Search

CN-121824996-B - Wet adhesive gel imitating frog toe pad structure, and preparation method and application thereof

CN121824996BCN 121824996 BCN121824996 BCN 121824996BCN-121824996-B

Abstract

The invention relates to the technical field of bionic functional gel. More particularly relates to a wet state adhesive gel imitating a frog toe pad structure, a preparation method and application thereof. The preparation method of the adhesive gel comprises the following steps of S1, spin-coating photoresist on an anodic aluminum oxide substrate, exposing, developing and drying after solidification to obtain an anodic aluminum oxide template with a micron-sized hexagonal pattern, mixing an anionic monomer, a cationic monomer, a photoinitiator and a cross-linking agent to prepare a polydiionic gel prepolymer, S2, dropwise adding the polydiionic gel prepolymer on the anodic aluminum oxide template in an inert atmosphere, forming patterned gel on the surface of the anodic aluminum oxide template after photopolymerization, soaking the patterned gel in a demolding solution containing sodium chloride and phosphoric acid to finish stripping the anodic aluminum oxide template, and S3, cleaning the residual photoresist to obtain the adhesive gel with the micro-nano structure of the artificial frog toe pad.

Inventors

  • WANG SHUTAO
  • ZHANG YIJIE

Assignees

  • 中国科学院理化技术研究所

Dates

Publication Date
20260508
Application Date
20260312

Claims (9)

  1. 1. The preparation method of the wet adhesive gel with the tree frog toe pad imitation structure is characterized by comprising the following steps of: S1, spin coating photoresist on an anodic aluminum oxide substrate, and obtaining an anodic aluminum oxide template with micron-sized hexagonal patterns after exposure, development and drying after solidification; mixing an anionic monomer, a cationic monomer, a photoinitiator and a crosslinking agent to prepare a polyzwitterionic gel prepolymer; s2, dropwise adding the polyzwitterionic gel prepolymer on an anodic aluminum oxide template in an inert atmosphere, forming patterned gel on the surface of the anodic aluminum oxide template after photopolymerization, and soaking the patterned gel in a demolding solution containing sodium chloride and phosphoric acid to finish stripping the anodic aluminum oxide template; s3, cleaning the residual photoresist to obtain adhesive gel with a tree frog toe pad imitation micro-nano structure, wherein the adhesive gel is provided with a periodically arranged hexagonal micro-column imitation structure consisting of nano columns; the anionic monomer is selected from sodium p-styrene sulfonate and/or sodium 2-acrylamido-2-methylpropane sulfonate; The cationic monomer is selected from acryloyloxyethyl trimethyl ammonium chloride and/or (3-acrylamide propyl) trimethyl ammonium chloride; The molar concentration ratio of chloride ions and sodium ions in the demolding solution to the molar concentration ratio of chloride ions and sodium ions in the polyzwitterionic gel prepolymer solution is 0.15-0.2; the concentration of sodium chloride in the demolding solution is 0.20-0.26 mol/L.
  2. 2. The method of preparation according to claim 1, wherein the photoinitiator is selected from the group consisting of α -ketoglutarate; the cross-linking agent is selected from N, N-methylene bisacrylamide; The molar ratio of the anionic monomer to the cationic monomer is 1-1.2.
  3. 3. The method of claim 1, wherein the photoresist is photoresist P4620; the curing temperature is 100-120 ℃ and the curing time is 70-90s; The exposure wavelength is 350nm, and the exposure time is 8-13s; The developing solution used for developing is developing solution 300MIF, and the developing time is 180-230s.
  4. 4. The preparation method according to claim 1, wherein the surface pore diameter of the anodized aluminum is 100-400nm and the pore depth is 0.5-20 μm; The side length of the hexagons in the micron-sized hexagon pattern is 18-20 mu m, and boundaries with the width of 2-5 mu m are reserved between the adjacent hexagons.
  5. 5. The preparation method according to claim 1, wherein 4-5ml of the polyzwitterionic gel prepolymer solution is added dropwise according to the anodic aluminum oxide template of each 4cm 2 ; The light source used for photopolymerization is ultraviolet light with the wavelength of 365 nm and the light intensity of 4 mW/cm 2 , and the photopolymerization time is 10-13h.
  6. 6. A wet adhesion gel of a tree frog toe pad structure for a crawling robot, which is characterized by being prepared by the preparation method of any one of claims 1-5.
  7. 7. The adhesive gel of claim 6, wherein the adhesive gel is a hexagonal micro-pillar biomimetic structure comprising periodically arranged nano-pillars; The height of the nano column is 0.5-20 mu m, and the column diameter of the nano column is 100-400nm; The side length of the hexagons in the bionic surface of the hexagonal micrometer column is 18-20 mu m, and the width of the boundary between adjacent hexagons is 2-5 mu m.
  8. 8. The wet adhesion gel is characterized in that the adhesion gel is obtained by photopolymerization of an anionic monomer and a cationic monomer serving as raw materials, the structure of the adhesion gel is provided with hexagonal micrometer columns which are periodically arranged, and each micrometer column consists of nanometer columns with equal height; The hexagonal side length of the hexagonal micron column is 18-20 mu m, and the boundary width between adjacent hexagons is 2-5 mu m; The height of the nano column is 0.5-20 mu m, and the column diameter of the nano column is 100-400nm; the anionic monomer is selected from sodium p-styrene sulfonate and/or sodium 2-acrylamido-2-methylpropane sulfonate; The cationic monomer is selected from acryloyloxyethyl trimethyl ammonium chloride and/or (3-acrylamidopropyl) trimethyl ammonium chloride.
  9. 9. Use of the adhesive gel according to any of claims 6-8 for the preparation of a crawling robot.

