Magnetic control soft robot and preparation method, control system and control method thereof

Abstract

The invention discloses a magnetic control soft robot and a preparation method, a control system and a control method thereof, and belongs to the technical field of biomedical engineering and soft robots. The magnetic control soft robot comprises a main body framework, a head magnetic sheet, a tail magnetic sheet, a magnetic box, a hollow needle plate and a magnetic foot pad. The magnetic control soft-bodied robot provided by the invention can be orally taken to enter the gastrointestinal tract in the body, an external rotating magnetic field is applied for control, the whole process of'movement-positioning-piercing-drug release 'is completed, in-vivo subcutaneous drug delivery is carried out, the drug utilization efficiency can be improved, and the robot is high in dynamic environment adaptability and can be recycled.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biomedical engineering and soft robot technology, and particularly relates to a magnetic control soft robot, a preparation method, a control system and a control method thereof. BACKGROUND

[0002] The transdermal drug delivery technology of the magnetic control soft robot is a frontier field of the cross and integration of biomedical engineering and soft robot technology. The technology precisely controls the movement and deformation of the soft robot through an external magnetic field, and realizes precise drug delivery in combination with minimally invasive puncture. The core is to use the magnetic response characteristics of magnetic materials to complete directional movement and targeted release without being tethered, which provides a new technical path for non-invasive or minimally invasive drug delivery. In recent years, the technology has made significant progress in the fields of micro medical robots, precision instruments and automated drug delivery systems, and has shown a number of key performance indicators, including magnetic driving force density, microneedle penetration force density, movement and drug delivery response time, system stability and precision, etc. These indicators together ensure the movement ability, tissue penetration ability, rapid response ability and drug delivery accuracy of the robot in complex biological environments.

[0003] At present, the drug delivery methods based on magnetic soft robots mainly include four mainstream forms of carrier loading, environment-responsive release, structure deformation and surface patch sustained release. The carrier loading method loads drugs through porous or polymer structures, and uses a magnetic field to guide to the target and trigger release through mechanical or chemical methods after the target, which has the advantages of toxicity isolation, drug protection, active targeting and broad spectrum compatibility; the environment-responsive release can trigger drug release according to the changes of in-vivo environmental parameters such as pH and temperature, to realize precise triggering and self-driven control; the structure deformation method relies on external stimuli (such as magnetic, light, heat) to cause the deformation of the carrier, thereby regulating the drug release behavior, and has the potential of controllable drug release, deep delivery and multifunctional integration; the surface patch method realizes local long-acting sustained release through adhesion or microneedles, which is suitable for the treatment of chronic diseases. Although the existing methods have their own advantages, there are still a series of general technical defects.

[0004] Firstly, in terms of general drug delivery performance, the prior art is difficult to achieve precise delivery to deep tissues. Most methods rely on passive diffusion or surface adhesion, which cannot penetrate biological barriers such as gastric mucosa, subcutaneous multi-layer tissues, etc. Drugs are limited to the release of the body surface or the shallow layer of the digestive tract, and it is difficult to reach the deep micro-cavity or lesion area, which limits its application in internal tissue treatment. Secondly, the drug release efficiency is low and the controllability is poor. The drug release of the carrier relies on diffusion or degradation mechanism, which is slow and has large diffusion resistance in the viscous body fluid environment. Although some methods support external triggering, they lack real-time control capability and are difficult to match the "dose-time" precise window. In addition, the system is easily disturbed by the dynamic environment in the body (such as gastrointestinal peristalsis, pH and temperature fluctuations), which leads to carrier displacement, drug degradation or premature release, and poor retention capacity on the wet mucosa surface, making it difficult to achieve stable drug delivery. In terms of operation process, most existing methods require separate positioning and release, which lacks coordination, prolongs the drug delivery time and introduces operation errors. Finally, most carriers are disposable and cannot be refilled or reused after sterilization, which not only increases the cost of medical treatment, but also brings problems of waste disposal.

[0005] In the field of magnetically controlled soft robots, there are still specific defects in motion accuracy and structural adaptability. Due to the use of homogeneous magnetic powder materials (such as single NdFeB concentration), the magnetic moment distribution is uniform, the torque difference is small, the turning ability is weak, the error is large, and it is difficult to achieve precise navigation in curved cavities. At the same time, the motion response delay is longer, which exceeds milliseconds, and it is difficult to compensate for the position deviation caused by environmental disturbances (such as mucus resistance or intestinal peristalsis) in real time. In terms of structure, rigid components or integrated design result in large motion resistance, which is easy to cause jamming or tissue damage, and due to the high synchronicity of magnetic response, it is difficult to achieve differential control of the head and tail, and the motion flexibility is limited. The size of the robot is mostly in centimeter level, which cannot enter the narrow cavity smaller than 5 millimeters, further limiting its application range.

