Miniature artificial muscle driver capable of bending and deforming in two directions and preparation method of miniature artificial muscle driver

Abstract

The invention relates to the technical field of miniature drivers, and particularly discloses a miniature artificial muscle driver capable of bending and deforming bidirectionally and a preparation method thereof.The miniature artificial muscle driver capable of bending and deforming bidirectionally comprises an elastic substrate, a nickel anchoring structure, an SMA wire, a photoetching array structure and a PDMS flexible layer; nickel anchoring structures, SMA wires and photoetching array structures are symmetrically arranged on the upper side and the lower side of the elastic substrate, the number of the photoetching array structures is multiple columns, the number of the SMA wires is multiple rows, the SMA wires vertically penetrate through the photoetching array structures and form a net-shaped structure with the photoetching array structures, the nickel anchoring structures are located at the two ends of the SMA wires, and the PDMS flexible layer is poured in gaps of the net-shaped structure. The micro artificial muscle driver which is miniaturized, light, high in energy density and capable of bending and deforming bidirectionally is prepared by selecting a light-weight and high-strength substrate material and using a micromachining technology.

Description

Technical Field

[0001] The invention relates to the technical field of micro-actuators, and in particular to a micro-artificial muscle actuator capable of bidirectional bending and deformation and a preparation method thereof. Background Art

[0002] As the size of robots decreases, traditional mechanical systems and processing and manufacturing processes will encounter many technical bottlenecks, especially the choice of drive mode. The traditional motor-driven system is heavy and cannot be further miniaturized, which limits the development of micro-robots. Currently, micro-drives have technical bottlenecks such as small deformation size, small output force, and large mass. Summary of the invention

[0003] The purpose of the present invention is to provide a micro artificial muscle actuator capable of bidirectional bending and deformation and a preparation method thereof, so as to solve the problems of small deformation size, small output force and large mass of the micro actuator in the prior art.

[0004] In order to solve the above technical problems, the present invention provides a micro-artificial muscle actuator that can be bent and deformed in both directions, including an elastic substrate, a nickel anchoring structure, an SMA wire, a photolithography array structure and a PDMS flexible layer. The nickel anchoring structure, the SMA wire and the photolithography array structure are symmetrically arranged on the upper and lower sides of the elastic substrate, the photolithography array structure is a plurality of columns, the SMA wire is a plurality of rows and vertically passes through the photolithography array structure to form a mesh structure therewith, the nickel anchoring structures are located at both ends of the SMA wire, and the PDMS flexible layer is cast in the gaps of the mesh structure.

[0005] Preferably, the elastic substrate includes a carbon fiber layer and a glass fiber structure, the glass fiber structure is symmetrically arranged on the upper and lower sides of the carbon fiber layer, the glass fiber structure and the nickel anchoring structure are the same in number and corresponding in position, and the carbon fiber layer is a plate with a hollow structure.

[0006] Preferably, a nickel anchoring structure is provided at each midpoint of the upper and lower sides of the elastic substrate.

[0007] A method for preparing a micro artificial muscle actuator capable of bidirectional bending and deformation comprises the following steps:

[0008] S1. preparing an elastic substrate;

[0009] S1-1. Use an ultraviolet laser cutting machine to process the carbon fiber layer and the glass fiber structure into a plate shape, and the glass fiber structure is symmetrically arranged on the upper and lower sides of the carbon fiber layer;

[0010] S1-2, placing the carbon fiber layer and the glass fiber structure in a high-pressure and high-temperature box, setting the pressure, temperature, and curing time, and after the high-temperature and high-pressure treatment, the carbon fiber layer and the glass fiber structure are tightly cured and bonded to form an elastic substrate;

[0011] S2, preparing SMA wire;

[0012] S2-1. At room temperature, a tensile test is performed on the SMA wire to determine the stress P at which the SMA wire undergoes a complete martensitic phase transformation. The SMA wire is subjected to stress P and subjected to thermal training. The SMA wire is heated by electricity to shrink it, and then cooled to restore it to its original state. The heating and cooling process is repeated multiple times.

