Flexible magnetic actuator with multi-stable nonlinearity

Abstract

The application discloses a flexible magnetic driving device with multi-stable nonlinearity, relates to the field of magnetic control, and comprises a middle soft layer, an internal liquid metal conductive path, electrodes installed at two ends, upper and lower hard layers, gaps designed in the hard layers, and embedded magnetic particles. The application provides a flexible magnetic driving device, solves the problems of a required large external magnetic field and a small deformation of a current magnetic driving device, has an accurate and stable current threshold in the aspect of a circuit protection switch, has a simple structure, and has the characteristics of shape adaptability and rapid grabbing in the aspect of a flexible magnetic gripper.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of magnetic control, and particularly relates to a flexible magnetic driving device with multi-stable nonlinearity. BACKGROUND

[0002] The soft magnetic material can continuously, rapidly and reversibly change shape, has the advantages of fast response speed and non-contact control, and can be used in scenes that cannot be realized by rigid robots, such as curved pipes and human bodies. At present, researchers around the world have carried out a lot of work on the basic principles of soft magnetic driving devices, sensor development, intelligent material forming process technology, potential applications and other fields, and have made some breakthroughs. However, there are still problems to be solved in the application of the soft magnetic driving device, such as the need for a large external magnetic field to drive deformation and a small deformation, which limits its development. SUMMARY

[0003] The application aims to provide a flexible magnetic driving device with multi-stable nonlinearity, which can make a large deformation in response to an external weak magnetic field.

[0004] The technical solution for achieving the application is as follows: a flexible magnetic driving device with multi-stable nonlinearity comprises: a middle soft layer capable of bending and deforming;

[0005] Hard layer units connected to the upper and lower sides of the middle soft layer, the upper and lower hard layer units form a hard layer module, gaps are provided between multiple hard layer modules, and the gaps are arranged at equal intervals along the length direction of the middle soft layer;

[0006] Magnetic modules embedded around the periphery of the hard layer units, used to make the middle soft layer have direction-selective bending deformation under the action of a magnetic field.

[0007] A flexible magnetic driving device with multi-stable nonlinearity is used for an automatic circuit protection switch, metal electrodes at both ends of the flexible magnetic driving device are connected to a loop composed of an electrometer, a resistor and a direct current power supply, the electrometer and the resistor are connected in series and then connected in parallel with an induction coil, and the induction coil faces the flexible magnetic driving device; the electrometer is used to monitor the current size of the circuit, when the current is too large, the induction coil generates a magnetic field to make the flexible magnetic driving device bend, and the electrodes are disconnected from the circuit.

[0008] A flexible magnetic driving device with multi-stable nonlinearity is used for a flexible magnetic gripper, a plurality of flexible magnetic driving devices and induction coils are assembled to obtain a magnetic gripper, the magnetic pole arrangement directions are the same, a direct current power supply is used to power the induction coils, different directions of current are applied to make the flexible magnetic driving devices bend inward or outward at the same time, and the gripping or opening state of the magnetic gripper is realized.

[0009] Compared with the prior art, the application has the following obvious advantages:

[0010] (1)The present application provides a flexible magnetic drive with multi-stable nonlinearity, which can make large deformation in response to external weak magnetic field; it is applied to the field of circuit protection as a current threshold switch, which has accurate and stable current threshold, simple structure and adjustable threshold; it is applied to the field of flexible gripper as a gripper, which has shape adaptability and fast grasping characteristics.

[0011] (2)By embedding magnetic particles in the upper and lower hard layers, and designing a gap to obtain a joint structure; the middle layer is made of flexible silica gel, which is the main deformation part, so that the drive can make large deformation under external weak magnetic field, and the drive has threshold deformation effect, that is, when the external magnetic field is lower than the field strength threshold, the drive deforms small, and when the external magnetic field exceeds the field strength threshold, the drive makes large deformation bending response quickly; and by adjusting the distance between the coil and the switch, the current threshold can be adjusted.

[0012] (3)Four magnetic drives and an induction coil are assembled to obtain a magnetic gripper, which is powered by a direct current source, and the gripper is in an open state when a reverse current is applied, and the gripper is in a gripping state when a forward current is applied, and the magnetic gripper has shape adaptability and fast grasping characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a front view of the magnetic drive of the present application

[0014] Figure 2 It is a front view of the magnetic drive of the present application in a bent state

[0015] Figure 3 It is an appearance view of the magnetic drive of the present application

[0016] Figure 4 It is a schematic view of the automatic circuit protection switch of the present application

[0017] Figure 5 It is a schematic view of the flexible magnetic gripper of the present application

[0018] In the figure: 1, middle soft layer; 2, hard layer unit; 3, magnetic particle; 4, liquid metal passage; 5, metal electrode; 6, flexible magnetic drive; 7, induction coil; 8, 6517A electrometer; 9, resistor; 10, direct current source; 11, flexible magnetic drive DETAILED DESCRIPTION

[0019] The present application will be further described below in combination with the drawings and specific embodiments.

[0020] Example 1

[0021] In combination with Figure 1 , Figure 2 ,Figure 3 This embodiment provides a flexible magnetostrictive actuator with multi-stable nonlinearity, including an intermediate soft layer 1, hard layer units 2, magnetic particles 3, liquid metal channels 4, and metal electrodes 5. The intermediate soft layer 1 is connected to both the upper and lower hard layer units 2, and the upper and lower hard layer units 2 form a hard layer module. Multiple hard layer modules are designed with gaps between them and are arranged at equal intervals along the length of the intermediate soft layer 1. Magnetic particles 3 are embedded in the interior of each hard layer unit 2, and the magnetic particles 3 are symmetrically arranged about the intermediate soft layer 1. The intermediate soft layer 1 is provided with a liquid metal channel 4, and metal electrodes 5 are installed at both ends of the liquid metal channel 4.