[0006] In the field of microneedle transdermal drug delivery, there are limitations in driving mechanism and system integration. Traditional hollow needle plates rely on external mechanical pressure to achieve penetration, and the depth is usually less than 500 microns, which is difficult to reach the target in the deep subcutaneous layer, and is easy to slip on the wet surface. The drug release process relies on passive diffusion, which is long and the rate cannot be controlled in real time, which cannot meet the rapid peak requirement of emergency treatment. At the same time, the control of microneedle penetration force is not accurate, which may cause tissue damage or penetration failure. In terms of integration, the microneedle and drug loading unit are usually designed separately, and the penetration and drug release are performed in steps, which reduces the drug delivery efficiency; the microfabrication process is complex and costly, which restricts its large-scale production; in addition, the integration of the microneedle system and the magnetically controlled module is low, and there are often exposed cables or mechanical interfaces, which not only easily cause biocompatibility problems, but also affect the stable operation of the system in the in vivo environment. SUMMARY

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a magnetically controlled soft robot and its preparation method, control system and control method. The magnetically controlled soft robot can be orally administered into the gastrointestinal tract and controlled by an external rotating magnetic field to complete the entire process of "movement-positioning-insertion-drug release" for subcutaneous drug delivery, which can improve drug utilization efficiency. Moreover, the robot has high dynamic environmental adaptability and can be recycled.

[0008] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0009] In a first aspect, the present invention provides a magnetically controlled soft robot, comprising: a main skeleton, a head magnetic plate, a tail magnetic plate, a magnetic box, a hollow needle plate, and magnetic foot pads;

[0010] The main frame includes a head magnetic plate and multiple tails extending outward from the head magnetic plate. The head magnetic plate and tail magnetic plates are arranged in sequence and fixedly connected to the outside of the tails. Both the head magnetic plate and the tail magnetic plate are made of a mixture of silicone and neodymium iron boron magnetic powder. The mass ratio of silicone to neodymium iron boron magnetic powder in the head magnetic plate is (1-2):1, and the mass ratio of silicone to neodymium iron boron magnetic powder in the tail magnetic plate is (2-4):1.

[0011] The magnetic foot pad includes a connecting section and a curled section in sequence. The connecting section is fixedly connected to the free end of the tail, and the curled section extends outward from the free end of the tail. The outer surface of the curled section is provided with needle-like fibers, and the surface of the fibers is coated with chitosan-MES buffer.

[0012] The chitosan-MES buffer solution is prepared by adding chitosan with a deacetylation degree ≥95% to a 2-(N-morpholino)ethanesulfonic acid buffer solution with a pH value of 6.0±0.1 to form a mixed solution A with a mass fraction of 2.0-5%, and then adding a cross-linking agent to mix it. The mass ratio of the mixed solution A to the cross-linking agent is (5-10):1.

[0013] The magnetic box is installed inside the magnetic sheet at the head of the main frame. The magnetic box has a liquid storage chamber inside and an opening at the bottom. The hollow needle plate is installed at the bottom opening of the magnetic box. The magnetic box is a magnetic box that has undergone magnetization pretreatment, and the magnetization direction is the same as the axis of the needle in the hollow needle plate.

[0014] Secondly, the present invention provides a method for manufacturing the magnetically controlled soft robot, comprising:

[0015] Head magnetic sheet, tail magnetic sheet, magnetic box, hollow needle plate and magnetic foot pad are prepared separately;

[0016] The prepared head magnetic plate, tail magnetic plate, magnetic box and magnetic foot pad are placed in a pre-made mold, the main skeleton is prepared by casting, and the hollow needle plate is installed to obtain the magnetically controlled soft robot.

[0017] Furthermore, the method for preparing the head magnetic sheet or tail magnetic sheet includes:

[0018] Mix the silicone and neodymium iron boron magnetic powder by centrifuging at 2000-3000 rpm for 5-10 minutes until homogeneous. Then centrifuge at 2000-3000 rpm for 1-2 minutes to remove air bubbles. Remove the mixture and spin-coat it onto a carrier plate for curing to obtain a cured mixture. Laser-cut the cured mixture according to the preset shape and then magnetize it to obtain a head magnetic sheet or a tail magnetic sheet.

[0019] Furthermore, the method for preparing the hollow needle plate includes:

[0020] Place a female mold and a guide wire positioning plate. The female mold has an arrangement of conical molds, and the guide wire positioning plate has an arrangement of through holes. The through holes correspond one-to-one with the positions of the conical molds. The taper of the conical mold is 15-25°, and the tip radius is less than 40μm.

