Magnetic mucus robot, composition for manufacturing same, and use thereof

Abstract

The invention provides a multifunctional magnetic composition which can be applied to mucus robots, sensors and the like. In one embodiment, the composition comprises: a) 0.005 to 5 wt.% of a source of tetrafunctional borate ions, the source of tetrafunctional borate ions being used to provide tetrafunctional borate ions; b) a buffer solution for maintaining the pH at 6.5 to 9.5; c) 0.005 to 80 wt.% of magnetic particles; and d) a polymer glue having a hydroxyl group; the tetrafunctional borate ions, the buffer solution and the magnetic particles are crosslinked in the polymer glue to form the non-Newtonian fluid composition.

Description

Technical Field

[0001] The invention relates to a small soft robot. Background Art

[0002] Microrobots that respond to external stimuli have the advantages of being less invasive and more accessible, and are ideal options for biomedical applications such as targeted drug delivery, minimally invasive surgery, and cell transplantation. Using external magnetic fields to drive small robots is a promising option due to its safety, precision, and fast response. To date, most magnetically driven soft robots are made of hard magnetic particles mixed with soft elastomers. Such elastomer-based soft robots are able to perform a variety of motion modes, adapt to complex interface environments, and enter small spaces for robotic manipulation applications. However, the functions of elastomer-based soft robots are limited by their pre-designed shapes and cannot be reconfigured on site. In addition, elastomer-based soft robots have limited deformation capabilities and cannot pass through small spaces that are much smaller than their size.

[0003] In contrast, the latest research shows that small fluid-based robots, such as those based on liquid metal or ferrofluid, behave more gently and softly. Fluid-based soft robots have better deformation capabilities than elastomer-based soft robots due to their fluid flow properties, which enables them to easily pass through extremely narrow and confined spaces without damaging surrounding biological tissues. For example, by constructing an electromagnetic array, researchers built an intelligently deformable and cooperative ferrofluid-based soft robot that can pass through a narrow channel with a diameter of 1.5 mm and perform various functions. In addition, researchers have also used liquid metal-based soft robots to realize the functions of circuit control and fluid pumping. However, robots based on ferrofluids and liquid metals require very harsh operating environments; for example, oil-based ferrofluids require hydrophilic surfaces surrounded by aqueous solutions to maintain their spherical droplet shape without adhering to the substrate, while liquid metals require alkaline or acidic solutions to maintain their spherical droplet morphology without adhering to the substrate. Therefore, it is necessary to combine the high deformation characteristics of liquid robots with the complex interface adaptability of elastomer robots to create new types of soft robots. Summary of the invention

[0004] The present invention provides a multifunctional magnetic composition. In one embodiment, the composition comprises: a) 0.005-5wt.% of a tetrafunctional borate ion source, the tetrafunctional borate ion source is used to provide tetrafunctional borate ions; b) a buffer for maintaining pH at 6.5 to 9.5; c) 0.005-80wt.% of magnetic particles; and d) a polymer glue having hydroxyl groups; the tetrafunctional borate ions, the buffer and the magnetic particles are cross-linked in the polymer glue to form a non-Newtonian fluid composition.

[0005] The present invention also provides a slime robot comprising the composition.

[0006] The present invention further provides a system comprising: a) one or more slime robots described in the present invention; and b) one or more magnetic field generators.

[0007] The present invention also provides a sensor comprising the composition. In one embodiment, the sensor measures the change in electrical properties of the composition in response to one or more mechanical stimuli.

[0008] The present invention also provides a device comprising the composition. In one embodiment, the composition is used to control the conductivity of a part in a circuit.

[0009] The present invention further provides a method for using the composition to achieve a certain function. In one embodiment, the method comprises the following steps: a) providing the composition to a location where the function needs to be achieved; b) placing the composition in a magnetic field; and c) controlling the magnetic field to guide the movement of the composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Examples of the present invention will be described in detail in conjunction with the following drawings. The embodiments and drawings disclosed herein should be considered as exemplary rather than restrictive. The same reference symbols and marks in the various drawings represent the same elements.

[0011] Figure 1 Schematic diagram showing the characteristics and application scenarios of the magnetic slime robot.

[0012] Figure 2 Schematic diagram showing the preparation of the magnetic slime robot, as well as its physical image and scanning electron microscope image.

[0013] Figure 3 shows the viscoelasticity of the magnetic slime robot.

[0014] Figure 4 Demonstrating in vitro cytotoxicity of the magnetic mucus robot.

[0015] Figure 5 Demonstrating the active and passive deformation capabilities of the magnetic slime robot.

[0016] Figure 6 It demonstrates the relationship between the deformation ability of the magnetic slime robot and the content of internal magnetic particles, the relationship between the deformation ability of the magnetic slime robot and the strength of the permanent magnet, and the relationship between the minimum diameter of the thin tube that the magnetic slime robot can pass through and the magnetic field strength.

[0017] Figure 7 Demonstrate a comparison of the deformation capabilities of the magnetic slime robot, ferrofluid droplet robot, and liquid metal robot.

[0018] Figure 8 It is a series of screenshots from a video showing the magnetic slime robot being driven through channels, pipes, mazes, and uneven surfaces in the atmosphere.

