Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex...Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.展开更多
In industrial applications,climbing robots are widely used for climbing and detection of rough or smooth pipe surfaces.Inspired by the special claws of longicorn is that can crawl on rough surfaces and the array of ti...In industrial applications,climbing robots are widely used for climbing and detection of rough or smooth pipe surfaces.Inspired by the special claws of longicorn is that can crawl on rough surfaces and the array of tiny bristles of geckos that can crawl on smooth surfaces,a new type of wall-climbing robot for rough or smooth surfaces is proposed in this paper.The bionic palms of the robot are suggested with special bionic hooks inspired by the longicorn and bionic adhesive materials inspired by the gecko with a good performance on adhering on the surfaces.The special bionic hooks are manufactured by the 3D printing method and the bionic adhesive materials are made by the polymer print lithography technology.These two different bionic adhere accessory are used on the robot’s palm to achieve climbing on the different surfaces.This foldable climbing robot can not only bend its own body to accommodate the cylindrical contact surfaces of different diameters,but also crawl on vertical rough and smooth surfaces using their bionic palms.展开更多
Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on water.Fluid physics indicates this feature is due to a surface-tension effect caused by the special hierar...Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on water.Fluid physics indicates this feature is due to a surface-tension effect caused by the special hierarchical structure of the legs,which are covered with a large number of inclined setae with fine nanogrooves inducing water resistance.This inspires us to fabricate special water-repellent structure on functional surfaces through the cooperation between the surface treatment and the surface micro-and nanostructures,which may bring great advantages in a wide variety of applications.In this paper we present a procedure for fabricating biomimetic water strider legs covered with setae using Polycarbonate Track-Etched(PCTE)membranes as templates.By choosing appropriate membrane lengths,diameters,pitches and densities of the setae,the biomimetic legs can be fabricated conveniently and at a low cost.Furthermore we investigated the relationship between stiffness of the molding materials,high aspect ratio and density,which affect the fidelity of fabrication and self adhesion,to optimize the stability of setae.The knowledge we gained from this study will offer important insights into the biomimetic design and fabrication of water strider setae.展开更多
Shrimps of the genus Synalpheus(Caridea)are commonly found in subtropical and tropical marine habitats around the world.The present work aims to provide the first description of the reproductive system of this genus u...Shrimps of the genus Synalpheus(Caridea)are commonly found in subtropical and tropical marine habitats around the world.The present work aims to provide the first description of the reproductive system of this genus using histological,histochemical,and morphological perspectives to elucidate the gonochoric or hermaphrodite sexual system in this genus.Males have a slender and very translucent reproductive system that is challenging to observe.The entire cephalothorax was histologically sectioned to ensure that all regions of the reproductive system could be identified.This non-gambarelloides group shows a gonochoric condition.The caridean pattern of the reproductive system was observed where the male has a pair of testes and a pair of very thin vasa deferentia,ending at the opening of the gonopore.Spermatophore structure is absent,without any layers surrounding the spermatozoa that are aggregated in a sperm mass.In females,the reproductive system consists of a pair of ovaries that extend to the end of the pleon.The extension of the ovary has a particular pattern compared to other caridean shrimps.Here,we hypothesize that males invest energy on somatic morphological structures to protect the host and female,using the larger pistol-like cheliped,while females invest energy in reproduction since all the members of this group are typical"pair-bond"examples.The observed pattern of the reproductive male morphology could also be evidence of a possible synapomorphy for this genus within theinfraorder.展开更多