[0021] A platinum-iridium alloy wire with a diameter of 20-30μm is inserted into the through hole of the guide wire positioning plate, making the platinum-iridium alloy wire vertical and placing its bottom end into a conical mold. A pretension of 0.1-0.5N is applied to the platinum-iridium alloy wire.

[0022] A mixed epoxy resin-PVA solution was obtained by mixing resin, PVA and curing agent in a mass ratio of 10:2:1.

[0023] The epoxy resin-PVA mixture is injected into the female mold, cured, and then demolded to obtain a hollow needle plate.

[0024] Furthermore, the method for preparing the magnetic box includes:

[0025] Mix silica gel and Fe3O4 magnetic powder at a mass ratio of 3:1 to 2:1, centrifuge at 2000-3000 rpm for 5-10 minutes to mix evenly, then centrifuge at 2000-3000 rpm for 1-2 minutes to remove air bubbles, remove the mixture, pour it into a pre-made mold, and cure at 25-30℃ for 4-6 hours or at 60-80℃ for 1-2 hours. Subsequently, perform longitudinal magnetization treatment in a 1-3T pulsed magnetic field to obtain a magnetic box.

[0026] Furthermore, the method for preparing the magnetic foot pad includes:

[0027] Mix silica gel and Fe3O4 magnetic powder in a mass ratio of 3:1 until uniform. Drop the mixed material onto a glass slide and place it in a spin coater. Spin coat at 800-1200 rpm for 30-60 seconds to obtain a material film. Then invert the glass slide and place a permanent magnet 10-15 cm below it. Let it stand for more than 20 minutes to form a needle-like fluffy layer on the surface of the material film.

[0028] Using 2-(N-morpholino)ethanesulfonic acid buffer as solvent, chitosan was added to prepare a mixed solution A with a mass fraction of 2.0-5%. Then, mixed solution A and crosslinking agent were mixed at a mass ratio of (5-10):1 to obtain chitosan-MES buffer. The chitosan-MES buffer was used to coat the fluff layer and cured at room temperature for 30-60 minutes to obtain the final magnetic foot pad.

[0029] Furthermore, the prepared head magnetic plate, tail magnetic plate, magnetic box, and magnetic foot pads are placed in a pre-made mold, and the main skeleton is prepared by casting. Hollow needle plates are then installed to obtain a magnetically controlled soft robot, comprising:

[0030] Based on the dimensions of the prepared head magnetic plate, tail magnetic plate, magnetic box and magnetic foot pad, and the installation positions of the head magnetic plate, tail magnetic plate, magnetic box and magnetic foot pad, the mold structure of the foot and main skeleton is designed, and the foot mold and main skeleton mold are prepared by 3D printing technology.

[0031] Polydimethylsiloxane monomer and crosslinking agent are mixed at a mass ratio of (5-10):1 and stirred until completely homogeneous to prepare a polydimethylsiloxane mixture.

[0032] Place the head magnetic plate, tail magnetic plate, and magnetic foot pad into the reserved placement slot in the foot mold, pour the polydimethylsiloxane mixture into the foot mold, and cure at 25°C for 24 hours or heat at 60°C for 2 hours to obtain the foot.

[0033] Place the magnetic box and feet into the reserved placement slots in the main skeleton mold, pour the polydimethylsiloxane mixture into the mold, and cure it at 25°C for 24 hours or heat it at 60°C for 2 hours. After curing, demold to obtain the final magnetically controlled soft robot.

[0034] Thirdly, the present invention provides a control system for the aforementioned magnetically controlled soft robot, comprising:

[0035] A magnetic field generator used to apply a magnetic field;

[0036] The host computer communicates with the magnetic field generator and is used to output external magnetic field parameters.

[0037] Fourthly, the present invention provides a control method for the aforementioned magnetically controlled soft robot, comprising:

[0038] A rotating magnetic field is applied, and the direction of the rotating magnetic field is controlled to control the movement path of the magnetically controlled soft robot until the robot reaches the drug delivery point;

[0039] A vertically pulsed magnetic field is applied to compress the magnetic box, generating a piercing force that propels the hollow needle plate into the tissue;

[0040] An alternating magnetic field is applied in the vertical direction to drive the magnetic box to vibrate and release the liquid medicine;

[0041] The vertical direction is the same as the axial direction of the needle in the hollow needle plate.

