to the magnetically controlled snake-scale-like soft actuator, the actuator expands and deforms along its length, with all of its fan-shaped scales warping out of plane in the same direction. When the external magnetic field is removed, the actuator contracts along its length, with all of its fan-shaped scales returning to their initial horizontal state. After the fan-shaped scales warp out of plane, the backward friction coefficient of the actuator becomes greater than the forward friction coefficient.

[0044] In this embodiment, a magnetic field generator is used to apply a second magnetic field to the magnetically controlled snake-scale-like soft actuator body, causing the magnetically controlled snake-scale-like soft actuator body to expand and deform, and causing its fan-shaped scales to change from a horizontal state to an out-of-plane warped state. The first magnetic field is a pulsed magnetic field, and the second magnetic field is a uniform magnetic field.

[0045] like Figure 2 As shown in the figure, the deformation and motion state of the magnetically controlled snake-scale-like soft actuator body after the magnetic field is applied and removed are simplified modeled, and the motion mechanism of the magnetically controlled snake-scale-like soft actuator body is analyzed to prove that the magnetically controlled snake-scale-like soft actuator body can imitate the snake's driving scales to crawl forward under the action of the second magnetic field. The analysis process is as follows:

[0046] The magnetically controlled snake-scale-like soft actuator is simplified into a model, and a force analysis diagram of the magnetically controlled snake-scale-like soft actuator's motion process after a single application and release of the second magnetic field is established, as shown in the figure. Figure 2 As shown. The forward and backward friction coefficients of the magnetically controlled snake-like soft actuator are set as u1 and u2 respectively. For the convenience of characterization, a three-dimensional structure with 8 groups of ordered tilted scales was prepared by 3D printing. Its cross-sectional shape is similar to that of the Figure 2 The simplified model shown in the figure remains the same, with a thickness of 5 mm, and the friction angles of the structure moving forward and backward are measured respectively. The measurement results show that the friction angle of the structure moving forward is smaller than that of the structure moving backward, that is, the friction coefficient forward is smaller than the friction coefficient backward. Similarly, the ordered scale structure of the magnetically controlled snake-like soft actuator makes its friction coefficient forward on the ground smaller than the friction coefficient backward, that is, u1 <u2。

[0047] The relationship between the relative position (x) of the magnetically controlled snake-scale soft actuator with respect to the ground anchor point and the front and rear friction coefficients within one motion cycle is derived below, where -1 / 2L < x < 1 / 2L, and L is the length of the magnetically controlled snake-scale soft actuator. The origin is set at the middle of the magnetically controlled snake-scale soft actuator body. Since the movement of the magnetically controlled snake-scale soft actuator body is very slow, the effect of inertial force can be ignored and a quasi-static force analysis can be performed. Further, it can be obtained that the frictional forces (F1 and F2) acting on both sides of the anchor point of the magnetically controlled snake-scale soft actuator at the moment of crawling are balanced in the motion direction.

[0048] Assume that the mass of the magnetically controlled snake-scale soft actuator is uniformly distributed along its length, so the linear density ρ = m / l. We find that after applying the second magnetic field, there is the following force balance relationship in the horizontal direction:

[0049]

[0050] When the second magnetic field is removed, there is the following force balance relationship in the horizontal direction:

[0051]

[0052] By solving the above two equations, we can obtain the following equalities. For the expansion deformation process of the magnetically controlled snake-scale soft actuator after applying the second magnetic field, there is:

[0053]

[0054] For the contraction process of the magnetically controlled snake-scale soft actuator after removing the second magnetic field, there is:

[0055]

[0056] The above two equations clearly express the relationship between the relative position of the magnetically controlled snake-scale soft actuator with respect to the ground anchor point and the front and rear friction coefficients during the expansion deformation and contraction movement processes under the magnetic field. Since u1 < u2. Therefore, during the expansion deformation process after applying the second magnetic field, the position of the relative ground anchor point is in the second half of the magnetically controlled snake-scale soft actuator; while during the contraction process after removing the second magnetic field, the position of the relative ground anchor point is in the first half of the magnetically controlled snake-scale soft actuator. Furthermore, forward crawling motion of the magnetically controlled snake-scale soft actuator can be achieved during both the process of applying and removing the second magnetic field.

[0057] Furthermore, according to the above two equations, the greater the difference between the front and rear friction coefficients of the magnetically controlled snake-scale soft actuator, the farther the position of the anchor point deviates from the middle of the magnetically controlled snake-scale soft actuator body, and the longer the forward movement distance in a single motion cycle.