Larvae of the processionary moths of the Palaearctic region bear urticating setae that are released against vertebrate predators,especially insectivorous birds.A few species are pests of forest and urban trees a...Larvae of the processionary moths of the Palaearctic region bear urticating setae that are released against vertebrate predators,especially insectivorous birds.A few species are pests of forest and urban trees and,consequently,may threaten human and animal health during outbreaks,causing dermatitis,conjunctivitis and respiratory distress.Although some studies provide detailed information about the setae,particularly those of the pine processionary moth Thaumetopoea pityocampa,there is little knowledge on the morphological traits of the setae and their release by the larvae.In the present study we identify major traits of the setae of 3 species of processionary moth,T.pityocampa,T.pinivora and T.processionea,which are potentially helpful in the understanding of setae dynamics in the environment:(i)diameter and length of setae and(ii)analysis of dynamical properties of the setae in the airborne state.Setae are highly variable in size,with bimodal distribution in T.pityocampa and T.pinivora;in these 2 species,short and long setae are interspersed within the integument fields where they occur.The difference in the seta size has important consequences in dispersion,as smaller setae can spread 5 times further than their bigger counterparts.This information is relevant for a full understanding of the defensive importance of larval setae against natural enemies of the processionary moths,as well for elucidating the importance of the processionary setae as air pollutants,both close to the infested trees and at longer distances.展开更多
Scanning electron microscopy (SEM) and histological techniques were used to observe and study the setae structures of two gecko species (G. gecko and G. swinhonis) and the relationships between these structures and th...Scanning electron microscopy (SEM) and histological techniques were used to observe and study the setae structures of two gecko species (G. gecko and G. swinhonis) and the relationships between these structures and the adhesive forces. The SEM results showed that the setae of these two species were densely distributed in an orderly fashion, and branched with curved tips. The setae of G. gecko had cluster structures, each cluster containing 4-6 setae whose terminal branches curved towards the center of the toes at ~ 10o, the tips of the branches like spatulae and densely arrayed at an interval of less than 0.2―0.3 μm. On the contrary, the branch tips in the setae of G. swinhonis were curled, and the terminal parts of setae curved towards the center of the toes at various angles. Usually the setae of these gecko species branch twice at the top at intervals greater than that of G. gecko. The histological observation found that inside the setae of these two species there were plenty of unevenly distributed contents, such as epithelia, fat cells, pigmental cells and muscle tissue, but no gland cells existed. The results of functional experiments suggested that modifying the structure of gecko’s setae could reduce its adhesive ability dramatically, demonstrating the positive correlation between the structure of the gecko’s setae and its adhesive ability. The above results provide important information in designing bio-mimic setae and bio-gecko robots.展开更多
The study of the adhesion of millions of setae on the toes of geckos has been advanced in recent years with the emergence of new technology and measurement methods. The theory of the mechanism of adhesion by van der W...The study of the adhesion of millions of setae on the toes of geckos has been advanced in recent years with the emergence of new technology and measurement methods. The theory of the mechanism of adhesion by van der Waals forces is now accepted and broadly understood. However, this paper presents limitations of this theory and gives a new hypothesis of the biomechanism of gecko adhesion. The findings are obtained through measurements of the magnitude of the adhesion of setae under three different conditions, to show the close relationship between adhesion and status of the setae. They are reinforced by demonstrating two setal structures, follicle cells and hair, the former making the setae capable of producing bioelectrical charges, which play an important role in attachment and detachment processes. It is shown that the abundant muscular tissues at the base of the setae cells, which are controlled by peripheral nerves, are instrumental in producing the foot movement involved in attachment and detachment. Our study will further uncover the adhesion mechanism of geckos, and provide new ideas for designing and fabricating synthetic setae.展开更多
Spark-erosion perforating technology was used to fabricate a Cu-based template characterized by pores with radius of 0.5 mm inclined at 75°. A commercial silicone elastomer of poly(dimethylsiloxane) (PDMS) with a...Spark-erosion perforating technology was used to fabricate a Cu-based template characterized by pores with radius of 0.5 mm inclined at 75°. A commercial silicone elastomer of poly(dimethylsiloxane) (PDMS) with a rich Si-H content was used to produce an inclined array of primary setae. The technique of argon ion plasma etching on crystalline silicon was used to fabricate negative templates with radii of 5, 10, and 20 μm. The Si-H rich PDMS was used to cast three types of fine array templates, which acted as the secondary setae. A vinyl-rich PDMS precursor was used to bind the primary and secondary setae by a hydrosilylation reaction, thus allowing the formation of three different hierarchical arrangements of setae. Adhesion tests demonstrated that shear adhesion was anisotropic, first increasing in strength then decreasing to a stable level as slippage occurred. The adhesion strength was significantly influenced by the nature of the secondary setae, showing a strong correlation with aspect-ratio and concentration.展开更多