[0013] S2-2, sputtering a TiW layer and a Ni layer next to the glass fiber structure;

[0014] S2-3, symmetrically arrange the SMA wires prepared as above on the upper and lower sides of the elastic substrate, and fix them through a temporary support structure so that the SMA wires maintain a certain distance from the elastic substrate.

[0015] S3, preparing a nickel anchoring structure;

[0016] S3-1, put the photoresist into a vacuum box to evacuate, and pour the vacuumized photoresist onto the substrate obtained in step S2;

[0017] S3-2, using a coating machine to coat the substrate with photoresist to obtain a first photoresist layer, placing the substrate coated with photoresist on a heating plate for baking, wherein the temperature of the heating plate is lower than the phase transition temperature of the SMA wire, and after natural cooling, using a maskless photolithography machine for exposure to obtain an exposure pattern;

[0018] S3-3, drawing an exposure pattern, and copying it to a maskless lithography machine, and after specifying an exposure dose, transferring the drawn exposure pattern to a substrate coated with a photoresist to obtain an exposed substrate;

[0019] S3-4, baking the exposed substrate on a heating plate, developing it in a developer for photoresist after cooling, taking it out after a certain period of development, and leaving the cured photoresist on the substrate;

[0020] S3-5, immersing the substrate in a mixed solution of HF and H2O to remove the oxide layer of the SMA wire and the oxide layer of the Ni layer;

[0021] S3-6, electroplating nickel in the area where the photoresist has fallen off to form a nickel anchoring structure, and peeling off the remaining solidified photoresist;

[0022] S4, preparing a photolithographic array structure;

[0023] S4-1, take the photoresist and put it into a vacuum box to evacuate, pour the vacuumized photoresist on the substrate obtained in step S3, and use a coating machine to spin-coat the photoresist to obtain a second photoresist layer;

[0024] S4-2, repeating steps S3-2 to S3-4 to form a photolithography array structure on the substrate, wherein the SMA wire, the nickel anchoring structure and the photolithography array structure form a mesh structure;

[0025] S5, using a coating machine to spin-coat PDMS on the substrate, so that the PDMS fills the gaps in the mesh structure to obtain a PDMS flexible layer;

[0026] S6. Remove the temporary support structure of the substrate and cut off the excess SMA wires at both ends to obtain a micro artificial muscle actuator that can bend and deform in both directions.

[0027] Preferably, in step S2-1, the substrate is cleaned with an alcohol brush, impurities are cut with a laser, rinsed with pure water, blown clean with high-purity nitrogen, and then immersed in an acetone solution, and then placed in an ultrasonic cleaning machine for vibration washing. After being taken out, it is rinsed with anhydrous ethanol, rinsed with pure water, and then blown clean with high-purity nitrogen to obtain a substrate with a clean surface.

[0028] Preferably, in step S3-2, the speed of the coating machine is first set according to the photoresist technical document to obtain a photoresist layer of a certain thickness, and then the layer is placed on a heating plate and baked at 65°C for 1 minute, 80°C for 2 minutes, and 65°C for 1 minute. The photoresist is spin-coated again and the baking is repeated until the photoresist is evenly coated on the substrate to obtain a first photoresist layer.

[0029] Preferably, in step S3-4, if there are areas where the development is not uniform and the photoresist remains, a developer is sucked with a micro-syringe and gently sprayed, and then rinsed with pure water, and the rinsed substrate is placed on a heating plate and baked at 85° C. for 5 minutes.