[0042] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0043] The magnetically controlled soft robot provided by this invention includes a head magnetic sheet and a tail magnetic sheet. By setting magnetic sheets with different magnetic powder mass concentrations, the magnetically controlled soft robot can be orally administered into the gastrointestinal tract. It can be controlled by applying an external rotating magnetic field. The high-concentration head magnetic sheet has a strong magnetic moment that dominates the movement, while the low-concentration tail magnetic sheet has a weak magnetic moment that assists in steering. The torque difference generated under the rotating magnetic field enables precise tracking and adaptive steering of complex paths, reducing positioning deviations. This is significantly different from traditional external microneedle patch drug delivery and oral drug delivery methods. The subcutaneous drug delivery method can improve drug utilization efficiency.

[0044] The magnetically controlled soft robot provided by this invention integrates a magnetic box and a hollow needle plate at the bottom of the robot. Through a single magnetic field sequence, it achieves coordinated control of the entire process of "movement-positioning-insertion-drug release", simplifying the operation process. It uses magnetic foot pads coated with biological adhesive to achieve strong adhesion on inverted and wet surfaces and to quickly detach via a magnetic field, significantly improving its adaptability to dynamic environments.

[0045] The magnetically controlled soft robot provided by this invention has its overall size compressed to the millimeter level, making it less affected by external conditions, thereby improving response speed and accuracy, reducing uncertainties during surgery, and allowing the liquid storage chamber in the magnetic box to be refilled with medication; the main skeleton is corrosion resistant and can be reused after disinfection, reducing waste. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the structure of the magnetically controlled soft robot provided in an embodiment of the present invention;

[0047] Figure 2 This is an exploded view of the structure of the magnetically controlled soft robot provided in an embodiment of the present invention;

[0048] Figure 3This is a schematic diagram of the principle of the magnetically controlled soft robot provided in the embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of the preparation process of the head magnetic sheet or tail magnetic sheet provided in the embodiments of the present invention;

[0050] Figure 5 This is a schematic diagram of the preparation process of the hollow needle plate provided in the embodiment of the present invention;

[0051] Figure 6 This is a schematic diagram of the preparation process of the magnetic foot pad provided in an embodiment of the present invention;

[0052] Figure 7 This is a schematic diagram of the preparation process of the magnetic foot pad provided in an embodiment of the present invention;

[0053] Figure 8 This is a schematic diagram of the preparation process of the main skeleton provided in an embodiment of the present invention;

[0054] Figure 9 This is a schematic diagram of the control process of the magnetically controlled soft robot provided in an embodiment of the present invention.

[0055] In the diagram: 1. Main frame; 2. Head magnetic plate; 3. Tail magnetic plate; 4. Magnetic box; 5. Hollow needle plate; 6. Magnetic foot pad. Detailed Implementation

[0056] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0057] In this invention, the raw material silicone was purchased from Dow Corning Incorporated, USA, and silicone with the model numbers Ecoflex A, Ecoflex B and Ecoflex 00-30 were used respectively. The neodymium iron boron magnetic powder was purchased from Magnequen Magnetics Co., Ltd., China.

[0058] Example 1

[0059] This embodiment provides a magnetically controlled soft robot and its control method. The robot can be orally administered into the gastrointestinal tract and precisely controlled by an external magnetic field to achieve the positioning of concealed sites, tissue insertion, and drug release.

[0060] like Figure 1 and Figure 2 As shown, it includes: main frame 1, head magnetic plate 2, tail magnetic plate 3, magnetic box 4, hollow needle plate 5, and magnetic foot pad 6;

[0061] The main frame 1 includes a head magnetic plate and four tail sections extending outward from the head. The head magnetic plate 2 and tail magnetic plates 3 are arranged sequentially and fixedly connected to the outside of the tail sections. Both the head magnetic plate 2 and the tail magnetic plate 3 are made of a mixture of silicone and neodymium iron boron magnetic powder. The mass ratio of silicone to neodymium iron boron magnetic powder in the head magnetic plate 2 is 2:1, and the mass ratio of silicone to neodymium iron boron magnetic powder in the tail magnetic plate 3 is 4:1. The head magnetic plate uses a high-concentration magnetic powder mixture, while the tail magnetic plates use a low-concentration magnetic powder mixture, which can respond to changes in the external magnetic field and drive the robot to move.

[0062] The magnetic foot pad 6 includes a connecting section and a curled section. The connecting section is fixedly connected to the free end of the tail, and the curled section extends outward from the free end of the tail. The outer surface of the curled section is provided with needle-like villi. The surface of the villi is coated with chitosan-MES buffer solution, which can form a strong biological bridge on the moist mucosa, forming a stable adsorption and resisting the flushing of gastrointestinal peristalsis.