Scanning electron microscopy(SEM)and histological techniques were used to observe and study the structure of setae on the integument surface of the dung beetle Copris ochus Motschulsky and on the foot pad of the gecko...Scanning electron microscopy(SEM)and histological techniques were used to observe and study the structure of setae on the integument surface of the dung beetle Copris ochus Motschulsky and on the foot pad of the gecko Gekko gecko and their relationship to anti-adherent and adherent functions respectively.There are very distinctive comparison between the structures and the constructs of the setae on the dung beetle and the gecko:the setae of the dung beetle are ramification of the integument,mainly distributing on the body abdomen surface and the lateral side of the legs,loosely arranging,having different length with many buds and sticks along the whole seta body but without side branches,uprightly directing to the contacting dung face.The setae of the gecko are protuberances from the skin,arranging in order and densely,regularly directing,branching in twice with curved top.The histological observation found that dung beetle’s setae are empty inside with lots micro-foramens communicating to the inner side on the base of the buds and sticks on the seta and also connecting with the oil glands below the integument,but without the erect muscle. Gecko setae are surrounded by fat cells and muscles.Results from functional experiments suggest that deformation of the setae of the bung beetle integument could reduce the anti-adherent function and also the same kind of change could reduce the adherent function of the gecko setae on the leg bottom.These results offer important information for preparation of the soil machine and components imitating dung beetle setae flexible non-adherence and for designing artificial setae imitating the gecko’s adherent setae.展开更多
基金supported by Jiangsu Special Project for Frontier Leading Base Technology(Grant Nos.BK20192004)Fundamental Research Funds for Central Universities(Grant Nos.B240201190)+3 种基金Changzhou Social Development Science and Technology Support Project(Grant Nos.CE20225037)Changzhou Science and Technology Project(Grant Nos.CM20223014)Suzhou Key Industrial Technology Innovation Forward-Looking Application Research Project(Grant Nos.SYG202143)Changzhou Science and Technology Project(Grant Nos.CJ20241061).
文摘Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.
基金This research was supported by the National Natural Science Foundation of China(No.11774355).
文摘In industrial applications,climbing robots are widely used for climbing and detection of rough or smooth pipe surfaces.Inspired by the special claws of longicorn is that can crawl on rough surfaces and the array of tiny bristles of geckos that can crawl on smooth surfaces,a new type of wall-climbing robot for rough or smooth surfaces is proposed in this paper.The bionic palms of the robot are suggested with special bionic hooks inspired by the longicorn and bionic adhesive materials inspired by the gecko with a good performance on adhering on the surfaces.The special bionic hooks are manufactured by the 3D printing method and the bionic adhesive materials are made by the polymer print lithography technology.These two different bionic adhere accessory are used on the robot’s palm to achieve climbing on the different surfaces.This foldable climbing robot can not only bend its own body to accommodate the cylindrical contact surfaces of different diameters,but also crawl on vertical rough and smooth surfaces using their bionic palms.
文摘Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on water.Fluid physics indicates this feature is due to a surface-tension effect caused by the special hierarchical structure of the legs,which are covered with a large number of inclined setae with fine nanogrooves inducing water resistance.This inspires us to fabricate special water-repellent structure on functional surfaces through the cooperation between the surface treatment and the surface micro-and nanostructures,which may bring great advantages in a wide variety of applications.In this paper we present a procedure for fabricating biomimetic water strider legs covered with setae using Polycarbonate Track-Etched(PCTE)membranes as templates.By choosing appropriate membrane lengths,diameters,pitches and densities of the setae,the biomimetic legs can be fabricated conveniently and at a low cost.Furthermore we investigated the relationship between stiffness of the molding materials,high aspect ratio and density,which affect the fidelity of fabrication and self adhesion,to optimize the stability of setae.The knowledge we gained from this study will offer important insights into the biomimetic design and fabrication of water strider setae.
