Magnetic control soft gripper

Abstract

The application provides a magnetic control soft gripper, characterized in that a magnetic control gripper comprises a coil, a soft magnetic elastic body, a hard magnetic elastic body, a plastic film and a magneto-rheological fluid; the soft magnetic elastic body is shaped as a U shape and has a rectangular cross section; the hard magnetic elastic body is tightly attached to the outer side edge line of the soft magnetic elastic body; the coil is wound around the surface of the soft magnetic elastic body and fixedly connected to the soft magnetic elastic body; the plastic film is attached to the inner side edge line profile of the soft magnetic elastic body and forms a closed space with the soft magnetic elastic body, and the space is filled with the magneto-rheological fluid; by controlling the energization direction of the coil, the soft magnetic elastic body, the hard magnetic elastic body and the magneto-rheological fluid form different magnetic circuits, so that the end of the gripper is elastically deformed; the magneto-rheological fluid is attached to the surface of an object and solidified under the action of a magnetic field, so that the adhesion is enhanced; and the two cooperate with each other to complete the clamping action. The soft gripper provided by the application is convenient to control and has high efficient grabbing capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soft gripper, in particular to a magnetic soft gripper. BACKGROUND

[0002] In the production, enterprises often use traditional mechanical hands or grippers as aids, and are not good at using soft materials. Therefore, in the past few years, people have been trying to come up with new methods to enable the mechanical hand to have the ability to grasp small or fragile objects. The national utility model patent CN206201012U discloses an octopus mechanical hand which can measure the orientation, size and shape of the target object through an inductor, process the data into signals and be controllable, and can grasp fragile things intact and undamaged with enough sensitive and subtle force from multiple dimensions.

[0003] The design inspiration of the soft gripper comes from soft animals, which cover the object and grasp and squeeze like the tentacles of octopus when they are stretched out, can wrap (or be wrapped) different parts of the object, and apply pressure. The pneumatic mechanical tentacle is a single plastic flexible tube, which contains several channels inside to fill with air to obtain the required pressure to control the object. Since each channel is independently pressurized, the tentacle can also form a curl in a directional way, wrap the object and squeeze. By increasing the air pressure enough, the tentacle can gently lift the object, but the independent pressurization control is more complex.

[0004] The current soft gripper structure is complex, mostly relying on pneumatic or hydraulic drive, high cost and not easy to control when grasping objects, so a new technical solution is needed to solve the above problems. The present application provides a magnetic soft gripper, which is simple, the coil of the driving part and the new intelligent magnetic control material are concentrated in the body part of the gripper, without adding external drive, greatly reducing the system complexity and improving the robustness of the system. SUMMARY

[0005] The present application aims at the existing technical problems, and proposes a magnetic soft gripper, which controls the on-off and direction of the internal coil to control the actions such as grasping and putting down of the whole soft gripper.

[0006] To achieve the above purpose, the present application provides the following technical scheme:

[0007] The application discloses a magnetic control soft gripper, which comprises a coil, a soft magnetic elastomer, a hard magnetic elastomer, a plastic film and a magnetorheological fluid. The soft magnetic elastomer is in a U shape and has a rectangular cross section. The hard magnetic elastomer is in a sheet shape and is tightly attached to the outer side edges of the soft magnetic elastomer. The coil is wound on the surface of the soft magnetic elastomer at the joint of the circular arc and the straight line part and is fixedly connected. The coil is symmetrically distributed on the soft magnetic elastomer. The plastic film is attached to the inner side edge contour of the soft magnetic elastomer and forms a closed space with the soft magnetic elastomer, and the closed space is filled with the magnetorheological fluid. The soft magnetic elastomer is composed of soft magnetic material particles with high magnetic permeability and low magnetic coercivity and an elastic matrix material. The average particle size of the soft magnetic particles is not more than 50 nm. The nano-level soft magnetic particles are uniformly dispersed in the elastic matrix material. The hard magnetic elastomer is composed of neodymium iron boron permanent magnetic particles and an elastic matrix material and is in a sheet shape. The hard magnetic elastomer is magnetized in the thickness direction. The diameter of the coil is greater than 0.5 mm, and the magnetic flux potential is not less than 20 AN. The magnetorheological fluid is composed of magnetic particles, a base carrier liquid and a thixotropic agent. The magnetic particles are made of any one of carbonyl iron powder, nickel and cobalt. The average particle size of the magnetic particles is between 1 and 50 microns. The base carrier liquid is made of any one of mineral oil, silicone oil and fluorine ether oil. The thixotropic agent is made of any one of organic bentonite, hydrogenated castor oil and silicon dioxide, and the thixotropic agent enhances the thixotropy. The plastic film is made of any one of low-density polyethylene film, polyester film and cast polypropylene film. The thickness of the plastic film is between 15 and 50 microns. The surface wet tension is between 33 and 40 dyn / cm. The plastic film is attached to the inner side edge contour of the soft magnetic elastomer and forms a closed space with the soft magnetic elastomer. The closed space is filled with the magnetorheological fluid, and the filling rate is between 40% and 75%. The gripper controls the energization direction of the coil. The soft magnetic elastomer, the hard magnetic elastomer and the magnetorheological fluid form different magnetic circuits, so that the gripper end is elastically deformed, the magnetorheological fluid is attached to the surface of an object, and the adhesion is enhanced under the action of the magnetic field, thereby completing the clamping action.