[0019] Fig. 9 It is an underwater stability test of the magnetic slime man.

[0020] Fig.10 Demonstrating the process of a magnetic slime robot traversing a narrow underwater channel.

[0021] Fig.11 It is a test of the adhesion performance of the magnetic slime robot.

[0022] Fig.12 Overlapping consecutive screenshots from a video showing the magnetic slime robot being driven along “S”, “L”, “I”, “M”, “E”, “B”, “O”, and “T” trajectories on different substrate surfaces in air.

[0023] Fig.13 It is a magnetic drive system for magnetic slime robots.

[0024] Fig.14 Demonstration of the magnetic slime robot grasping a single target object (top) and multiple target objects (bottom) in curling mode.

[0025] Fig.15 Demonstration of the magnetic slime robot grasping a target object in an open environment (top) and a complex constrained environment (bottom) in endocytosis mode.

[0026] Fig.16 Shows two button batteries (unwrapped and wrapped in the mucus robot) placed between the intestinal lining.

[0027] Fig.17 Demonstrating the operation of the magnetic slime robot in sickle mode.

[0028] Fig.18 It is an analysis of the self-healing performance of the magnetic slime robot.

[0029] Fig.19 Demonstrate that the magnetic slime robot can act as a circuit switch or be used to repair circuits.

[0030] Fig. 20 The relationship between the relative resistance and strain, the relative resistance and bending angle, and the relative resistance and twisting angle of the magnetic slime robot are shown.

[0031] Fig.21 Demonstrating that magnetic slime robots can be used to monitor human movement. DETAILED DESCRIPTION

[0032] The present invention discloses materials, devices, methods and systems for a multifunctional magnetic mucus robot. The magnetic mucus robot may include hydrogel and magnetic material. The device of the magnetic mucus robot includes a magnetic drive system consisting of a non-Newtonian fluid mucus robot body and a three-axis robotic arm. The method may include: a method for actively and passively deforming the magnetic mucus robot; a method for causing the magnetic mucus robot to produce curling behavior; and a control strategy for causing the magnetic mucus robot to produce an endocytosis mode. An operating system based on a magnetic mucus robot can be used to grab foreign objects in a living body and can also be used for circuit repair.

[0033] Embodiments of the present invention relate to materials, devices, methods and systems for preparing and driving a multifunctional magnetic mucus robot. The magnetic mucus robot can be prepared based on viscoelastic hydrogels and magnetic particles. The present invention includes a magnetic field generating device for driving the movement of the magnetic mucus robot. The present invention also includes a method for driving the magnetic mucus robot to produce curling behavior and endocytosis behavior. In addition, the present invention relates to all materials, devices and systems for a multifunctional magnetic mucus robot.

[0034] In one aspect, the present invention provides a magnetic slime robot with large deformation ability and adaptability. Existing elastomer-based soft robots have good environmental adaptability, while liquid-based soft robots have the characteristic of being able to deform significantly. The magnetic slime robot combines the characteristics of strong deformation ability and environmental adaptability. Compared with existing elastomer-based soft robots, the slime robot proposed in the present invention has better deformation ability, for example, it can pass through narrow pipes (1.5 mm) and complex maze environments. In addition, compared with existing fluid-based soft robots, the slime robot has stronger environmental adaptability, and can not only move in two-phase fluids, but also in the atmosphere, and even on various surfaces such as hydrogels, metals and plastics.

[0035] On the other hand, the present invention provides a magnetic slime robot with multiple functions. The magnetic slime robot is reconfigurable, self-healing and conductive, and thus has multiple functions. In some embodiments, the slime robot may have multiple reconfigurable functions, such as grasping and transferring objects through a curling mode, and wrapping and transporting harmful substances through an endocytosis mode. In addition, the self-healing and conductive capabilities enable the slime robot to be used as an electrical device, such as a piezoresistive strain sensor to monitor human body movement, and as a circuit control switch or circuit breaker repair agent. The magnetic slime robot with large deformation ability, reconfigurability, self-healing and conductivity is expected to be of great value in wearable devices and biomedical applications.

[0036] The magnetic slime robot with large deformation ability, reconfigurability, self-healing and conductivity is expected to be of great value in wearable devices and biomedical applications, such as targeted drug delivery and minimally invasive surgery. The details of one or more embodiments of the present invention are set forth in the accompanying drawings and the following description. Other features, objects and advantages of the present invention are apparent from the drawings, detailed description and claims.

[0037] The present invention provides a multifunctional magnetic mucus robot. In one embodiment, the multifunctional magnetic mucus robot comprises: a compound, solution or salt containing / releasing borate ions, the content of which is about 0.005 weight percent to about 5 weight percent; and a buffer solution, the content of which is sufficient to maintain the pH of the composition in the range of about 6.5 to about 9.5; and magnetic particles, the content of which is about 0.005 weight percent to about 80 weight percent; the mucus robot is cross-linked with a polyvinyl alcohol-based glue or other polymer glue / adhesive to form a magnetic mucus robot composition; by applying external stimulation, a magnetic mucus robot is guided to a part of the patient's gastrointestinal tract that needs treatment, the external stimulation comes from outside the patient's body, and enables the mucus robot to expand, curl and grasp; the mucus robot is driven to reach a restricted environment that is difficult for traditional robotic arms and humans to reach, to repair the broken part of the circuit; the magnetic mucus robot is encapsulated to serve as a piezoresistive sensor for wearable devices.