[0058] Example 2:

[0059] As Figure 3 As shown, this embodiment provides a method for manufacturing a magnetically controlled snake-scale-like soft actuator inspired by paper-cutting design, the method comprising:

[0060] Step 1: Use magnetically active programmable soft materials and 3D printing technology to make a magnetic elastomer sheet, and then cure the printed magnetic elastomer sheet at a high temperature of 100° for 5 hours.

[0061] It should be noted that the specific form of 3D printing technology in this embodiment is not limited, and it can be any of the conventional technologies such as direct ink writing technology (DIW), stereolithography technology (SLA), fused deposition modeling technology (FDM) and rapid liquid printing (RLP) technology.

[0062] Preferably, this embodiment uses direct ink 3D printing technology, which is more suitable for flexible composite inks. The printing parameters mainly include extrusion pressure, movement speed, and filling density. Among them, the extrusion pressure is 100-300kPa, the movement speed is 15-40mm / s, and the filling density is 90%.

[0063] Specifically, the magnetically active programmable soft material can use a silicone-based elastic material as its base material, or can use a hydrogel, liquid crystal elastomer, shape memory polymer, etc. This embodiment uses a silicone-based elastic material as an example for description.

[0064] It should be noted that the specific material of the magnetic particles in this embodiment is not limited and can be at least one of Ru-Fe-B particles, Fe-Fe-O-4 particles, chromium dioxide powder, ferrite powder, iron-nickel powder, and iron powder, with a content of 1-80 wt %. Preferably, Ru-Fe-B particles with higher remanence and better programmable properties are used in this embodiment.

[0065] It should be noted that the direct ink writing technology requires the printing ink to have certain rheological properties, including shear thinning and shear yielding properties. Preferably, in this embodiment, nano-silica particles are used to control the rheological properties of the ink.

[0066] Specifically, materials are added according to the mass ratio of PDMS SE1700 (Dow Corning Corp.): Ecoflex-10 part B (Smooth-on Inc.): Ruthenium iron boron hard magnetic particles: nano-silica: platinum catalyst = 1:1:1:0.1:0.1, uniformly stirred and vacuum-removed bubbles to prepare a composite magnetic ink to obtain a magnetically active programmable soft material.

[0067] The prepared composite magnetic ink is poured into a printing barrel, and the model is sliced and 3D printed to produce a magnetic elastomer sheet, wherein the size of the magnetic elastomer sheet is 46mm x 24mm x 0.5mm.

[0068] Step 2: Use carbon dioxide laser cutting technology to cut a series of regularly distributed arc-shaped plane cuts on the solidified magnetic elastomer sheet under the guidance of CAD two-dimensional drawings. When designing, pay attention to retaining 8mm length on both ends as the clamping part. The cutting design size diagram of the magnetic elastomer sheet is as follows: Figure 4 shown.

[0069] Specifically, the radius of the arc-shaped plane shear mark is set to 3.5mm, the arc length is 6.5mm, the thickness of the shear mark is 0.2mm, the distance between adjacent arcs in the same row is 2mm, the adjacent distance in the same column is 4mm, the distance between the centers of adjacent staggered arcs is 4mm x2mm, and the thickness of the elastomer mesh sheet is 0.5mm.

[0070] In this embodiment, the process parameters of the selected carbon dioxide laser cutting machine are: laser power of 12w, cutting speed of 30mm / s.

[0071] Step 3: clamp the cut magnetic elastomer sheet on a uniaxial stretching device and stretch it a certain distance along its length. The arc-shaped scales on the sheet will bend outward due to the out-of-plane buckling force generated by the stretching.

[0072] Specifically, such as Figure 5 As shown, the existing uniaxial stretching device is used to stretch the cut magnetic elastic body sheet. The total length of the stretching is 8 mm. The positions of the clamping areas are located at the left and right ends of the corresponding magnetic elastic body sheet, and the lengths are both about 5 mm. Figure 4 As shown in the dashed boxes in the figure, the clamping areas on the left and right sides cover the entire edge of the magnetoelastic sheet. After the stretching process is completed, the obtained tensile strain is stably maintained by a fixture.

[0073] Step 4: Place the stretched and deformed magnetic elastomer sheet in a first magnetic field (pulsed magnetic field) and magnetize it to saturation, wherein the magnitude of the pulsed magnetic field M is between 1-4T, and is set to 3T in this embodiment.

[0074] Specifically, the stretched magnetic elastomer sheet and the uniaxial stretching device are placed inside the magnetizing coil of the magnetizer. The voltage of the magnetizer is set to 1200V, and the corresponding magnetic field size inside the magnetizing coil is about 3T. The magnetic field is instantly released within a short time (about 10ms) to complete the magnetization programming process of the magnetic elastomer sheet.