基金I.R.R.M.andA.L.C.were fundedby"Conselho Nacional de Desenvolvimento Cientifico e Tecnologico"(CNPQ grantPQ311034/2018-7)"Coordenacaode Aperfeicoamento deNivelSuperior-CAPES,Brazil(CAPES PRINT 88881.310767/2018-01,CAPES PROEX 23038.000802/2018-25)+2 种基金FJ.Z.would like to thank the laboratory support provided by the_Sao Paulo Research Foundation-FAPESP(JP#2005/04707-5 and Biota Intercrusta#2018/13685-5)CAPES-Ciencias do Mar II program(grant#1989/2014,23038.004309/2014-51)CNPq Research Scholarship(PQ2#309298-2020-2,PQ1D#308324/2023-4),and CNPq PPBio 2023/0723.
文摘Shrimps of the genus Synalpheus(Caridea)are commonly found in subtropical and tropical marine habitats around the world.The present work aims to provide the first description of the reproductive system of this genus using histological,histochemical,and morphological perspectives to elucidate the gonochoric or hermaphrodite sexual system in this genus.Males have a slender and very translucent reproductive system that is challenging to observe.The entire cephalothorax was histologically sectioned to ensure that all regions of the reproductive system could be identified.This non-gambarelloides group shows a gonochoric condition.The caridean pattern of the reproductive system was observed where the male has a pair of testes and a pair of very thin vasa deferentia,ending at the opening of the gonopore.Spermatophore structure is absent,without any layers surrounding the spermatozoa that are aggregated in a sperm mass.In females,the reproductive system consists of a pair of ovaries that extend to the end of the pleon.The extension of the ovary has a particular pattern compared to other caridean shrimps.Here,we hypothesize that males invest energy on somatic morphological structures to protect the host and female,using the larger pistol-like cheliped,while females invest energy in reproduction since all the members of this group are typical"pair-bond"examples.The observed pattern of the reproductive male morphology could also be evidence of a possible synapomorphy for this genus within theinfraorder.
基金This work was funded by the French National Research Agency in the framework of project ANR No.07BDIV 013‘URTICLIM’by the University of Padova grant 2010-C91J10000320001.
文摘Larvae of the processionary moths of the Palaearctic region bear urticating setae that are released against vertebrate predators,especially insectivorous birds.A few species are pests of forest and urban trees and,consequently,may threaten human and animal health during outbreaks,causing dermatitis,conjunctivitis and respiratory distress.Although some studies provide detailed information about the setae,particularly those of the pine processionary moth Thaumetopoea pityocampa,there is little knowledge on the morphological traits of the setae and their release by the larvae.In the present study we identify major traits of the setae of 3 species of processionary moth,T.pityocampa,T.pinivora and T.processionea,which are potentially helpful in the understanding of setae dynamics in the environment:(i)diameter and length of setae and(ii)analysis of dynamical properties of the setae in the airborne state.Setae are highly variable in size,with bimodal distribution in T.pityocampa and T.pinivora;in these 2 species,short and long setae are interspersed within the integument fields where they occur.The difference in the seta size has important consequences in dispersion,as smaller setae can spread 5 times further than their bigger counterparts.This information is relevant for a full understanding of the defensive importance of larval setae against natural enemies of the processionary moths,as well for elucidating the importance of the processionary setae as air pollutants,both close to the infested trees and at longer distances.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 30400086, 30470230, 30770285 and 60535020)
文摘Scanning electron microscopy (SEM) and histological techniques were used to observe and study the setae structures of two gecko species (G. gecko and G. swinhonis) and the relationships between these structures and the adhesive forces. The SEM results showed that the setae of these two species were densely distributed in an orderly fashion, and branched with curved tips. The setae of G. gecko had cluster structures, each cluster containing 4-6 setae whose terminal branches curved towards the center of the toes at ~ 10o, the tips of the branches like spatulae and densely arrayed at an interval of less than 0.2―0.3 μm. On the contrary, the branch tips in the setae of G. swinhonis were curled, and the terminal parts of setae curved towards the center of the toes at various angles. Usually the setae of these gecko species branch twice at the top at intervals greater than that of G. gecko. The histological observation found that inside the setae of these two species there were plenty of unevenly distributed contents, such as epithelia, fat cells, pigmental cells and muscle tissue, but no gland cells existed. The results of functional experiments suggested that modifying the structure of gecko’s setae could reduce its adhesive ability dramatically, demonstrating the positive correlation between the structure of the gecko’s setae and its adhesive ability. The above results provide important information in designing bio-mimic setae and bio-gecko robots.
