A temperature-responsive hydrogel artificial muscle and its preparation method and application

Abstract

The present invention discloses a temperature-responsive hydrogel artificial muscle and its preparation method and application. The method comprises: dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and a promoter in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel; continuously orienting the chemically crosslinked hydrogel to obtain a spiral hydrogel; and immersing the spiral hydrogel in a zirconium salt solution to obtain a hydrogel artificial muscle. The hydrogel artificial muscle can achieve expansion and contraction deformation through temperature stimulation and can be applied to soft actuator robots.

Description

Technical Field

[0001] The present invention relates to the technical fields of chemistry and chemical engineering, and polymer functional materials, and in particular to a temperature-responsive hydrogel artificial muscle and a preparation method and application thereof. Background Art

[0002] Unlike the electromagnetic and fluidic actuators long used to power robots and prosthetic devices, artificial muscles are lightweight, flexible actuators that can reversibly contract, extend, rotate, or bend in response to changes in the external environment (such as electricity, temperature, light, or solvents). This overcomes the rigidity, bulkiness, and limited contraction stroke of these traditional actuators, and has diverse applications in miniaturized soft robotics and biomedical devices. Consequently, many types of artificial muscles have been rapidly developed, showing great potential in biomedical applications.

[0003] Hydrogels, a class of extremely hydrophilic three-dimensional network gels, possess high water content, high permeability, softness, and excellent biocompatibility. These properties closely resemble the structure of human soft tissue, offering significant advantages for the construction of artificial muscles. While currently reported hydrogel artificial muscles exhibit excellent performance and high stability, they are limited by their simple network structure, low cross-linking density, and single cross-linking pattern, resulting in slow response, small response deformation, and limited functionality, significantly limiting their practical applications.

[0004] Therefore, how to prepare fast temperature-responsive hydrogel artificial muscles remains a challenge. Summary of the Invention

[0005] The purpose of the present invention is to provide a temperature-responsive hydrogel artificial muscle and its preparation method and application. The temperature-responsive hydrogel artificial muscle of the present invention benefits from its rapid and cyclic response to temperature and can be applied to soft actuator robots.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect of the present invention, a method for preparing a temperature-responsive hydrogel artificial muscle is provided, the method comprising:

[0008] Dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0009] performing a continuous orientation operation on the chemically cross-linked hydrogel to obtain a helical hydrogel;

[0010] The spiral hydrogel is immersed in a zirconium salt solution to obtain a hydrogel artificial muscle.

[0011] Furthermore, the sulfuric acid-hydrolyzed ascidian cellulose nanocrystals aqueous dispersion is a suspension obtained by dispersing ascidian cellulose nanocrystals prepared by sulfuric acid hydrolysis in deionized water.

[0012] Furthermore, the mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, promoter, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 4-8:5-15:1-2:0.1-0.4:0.1-0.4:0.04-0.16:0.3-0.6, and the rest is deionized water.

[0013] Furthermore, the molar ratio of N-isopropylacrylamide to 3-sulfopropyl methacrylate potassium salt is 5.5-7.5:2.5-4.5.

[0014] Furthermore, the cross-linking agent is N,N'-methylenebisacrylamide, the initiator is potassium persulfate, and the accelerator is tetramethylethylenediamine.

[0015] Furthermore, the polymerization conditions are: polymerization at 20-30° C. for 8-15 hours.

[0016] Furthermore, the chemically cross-linked hydrogel is subjected to a continuous orientation operation to obtain a helical hydrogel, comprising:

[0017] The chemically cross-linked hydrogel is stretched to 3.5 to 4.5 times its original length and twisted at a speed of 25 to 35 rpm to obtain a series of hydrogels with twisting densities, which are then spirally wrapped around the outside of a polytetrafluoroethylene tube with a diameter of 2.5 to 3.5 mm to obtain a spiral hydrogel.

[0018] Furthermore, the zirconium salt solution is a 0.05-0.2 mol / L zirconium oxychloride solution.

[0019] The second aspect of the present invention provides a temperature-responsive hydrogel artificial muscle prepared by the method.

[0020] In a third aspect of the present invention, there is provided a use of the temperature-responsive hydrogel artificial muscle in preparing a soft actuator robot.