[0063] The magnetic box 4 is installed inside the head magnetic sheet of the main frame 1. The magnetic box 4 has a liquid storage chamber inside and an opening at the bottom. The hollow needle plate 5 is installed at the bottom opening of the magnetic box 4. The magnetic box 4 is a magnetic box 4 that has undergone magnetization pretreatment, and the magnetization direction is the same as the axis of the needle in the hollow needle plate 5.

[0064] The control method for the magnetically controlled soft robot includes:

[0065] A rotating magnetic field is applied, and the direction of the rotating magnetic field is controlled to control the movement path of the magnetically controlled soft robot until the robot reaches the drug delivery point;

[0066] A vertically pulsed magnetic field is applied to compress the magnetic box, generating a piercing force that propels the hollow needle plate into the tissue;

[0067] An alternating magnetic field is applied in the vertical direction to drive the magnetic box to vibrate and release the liquid medicine;

[0068] The vertical direction is the same as the axial direction of the needle in the hollow needle plate.

[0069] The control principle of the magnetically controlled soft robot provided in this embodiment is as follows:

[0070] 1. The principle of magnetic drive

[0071] The direction of the magnetic moment tends to be parallel to the external magnetic field to reduce energy. If the direction of the robot's magnetic moment makes an angle with the external field, it will be subject to magnetic torque, driving it to rotate around its own axis. The gradient magnetic field generates a translational force, causing the object to move towards the region of higher field strength. Therefore, Figure 3 This is a schematic diagram of the principle of the magnetically controlled soft robot provided in an embodiment of the present invention, as shown below. Figure 3 As shown, in Figure 3In the uniform magnetic field shown in (a), a hard magnet is subjected to a magnetic moment that rotates around its own axis, combining magnetic powder with soft materials to form a composite. Figure 3 In the uniform magnetic field shown in (b), the directional alignment of magnetic moments induces internal stress, causing the composite to bend as a whole. Figure 3 In the gradient magnetic field shown in (c), the hard magnet rotates while simultaneously translating towards the high field strength region. When applied to a magnetic soft composite material, the composite material is forced to bend and move towards the high field strength region, as shown in (c). Figure 3 As shown in (d).

[0072] 2. Effects of the three magnetic fields used in the design

[0073] In this embodiment of the invention, the control method for the magnetically controlled soft robot employs three different magnetic fields: a rotating magnetic field, a pulsed magnetic field in the vertical direction, and an alternating magnetic field in the vertical direction.

[0074] The direction of the rotating magnetic field changes continuously, controlling the robot's movement based on the principle of magnetic moment difference. When an external rotating magnetic field is applied, the magnetized head and tail magnetic plates respond quickly, controlling the robot's path by controlling the rotation direction of the magnetic field, enabling the robot to accurately locate itself in complex human environments.

[0075] A vertically oriented pulsed magnetic field is used to drive the microneedles into the tissue, based on the principles of magnetic attraction and pulsed pressure. Once the robot reaches the drug delivery point, a vertically oriented pulsed magnetic field is applied externally. The instantaneous magnetic field pulse attracts the longitudinally magnetized magnetic box, generating downward pressure that causes the microneedles on the hollow needle plate to pierce the gastric mucosa. Simultaneously, the pressure compresses the liquid reservoir within the magnetic box, releasing the medication.

[0076] A vertically oriented alternating magnetic field is used to enhance drug release after administration, based on the principle of magnetostrictive vibration. After microneedle insertion, a vertically oriented alternating magnetic field is applied externally. The alternating direction of the magnetic field causes the magnetic material inside the magnetic box to vibrate, generating mechanical oscillations that stir the drug solution and promote its diffusion.

[0077] Example 2

[0078] This embodiment provides a method for fabricating a magnetically controlled soft robot.

[0079] In this invention, Fe3O4 nanoparticles exhibit superparamagnetism because their thermal perturbation kinetic energy exceeds their magnetocrystalline anisotropy. This means that under an external magnetic field, the magnetic moments are oriented in a specific direction, but rapidly become disordered due to thermal motion after the field is removed, resulting in a closed hysteresis loop and no coercivity. This makes them suitable for high-frequency alternating magnetic field scenarios and applicable to the fabrication of magnetic boxes. NdFeB particles, as permanent magnet materials, rely on the high magnetocrystalline anisotropy barrier of their tetragonal crystal system to lock the direction of the magnetic moments. High coercivity and high remanence are achieved through pre-orientation and pulsed saturation magnetization. The magnetic moments remain oriented after the field is removed, making them suitable for steady-state magnetic control and applicable to the fabrication of head and tail magnetic sheets.