[0038] In one embodiment, the slime robot comprises a compound, solution or salt containing / releasing borate ions, and the compound, solution or salt containing / releasing borate ions is boric acid, sodium borate, sodium tetraborate, disodium tetraborate, sodium tetraborate decahydrate or any combination thereof.

[0039] In one embodiment, the content of the compound, solution or salt containing / releasing borate ions is about 0.005 weight percent to about 0.5 weight percent.

[0040] In one embodiment, the glue / adhesive is a polyvinyl acetate-based glue / adhesive, a polyvinyl alcohol-based glue / adhesive, or other polymer-based glue / adhesive with appropriate cross-linking function (applicable to all molecular weights).

[0041] In one embodiment, the slime robot includes magnetic particles, such as neodymium iron boron (NdFeB), nickel, iron and its oxides, other magnetic metal oxides or any combination thereof.

[0042] In one embodiment, the content of the magnetic particles is about 0.005 weight percent to about 80 weight percent.

[0043] In one embodiment, the content of the magnetic particles is about 0.005 weight percent to about 80 weight percent.

[0044] The present invention also provides a method for preparing a slime robot composition. In one embodiment, the method comprises: combining a compound containing / releasing borate ions, magnetic particles, and a polyvinyl alcohol-based glue / adhesive or other polymer-based glue / adhesive with appropriate cross-linking function.

[0045] The present invention also provides a system for driving the magnetic slime robot of the present invention. In one embodiment, the system comprises: a plurality of controllable magnetic slime robots; and a magnetic field generator capable of guiding the plurality of magnetic slime robots through a magnetic field.

[0046] The present invention further provides a method for treating a patient using the multifunctional magnetic mucus robot of the present invention. In one embodiment, the method comprises the following steps: i) delivering the multifunctional magnetic mucus robot into the gastrointestinal tract of a patient through an endoscope; ii) causing the multifunctional magnetic mucus robot to reach an operable position in the gastrointestinal tract through external stimulation; and iii) guiding the multifunctional magnetic mucus robot to a part of the gastrointestinal tract that needs to be treated through X-ray fluoroscopic imaging.

[0047] In one embodiment, the area in need of treatment includes debris or swallowed foreign matter in the gastrointestinal tract.

[0048] In one embodiment, guiding the magnetic mucus robot to a site in need of treatment comprises manipulating the mucus robot via one or more external magnetic fields.

[0049] The present invention also provides a method for circuit repair using the multifunctional magnetic slime robot of the present invention. In one embodiment, the method comprises: sending the magnetic slime robot into a restricted position; and controlling the magnetic slime robot to curl by an external magnetic field.

[0050] In one embodiment, the restricted location includes an environment with or without gravity, or an environment with or without radiation.

[0051] The present invention also provides a method for using the multifunctional magnetic slime robot of the present invention to monitor motion. In one embodiment, the method comprises: encapsulating the magnetic slime robot in tape as a piezoresistive sensor; and adhering the piezoresistive sensor to the moving part.

[0052] The present invention also provides a method for removing biofilm using the multifunctional magnetic mucus robot of the present invention. In one embodiment, the method comprises: modifying the mucus robot with an antimicrobial agent, then arranging the mucus robot at the location of the biofilm, and using the mucus robot to mechanically scrape the biofilm.

[0053] The present invention also provides a method for cleaning ultra-precision instruments using the multifunctional magnetic slime robot of the present invention. In one embodiment, the method comprises: driving the slime robot into the interior of the instrument and using its viscosity to remove dust or other dirt.

[0054] The present invention provides a multifunctional magnetic composition. In one embodiment, the composition comprises: a) 0.005-5wt.% of a tetrafunctional borate ion source, the tetrafunctional borate ion source is used to provide tetrafunctional borate ions; b) a buffer for maintaining pH at 6.5 to 9.5; c) 0.005-80wt.% of magnetic particles; and d) a polymer glue having hydroxyl groups; wherein the tetrafunctional borate ions, the buffer and the magnetic particles are cross-linked in the polymer glue to form a non-Newtonian fluid composition.

[0055] In one embodiment, the tetrafunctional borate ion source is selected from one or more of boric acid, sodium borate, disodium tetraborate, sodium tetraborate decahydrate or sodium tetraborate.

[0056] In one embodiment, the buffer comprises deionized water or phosphate buffer.

[0057] In one embodiment, the magnetic particles are: a) metal oxide particles; b) NdFeB particles; or c) coated with silicon dioxide (SiO2).

[0058] In one embodiment, the polymer glue is polyvinyl alcohol. In another embodiment, the polyvinyl alcohol includes one or more selected from PVA 07-18, PVA 07-19, PVA 08-08 or PVA 08-18.

[0059] The present invention also provides a slime robot comprising the composition of the present invention.

[0060] The present invention further provides a system comprising: a) one or more slime robots described in the present invention; and b) one or more magnetic field generators.

[0061] In one embodiment, the one or more magnetic field generators include a robotic arm, a stepper motor, and a permanent magnet, wherein the stepper motor is located at the end of the robotic arm and adjusts the speed and direction of the permanent magnet.