[0021] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0022] 1. The experimental materials in the preparation method of the temperature-responsive hydrogel artificial muscle provided by the present invention are widely available. The prepared chemically cross-linked hydrogel has high elongation at break and toughness, and can be stretched, twisted, and spirally wound, providing a basis for shape programming of the hydrogel. The mechanical properties of the temperature-responsive hydrogel can be enhanced by introducing sea squirt cellulose nanocrystals; by polymerizing N-isopropylacrylamide monomers, the hydrogel artificial muscle has temperature-responsive properties and can undergo elongation / contraction deformation under stimulation of 60°C-25°C; by introducing -SO 3- With Zr 4+ The ionic coordination between them fixes the spring-like structure of the hydrogel artificial muscle to amplify its elongation and contraction deformation.

[0023] 2. The temperature-responsive hydrogel artificial muscle of the present invention has two chiral helical structures and repeatedly stretches and contracts under cyclic stimulation from 60°C to 25°C. This hydrogel has a fast response speed and a large response deformation, surpassing the performance of other existing hydrogel artificial muscles.

[0024] 3. The fast temperature-responsive hydrogel artificial muscle of the present invention can imitate the movement pattern of the human body playing football through expansion and contraction deformation stimulated by temperature, demonstrating the potential application of this hydrogel artificial muscle in intelligent response materials, soft actuator robots, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 Scanning electron micrographs of temperature-responsive hydrogel artificial muscles. (a) Isotropic chiral hydrogel and (b) surface pore orientation.

[0027] Figure 2 Figure 2 is the driving performance diagram of two temperature-responsive hydrogel artificial muscles. Figure 2 a is the actual picture of the temperature response of the isotropic chiral hydrogel artificial muscle. Figure 2 b is the actual picture of the anisotropic chiral hydrogel artificial muscle in temperature response

[0028] Figure 3 This is a real picture of temperature-responsive hydrogel artificial muscles simulating human body playing football. Figure 3 a is a real picture of hydrogel artificial muscle simulating human body playing football before temperature response. Figure 3 b is a real picture of the temperature-responsive hydrogel artificial muscle simulating the human body playing football. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below in conjunction with specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific embodiments and examples are for illustrating the present invention, rather than for limiting the present invention.

[0030] Throughout this specification, unless otherwise specified, the terms used herein should be understood as having the same meaning as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event of any conflict, the present specification shall take precedence.

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or obtained through existing methods.

[0032] The embodiment of the present invention provides a temperature-responsive hydrogel artificial muscle. The overall concept is as follows:

[0033] According to a typical embodiment of the present invention, a method for preparing a temperature-responsive hydrogel artificial muscle is provided, the method comprising:

[0034] Step S1, dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0035] In the step S1,

[0036] The cross-linking agent is N,N'-methylenebisacrylamide, the initiator is potassium persulfate, and the accelerator is tetramethylethylenediamine.

[0037] The mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinker, initiator, accelerator, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 4-8:5-15:1-2:0.1-0.4:0.1-0.4:0.04-0.16:0.3-0.6, with the remainder being deionized water. If the mass ratio of the components is outside this range, the hydrogel will not form and subsequent twisting will be impossible.

[0038] The molar ratio of N-isopropylacrylamide to 3-sulfopropyl methacrylate potassium salt is 5.5-7.5:2.5-4.5. For example, 7.5:2.5, 7:3, 6.5:3.5, 6:4, or 5.5:4.5. The molar ratio of N-isopropylacrylamide to 3-sulfopropyl methacrylate potassium salt is crucial to the technical effect. A molar ratio outside the specified range can affect hydrogel formation and reduce the actuation rate and strain of the hydrogel artificial muscle.

[0039] The reaction principle of the present invention is as follows: free radical polymerization is initiated by potassium persulfate as an initiator, and under the crosslinking effect of N,N'-methylenebisacrylamide as a crosslinking agent, three monomers, N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt and acrylamide, are copolymerized to form a high molecular hydrogel with a three-dimensional network structure. 3- With Zr 4+ The ionic coordination between the hydrogel and the fibers stabilizes the initial columnar hydrogel into a spring-like structure. Adding ascidian cellulose nanocrystals as nanofillers improves the mechanical properties of the initial columnar hydrogel, facilitating subsequent twisting and fixation.