[0075] Step 5: After the magnetization is completed, the stretching device and the magnetic elastomer sheet are taken out from the magnetizing device, and then the magnetic elastomer sheet is removed from the uniaxial stretching device, and the magnetic elastomer sheet is cut into pieces to make the magnetically controlled snake-scale-like soft actuator body.

[0076] Specifically, after the clamping device is opened and the magnetic elastomer sheet is removed from the uniaxial stretching device, the magnetic elastomer sheet will return to its initial cut shape (horizontal state) due to the release of the tensile strain constraint.

[0077] In order to ensure that the magnetically controlled snake-scale-like soft actuator has a stable difference in friction coefficient along the length direction during the application and release of the second magnetic field, thereby providing the magnetically controlled snake-scale-like soft actuator with a forward driving force under the action of the magnetic field, the portion of the magnetic elastomer sheet without fan-shaped scales and the edge portion where the buckling deformation is unstable due to the boundary effect are removed, and the fan-shaped scale portion of about 3 rows and 4 columns of the same size is finally retained as the main body of the magnetically controlled snake-scale-like soft actuator, as shown in FIG. Figure 4 As shown in the solid box.

[0078] Combine Figure 3 and Figure 4 It can be seen that once the magnetically controlled snake-scale-like soft actuator body is manufactured and a second magnetic field B is applied to it, the actuator body will expand and deform, and its internal fan-shaped scales will change from a horizontal state to a warped state, similar to the state when a snake's body expands and deforms, driving the scales of its skin. In this deformed state, the friction coefficient of the magnetically controlled snake-scale-like soft actuator body moving backward will be greater than the friction coefficient of forward movement. Based on the force analysis above, it can be seen that during the expansion and deformation process, the position of the magnetically controlled snake-scale-like soft actuator body's anchor point with the ground will be located at the rear end of the middle part of the magnetically controlled snake-scale-like soft actuator body, that is, the magnetically controlled snake-scale-like soft actuator will expand and deform forward.

[0079] After removing the second magnetic field B, the actuator contracts and flattens the skin scales. During this deformation, the ground anchor point is located at the front end of the actuator's middle section, indicating that the actuator will continue to contract forward. The detailed force analysis is omitted here.

[0080] After that, the magnetically controlled snake-scale-like soft actuator body can be passed through an external uniform magnetic field B (second magnetic field) of about 150mT and driven in a cyclic manner, so that the magnetically controlled snake-scale-like soft actuator body can continuously crawl forward in the same way as a snake drives its skin scales. The result of its crawling on flat ground is as follows: Figure 6 shown.

[0081] It should be noted that, since this scale-like structure can generate a large reverse friction force, it helps to prevent the magnetically controlled snake-scale-like soft actuator body from sliding in the reverse direction. Therefore, the magnetically controlled snake-scale-like soft actuator body in this embodiment can also continuously climb upward under the cyclic drive of the second magnetic field. The result of its climbing on the inclined plane with an inclination angle of 20° is shown in FIG. Figure 7 shown.

[0082] The technical solution proposed in this application demonstrates a new structure and actuation mode for a magnetically controlled, snake-scale-like soft actuator inspired by paper-cutting, compared to existing magnetically controlled soft robots. It also possesses certain climbing and obstacle-crossing capabilities, facilitating the further application of magnetically controlled soft robots in fields such as biomedicine and pipelines. By combining the ancient art of paper-cutting with mechanical stretching-guided out-of-plane buckling deformation, a complex three-dimensional structure difficult to achieve using traditional mold manufacturing is achieved, significantly reducing the manufacturing difficulty of the magnetically controlled, snake-scale-like soft actuator.

[0083] The steps in this application may be adjusted in order, combined, and deleted according to actual needs. The units in the device of this application may be combined, divided, and deleted according to actual needs. Although the present application is disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and are not intended to limit the application of this application. The scope of protection of this application is defined by the appended claims and may include various modifications, variations, and equivalents made to the invention without departing from the scope and spirit of protection of this application.

