Wood-based biomimetic artificial muscle and preparation method and application thereof

A preparation method of wood-based biomimetic artificial muscles, including the following steps:

• Step S1:
• slicing wood, and subjecting the obtained wood slices to ammonia treatment and delignification in sequence;
• Step S2:
• soaking the wood slices in S1 in a solution of citric acid and/or citrate;
• Step S3:
• preparing a water solution of an ionic polymer and preparing a dimethyl sulfoxide water solution of polyvinyl alcohol separately, and mixing the two solutions to obtain a polymer solution;
• Step S4:
• subjecting the wood slices in S2 and to vacuum treatment in a container, filling the polymer solution into the container, releasing vacuum, and pressurizing to infiltrate the polymer into the wood slices until saturation;
• Step S5:
• freezing the wood slices in S4 in a refrigerator and thawing;
• and
• Step S6:
• repeating Step S5 for 5-10 times, washing the wood slices and drying, wherein:
• the ammonia treatment in Step S1 includes soaking the wood slices in 10-25 wt % ammonia water for 5-60 minutes;
• the delignification treatment in Step S1 includes boiling the wood slices in a sodium hydroxide-sodium sulfite water solution at 85-100° C. for 2-4 hours, and washing in deionized water;
• the concentration of sodium hydroxide is 0.01-5 mol/L and the concentration of sodium sulfite is 0.01-3 mol/L;
• in Step S2, the citrate is trisodium citrate, the soaking temperature is 25-50° C., the soaking time is 1-60 minutes, and the total of citric acid and citrate accounts for 1-10 wt % of the solution of citric acid and/or citrate;
• the water solution of the ionic polymer in Step S3 is 10-60 wt % polyacrylic acid water solution, 10-60 wt % polymethacrylic acid water solution, 10-60 wt % sodium polyacrylate water solution or 10-60 wt % sodium polymethacrylate water solution;
• the mass fraction of polyvinyl alcohol in the dimethyl sulfoxide water solution of polyvinyl alcohol is 10-60%;
• the dimethyl sulfoxide water solution of polyvinyl alcohol is prepared by adding polyvinyl alcohol as solute into 20-50 wt % dimethyl sulfoxide water solution as solvent, and standing in a water bath at 70-90° C. until polyvinyl alcohol is fully dissolved;
• in Step S3, the volume ratio of the water solution of the ionic polymer to the dimethyl sulfoxide water solution of polyvinyl alcohol is 2-4:1;
• in Step S4, the vacuum treatment includes treating under 0.6-0.8 MPa for 1 minute-1 hour, holding for 1-20 minutes after vacuum release, pressurizing to 0.6-3 MPa and holding the pressure for 10 minutes-6 hours;
• and
• in Step S5, the freezing temperature ranges from −60° C. to −5° C., the freezing time lasts for 10-20 hours, and the thawing time lasts for 6-10 hours.