[0030] Preferably, in step S1-2, the pressure is set to 1000KG / m 2 , temperature 120°C, curing for 2 hours, in step S2-1, the thermal training cycle is 1000 times of heating and cooling, and in step S3-5, the mixing ratio of HF and H2O mixed solution is 1:10.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention selects lightweight and high-strength carbon fiber and glass fiber as base materials, and uses micro-processing technologies such as ultraviolet laser cutting and photolithography technology to achieve the design and manufacture of a miniaturized, lightweight, high-energy-density, bidirectionally bendable micro-artificial muscle actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of a micro artificial muscle actuator capable of bidirectional bending and deformation according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of a single carbon fiber prepreg and a single glass fiber prepreg after cutting according to an embodiment of the present invention;

[0035] Figure 3 for Figure 2 A front view of

[0036] Figure 4 This is a schematic diagram of an elastic substrate formed after curing the prepreg in an embodiment of the present invention;

[0037] Figure 5 for Figure 4 A front view of

[0038] Figure 6 This is a schematic diagram of fixing the SMA wire with a temporary support structure according to an embodiment of the present invention;

[0039] Figure 7 for Figure 6 A front view of

[0040] Figure 8 This is a schematic diagram of spin coating a first photoresist layer according to an embodiment of the present invention;

[0041] Fig. 9 for Figure 8 A front view of

[0042] Fig.10 A schematic diagram of a portion of the first photoresist layer being peeled off by development according to an embodiment of the present invention;

[0043] Fig.11 for Fig. 9 A front view of

[0044] Fig.12 This is a schematic diagram of nickel electroplating according to an embodiment of the present invention;

[0045] Fig.13 for Fig.12 A front view of

[0046] Fig.14 This is a schematic diagram of stripping the cured photoresist according to an embodiment of the present invention;

[0047] Fig.15 for Fig.14 A front view of

[0048] Fig.16 This is a schematic diagram of spin coating a second photoresist layer according to an embodiment of the present invention;

[0049] Fig.17 for Fig.16 A front view of

[0050] Fig.18 A schematic diagram of a photolithography array structure formed according to an embodiment of the present invention;

[0051] Fig.19 for Fig.18 A front view of

[0052] Fig. 20This is a schematic diagram of pouring PDMS to form a PDMS flexible layer according to an embodiment of the present invention;

[0053] Fig.21 for Fig. 20 Front view of .

[0054] In the figure, 1, elastic substrate; 101, carbon fiber layer; 102, glass fiber structure; 103, TiW layer; 104, Ni layer; 2, nickel anchoring structure; 201, first photoresist layer; 202, cured photoresist; 203, second photoresist layer; 3, SMA wire; 301, temporary support structure; 4, photolithography array structure; 5, PDMS flexible layer DETAILED DESCRIPTION

[0055] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0056] A micro artificial muscle actuator capable of bidirectional bending and deformation, such as Figure 1 As shown, it includes an elastic substrate 1, a nickel anchoring structure 2, an SMA wire 3, a photolithography array structure 4 and a PDMS flexible layer 5. The nickel anchoring structure 2, the SMA wire 3 and the photolithography array structure 4 are symmetrically arranged on the upper and lower sides of the elastic substrate 1. The photolithography array structure 4 is in multiple columns, and the SMA wire 3 is in multiple rows and vertically passes through the photolithography array structure 4 to form a mesh structure therewith.

[0057] The elastic substrate 1 includes a carbon fiber layer 101 and a glass fiber structure 102. The thickness of the carbon fiber layer 101 and the glass fiber structure 102 can be selected between tens of microns. The carbon fiber layer 121 has the mechanical property of high elastic modulus, providing support and rebound deformation for the entire micro-artificial muscle actuator. The glass fiber structure 102 has high strength and insulation effect, and is the base of the nickel anchoring structure 2. The glass fiber structure 102 is evenly and symmetrically arranged on the upper and lower sides of the carbon fiber layer 101. The glass fiber structure 102 and the nickel anchoring structure 2 are the same in number and corresponding in position. The carbon fiber layer 101 is a plate with a hollow structure.