基金supported by the National Basic Research Program of China (Grant No. 2011CB302106)the National Natural Science Foundation of China (Grant Nos. 30770285, 51175249, 61175105 and 51105201)the Jiangsu Natural Science Foundation (Grant No. BK2009376)
文摘The study of the adhesion of millions of setae on the toes of geckos has been advanced in recent years with the emergence of new technology and measurement methods. The theory of the mechanism of adhesion by van der Waals forces is now accepted and broadly understood. However, this paper presents limitations of this theory and gives a new hypothesis of the biomechanism of gecko adhesion. The findings are obtained through measurements of the magnitude of the adhesion of setae under three different conditions, to show the close relationship between adhesion and status of the setae. They are reinforced by demonstrating two setal structures, follicle cells and hair, the former making the setae capable of producing bioelectrical charges, which play an important role in attachment and detachment processes. It is shown that the abundant muscular tissues at the base of the setae cells, which are controlled by peripheral nerves, are instrumental in producing the foot movement involved in attachment and detachment. Our study will further uncover the adhesion mechanism of geckos, and provide new ideas for designing and fabricating synthetic setae.
基金supported by the National Natural Science Foundation of China (50805076, 60910007)Doctoral Fund of Ministry of Education of China (200802871043)Science Research Foundations of Nanjing University of Aeronautics & Astronautics (NS2010216, NS2012014)
文摘Spark-erosion perforating technology was used to fabricate a Cu-based template characterized by pores with radius of 0.5 mm inclined at 75°. A commercial silicone elastomer of poly(dimethylsiloxane) (PDMS) with a rich Si-H content was used to produce an inclined array of primary setae. The technique of argon ion plasma etching on crystalline silicon was used to fabricate negative templates with radii of 5, 10, and 20 μm. The Si-H rich PDMS was used to cast three types of fine array templates, which acted as the secondary setae. A vinyl-rich PDMS precursor was used to bind the primary and secondary setae by a hydrosilylation reaction, thus allowing the formation of three different hierarchical arrangements of setae. Adhesion tests demonstrated that shear adhesion was anisotropic, first increasing in strength then decreasing to a stable level as slippage occurred. The adhesion strength was significantly influenced by the nature of the secondary setae, showing a strong correlation with aspect-ratio and concentration.
文摘Scanning electron microscopy(SEM)and histological techniques were used to observe and study the structure of setae on the integument surface of the dung beetle Copris ochus Motschulsky and on the foot pad of the gecko Gekko gecko and their relationship to anti-adherent and adherent functions respectively.There are very distinctive comparison between the structures and the constructs of the setae on the dung beetle and the gecko:the setae of the dung beetle are ramification of the integument,mainly distributing on the body abdomen surface and the lateral side of the legs,loosely arranging,having different length with many buds and sticks along the whole seta body but without side branches,uprightly directing to the contacting dung face.The setae of the gecko are protuberances from the skin,arranging in order and densely,regularly directing,branching in twice with curved top.The histological observation found that dung beetle’s setae are empty inside with lots micro-foramens communicating to the inner side on the base of the buds and sticks on the seta and also connecting with the oil glands below the integument,but without the erect muscle. Gecko setae are surrounded by fat cells and muscles.Results from functional experiments suggest that deformation of the setae of the bung beetle integument could reduce the anti-adherent function and also the same kind of change could reduce the adherent function of the gecko setae on the leg bottom.These results offer important information for preparation of the soil machine and components imitating dung beetle setae flexible non-adherence and for designing artificial setae imitating the gecko’s adherent setae.