[0022] In this embodiment, the intermediate soft layer 1 is made of silicone with a low elastic modulus, coated and cured using a scraper, with a thickness of 0.2-2mm. Fine copper wires are placed during curing, and after curing, the copper wires are removed. Liquid metal is injected using a syringe, and electrodes 5 are installed at both ends for circuit connection and to prevent liquid metal leakage. The hard layer unit 2 is made of silicone with a high elastic modulus, cured using a mold in two steps. After the first curing, magnetic particles 3 are placed, coated with silicone slurry, and cured again to embed the magnetic particles 3 internally. The thickness of a single hard layer unit 2 is 1.5-5mm, and the gap width between hard layer modules is 0.5-5mm. The number of magnetic particles 3 is twice the number of hard layer units 2; in this embodiment, the number is 20, arranged in two rows side-by-side. The magnetization intensity of the magnetic particles is 100-150mT, and the magnetization direction is horizontal to the right. When the flexible magnetostrictive actuator is attracted and bent by an external magnetic field, the spacing between the magnetic particles on the inner side of the bend decreases, while the spacing between the magnetic particles on the outer side of the bend increases. The magnetic particles on both sides generate a magnetic force difference. When the magnetic force difference on both sides is greater than the elastic reaction force of the middle soft layer, the flexible magnetostrictive actuator will quickly bend to its maximum state.

[0023] Example 2

[0024] Combination Figure 3 As shown, based on the previous embodiment, this embodiment provides an automatic circuit protection switch. A flexible magnetostrictive actuator 6 is connected to the analog circuit as a current threshold switch. An induction coil 7 is set next to the current threshold switch. A 6517A electrometer 8 and a resistor 9 are connected in series with it and in parallel with the induction coil 7. A DC power supply 10 is used to power the analog circuit.

[0025] In this example, the metal electrodes 5 at both ends of the flexible magnetic driver 6 are connected into the circuit, and the control circuit is turned on and off as a whole. The sensing coil 7 is placed near the current threshold switch. The 6517A electrometer 8 collects the current signal and transmits it to the CPU. The upper limit of current collection is 200 mA. After being connected in series with the resistor 9, it is connected in parallel with the sensing coil 7. The current size of the circuit can be monitored in real time. A DC power supply 10 is used for power supply. When the current is normal, the switch remains in the on state. When the current becomes larger and reaches the set threshold, the switch is attracted by the magnetic field generated by the sensing coil and quickly deforms to the bent state, thereby disconnecting the protection circuit. The switch is reset afterwards, and the circuit remains connected. Users can adjust the distance between the sensing coil 7 and the magnetic driver 6 according to different circuit requirements to adjust the current threshold size.

[0026] Embodiment 3

[0027] In combination Figure 4 On the basis of Embodiment 1, this embodiment provides a flexible magnetic gripper. Four flexible magnetic drivers 11 without liquid metal passages 4 are assembled with the sensing coil 7 to obtain a magnetic gripper. A DC power supply supplies power to the sensing coil 7. In this example, the four magnetic drivers 11 are assembled around the sensing coil 7, and the magnetic pole arrangement direction is the same. The user controls the current direction of the DC power supply. When the reverse current is applied, the sensing coil generates a magnetic field, and the magnetic driver is repelled outward to the open state. When the forward current is applied, the sensing coil generates a magnetic field, and the magnetic driver is attracted inward to the gripping state. The magnetic gripper has the characteristics of shape adaptability and rapid grabbing.

Claims

1. A flexible magnetic actuator having a multi-stable non-linearity, characterized in that, It comprises: a middle soft layer capable of bending deformation; hard layer units connected to the upper and lower sides of the middle soft layer, the upper and lower hard layer units forming a hard layer module, gaps being provided between multiple hard layer modules and being arranged at equal intervals along the length direction of the middle soft layer; magnetic modules embedded in the periphery of the hard layer units, for generating magnetic force under the action of a magnetic field to make the middle soft layer have direction-selective bending deformation; a liquid metal conductive path provided inside the middle soft layer, and electrodes installed at both ends of the liquid metal conductive path.

2. The flexible magnetic actuator with a multi-stable nonlinearity of claim 1, wherein, For an automatic circuit protection switch, metal electrodes at both ends of a flexible magnetic drive are connected to a loop composed of an electrometer, a resistor and a direct current power supply, the electrometer and the resistor are connected in series and then connected in parallel with an induction coil, the induction coil is opposite to the flexible magnetic drive; the electrometer is used for monitoring the current size of the circuit, when the current is too large, the induction coil generates a magnetic field to make the flexible magnetic drive bend, and the electrodes are disconnected from the circuit.

3. The flexible magnetic actuator with a multi-stable nonlinearity of claim 1, wherein, For a flexible magnetic gripper, multiple flexible magnetic drives and an induction coil are assembled to obtain a magnetic gripper, the magnetic pole arrangement directions are the same, a direct current power supply is used to power the induction coil, by applying currents in different directions, the flexible magnetic drives bend inward or outward at the same time, and the gripping or opening state of the magnetic gripper is realized.

4. The flexible magnetic actuator with a multi-stable nonlinearity of claim 1, wherein, The thickness of the single-layer hard layer unit is 1.5-5 mm, and the gap width between the hard layer modules is 0.5-5 mm.

5. The flexible magnetic actuator with a multi-stable nonlinearity of claim 1, wherein, The particle magnetization is 100-150 mT.

6. The flexible magnetic actuator with a multi-stable nonlinearity of claim 1, wherein, The middle soft layer and the hard layer unit are both made of silica gel, and the elastic modulus of the hard layer unit is greater than that of the middle soft layer.

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