[0080] The method for manufacturing the magnetically controlled soft robot includes:

[0081] 1. Preparation of head and tail magnetic sheets

[0082] like Figure 4 As shown, during the preparation of the head magnetic sheet, firstly, Ecoflex A and Ecoflex B silicones are thoroughly mixed in a 1:1 ratio to form a uniform polymer matrix. The mixed polymer matrix is ​​then mixed with neodymium iron boron (NdFeB) magnetic powder in a 2:1 mass ratio. The mixture is placed in a centrifuge and centrifuged at 2000 rpm for 5 minutes to ensure uniform dispersion of the magnetic powder. The speed is then increased to 2200 rpm for 45 seconds to remove air bubbles. The treated mixture is then spin-coated onto a circular acrylic plate and allowed to cure at room temperature for 4 hours. After curing, the plate is laser-cut to achieve the required shape and size. Finally, the head magnetic sheet is magnetized laterally or at a specific angle to obtain the final head magnetic sheet.

[0083] When preparing the tail magnetic sheet, the same polymer matrix as the head magnetic sheet is used, but the mass ratio of polymer matrix to magnetic powder is 4:1. The subsequent centrifugation, defoaming, curing and other processes are completely consistent with those of the head magnetic sheet.

[0084] This dual-gradient design achieves high precision in motion control. The high magnetic content at the front ensures powerful propulsion, while the low magnetic content at the rear generates precise steering torque. The material ratio has been optimized and tested, resulting in stable performance. The manufacturing process is mature and highly repeatable.

[0085] 2. Preparation of hollow needle plate

[0086] like Figure 5 In the preparation of the hollow needle plate, medical-grade stainless steel is used to prepare the female mold. The female mold has an arrangement of conical molds with a taper of 15° and a tip radius of less than 40μm. High-precision 3D printing technology is used to make the guide wire positioning plate, which has an arrangement of through holes. Φ20μm platinum-iridium alloy wire is selected as the forming core material. The platinum-iridium alloy wire is subjected to a pretension of 0.1N to ensure that the guide wire remains straight during the forming process.

[0087] Prepare an epoxy resin-PVA mixed solution by mixing resin, PVA and curing agent in a mass ratio of 10:2:1.

[0088] Place the female mold and the guide wire positioning plate, with the through holes corresponding one-to-one with the positions of the conical mold. Insert a platinum-iridium alloy wire into the through hole of the guide wire positioning plate, making the platinum-iridium alloy wire vertical, and place the bottom end into the conical mold. Use a micro-injection system to inject the epoxy resin-PVA mixed solution into the mold. After curing, demold to obtain the final hollow needle plate.

[0089] 3. Preparation of magnetic box

[0090] During the preparation of the magnetic box, the polymer matrix and Fe3O4 magnetic powder were precisely mixed at a mass ratio of 3:1. A precision electronic balance was used for weighing to ensure minimal mixing error. The polymer matrix used was the same as that used in preparing the head magnetic sheet. After mixing, the mixture was placed in a vacuum mixer and initially mixed at a low speed of 2000 rpm for 5 minutes to initially disperse the magnetic powder. The speed was then increased to 2200 rpm and mixing continued for 45 seconds, followed by thorough removal of air bubbles using a vacuum pump. The uniformly mixed material was then injected into a pre-prepared mold and cured in a constant temperature and humidity chamber. Curing was performed at room temperature (25℃) for 4 hours or accelerated at 60℃ for 1 hour. After curing, longitudinal magnetization was performed in a 1.1T pulsed magnetic field, and the edges were trimmed using a high-precision laser cutter to obtain the final magnetic box.

[0091] 4. Preparation of magnetic foot pads

[0092] The matrix material is Ecoflex 00-30 silicone, and the magnetic filler is Fe3O4 nanoparticles with a diameter of 20nm and a saturation magnetization of 92. Silica gel and Fe3O4 nanoparticles were mixed at a mass ratio of 1:(1-2). The mixed material was dropped onto a circular glass slide and placed in a spin coater. The slide was selectively coated at 800-1200 rpm for 30-60 seconds. The film thickness was repeatedly measured with a high-precision thickness gauge to ensure that it was controlled within 200±10 mm. ,like Figure 6 As shown, the spin-coated glass slide is inverted, and a permanent magnet is placed 10 cm below it for at least 20 minutes to form the pile. In the preparation of the bio-adhesive, a mixed solution A with a mass fraction of 2.0-5% is prepared by adding chitosan with a deacetylation degree ≥95% to a 2-(N-morpholino)ethanesulfonic acid buffer solution at pH 6.0±0.1 as the solvent. A crosslinking agent is then added to prepare the bio-adhesive, wherein the mass ratio of mixed solution A to the crosslinking agent is (5-10):1. The bio-adhesive is then applied to the pile layer and cured at room temperature for 30 minutes to obtain the final magnetic footpad.