[0008] Compared with the prior art, the method has the following advantages: the magnetic control soft gripper is provided with the magnetorheological fluid on one side of the gripper for grabbing objects, and the outer part is composed of soft material, so that the soft gripper has good grabbing flexibility and can self-adapt to objects with various shapes without damaging the surface of the objects. The bending degrees of the fingers are independently controlled, so that the soft gripper has the flexibility and multi-mode similar to human hands. Due to the good physical properties of the magnetorheological fluid, the soft gripper has a rapid response and does not need to be provided with sensors, so that the soft gripper can adapt to complex external environments. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 It is a schematic view of the original state of the soft gripper.

[0010] Figure 2A schematic diagram showing the energization and gripping of the soft gripper coil.

[0011] Figure 3 This is a schematic diagram showing the energization and release of the coil in a soft gripper.

[0012] Explanation of main component symbols: 1-coil, 2-soft magnetic elastomer, 3-hard magnetic elastomer, 4-plastic film, 5-magnetorheological fluid. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, embodiments of the invention are described in detail below, providing further elaboration. It should be understood that the following embodiments are intended to explain the invention but are not intended to limit it.

[0014] like Figure 1 As shown, the magnetically controlled soft gripper includes: a coil 1, a soft magnetic elastomer 2, a hard magnetic elastomer 3, a plastic film 4, and a magnetorheological fluid 5. The soft magnetic elastomer 2 is U-shaped, and the hard magnetic elastomer 3 is a thin sheet tightly attached to the outer edge of the soft magnetic elastomer 2. The coil 1 is wound around the surface at the intersection of the arc and straight sections of the soft magnetic elastomer 2 and fixedly connected. The coil 1 is symmetrically distributed on the soft magnetic elastomer 2. The plastic film 4 is adhered to the inner edge contour of the soft magnetic elastomer 2 and forms a sealed space with the soft magnetic elastomer 2. This space is filled with the magnetorheological fluid 5, with a filling rate of 50%. The soft magnetic elastomer 2 is composed of soft magnetic material particles with high permeability and low magnetic coercivity and an elastic matrix material. The average particle size of the soft magnetic particles is 50 nm, and the nanoscale soft magnetic particles are uniformly dispersed in the elastic matrix material. The magnetic particles of the magnetorheological fluid 5 are made of carbonyl iron powder with an average particle size of 25 μm. The base carrier of the magnetorheological fluid is silicone oil. Organic bentonite is added to the magnetorheological fluid to enhance its thixotropy.

[0015] like Figure 2 As shown, the grasping action of the soft gripper system is achieved by passing a pulsed high current through two coils. The end faces of the coils form a magnetic pole distribution: the left coil has an N pole above and a S pole below; the right coil has an S pole above and an N pole below. Under the influence of an external magnetic field, utilizing the magnetic permeability of the soft magnetic elastic body, the magnetic poles generated by the coils will attract the magnetic poles of the hard magnetic elastic body, causing the soft magnetic elastic body to bend and deform, thus achieving the grasping purpose.