[0058] There are three nickel anchoring structures 2 on both sides of the elastic substrate 1, with two nickel anchoring structures 2 on each side respectively located at the two ends of the SMA wire 3, and the remaining nickel anchoring structure 2 is located at any position between the nickel anchoring structures 2 at both ends. It can be arranged according to the actual output deformation requirements of the micro-artificial muscle driver. If it is at the midpoint position, it is symmetrically distributed. At this time, the output of the two ends of the micro-artificial muscle driver is also symmetrical. The nickel anchoring structure 2 has two functions. One is to fix the SMA wire 3 and the elastic substrate 1, and the other is to form a conductive path with the contacting SMA wire 3.

[0059] The SMA wire 3 can achieve bidirectional deformation after thermal training, shrink in length when heated, and return to its initial state when cooled. The specific number of SMA wires 3 can be determined according to the output mechanical characteristics of the driver. The SMA wire 3 will undergo phase change due to the geothermal effect of electric current, thereby causing shrinkage deformation and shortening in length. The SMA wire 3 will cool down when the power is off, thereby returning to its initial state.

[0060] The photolithography array structure 4 is formed by solidifying photoresist and is also evenly distributed on the upper and lower layers of the elastic substrate 1, thereby embedding the SMA wire 3 inside the micro-artificial muscle actuator. When the SMA wire 3 is energized and contracts to generate strain, bending will occur on the elastic substrate 1. Since the photolithography array structure 4 binds the SMA wire 3 to the elastic substrate 1, its distance from the elastic substrate 1 will remain consistent, which will increase the bending effect of the elastic substrate 1.

[0061] The PDMS flexible layer 5 is cast in the gaps of the mesh structure to increase the structural strength and elasticity of the entire micro-artificial muscle actuator.

[0062] A method for preparing a micro artificial muscle actuator capable of bidirectional bending and deformation comprises the following steps:

[0063] S1, preparing an elastic substrate 1;

[0064] S1-1, the carbon fiber layer 101 and the glass fiber structure 102 are formed by curing a single carbon fiber prepreg and a single glass fiber prepreg, and the single carbon fiber prepreg and the single glass fiber prepreg are processed into a plate shape by an ultraviolet laser cutting machine, such as Figure 2 and 3 As shown, through appropriate tooling alignment, the single-item carbon fiber prepreg is symmetrically arranged on the upper and lower sides of the single-item glass fiber prepreg to form the original design structure;

[0065] S1-2, put it into a high-pressure and high-temperature box, set the pressure, temperature, and curing time. In this embodiment, the pressure is set to 1000KG / m 2 , the temperature is 120°C, and the curing time is 2 hours. After the high temperature and high pressure treatment, the single carbon fiber prepreg and the single glass fiber prepreg are cured into a carbon fiber layer 101 and a glass fiber structure 102. The carbon fiber layer 101 and the glass fiber structure 102 are tightly cured and bonded to form an elastic substrate 1, such as Figure 4 and 5 As shown;

[0066] S2, preparing SMA wire 3;

[0067] S2-1. At room temperature of 25°C, a tensile test is performed on the experimental SMA wire to determine the stress magnitude of the thermal cycle under the constant load training process. The stress-strain diagram is obtained through the experiment to determine the stress magnitude P at which the experimental SMA wire undergoes a complete martensitic phase transformation;

[0068] Take a new SMA wire 3 of the same model as the experimental SMA wire, load stress P on the SMA wire 3 and perform thermal training, heat it to shrink it, and then cool it to restore it to its original state, and repeat the heating and cooling process for many times. In this embodiment, the cycle is 1000 times. After 1000 times, the thermal strain of the SMA wire 3 is about 5%, and the phase change activation current of the trained SMA wire 3 starts from about 500mA and ends at 800mA;

[0069] The substrate is cleaned with an alcohol brush, impurities are cut with a laser, rinsed with pure water, blown clean with high-purity nitrogen, and then immersed in an acetone solution, and then placed in an ultrasonic cleaner for vibration washing. In this embodiment, the vibration washing is performed for 5 minutes. After being taken out, it is rinsed with anhydrous ethanol and pure water. The characteristics of acetone being soluble in ethanol and ethanol being soluble in water are utilized to achieve the purpose of thorough cleaning. Then, it is blown clean with high-purity nitrogen to obtain a substrate with a clean surface, laying a foundation for uniform and tight coating of photoresist.