[0062] In one embodiment, the permanent magnet is a spherical magnet.

[0063] The present invention also provides a sensor comprising the composition of the present invention. In one embodiment, the sensor measures the change in electrical properties of the composition in response to one or more mechanical stimuli.

[0064] In one embodiment, the electrical property includes one or more of impedance or resistance.

[0065] In one embodiment, the one or more mechanical stimuli include one or more of stretching, bending or twisting.

[0066] The present invention further provides a device comprising the composition of the present invention. In one embodiment, the composition is used to control the conductivity of a portion of a circuit.

[0067] In one embodiment, the part is: a) an electrical switch or a resistor; or b) a damaged part.

[0068] The present invention further provides a method for using the composition of the present invention to achieve a certain function. In one embodiment, the method comprises the following steps: a) providing the composition to a location where the function needs to be achieved; b) placing the composition in a magnetic field; and c) controlling the magnetic field to guide the movement of the composition.

[0069] In one embodiment, the functions include one or more of: a) removing biofilm; b) cleaning ultra-precision instruments; c) repairing circuits; or d) retrieving one or more objects from a cavity.

[0070] In one embodiment, the one or more objects are swallowed foreign bodies and the cavity is the gastrointestinal tract.

[0071] In one embodiment, the movement comprises grasping, wrapping, unfolding, curling or endocytosis.

[0072] In one embodiment, the location is: a) an environment with or without gravity; or b) an environment with or without radiation.

[0073] The present invention may be more readily understood by reference to the detailed description which forms a part hereof. The present invention is not limited to the specific materials, apparatus, methods or systems described and / or illustrated herein. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although materials, apparatus, methods and systems similar or equivalent to those described herein may be used to practice or test the present invention, suitable methods and materials are described below. The present invention describes specific embodiments of magnetic slime robots, including preparation methods, drive systems, and various potential application scenarios ( Figure 1 ).

[0074] The preparation scheme of the magnetic slime robot of the present invention is as follows Figure 2As shown, magnetic particles (NdFeB) and borax are sequentially added to a polyvinyl alcohol (PVA) solution to obtain a magnetic slime robot. The magnetic particles can be extended to other magnetic particles such as nickel, iron and their oxides, as well as other magnetic metal oxides. The inset shows the key reactions required to form the magnetic slime robot 201. The formation of the magnetic slime robot is mainly through the interaction between tetrafunctional borate ions and the -OH groups of PVA, where the tetrafunctional borate ions are generated by the hydrolysis of borax. It is worth noting that the water content in the magnetic slime robot exceeds 90wt%, which means that it is essentially a hydrogel. Scanning electron microscopy (SEM) image 202 shows that the microstructure of the magnetic slime is a three-dimensional (3D) porous network formed by cross-linking magnetic particles with immobilized polymers. The porous structure is conducive to the ductility and rapid response ability of the magnetic slime robot.

[0075] To evaluate the rheological properties and magnetorheological characteristics of the slime robot of the present invention ( FIG. 3 ), a rheometer (Anton Paar MCR302) equipped with a 25 mm parallel plate setting was used in the present embodiment. First, a dynamic strain sweep ranging from 0.1% to 100% was performed at ω = 10.0 Hz, and the storage modulus (G') 301 was recorded to define the linear viscoelastic region (LVR) where the storage modulus is not affected by the strain amplitude. A strain of 1.0% was selected in subsequent oscillation tests to ensure that the dynamic oscillation deformation of each sample was within the LVR range. 302 shows the storage modulus (G', solid symbols) and loss modulus (G", open symbols) of non-magnetic mucus (NdFeB: 0%) and magnetic mucus (NdFeB: 50%) as a function of angular frequency. Both mucus robots are in the solid state, and the storage modulus is higher than the loss modulus over the entire frequency range. The presence of NdFeB particles increases the modulus and enhances the elastic response of the mucus robot. In addition, 303 shows the dependence of G' on the magnetic field at a fixed strain amplitude (0.2%) and angular frequency (6rad / s). As The storage modulus of the magnetic slime robot changes significantly with the increase of magnetic field intensity, indicating a significant magnetorheological effect. Due to the effect of magnetic dipole-dipole forces, the application of a magnetic field can enhance the mechanical properties of the magnetic slime robot. The magnetic field-dependent dynamic viscoelasticity is mainly attributed to the interaction between adjacent particles during magnetization. This interaction tightens the polymer chains, making the structure more rigid. The magnetorheological effect enables the magnetic slime robot to exhibit adjustable stiffness by applying a magnetic field. Therefore, the stiffness of the magnetic slime robot can be controlled to adapt it to different working environments.

[0076] To evaluate the cytotoxicity of the mucus robot of the present invention, NIH 3T3 cells were seeded in a 96-well plate at a density of 2,000 cells per well and cultured in 100 μL Eagle's minimum essential medium containing 10% fetal bovine serum for 12 hours. Figure 4 As shown, at concentrations up to 400μg / mL, the non-magnetic mucus material was non-toxic to NIH 3T3 cells, indicating good biocompatibility. However, NdFeB particles are toxic, making the magnetic mucus robot (NdFeB: 30%) not biocompatible. Therefore, the NdFeB microparticles were coated with silicon dioxide (SiO2). Transmission electron microscopy images showed that the NdFeB microparticles were coated with a 35nm layer of SiO2. Subsequently, they were added to a PVA solution to prepare the magnetic mucus robot. Cytotoxicity tests showed that the 400μg / mL magnetic mucus robot prepared using NdFeB@SiO2401 was non-toxic to cells.