[0016] like Figure 3 As shown, by supplying electricity to the two coils... Figure 2The reverse pulse strong current realizes the releasing action of the soft gripper system. The magnetic pole distribution on the end surface is that the upper of the left coil is S pole, the lower is N pole; the upper of the right coil is N pole, the lower is S pole. Under the circulation effect in the magnetic field, the magnetic pole produced by the coil will have the same sex repulsion effect with the magnetic pole of the hard magnetic elastomer, so that the soft magnetic elastomer is deformed to release the object.

[0017] The embodiments are the preferred embodiments of the present application, but the present application is not limited to the above embodiments, any obvious improvement, replacement or modification made by those skilled in the art without departing from the essential content of the present application shall fall within the protection scope of the present application.

Claims

1. A magnetically controlled soft gripper, characterized in that, include: Coil (1), soft magnetic elastomer (2), hard magnetic elastomer (3), plastic film (4), magnetorheological fluid (5); the soft magnetic elastomer (2) is U-shaped with a rectangular cross-section; the hard magnetic elastomer (3) is sheet-like, and the hard magnetic elastomer (3) is closely attached to the outer edge of the soft magnetic elastomer (2); the coil (1) is wound around the surface at the intersection of the arc and straight part of the soft magnetic elastomer (2) and fixedly connected; the plastic film (4) is bonded to the inner edge contour of the soft magnetic elastomer (2) and forms a sealed space with the soft magnetic elastomer (2), which is filled with magnetorheological fluid (5); wherein, the hard magnetic elastomer (3) is magnetized in the thickness direction, and the grasping action of the soft gripper system is realized by passing a pulsed strong current through the two coils, and it forms on the end face: left line The left coil has an N pole at the top and an S pole at the bottom; the right coil has an S pole at the top and an N pole at the bottom. Under the influence of the external magnetic field, the magnetic conductivity of the soft magnetic elastomer causes the magnetic poles generated by the coils to attract the magnetic poles of the hard magnetic elastomer, causing the soft magnetic elastomer to bend and deform, thus achieving the purpose of grasping. By passing a strong pulse current in opposite directions through the two coils, the release action of the soft gripper system is achieved. On the end face, the left coil has an S pole at the top and an N pole at the bottom; the right coil has an N pole at the top and an S pole at the bottom. Under the influence of the internal magnetic field, the magnetic conductivity of the soft magnetic elastomer causes the magnetic poles generated by the coils to repel the magnetic poles of the hard magnetic elastomer, thus causing the soft magnetic elastomer to bend and deform, thus achieving the purpose of releasing.

2. The magnetically controlled soft gripper according to claim 1, characterized in that, The soft magnetic elastomer (2) is composed of soft magnetic particles and elastic matrix material, with nano-sized soft magnetic particles uniformly dispersed in the elastic matrix material, and the average particle size of the soft magnetic particles not exceeding 50 nm.

3. The magnetically controlled soft gripper according to claim 1, characterized in that, The hard magnetic elastomer (3) is composed of neodymium iron boron permanent magnet particles and elastic matrix material, and is in the form of a thin sheet. The hard magnetic elastomer (3) is magnetized in the thickness direction.

4. The magnetically controlled soft gripper according to claim 1, characterized in that, The plastic film (4) is made of any one of low-density polyethylene film, polyester film, or cast polypropylene film, with a thickness between 15 and 50 μm and a surface wet tension between 33 and 40 dyn / cm. The plastic film (4) is bonded to the inner side outline of the soft magnetic elastomer (2) and forms a closed space with the soft magnetic elastomer (2). The space is filled with magnetorheological fluid (5) with a filling rate between 40% and 75%.

5. A magnetically controlled soft gripper according to claim 1, characterized in that, The magnetorheological fluid (5) is composed of magnetic particles, a base liquid, and a thixotropic agent; the magnetic particles are made of carbonyl iron powder, nickel, or cobalt, and the average particle size of the magnetic particles is between 1 and 50 μm; the base liquid is made of mineral oil, silicone oil, or fluoroether oil; and the thixotropic agent is made of organic bentonite, hydrogenated castor oil, or silicon dioxide.

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