[0040] The sulfuric acid-hydrolyzed ascidian cellulose nanocrystal aqueous dispersion is a suspension obtained by dispersing ascidian cellulose nanocrystals prepared by sulfuric acid hydrolysis in deionized water. The specific preparation method of the sulfuric acid hydrolysis method is described in the document "Phase transition identification of cellulose nanocrystal suspensions derived from various raw materials, Yuanyuan Zhang, Qiaoyun Cheng, Chunyu Chang, Lina Zhang".

[0041] As a specific embodiment, the mold into which the dispersion is injected is a polytetrafluoroethylene tube with a diameter of 3 mm.

[0042] Step S2, continuously orienting the chemically cross-linked hydrogel to obtain a spiral hydrogel;

[0043] The step S2 specifically includes:

[0044] The chemically cross-linked hydrogel is stretched to 3.5 to 4.5 times its original length and twisted at a speed of 25 to 35 rpm to obtain a series of hydrogels with twisting densities, which are then spirally wrapped around the outside of a polytetrafluoroethylene tube with a diameter of 2.5 to 3.5 mm to obtain a spiral hydrogel.

[0045] In the twisting, the twisting density is 50 to 200 turns / m, preferably 100 turns / m. A twisting density that is too high may cause the hydrogel to break, while a twisting density that is too low may reduce the driving rate and driving strain of the hydrogel artificial muscle.

[0046] Step S3: soaking the spiral hydrogel in a zirconium salt solution to obtain a hydrogel artificial muscle.

[0047] The zirconium salt solution is a 0.05-0.2 mol / L zirconium oxychloride solution. Preferably, it is a 0.1 mol / L zirconium oxychloride solution. In other embodiments, the zirconium salt solution may also be a ZnSO4 solution, or other solutions containing Zr 4+ of solution.

[0048] The following will describe in detail a temperature-responsive hydrogel artificial muscle of the present application, its preparation method, and its application in combination with examples and experimental data.

[0049] Example 1: A temperature-responsive hydrogel artificial muscle and its preparation method

[0050] 1. Preparation method of temperature-responsive hydrogel artificial muscle

[0051] Step S1, dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0052] The mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, accelerator, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 5.6:9.2:1.4:0.1:0.4:0.07:0.4, and the rest is deionized water, wherein the molar ratio of N-isopropylacrylamide and 3-sulfopropyl methacrylate potassium salt monomers is 6.5:3.5;

[0053] Step S2: stretching the chemically cross-linked hydrogel to 4 times its original length, twisting it at a speed of 25 to 35 rpm to obtain a hydrogel with a twist density of 100 turns / m, and then spirally winding it clockwise around the outside of a polytetrafluoroethylene tube with a diameter of 3 mm to obtain a spiral hydrogel.

[0054] Step S3: Soaking the spiral hydrogel in a 0.1 mol / L zirconium oxychloride solution to obtain a hydrogel artificial muscle.

[0055] 2. The temperature-responsive hydrogel artificial muscle prepared by the above method has an elongation rate of 0.7% / s and a driving strain of 199.2% in 60°C water.

[0056] Figure 1 This is a scanning electron microscope image of a temperature-responsive hydrogel artificial muscle. (a) Isotropic chiral hydrogel and (b) surface pore orientation. Figure 1 It can be seen that the hydrogel artificial muscle has an oriented network structure.

[0057] Figure 2 These are the driving performance diagrams of hydrogel artificial muscles responding to two temperatures (60°C and 20°C). Figure 3 This is a photo of a temperature-responsive hydrogel artificial muscle simulating the human body's soccer game. Figure 2 and Figure 3 It can be seen that temperature-responsive hydrogel artificial muscles with different chirality have different movement patterns and can simulate some simple movements of the human body.