[0077] In some embodiments, the magnetic slime robot can be deformed into complex shapes, such as circles, hexagons, and rings, under the configured magnetic field. Since the unmagnetized magnetic particles in the slime tend to move to the position with the lowest magnetic field strength, the shape of the magnetic slime robot is similar to the shape of the permanent magnet 501 at the bottom. This allows the magnetic slime robot to change its shape according to the needs of different tasks. Figure 5 It shows that the magnetic slime robot can be stretched to more than seven times its original length along the direction of magnet movement under the drive of the permanent magnet 502. At t = 0 seconds, a magnetic slime robot with a diameter of 9 mm is placed on a polymethyl methacrylate substrate, and a circular permanent magnet with a diameter of 20 mm and a height of 10 mm is set 4 mm below the substrate. When the circular permanent magnet moves at a speed of 2 mm / s, the slime robot begins to stretch and stretches to 60 mm after 71 seconds.

[0078] In order to achieve the best deformation control of the magnetic slime robot, the present invention carefully studied the aspect ratio of the slime robot under different magnetic particle contents and external magnetic field strengths. Figure 6As shown, under the same external magnetic field, the aspect ratio of the deformation of the magnetic slime robot is proportional to the magnetic particle content. Under the action of an external magnetic field, the increase in the magnetic powder content significantly enhances the magnetic response of the slime robot, causing it to be subjected to a stronger deformation force. In addition to the magnetic particle content, the external magnetic field strength also affects the deformation behavior of the magnetic slime. The deformation ability of the magnetic slime robot is positively correlated with the intensity of the external magnetic field. The movement behavior of the particles inside the slime robot is determined by the magnetic field intensity, which in turn affects its overall deformation characteristics. In order to demonstrate the movement ability of the magnetic slime robot in a confined environment, the present invention studies the minimum diameter of the pipe it can pass through. The experimental results show that at a fixed magnetic particle content and slime volume, the minimum diameter of the channel that the magnetic slime robot can pass through is 1.5 mm. As the external magnetic field intensity decreases, the minimum diameter of the pipe it can pass through increases. The present invention compares the deformation capabilities of ferrofluid droplets, magnetic liquid metals, and magnetic slime robots under the same magnetic field intensity. As Figure 7 As shown, under low magnetic field strength, the ferrofluid droplet robot has the best deformation ability; however, as the magnetic field strength increases, it is difficult for the ferrofluid droplet robot to maintain integrity. The maximum elongation lengths of the mucus robot and the liquid metal robot increase linearly with the increase of the magnetic field strength. Under the same magnetic field strength, the elongation length of the mucus robot is greater than that of the magnetic liquid metal robot. In addition, the present invention also compares the maximum elongation lengths of ferrofluid droplets, magnetic liquid metals and mucus robots of the same volume. The results show that the mucus robot has the greatest elongation when the volumes are equal.

[0079] In some embodiments, the passive and active deformation capabilities of the magnetic slime robot bring significant advantages to it, not only being able to adapt to complex terrain environments, but also being able to enter narrow spaces in a controlled manner while maintaining its mobility and integrity. Its deformation characteristics enable the slime robot to adapt to the ever-changing external environment to meet the needs of multi-tasking. Figure 8As shown, under the control of a magnetic field, the slime robot can freely traverse various terrains, such as narrow channels 801, confined pipes 802, complex mazes 803, and uneven substrates 804. First, an array consisting of channels with diameters of 6, 4.5, 3, and 1.5 mm was prepared to test the deformation ability of the magnetic slime robot. According to the experimental results, although the magnetic slime robot took a long time (about 180 seconds) to pass through the 1.5 mm diameter channel, it was eventually able to pass through each channel in turn. Subsequently, 1 mL of the magnetic slime robot was able to flow smoothly in a liquid-free pipe with an inner diameter of 5 mm. The deformation ability enables the slime robot to quickly adapt to the curved pipe structure and stretch its shape along the direction of its movement in the pipe. In addition, the present invention also prepared a maze with different inner diameters (minimum gap: 1.5 mm) and complex branches to demonstrate the deformation ability and controllability of the slime robot. Finally, the slime robot was able to migrate on an uneven terrain with a width of 6.28 mm and a height of 3 mm. In addition to the demonstrated controllable deformation behavior under the atmosphere, the slime robot can also work stably in underwater environments 901, 902 and meet the needs of various tasks ( Fig. 9 and Fig.10 ). By actively and passively changing its shape, the magnetic slime robot can operate without obstacles on a variety of terrains, significantly reducing damage to the surrounding environment and expanding its application scenarios.