[0093] 5. Preparation of the main skeleton

[0094] Based on the dimensions of the prepared head magnetic plate, tail magnetic plate, magnetic box, and magnetic foot pads, and their installation positions, the mold structure of the main skeleton is designed, and the foot mold and main skeleton mold are fabricated using 3D printing technology. Figure 7As shown, first place the head magnetic plate, tail magnetic plate, and magnetic foot pads in their corresponding positions within the foot mold, with the magnetic foot pads wound around the cylinder to form hollow cylindrical feet. Mix polydimethylsiloxane monomer and crosslinking agent at a mass ratio of 10:1, stirring until completely homogeneous to prepare a polydimethylsiloxane mixture. To avoid uneven curing, slowly pour the polydimethylsiloxane mixture into the foot mold, ensuring the liquid completely covers the magnetic plates. Use a scraper to remove excess material from the surface, and cure at room temperature for 24 hours or at 60°C for 2 hours to accelerate the process. After curing, carefully demold, avoiding damage to the delicate structure. Check the integrity of each connection point, and make local repairs if necessary, completing the fabrication of the robot's foot position. Figure 8 As shown, the feet and magnetic box are placed in the corresponding positions in the main skeleton mold, and polydimethylsiloxane mixture is injected into the round hole of the head. After curing and demolding as above, the final magnetically controlled soft robot is obtained.

[0095] Example 3

[0096] This embodiment provides a control system for a magnetically controlled soft robot, including: a magnetic field generator for applying a magnetic field; and a host computer, which is communicatively connected to the magnetic field generator for outputting external magnetic field parameters.

[0097] Figure 9 This is a schematic diagram of the process of the control system controlling the magnetically controlled soft robot provided in this embodiment. In this embodiment, a magnetic positioning system is also included for tracking and positioning the robot and checking the stability of the magnetic field output.

[0098] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to explain the relative positional relationship and movement between components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0099] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0100] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A magnetically controlled soft robot, characterized in that, include: Main frame (1), head magnetic plate (2), tail magnetic plate (3), magnetic box (4), hollow needle plate (5) and magnetic foot pad (6); The main frame (1) includes a head magnetic plate and multiple tails extending outward from the head magnetic plate. The head magnetic plate (2) and tail magnetic plates (3) are arranged in sequence and fixedly connected to the outside of the tails. The head magnetic plate (2) and tail magnetic plates (3) are both made of a mixture of silicone and neodymium iron boron magnetic powder. The mass ratio of silicone to neodymium iron boron magnetic powder in the head magnetic plate (2) is (1-2):1, and the mass ratio of silicone to neodymium iron boron magnetic powder in the tail magnetic plate (3) is (2-4):

1. The magnetic foot pad (6) includes a connecting section and a curled section in sequence. The connecting section is fixedly connected to the free end of the tail, and the curled section extends outward from the free end of the tail. The outer surface of the curled section is provided with needle-like hairs, and the surface of the hairs is coated with chitosan-MES buffer. The chitosan-MES buffer solution is prepared by adding chitosan with a deacetylation degree ≥95% to a 2-(N-morpholino)ethanesulfonic acid buffer solution with a pH value of 6.0±0.1 to form a mixed solution A with a mass fraction of 2.0-5%, and then adding a cross-linking agent to mix it. The mass ratio of the mixed solution A to the cross-linking agent is (5-10):

1. The magnetic box (4) is installed inside the head magnetic sheet of the main frame (1). The magnetic box (4) has a liquid storage chamber inside and an opening at the bottom. The hollow needle plate (5) is installed at the opening at the bottom of the magnetic box (4). The magnetic box (4) is a magnetic box (4) after magnetization pretreatment. The magnetization direction is the same as the axis of the needle in the hollow needle plate (5).

2. A method for manufacturing a magnetically controlled soft robot as described in claim 1, characterized in that, include: Head magnetic sheet, tail magnetic sheet, magnetic box, hollow needle plate and magnetic foot pad are prepared separately; The prepared head magnetic plate, tail magnetic plate, magnetic box and magnetic foot pad are placed in a pre-made mold, the main skeleton is prepared by casting, and the hollow needle plate is installed to obtain the magnetically controlled soft robot.

3. The preparation method according to claim 2, characterized in that, The method for preparing the head magnetic sheet or tail magnetic sheet includes: Mix the silicone and neodymium iron boron magnetic powder by centrifuging at 2000-3000 rpm for 5-10 minutes until homogeneous. Then centrifuge at 2000-3000 rpm for 1-2 minutes to remove air bubbles. Remove the mixture and spin-coat it onto a carrier plate for curing to obtain a cured mixture. Laser-cut the cured mixture according to the preset shape and then magnetize it to obtain a head magnetic sheet or a tail magnetic sheet.