Description

Wet adhesive gel imitating frog toe pad structure, and preparation method and application thereof Technical Field The invention relates to the technical field of bionic functional gel. More particularly relates to a wet state adhesive gel imitating a frog toe pad structure, a preparation method and application thereof. Background The anti-skid performance is a core guarantee for realizing stable operation of the crawling robot on complex unstructured terrains, and related researches in recent years are continuously deepened around four large dimensions of bionic mechanism, material design, motion control and environment self-adaption, so that a multi-disciplinary crossing technical system is formed. The bionic anti-slip structure such as mushroom-shaped/shovel-shaped microstructures, composite hooves, claw thorn tracks, bionic toe hook arrays and the like is developed by researching the inspiration from biological anti-slip prototypes such as gecko dry adhesion, octopus negative pressure adsorption, snail mucus adhesion, goat hoof-shaped grabbing and caterpillar claw thorn opposite grabbing, the grabbing and desorption suitability of multiple interfaces such as drying, wet sliding, rough, abrupt slope and the like is considered, and meanwhile, the friction characteristics and stress distribution of contact surfaces are optimized through anti-slip materials such as flexible polymers, surface micro-nano textures, composite wear-resistant liners and the like, so that the adaptation capability and durability of the materials to different ground surfaces are improved. This technical idea has received a great deal of attention from those skilled in the art by introducing a material with patterned structures into the feet of a crawling robot to obtain excellent anisotropic adhesion in a wet surface environment. A great deal of research is focused on constructing a bionic structure similar to a frog toe pad on the surface of a material so as to realize anisotropic adhesion performance in a wet surface scene. However, the current surface patterning adhesive material still has significant technical limitations that on one hand, most of the existing materials adopt PDMS, PVS, PCL, PU and other easily-formed hydrophobic materials, when the materials are used for wet surface adhesion, hydrophilization treatment is needed to be carried out on the surfaces of the materials, but hydrophilization modification is easy to fail, so that long-term anisotropic adhesion of wet surfaces is difficult to effectively realize, and the overall adhesive performance is poor, and on the other hand, the existing patterning gel materials applied to the anisotropic adhesion of the wet surfaces have the surface structure sizes of micrometers to millimeter, and also have the problem of insufficient adhesive performance of the wet surfaces, so that the limitation severely restricts the large-area preparation and practical application popularization of the materials. Therefore, the development of a technical scheme which can construct the wood frog toe pad imitation micro-nano structure on the gel surface through a one-step method and realize long-acting stable anisotropic adhesion performance still has important research value and practical application significance. Disclosure of Invention In order to solve the problems, a first object of the present invention is to provide a method for preparing a wet adhesive gel with a tree frog toe pad structure. The preparation method comprises the steps of firstly constructing a hexagonal micron column pattern on an anodic aluminum oxide substrate, and then forming a hexagonal micron column bionic structure which consists of nano columns and is periodically arranged on the hexagonal micron column pattern by utilizing the photopolymerization of the polydioxanone gel prepolymer, wherein the whole technological process is simple and easy to operate. The second aim of the invention is to provide the wet adhesion gel with the tree frog toe pad imitation structure, which is prepared by adopting the preparation method. The adhesive gel has a periodically arranged hexagonal micro-column bionic structure composed of nano-columns, and can realize anisotropic adhesive performance of strong shearing and easy stripping on a wet surface. The third object of the invention is to provide a wet adhesion gel of a tree frog toe pad imitation structure for a crawling robot. The adhesive gel is prepared by photopolymerization of an anionic monomer and a cationic monomer serving as raw materials, and has a structure with periodically arranged hexagonal micrometer columns, wherein each micrometer column consists of nanometer columns with equal height. The fourth object of the invention is to provide an application of the wet adhesive gel with the wood frog toe pad structure in preparation of a crawling robot. In combination with the use scene of the crawling robot, the wet surface disclosed by the invention is a surface covered