[0080] In order to further understand the adhesion performance of the slime robot, the present invention studied the peel strength between the slime robot and the substrate. Fig.11 As shown, the experimental results show that paper has the highest adhesion strength, and it decreases with the increase of magnetic particle content. This is mainly due to the better water absorption effect and rough surface of paper, which enables the slime robot to diffuse into its micropores and remain on the paper during the peeling process. When the binding force of hydrogen bonds is greater than the van der Waals force, the hydrogen bonds between the PVA molecular chains enhance the adhesion of the material during the material tearing process. In addition, magnetic particles reduce the adhesion performance of the slime robot because they prevent the hydroxyl groups in the PVA molecular chains from binding to water molecules. This adhesion performance reduces the deformation speed and overall movement speed; however, the driving magnetic field can overcome this effect and avoid it affecting the final deformation and reachable range. The magnetic slime robot described in the present invention can adapt to a variety of substrates. The present invention prepared eight commonly used substrates including hydrogels, metals, plastics, glass, silicone, silicon, polydimethylsiloxane (PDMS) and paper, and cut them into 10cm×10cm samples. As shown Fig.12 As shown, a 500 μL slime robot can follow the trajectory of “SLIMEBOT” on these substrates when driven by a permanent magnet.

[0081] The magnetic drive system of the present invention is composed of a mechanical arm 1301, a stepping motor 1302 and a spherical permanent magnet 1303 with a diameter of 20 mm. Fig.13 As shown, the three-degree-of-freedom robotic arm is loaded with a permanent magnet driven by a motor, and the robotic arm can move to a target position that is autonomously encoded according to task requirements. In addition, a stepper motor is provided at the end of the robotic arm, which can adjust the speed and direction of the permanent magnet as needed. Therefore, the entire system can generate a directional gradient magnetic field and a non-uniform rotating magnetic field. The magnetic field strength on the surface of the permanent magnet is about 700mT, and the magnetic field strength at a distance of 10mm from the permanent magnet is about 200mT. The magnetic field strength required to drive the magnetic slime robot to traverse complex terrain, grasp and transport objects is about 200mT. In addition, the magnetic slime robot can also be driven by two robotic arm systems controlled in a collaborative manner.

[0082] The present invention will be better understood by reference to the following experimental details, but those skilled in the art will readily appreciate that the specific experiments described are for illustrative purposes only and are not intended to limit the invention described herein, the scope of which is defined by the following claims.

[0083] Various references or publications are cited in this application. The entire contents of these references or publications are hereby incorporated by reference into this application to more fully describe the prior art in the technical field to which the present invention belongs. It should be noted that the transitional term "comprising", with its synonyms "including", "containing" or "characterized by", is inclusive or open, and does not exclude additional, unmentioned elements or method steps. Example 1

[0084] In some embodiments, the magnetic slime robot can also use its reconfigurability to achieve flexible manipulation. Fig.14 As shown in (above), the slime robot can grab the copper wire 1401 in a curling mode after being stretched. At t = 0 seconds, the magnetic slime robot driven by an external permanent magnet begins to stretch. After 46 seconds, the slime robot stretches to the bottom of the target object. During the stretching process, the magnetic particles in the slime robot are magnetized by the external permanent magnet and maintain a consistent magnetization direction. Because the slime robot exhibits non-Newtonian fluid behavior, its dimensional stability is limited. When the external permanent magnet is removed, the direction of the magnetic particles with residual magnetism inside will not change in a short time. At this time, if a rotating magnetic field is applied, the stretched magnetic slime robot will begin to curl and hook the target object (t = 83 seconds). Finally, driven by the rotating magnetic field, the slime robot continues to curl until it finally completely wraps the target object and can carry the object for rolling motion (t = 140 seconds). In addition, as Fig.14As shown below, the magnetic slime robot can use its deformation characteristics to grasp multiple target objects at the same time. When the target objects exist in three directions, the slime robot can extend its tentacles from three directions like an octopus arm (t = 43 seconds). After that, the external rotating magnetic field is applied in sequence, and the three tentacles of the slime robot begin to curl up in sequence. Finally, three target objects are grasped through the curling mode. The curling operation mode helps to complete the grasping function in a long-distance restricted environment.

[0085] In some embodiments, due to its deformable properties, the slime robot can also grasp and transport objects through endocytosis. Fig.15 As shown in (above), the slime robot can engulf the target object by wrapping, unfolding and curling in sequence. At t = 0 seconds, the magnetic slime robot begins to deform under the action of the bottom annular permanent magnet. When the annular permanent magnet is tilted, the circular slime robot gradually changes into a C-shape, and the moving permanent magnet can induce the slime robot to surround the target object (t = 60s). Subsequently, when the annular permanent magnet is placed parallel to the operating surface, the C-shaped slime robot changes into a ring shape. Next, the slime robot is unfolded on a flat surface by reciprocating the permanent magnet outward in a mutual manner (t = 192s). As the slime robot expands, the permanent magnet magnetizes the magnetic particles in the slime robot. Finally, the slime robot curls up and engulfs the target object above it under the action of a rotating magnetic field (t = 237s). When an object is engulfed by the slime robot, it will be completely isolated from the external environment, making it easier to capture dangerous objects.