4. The preparation method according to claim 2, characterized in that, The method for preparing the hollow needle plate includes: Place a female mold and a guide wire positioning plate. The female mold has an arrangement of conical molds, and the guide wire positioning plate has an arrangement of through holes. The through holes correspond one-to-one with the positions of the conical molds. The taper of the conical mold is 15-25°, and the tip radius is less than 40μm. A platinum-iridium alloy wire with a diameter of 20-30μm is inserted into the through hole of the guide wire positioning plate, making the platinum-iridium alloy wire vertical and placing its bottom end into a conical mold. A pretension of 0.1-0.5N is applied to the platinum-iridium alloy wire. A mixed epoxy resin-PVA solution was obtained by mixing resin, PVA and curing agent in a mass ratio of 10:2:

1. The epoxy resin-PVA mixture is injected into the female mold, cured, and then demolded to obtain a hollow needle plate.

5. The preparation method according to claim 2, characterized in that, The method for preparing the magnetic box includes: Mix silica gel and Fe3O4 magnetic powder at a mass ratio of 3:1 to 2:1, centrifuge at 2000-3000 rpm for 5-10 minutes to mix evenly, then centrifuge at 2000-3000 rpm for 1-2 minutes to remove air bubbles, remove the mixture, pour it into a pre-made mold, and cure at 25-30℃ for 4-6 hours or at 60-80℃ for 1-2 hours. Subsequently, perform longitudinal magnetization treatment in a 1-3T pulsed magnetic field to obtain a magnetic box.

6. The preparation method according to claim 2, characterized in that, The method for preparing the magnetic foot pad includes: Mix silica gel and Fe3O4 magnetic powder in a mass ratio of 3:1 until uniform. Drop the mixed material onto a glass slide and place it in a spin coater. Spin coat at 800-1200 rpm for 30-60 seconds to obtain a material film. Then invert the glass slide and place a permanent magnet 10-15 cm below it. Let it stand for more than 20 minutes to form a needle-like fluffy layer on the surface of the material film. Using 2-(N-morpholino)ethanesulfonic acid buffer as solvent, chitosan was added to prepare a mixed solution A with a mass fraction of 2.0-5%. Then, mixed solution A and crosslinking agent were mixed at a mass ratio of (5-10):1 to obtain chitosan-MES buffer. The chitosan-MES buffer was used to coat the fluff layer and cured at room temperature for 30-60 minutes to obtain the final magnetic foot pad.

7. The preparation method according to claim 2, characterized in that, The prepared head magnetic plate, tail magnetic plate, magnetic box, and magnetic foot pads are placed in a pre-made mold, and the main skeleton is prepared by casting. Hollow needle plates are then installed to obtain a magnetically controlled soft robot, comprising: Based on the dimensions of the prepared head magnetic plate, tail magnetic plate, magnetic box and magnetic foot pad, and the installation positions of the head magnetic plate, tail magnetic plate, magnetic box and magnetic foot pad, the mold structure of the foot and main skeleton is designed, and the foot mold and main skeleton mold are prepared by 3D printing technology. Polydimethylsiloxane monomer and crosslinking agent are mixed at a mass ratio of (5-10):1 and stirred until completely homogeneous to prepare a polydimethylsiloxane mixture. Place the head magnetic plate, tail magnetic plate, and magnetic foot pad into the reserved placement slot in the foot mold, pour the polydimethylsiloxane mixture into the foot mold, and cure at 25°C for 24 hours or heat at 60°C for 2 hours to obtain the foot. Place the magnetic box and feet into the reserved placement slots in the main skeleton mold, pour the polydimethylsiloxane mixture into the mold, and cure it at 25°C for 24 hours or heat it at 60°C for 2 hours. After curing, demold to obtain the final magnetically controlled soft robot.

8. A control system for a magnetically controlled soft robot as described in claim 1, characterized in that, include: A magnetic field generator used to apply a magnetic field; The host computer communicates with the magnetic field generator and is used to output external magnetic field parameters.

9. A control method for a magnetically controlled soft robot as described in claim 1, characterized in that, include: A rotating magnetic field is applied, and the direction of the rotating magnetic field is controlled to control the movement path of the magnetically controlled soft robot until the robot reaches the drug delivery point; A vertically pulsed magnetic field is applied to compress the magnetic box, generating a piercing force that propels the hollow needle plate into the tissue; An alternating magnetic field is applied in the vertical direction to drive the magnetic box to vibrate and release the liquid medicine; The vertical direction is the same as the axial direction of the needle in the hollow needle plate.

Images