[0058] Example 2: A temperature-responsive hydrogel artificial muscle and its preparation method

[0059] 1. Preparation method of temperature-responsive hydrogel artificial muscle

[0060] Step S1, dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0061] The mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, accelerator, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 5.0:10.5:1.4:0.1:0.4:0.07:0.4, and the rest is deionized water, wherein the molar ratio of N-isopropylacrylamide and 3-sulfopropyl methacrylate potassium salt monomers is 6:4;

[0062] Step S2: stretching the chemically cross-linked hydrogel to 4 times its original length, twisting it at a speed of 25 to 35 rpm to obtain a hydrogel with a twist density of 100 turns / m, and then spirally winding it clockwise around the outside of a polytetrafluoroethylene tube with a diameter of 3 mm to obtain a spiral hydrogel.

[0063] Step S3: Soaking the spiral hydrogel in a 0.1 mol / L zirconium oxychloride solution to obtain a hydrogel artificial muscle.

[0064] 2. The temperature-responsive hydrogel artificial muscle prepared by the above method has an elongation rate of 1.4% / s and a driving strain of 183.2% in 60°C water.

[0065] Example 3: A temperature-responsive hydrogel artificial muscle and its preparation method

[0066] 1. Preparation method of temperature-responsive hydrogel artificial muscle

[0067] Step S1, dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0068] The mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, accelerator, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 4.4:11.8:1.4:0.1:0.4:0.07:0.4, and the rest is deionized water, wherein the molar ratio of N-isopropylacrylamide and 3-sulfopropyl methacrylate potassium salt monomers is 5.5:4.5;

[0069] Step S2: stretching the chemically cross-linked hydrogel to 4 times its original length, twisting it at a speed of 25 to 35 rpm to obtain a hydrogel with a twist density of 100 turns / m, and then spirally winding it clockwise around the outside of a polytetrafluoroethylene tube with a diameter of 3 mm to obtain a spiral hydrogel.

[0070] Step S3: Soaking the spiral hydrogel in a 0.1 mol / L zirconium oxychloride solution to obtain a hydrogel artificial muscle.

[0071] 2. The temperature-responsive hydrogel artificial muscle prepared by the above method has an elongation rate of 1.6% / s and a driving strain of 167.3% in 60°C water.

[0072] Example 4: A temperature-responsive hydrogel artificial muscle and its preparation method

[0073] 1. Preparation method of temperature-responsive hydrogel artificial muscle

[0074] Step S1, dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0075] The mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, accelerator, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 5.6:9.2:1.4:0.1:0.4:0.07:0.4, and the rest is deionized water, wherein the molar ratio of N-isopropylacrylamide and 3-sulfopropyl methacrylate potassium salt monomers is 6.5:3.5;

[0076] Step S2: stretching the chemically cross-linked hydrogel to 4 times its original length, twisting it at a speed of 25 to 35 rpm to obtain a hydrogel with a twist density of 100 turns / m, and then spirally winding it clockwise around the outside of a polytetrafluoroethylene tube with a diameter of 3 mm to obtain a spiral hydrogel.

[0077] Step S3: Soaking the spiral hydrogel in a 0.1 mol / L zirconium oxychloride solution to obtain a hydrogel artificial muscle.

[0078] 2. The temperature-responsive hydrogel artificial muscle prepared by the above method has an elongation rate of -1% / s and a driving strain of -75.2% in 60°C water.

[0079] Example 5: A temperature-responsive hydrogel artificial muscle and its preparation method

[0080] 1. Preparation method of temperature-responsive hydrogel artificial muscle

[0081] Step S1, dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0082] The mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, accelerator, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 5.0:10.5:1.4:0.1:0.4:0.07:0.4, and the rest is deionized water, wherein the molar ratio of N-isopropylacrylamide and 3-sulfopropyl methacrylate potassium salt monomers is 6:4;

[0083] Step S2: stretching the chemically cross-linked hydrogel to 4 times its original length, twisting it at a speed of 25 to 35 rpm to obtain a hydrogel with a twist density of 100 turns / m, and then spirally winding it clockwise around the outside of a polytetrafluoroethylene tube with a diameter of 3 mm to obtain a spiral hydrogel.

[0084] Step S3: Soaking the spiral hydrogel in a 0.1 mol / L zirconium oxychloride solution to obtain a hydrogel artificial muscle.

