Design And Performance Study Of High-performance Coupling Bionic Suction Cups Based On The Leech Sucker

As a kind of adsorption,fixing and handling device,suction cup is widely used in industrial production,biomedicine,robot,logistics transportation,automobile manufacturing and other fields.With the development of science and technology,the demand for high performance suction cups with high adsorption strength and surface adaptability is increasing day by day.High-performance suction cups play an important role in realizing industrial cost reduction and efficiency improvement,improving working environment,improving quality of life and improving medical conditions.However,while the suction cup is widely used,it also faces some problems such as insufficient adsorption strength and poor surface adaptability.In order to solve the current problems faced by suction cups,this paper proposed a morphology-mucus coupling bionic suction cup based on the high-performance adsorption mechanism of leeches under the guidance of bionics method,and explored its high-performance adsorption mechanism.In this paper,the high-performance adsorption mechanism of the posterior sucker of leech was studied.The surface morphology,tissue,and the mucus of the sucker were observed by means of microscope.The adhesion property of leech sucker mucus was tested by tensile testing machine,and the adsorption strength of leech suckers on different roughness surfaces and different sealing surfaces was tested.Based on the test results,the high-performance adsorption mechanism of leech suckers was explored.The results showed that there were a lot of folds and pits on the surface of the suckers,and the mucus was widely covered on the surface of the suckers with fibrous structure.Vacuum negative pressure is the main source of the adsorption of leech.The coupling sealing mechanism of the leech sucker surface tissue and mucus makes the leech sucker have excellent sealing performance.The adhesion of the mucus on the surface of the leech sucker coupled with a large number of secondary micro suckers formed by the concave structure effectively improves the adsorption strength of the leech sucker.The coupling effects of vacuum negative pressure,tissue deformation,micro-sucker and mucus make up the high-performance adsorption of leech sucker.In this paper,the coupling bionic suction cup was designed and studied based on the surface pit morphology and mucus of the leech sucker.Based on the pit structure on the surface of the leech sucker,the morphological bionic suction cup with bionic pit structure array was studied.By using Box-Behnken Design experimental design method,the shape bionic suction cup was designed,the mold method was used to prepare the suction cup and its adsorption strength was tested,and the influence of design factors on the normal and tangential adsorption strength of the shape bionic suction cup was explored.The No.8 bionic suction cup with the bionic pit morphological parameter l,n and r of 12 mm,40 and 0.75 mm,respectively,has the best adsorption performance.Its bionic morphological parameters are highly coexisting with the results obtained from the experimental optimization design and the analysis of the influence law of adsorption strength,and it is the best morphological bionic suction cup.The drying and underwater normal adsorption strength of the optimal biomimetic sucker were increased by 10.28%and 9.70%,and the tangential adsorption strength was increased by 17.60%and 16.87%,respectively,compared with the standard suction cup.Based on the mechanism and material composition of leech sucker mucus,a low-cost,pollution-free TA-PEG biomimetic mucus was proposed.The preparation and optimization experiments of bionic mucus with different concentration ratio were carried out,and the adhesion properties of the optimal bionic slime on different substrate surfaces were tested,and the surface morphology and composition distribution of the bionic mucus were observed.The results showed that the bionic mucus withρ_TA=800 mg/3m L and V_PEG=0.2 m L had the best normal and tangential adhesion between the glass substrates.The normal and tangential adhesion strengths were 37.76 times and 294.06 times of deionized water,and 23.41 times and29.24 times of leech sucker mucus,respectively.The optimal bionic mucus showed strong adhesion to various substrate surfaces,indicating that the bionic mucus has strong surface applicability.Meanwhile,the material inside the bionic mucus is evenly distributed and has a certain fluidity,which is conducive to the uniform adhesion and sealing effect on the substrate surface.Based on the optimal shape bionic suction cup and bionic mucus,a morphology-mucus coupling bionic suction cup was proposed.The normal and tangential adsorption strength of standard suction cup,single factor bionic suction cup and morphology-mucus coupling bionic suction cup were compared in air and underwater environment,and the sealing performance of suction cup on rough substrate surface was compared.The results show that the bionic morphology has a weak effect on the adsorption performance of the suction cup on the rough substrate surface.The bionic mucus can significantly improve the adsorption strength and the adsorption stability of the suction cup on the rough substrate surface.Compared with standard and single factor bionic suction cups,the morphology-mucus coupling bionic suction cup has a higher adsorption strength.Bionic morphology and bionic mucus promoted the sealing performance of the suction cup,while the coupling effect of morphology and mucus significantly improved the sealing performance of the suction cup.Based on the test results of adsorption strength and sealing performance of the morphology-mucus coupling bionic suction cup,the adsorption mechanism of the morphological bionic suction cup and the adhesion mechanism of the bionic mucus were analyzed by finite element simulation and high-speed camera observation,and the adsorption mechanism of the morphology-mucus coupling bionic suction cup was revealed.The finite element simulation results show that the contact pressure between the morphological bionic suction cup and the substrate surface is improved,the sealing performance of the suction cup is improved,the friction stress between the morphological bionic suction cup and the substrate surface is increased,and the damage of the sealing cavity of the suction cup is reduced.The surface pit structure of the morphological bionic suction cup can be mechanically connected with the granular protrusions on the surface of the rough substrate,which effectively inhibits the radial sliding of the suction cup and maintains the adsorption state of the suction cup.The bionic mucus forms a viscous film between the suction cup and the substrate surface,which promotes the adhesion contact between the suction cup and the substrate surface,alleviates the edge buckling phenomenon caused by the suction cup being pulled off,and reduces the number of leakage points of the suction cup.The morphology-mucus coupling bionic suction cup can form an effective seal on the surface of the rough substrate,which is not affected by the working medium.Combined with the adhesion of the bionic mucus and the mechanical connection between the surface pit structure and the rough surface,the adsorption strength and surface adaptability of the morphology-mucus coupling bionic suction cup are effectively improved.In this study,a coupling bionic suction cup based on bionic morphology and bionic mucus is developed by using the coupling bionic design method,which effectively improved the adsorption strength and adaptability of the suction cup under various working conditions,and provides a new method to solve the problems of insufficient adsorption strength and poor surface adaptability in the research and application of suction cups.