[0086] For example, the magnetic mucus robot can be used for clinical intervention to deal with serious life-threatening button battery swallowing. The button battery 1601 is sandwiched between the inner wall of the pig's large intestine 1602 to simulate human swallowing. After 30 minutes, the battery caused serious damage to the intestinal wall ( Fig.16 To reduce the risk of battery swallowing, a magnetic mucus robot is used and controlled to guide it to the injured area and remove the stuck button battery through endocytosis ( Fig.15 (Below)). This embodiment prepares a simulated stomach model 1501 with an inner wall filled with wrinkles. When the magnetic mucus robot enters the stomach, it can move along the uneven inner wall driven by an external magnetic field (t=42s). When the mucus robot reaches the damaged part, the button battery can be wrapped in the mucus robot by covering and curling to prevent the battery from further discharging and causing damage to the inner wall of the stomach. The magnetic mucus robot described in the present invention can also be used for clinical applications of gallstone fragments, and the fragments can be removed by unfolding the magnetic mucus machine. The magnetic mucus robot described in the present invention can also be transformed into a sickle shape 1701 underwater, and complete the collection and transportation of solid spherical particles 1702 ( Fig.17 ). Example 2

[0087] The non-Newtonian fluid behavior of the slime robot combined with the magnetization properties of its internal magnetic particles gives it significant deformability and reconfigurability. The breaking and recovery of hydrogen bonds between tetrafunctional borate ions and -OH groups inside the slime robot enables it to have self-healing ability. This crosslink can dynamically combine and dissociate at room temperature, thereby exhibiting self-healing properties at room temperature. This process occurs spontaneously without the help of external sources such as chemical reagents. Self-healing is mainly due to the sufficient fluidity and tetrafunctional borate free ions inside the slime robot, so that the hydrogen bonds at the broken interface can quickly trigger the self-healing process without external stimulation. To demonstrate its self-healing ability, two slime samples without added magnetic particles were cut into four pieces and placed together. The two samples were dyed green and blue to distinguish the cutting positions; then, the four small pieces of slime were connected together at intervals and began to heal. Fig.18 As shown in the figure, the interface at the cut position reconnected instantly (less than 1 second). The healed mucus was well connected and maintained excellent plasticity. Even after being stretched to 8.6 times its original length, it could withstand large strains, and the reconnected part was not damaged. Fig.18 As shown in the figure, a long magnetic slime robot can be cut into multiple pieces and finally healed into a circle. First, the strip of slime robot is cut into five small pieces at room temperature; then, driven by a magnetic field, the five slime robots contact each other in turn, and finally complete the self-healing process.

[0088] The slime robot has conductive properties. Afterwards, by measuring the resistance of the slime robot changing over time during the cutting-healing process, the self-healing time of the magnetic slime robot can be obtained. Fig.18 As shown, cutting-repairing was repeated ten times at the same location of the magnetic slime robot. When the magnetic slime robot was completely cut, an open circuit was formed and the resistance became infinite. When the broken parts were recombined, the resistance dropped rapidly and recovered to nearly the initial value within 1 second. The magnetic slime robot has remarkable and repeatable electrical repair performance, showing excellent self-healing efficiency during each cutting and repair process. Therefore, this self-healing ability can also achieve electrical healing, that is, the restoration of conductivity after the damage-healing cycle.

[0089] Self-healing and deformable conductive slime robots show broad application prospects in various electronic devices. Fig.19As shown in the schematic diagram, the conductivity of the magnetic slime robot enables it to act as a circuit switch. This embodiment makes a three-way circuit, which lights up the red, blue, and yellow LED bulbs respectively when connected to each circuit. In the initial state, the three LED bulbs are disconnected. Driven by an external magnetic field, the magnetic slime robot is controlled to light up the blue, yellow, and red LED bulbs in turn. Interestingly, the slime robot can also transform into an octopus shape and turn on three circuits at the same time to light up the three LED bulbs. In addition to being a circuit switch on a two-dimensional plane, the slime robot can also be used to repair damaged circuits. Electronic devices may fail due to partial circuit breaks under long-term environmental influences or scratches by sharp objects. As Fig.19 As shown in Figure 1, the circuit repair process includes three steps: stretching, unfolding, and curling. The repaired circuit can function normally and light up the bulb. Fig.19 As shown, the magnetic slime robot can also achieve three-dimensional open circuit connection. The ability of the magnetic slime robot to repair circuits can also be extended to places such as space stations where it is difficult for humans to repair circuits. Example 3

[0090] The deformation and self-healing ability of the magnetic slime robot enables it to be used as a motion sensor that adapts to bending and dynamic mechanical environments. In combination with the human body movement patterns (stretching, bending, and twisting), the electromechanical properties of the magnetic slime robot can be expressed. First, the magnetic slime robot was encapsulated between two pieces of VHB tape and copper electrodes were used to connect its two ends ( Fig. 20). VHB tape can create a strong connection between the magnetic slime robot and the copper electrode to ensure repeatability during testing and prevent the evaporation of water in the ion-conductive magnetic slime robot, thereby avoiding changes in the quality of the electromechanical signal. The results of the relative resistance change with strain show that the resistance increases with increasing strain. At 500% strain, the relative resistance of the magnetic slime robot reaches 1600%, and this response is repeatable. In addition, there is an obvious hysteresis in the stretch-release cycle of large deformation (500%). In both cases, the initial resistance of the slime robot is fully recovered after being released from the strain. The response of the magnetic slime-based strain sensor to bending and twisting deformation was then tested. There is a relationship between the resistance change of the magnetic slime robot-based strain sensor and the bending angle. The experimental results show that when the bending angle increases from 0° to 180°, the resistance increases from the initial value to 220%. When the slime-based strain sensor is twisted, the change in resistance obeys a parabolic equation within the twisting angle range of less than 540°. However, at larger twist angles (over 540°), the magnetic slime robots separated from each other around the twist point and the resistance increased rapidly. After three turns (1080°), the resistance increased to 1200% from the value in the untwisted state. In summary, the magnetic slime robots can be transformed into stable and repeatable piezoresistive strain sensors that can maintain operation in various mechanically demanding parts of the human body.