[0085] 2. The temperature-responsive hydrogel artificial muscle prepared by the above method has an elongation rate of -1.1% / s and a driving strain of -74.8% in 60°C water.

[0086] Example 6: A temperature-responsive hydrogel artificial muscle and its preparation method

[0087] 1. Preparation method of temperature-responsive hydrogel artificial muscle

[0088] Step S1, dissolving N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator in proportion in an aqueous dispersion of ascidian cellulose nanocrystals hydrolyzed with sulfuric acid to obtain a mixed solution; then injecting the mixed solution into a mold for polymerization to obtain a chemically crosslinked hydrogel;

[0089] The mass ratio of N-isopropylacrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, accelerator, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 4.4:11.8:1.4:0.1:0.4:0.07:0.4, and the rest is deionized water, wherein the molar ratio of N-isopropylacrylamide and 3-sulfopropyl methacrylate potassium salt monomers is 5.5:4.5;

[0090] Step S2: stretching the chemically cross-linked hydrogel to 4 times its original length, twisting it at a speed of 25 to 35 rpm to obtain a hydrogel with a twist density of 100 turns / m, and then spirally winding it clockwise around the outside of a polytetrafluoroethylene tube with a diameter of 3 mm to obtain a spiral hydrogel.

[0091] Step S3: Soaking the spiral hydrogel in a 0.1 mol / L zirconium oxychloride solution to obtain a hydrogel artificial muscle.

[0092] 2. The temperature-responsive hydrogel artificial muscle prepared by the above method has an elongation rate of -2.3% / s and a driving strain of -58.8% in 60°C water.

[0093] Finally, it should be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0094] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0095] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for preparing a temperature-responsive hydrogel artificial muscle, characterized in that: The method comprises: Will N - isopropyl acrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, a crosslinking agent, an initiator, and an accelerator are dissolved in a sulfuric acid-hydrolyzed aqueous dispersion of ascidian cellulose nanocrystals in proportion to obtain a mixed solution; the mixed solution is then injected into a mold and polymerized to obtain a chemically crosslinked hydrogel; The chemically cross-linked hydrogel is stretched to 3.5 to 4.5 times its original length, twisted at a speed of 25 to 35 rpm to obtain a range of hydrogel twist densities, and then spirally wrapped around the outside of a polytetrafluoroethylene tube with a diameter of 2.5 to 3.5 mm to obtain a spiral hydrogel; The spiral hydrogel is immersed in a zirconium salt solution to obtain a hydrogel artificial muscle; N The mass ratio of isopropyl acrylamide, 3-sulfopropyl methacrylate potassium salt, acrylamide, crosslinking agent, initiator, promoter, and sulfuric acid-hydrolyzed ascidian cellulose nanocrystals is 4-8:5-15:1-2:0.1-0.4:0.1-0.4:0.04-0.16:0.3-0.

6.

2. The method for preparing a temperature-responsive hydrogel artificial muscle according to claim 1, wherein: The sulfuric acid-hydrolyzed ascidian cellulose nanocrystal aqueous dispersion is a suspension obtained by dispersing ascidian cellulose nanocrystals prepared by sulfuric acid hydrolysis in deionized water.

3. The method for preparing a temperature-responsive hydrogel artificial muscle according to claim 1, characterized in that: described N The molar ratio of isopropyl acrylamide to 3-sulfopropyl methacrylate potassium salt is 5.5-7.5:2.5-4.

5.

4. The method for preparing a temperature-responsive hydrogel artificial muscle according to claim 1, wherein: The cross-linking agent is N , N '-methylenebisacrylamide, the initiator is potassium persulfate, and the accelerator is tetramethylethylenediamine.

5. The method for preparing a temperature-responsive hydrogel artificial muscle according to claim 1, wherein: The polymerization conditions are: polymerization at 20-30° C. for 8-15 h.

6. The method for preparing a temperature-responsive hydrogel artificial muscle according to claim 1, characterized in that: The zirconium salt solution is a 0.05-0.2 mol / L zirconium oxychloride solution.

7. A temperature-responsive hydrogel artificial muscle prepared by the method according to any one of claims 1 to 6.

8. Use of the temperature-responsive hydrogel artificial muscle according to claim 7 in preparing a soft actuator robot.

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