[0070] S2-2, sputtering TiW layer 103 and Ni layer 104 next to glass fiber structure 102, TiW alloy has strong adhesion to many common substrate materials, such as silicon, silicon oxide, etc. This allows other films to be successfully deposited on it without peeling or cracking, these properties make TiW alloy an ideal choice for adhesion layer, on this basis, sputtering 300nm Ni layer 104 as a preparation for subsequent electroplating anchor nickel;

[0071] S2-3, the SMA wires 3 prepared above are evenly and symmetrically arranged on the upper and lower sides of the elastic substrate 1, and fixed by a temporary support structure 301, such as Figure 6 and 7 As shown, the SMA wire 3 is kept at a certain distance from the elastic substrate 1, and the distance can be within tens of microns. Different values ​​will affect the output deformation angle of the micro-artificial muscle driver. The larger the value, the smaller the output deformation angle of the micro-artificial muscle driver. The specific relationship is:

[0072] h·θ=ε·l;

[0073] Wherein, h is the height of the SMA wire 3 from the neutral line of the elastic substrate 1 , θ is the angle between the end of the micro-artificial muscle actuator and the position before deformation, ε is the contraction rate of the SMA wire 3 , and l is the original length of the SMA wire 3 .

[0074] S3, preparing nickel anchoring structure 2;

[0075] S3-1, take a certain amount of photoresist, which can be a type of photoresist that is easy to remove after curing, put it into a vacuum box to evacuate to eliminate bubbles in the photoresist, and pour the vacuumized photoresist on the substrate obtained in step S2;

[0076] S3-2. According to the characteristics of the photoresist, refer to the corresponding photoresist technical documents, set the rotation speed and spin coating time of the coating machine, use the coating machine to spin coat the photoresist on the substrate to obtain a photoresist layer of a certain thickness, place the substrate coated with the photoresist layer of a certain thickness on a heating plate and bake it at 65°C for 1 minute, 80°C for 2 minutes, and 65°C for 1 minute in sequence, and the temperature of the heating plate is lower than the phase transition temperature of the SMA wire 3.

[0077] Repeat the spin coating of photoresist and the heating plate baking until the photoresist is evenly coated on the substrate by the coating machine to obtain the first photoresist layer 201. Figure 8 and 9 As shown, after natural cooling, a maskless photolithography machine is used for exposure to obtain an exposure pattern;

[0078] S3-3, using AutoCAD to draw an exposure pattern, and copying it to a maskless lithography machine, according to the photoresist model and lithography machine used, refer to the corresponding photoresist technical documents, calculate the exposure dose, and after multiple experiments, transfer the drawn exposure pattern to a substrate coated with photoresist at a suitable exposure dose to obtain an exposed substrate;

[0079] S3-4, placing the exposed substrate on a heating plate and baking at 65°C for 1 minute, 80°C for 2 minutes, and 65°C for 1 minute in sequence, and placing it in a special developer for photoresist for development after natural cooling, taking it out after 30 seconds of development and rinsing it with pure water. If there are parts that are not developed evenly and where photoresist remains, use a micro-syringe to absorb the developer and gently spray it, then rinse it with pure water, and place the rinsed substrate on a heating plate and bake it at 85°C for 5 minutes. If negative photolithography is used, the photoresist in the exposed part will be cross-linked and become insoluble and will not be washed away by the developer. If positive photolithography is used, on the contrary, the photoresist in the exposed part will be destroyed and thus washed away by the developer;

[0080] The cured photoresist 202 remains on the substrate, such as Fig.10 and 11 As shown;

[0081] S3-5, immersing the substrate in a mixed solution of HF and H2O, the mixing ratio of which is HF:H2O=1:10, to remove the oxide layer of the SMA wire 3 and the oxide layer of the Ni layer 104;