[0091] In addition, sensors are an important component of soft robots. Therefore, this embodiment explores the possibility of using slime robots as sensors. For example, magnetic slime robots encapsulated in VHB tape 2101 are directly applied to human skin to detect bending and stretching behaviors such as fingers, wrists, shoulders, and elbows. Fig.21As shown, the relationship between the bending angle and resistance of the index finger, wrist, shoulder and elbow joints was monitored. When the index finger was repeatedly bent from a relaxed state (0°) to a bent state (90°) at a frequency of about 1 Hz, the resistance change of the slime robot monitored by the impedance analyzer showed a rapid and repetitive response to the finger movement. To detect the bending of the wrist, the resistance change of the sensor at 45° and 90° bending angles was measured respectively. Interestingly, the resistance of the slime robot-based sensor increased with the increase of the bending angle (about 1.15 at 45° and about 1.35 at 90°), so that different bending angles of the wrist joint can be distinguished. The sensor can also measure the shoulder and elbow movements of the body separately. The sensor signal shown showed good stability during the cyclic measurement. The magnetic slime robot can use external deformation to obtain human motion signals, and in the future it may also be possible to infer the position or stiffness of the robot through deformation signals. In theory, the magnetic slime robot combines motion and perception functions, and will play a role in a wider range of application scenarios in the future. In summary, this deformable conductive magnetic slime robot can be used in various applications including wearable devices and soft robots.

Claims

1. A composition comprising: a. 0.005-5 wt.% of a tetrafunctional borate ion source, wherein the tetrafunctional borate ion source is used to provide tetrafunctional borate ions; b. a buffer for maintaining the pH at 6.5 to 9.5; c. 0.005-80 wt.% magnetic particles; and d. a polymer glue having a hydroxyl group; The invention is characterized in that the tetrafunctional borate ions, buffer solution and magnetic particles are cross-linked in the polymer glue to form a non-Newtonian fluid composition.

2. The composition according to claim 1, characterized in that: The tetrafunctional borate ion source is selected from one or more of boric acid, sodium borate, disodium tetraborate, sodium tetraborate decahydrate or sodium tetraborate.

3. The composition according to claim 1, characterized in that: The buffer includes deionized water or phosphate buffer.

4. The composition according to claim 1, characterized in that: The magnetic particles are: a. Metal oxide particles; b. Neodymium iron boron (NdFeB) particles; or c. Coated with silicon dioxide (SiO2).

5. The composition according to claim 1, characterized in that: The polymer glue is polyvinyl alcohol.

6. The composition according to claim 5, characterized in that: The polyvinyl alcohol includes one or more selected from PVA 07-18, PVA 07-19, PVA 08-08 or PVA 08-18.

7. A slime robot comprising the composition of claim 1.

8. A system comprising: a. One or more slime robots as described in claim 7; as well as b. One or more magnetic field generators.

9. The system according to claim 8, characterized in that: The one or more magnetic field generators include a robotic arm, a stepper motor and a permanent magnet, wherein the stepper motor is located at the end of the robotic arm and adjusts the speed and direction of the permanent magnet.

10. The system according to claim 9, characterized in that: The permanent magnet is a spherical magnet.

11. A sensor comprising the composition of claim 1, characterized in that: The sensor measures changes in electrical properties of the composition in response to one or more mechanical stimuli.

12. The sensor according to claim 11, characterized in that: The electrical property includes one or more of impedance or resistance.

13. The sensor according to claim 11, characterized in that: The one or more mechanical stimuli include one or more of stretching, bending or twisting.

14. A device comprising the composition of claim 1, characterized in that: The composition is used to control the conductivity of a portion of an electrical circuit.

15. The device according to claim 14, characterized in that: The parts are: a. an electrical switch or a resistor; or b. A damaged part.

16. A method for achieving a function using the composition of claim 1, the method comprising the following steps: a. providing the composition to a location where the function needs to be achieved; b. placing the composition in a magnetic field; as well as c. controlling the magnetic field to direct the movement of the composition.

17. The method according to claim 16, characterized in that: The functions include one or more of the following: a. Remove biofilm; b. Cleaning ultra-precision instruments; c. Repair the circuit; or d. Retrieve one or more objects from a cavity.

18. The method according to claim 17, characterized in that: The one or more objects are swallowed foreign bodies, and the cavity is the gastrointestinal tract.

19. The method according to claim 16, characterized in that: Such movements include grasping, wrapping, unfolding, curling or endocytosis.

20. The method according to claim 16, characterized in that: The locations are: a. a gravity or no gravity environment; or b. A radiation-containing or radiation-free environment.

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