Claims

1. A magnetically controlled snake-scale-like soft actuator, comprising a magnetically controlled snake-scale-like soft actuator body and a magnetic field generator; The magnetically controlled snake-scale-like soft actuator body comprises a series of magnetic elastomer sheets with regularly distributed arc-shaped planar shear marks. Magnetic particles are mixed into the magnetic elastomer sheets to form fan-shaped scales formed by the arc-shaped planar shear marks. The magnetic particles are magnetized in a first magnetic field so that all the fan-shaped scales of the magnetically controlled snake-scale-like soft actuator body are programmed to have a non-uniform magnetic domain distribution, resulting in out-of-plane warping and expansion deformation along the length direction in a uniform magnetic field. The magnetic field generator is used to apply a second magnetic field to the magnetically controlled snake-scale-like soft actuator body, so that all the fan-shaped scales of the magnetic elastomer sheet change from a horizontal state to an out-of-plane warped curved state, and at the same time, the magnetically controlled snake-scale-like soft actuator body expands and deforms along the length direction; The magnetically controlled snake-scale-like soft actuator body comprises at least four groups of fan-shaped scales arranged along the length direction. All the fan-shaped scales are warped out of the plane in the same direction in the second magnetic field, similar to the warping state of the scales on the surface of snake skin. When a second magnetic field is applied, the backward friction coefficient of the magnetically controlled snake-scale-like soft actuator body is greater than the forward friction coefficient after expansion and deformation, and a forward expansion movement will occur; when the magnetic field is removed, the magnetically controlled snake-scale-like soft actuator body recovers its deformation and can imitate the snake-driven scales to continue to contract and crawl forward under the action of its own contraction and anisotropic friction coefficient.

2. The magnetically controlled snake-scale-like soft actuator according to claim 1, characterized in that: The first magnetic field is a pulsed magnetic field, and the second magnetic field is a uniform magnetic field.

3. The magnetically controlled snake-scale-like soft actuator according to any one of claims 1 to 2, characterized in that: The magnetically controlled snake-scale-like soft actuator is made of soft materials, 3D printing and laser cutting technology; The soft material uses a silicone-based elastic material as the matrix material, and then adds Ruthenium-iron-boron magnetic particles to the matrix material with a content of 1-80wt%. The silicone-based elastic material with added Ruthenium-iron-boron magnetic particles is used to 3D print magnetic elastomer sheets and laser cut to make the magnetically controlled snake-scale-like soft actuator body.

4. A method for manufacturing the magnetically controlled snake-scale-like soft actuator according to any one of claims 1 to 3, the method comprising: Step 1: Using magnetically active programmable soft materials and 3D printing technology to make a magnetic elastomer sheet and curing it at high temperature; Step 2: Using laser cutting technology, a series of regularly distributed arc-shaped plane cuts are cut on the solidified magnetic elastomer sheet, and a certain length is retained at the left and right ends as the clamped parts; Step 3: clamp the cut magnetic elastomer sheet on a uniaxial stretching device and stretch it a certain distance along its length. The fan-shaped scales on the sheet will bend outward due to the out-of-plane buckling force generated by the stretching. Step 4, placing the stretched and deformed magnetic elastomer sheet in a first magnetic field and magnetizing it to saturation; Step 5: remove the magnetic elastomer sheet from the uniaxial stretching device and cut the magnetic elastomer sheet into pieces to make the magnetically controlled snake-scale-like soft actuator body.

5. The method for manufacturing the magnetically controlled snake-scale-like soft actuator according to claim 4, characterized in that: In step 1, the 3D printing technology adopts the ink direct writing 3D printing technology of flexible composite material ink, wherein the extrusion pressure is 100-300kPa, the moving speed is 15-40mm / s, and the filling density is 90%.

6. The method for manufacturing the magnetically controlled snake-scale-like soft actuator according to any one of claims 4 or 5, characterized in that: In step 2, the radius of the arc-shaped plane shear mark is set to 3.5 mm, the arc length is 6.5 mm, the thickness of the shear mark is 0.2 mm, the distance between adjacent arcs in the same row is 2 mm, the adjacent distance in the same column is 4 mm, the distance between the centers of adjacent staggered arcs is 4 mm x 2 mm, and the thickness of the elastomer mesh sheet is 0.5 mm.

7. The method for manufacturing the magnetically controlled snake-scale-like soft actuator according to any one of claims 4 to 6, characterized in that: In step 3, the cut magnetic elastomer sheet is stretched using an existing uniaxial stretching device, and the total stretching length is 8 mm. The clamping areas are located at the left and right ends of the corresponding magnetic elastomer sheet, and the lengths are both about 5 mm. The clamping areas at the left and right ends cover the entire edge of the magnetic elastomer sheet. After the stretching process is completed, the obtained tensile strain is stably maintained using a fixing device.

8. The method for manufacturing the magnetically controlled snake-scale-like soft actuator according to any one of claims 4 to 7, characterized in that: In step 4, the stretched magnetic elastomer sheet and the uniaxial stretching device are placed inside the magnetizing coil of the magnetizer. The voltage of the magnetizer is set to 1200V, and the magnetic field size inside the magnetizing coil is correspondingly 1-4T. The magnetic field is released instantaneously in a short time to complete the magnetization programming process of the magnetic elastomer sheet.

Images