[0082] S3-6, electroplating nickel in the area where the photoresist falls off to form a nickel anchoring structure 2, such as Fig.12 and 13 As shown, the plating conditions are selected according to the guidelines provided by the manufacturer and the processing data provided in the literature, and the remaining cured photoresist 202 is stripped, as shown in FIG. Fig.14 and 15 As shown;

[0083] S4, preparing a photolithography array structure 4;

[0084] S4-1, take the photoresist and put it into a vacuum box to evacuate, pour the vacuumized photoresist on the substrate obtained in step S3, use a coating machine to spin-coat the photoresist, and obtain a second photoresist layer 203, such as Fig.16 and 17 As shown;

[0085] S4-2, repeating steps S3-2 to S3-4, forming a photolithographic array structure 4 on the substrate, such as Fig.18 and 19 As shown, at this time, the SMA wire 3, the nickel anchoring structure 2 and the photolithography array structure 4 form a mesh structure;

[0086] S5. Use a glue spreader to evenly apply PDMS on the substrate so that PDMS fills the gaps in the mesh structure. Fig. 20 and 21 As shown, a PDMS flexible layer 5 is obtained;

[0087] S6. Remove the temporary support structure 301 of the substrate, cut off the redundant SMA wires 3 at both ends, and obtain a micro artificial muscle actuator capable of bidirectional bending and deformation.

[0088] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A micro artificial muscle actuator capable of bidirectional bending and deformation, characterized in that: The invention comprises an elastic substrate (1), a nickel anchoring structure (2), an SMA wire (3), a photolithography array structure (4) and a PDMS flexible layer (5); the nickel anchoring structure (2), the SMA wire (3) and the photolithography array structure (4) are symmetrically arranged on the upper and lower sides of the elastic substrate (1); the photolithography array structure (4) is in multiple columns; the SMA wire (3) is in multiple rows and vertically passes through the photolithography array structure (4) to form a mesh structure with the SMA wire (3); the nickel anchoring structure (2) is located at both ends of the SMA wire (3); and the PDMS flexible layer (5) is cast in the gaps of the mesh structure.

2. The micro artificial muscle actuator capable of bidirectional bending and deformation according to claim 1, characterized in that: The elastic substrate (1) comprises a carbon fiber layer (101) and a glass fiber structure (102), wherein the glass fiber structure (102) is symmetrically arranged on the upper and lower sides of the carbon fiber layer (101), the glass fiber structure (102) and the nickel anchoring structure (2) are the same in number and have corresponding positions, and the carbon fiber layer (101) is in the shape of a plate with a hollow structure.

3. The micro artificial muscle actuator capable of bidirectional bending and deformation according to claim 1, characterized in that: A nickel anchoring structure (2) is also provided at each of the midpoints of the upper and lower sides of the elastic base (1).

4. A method for preparing a micro artificial muscle actuator capable of bidirectional bending and deformation, characterized in that: The following steps are involved: S1. preparing an elastic substrate (1); S1-1, using an ultraviolet laser cutting machine to process the carbon fiber layer (101) and the glass fiber structure (102) into a plate shape, wherein the glass fiber structure (102) is symmetrically arranged on the upper and lower sides of the carbon fiber layer (101); S1-2, placing the carbon fiber layer (101) and the glass fiber structure (102) in a high-pressure and high-temperature box, setting the pressure, temperature, and curing time, and after the high-temperature and high-pressure treatment, the carbon fiber layer (101) and the glass fiber structure (102) are tightly cured and bonded to form an elastic substrate (1); S2, preparing SMA wire (3); S2-1. At room temperature, a tensile test is performed on the SMA wire (3) to determine the stress P at which the SMA wire (3) undergoes a complete martensitic phase transformation. The SMA wire (3) is subjected to a stress P and subjected to thermal training. The SMA wire (3) is heated by electricity to shrink it, and then cooled to restore it to its original state. The heating and cooling process is repeated multiple times. S2-2, sputtering a TiW layer (103) and a Ni layer (104) next to the glass fiber structure (102); S2-3, symmetrically arranging the SMA wire (3) prepared as above on the upper and lower sides of the elastic substrate (1), and fixing them via a temporary support structure (301), so that the SMA wire (3) and the elastic substrate (1) maintain a certain distance. S3, preparing a nickel anchoring structure (2); S3-1, put the photoresist into a vacuum box to evacuate, and pour the vacuumized photoresist onto the substrate obtained in step S2; S3-2, using a coating machine to coat the substrate with photoresist to obtain a first photoresist layer (201), placing the substrate coated with photoresist on a heating plate for baking, wherein the temperature of the heating plate is lower than the phase transition temperature of the SMA wire (3), and after natural cooling, using a maskless photolithography machine for exposure to obtain an exposure pattern; S3-3, drawing an exposure pattern, and copying it to a maskless lithography machine, and after specifying an exposure dose, transferring the drawn exposure pattern to a substrate coated with a photoresist to obtain an exposed substrate; S3-4, placing the exposed substrate on a heating plate for baking, placing it in a photoresist developer for development after cooling, taking it out after a certain period of development, and leaving the cured photoresist on the substrate (202); S3-5, immersing the substrate in a mixed solution of HF and H2O to remove the oxide layer of the SMA wire (3) and the oxide layer of the Ni layer (104); S3-6, electroplating nickel in the area where the photoresist has fallen off to form a nickel anchoring structure (2), and stripping off the remaining solidified photoresist (202); S4, preparing a photolithographic array structure (4); S4-1, taking the photoresist and putting it into a vacuum box to evacuate, pouring the vacuumized photoresist on the substrate obtained in step S3, and using a coating machine to spin-coat the photoresist to obtain a second photoresist layer (203); S4-2, repeating steps S3-2 to S3-4, forming a photolithographic array structure (4) on the substrate, wherein the SMA wire (3), the nickel anchoring structure (2) and the photolithographic array structure (4) form a mesh structure; S5, using a coating machine to spin-coat PDMS on the substrate so that the PDMS fills the gaps in the mesh structure to obtain a PDMS flexible layer (5); S6. Remove the temporary support structure (301) of the substrate, cut off the redundant SMA wires (3) at both ends, and obtain a micro artificial muscle actuator capable of bidirectional bending and deformation.

5. The method for preparing the micro artificial muscle actuator capable of bidirectional bending and deformation according to claim 4, characterized in that: In step S2-1, the substrate is cleaned with an alcohol brush, impurities are cut with a laser, rinsed with pure water, blown clean with high-purity nitrogen, immersed in an acetone solution, and then vibrated in an ultrasonic cleaner. After being taken out, it is rinsed with anhydrous ethanol, rinsed with pure water, and blown clean with high-purity nitrogen to obtain a substrate with a clean surface.

6. The method for preparing the micro artificial muscle actuator capable of bidirectional bending and deformation according to claim 4, characterized in that: In step S3-2, the rotation speed of the coating machine is first set according to the photoresist technical document to obtain a photoresist layer of a certain thickness, which is then placed on a heating plate and baked at 65°C for 1 minute, 80°C for 2 minutes, and 65°C for 1 minute. The photoresist is spin-coated again and baked repeatedly until the photoresist evenly coats the substrate to obtain a first photoresist layer (201).

7. The method for preparing the micro artificial muscle actuator capable of bidirectional bending and deformation according to claim 4, characterized in that: In step S3-4, if there are areas where the development is not uniform and the photoresist remains, a developer is sucked with a micro-syringe and gently sprayed, and then rinsed with pure water, and the rinsed substrate is placed on a heating plate and baked at 85° C. for 5 minutes.

8. The method for preparing the micro artificial muscle actuator capable of bidirectional bending and deformation according to claim 4, characterized in that: In step S1-2, the pressure is set to 1000KG / m 2 , temperature 120°C, curing for 2 hours, in the step S2-1, the thermal training cycle is 1000 times of heating and cooling, and in the step S3-5, the mixing ratio of the HF and H2O mixed solution is 1:10.

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