The soft actuator is characterized by high safety,flexibility,and adaptability.It is capable of both active and passive defor-mations.This paper presents a discrete degree of freedom(DOF)method for soft actuators to r...The soft actuator is characterized by high safety,flexibility,and adaptability.It is capable of both active and passive defor-mations.This paper presents a discrete degree of freedom(DOF)method for soft actuators to reveal DOF characteristics.The method draws on the superposition mechanism of the deformation characteristics of the sarcomere in the skeletal muscles of living organisms.Firstly,the multi-DOF deformation characteristics of the soft actuator are discretized into superimposed combinations of single-DOF micro-units.Then,the soft actuator was determined to contain deformation characteristics such as extension-contraction,bending,and twisting.Eighteen types of micro-units with basic deforma-tion characteristics were obtained depending on the axis and orientation.Further,the mapping relationship between the combination of micro-units and the motion characteristics of the soft actuator based on the GF set theory was established.Finally,an active-passive DOF co-structured soft actuator(APCSA)was developed.The graphical approach analyzes the experimental results,and it can be concluded that active and passive DOFs can coexist in the composite deformation of the soft actuator.展开更多
Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in lo...Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in long-distance and miniaturized environments.Fuel-driven actuators offer a promising solution by enabling the conversion of chemical energy into mechanical energy,supporting selfsustaining operations.Chemical energy from fuel can be converted into mechanical energy either directly or indirectly through methods such as electron transfer-induced charge injection,structural changes,fuel-to-electricity conversion,fuel combustioninduced heat,or fuel-induced pneumatic actuation.This paper provides a comprehensive review of recent developments in fuel-powered actuators,covering their fundamental principles,advancements,and challenges.It concludes with an outlook for miniaturized and autonomous robots,highlighting the great potential of integrating fuel-powered actuators.展开更多
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
Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators d...Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators driven by magnetic force remotely.Nevertheless,the further study of magnetic responsive actuators with complex three-dimensional geometries and multiple functions is still limited by uncomplicated de-sign and flexible locomotion.This work provides a novel scheme integrating the origami method and modular designs,which defines the inner properties of magnetic material,extending the functions of magnetic responsive actuators with various modules.The directions of the inner magnetic moments can be programmed and the deformation degrees can be regulated by this approach,which promotes the fabrication of complicated soft actuators with multiple functions by integrating with modular designs.Especially,a movable actuator with various sensing modulus is designed by the origami method,which can perform the sensing application to external ultra-violet(UV),heat,and pH stimuli.Moreover,a mi-croneedle modular actuator which can be controlled wirelessly by a magnetic field was demonstrated for the potential application in the biomedical field.This proposed scheme for engineering magnetic respon-sive material with modular designs has shown great potential to improve the feasibility,versatility,and multiple functionalities of soft actuators.展开更多
In nature,many living organisms exhibiting unique structural coloration and soft-bodied actuation have inspired scientists to develop advanced structural colored soft actuators toward biomimetic soft robots.However,it...In nature,many living organisms exhibiting unique structural coloration and soft-bodied actuation have inspired scientists to develop advanced structural colored soft actuators toward biomimetic soft robots.However,it is challenging to simultaneously biomimic the angle-independent structural color and shape-morphing capabilities found in the plum-throated cotinga flying bird.Herein,we report biomimetic MXene-based soft actuators with angle-independent structural color that are fabricated through controlled self-assembly of colloidal SiO_(2) nanoparticles onto highly aligned MXene films followed by vacuum-assisted infiltration of polyvinylidene fluoride into the interstices.The resulting soft actuators are found to exhibit brilliant,angle-independent structural color,as well as ultrafast actuation and recovery speeds(a maximum curvature of 0.52 mm−1 can be achieved within 1.16 s,and a recovery time of~0.24 s)in response to acetone vapor.As proof-of-concept illustrations,structural colored soft actuators are applied to demonstrate a blue gripper-like bird’s claw that can capture the target,artificial green tendrils that can twine around tree branches,and an artificial multicolored butterfly that can flutter its wings upon cyclic exposure to acetone vapor.The strategy is expected to offer new insights into the development of biomimetic multifunctional soft actuators for somatosensory soft robotics and next-generation intelligent machines.展开更多
Soft robots and actuators are emerging devices providing more capabilities in the field of robotics.More flexibility and compliance attributing to soft functional materials used in the fabrication of these devices mak...Soft robots and actuators are emerging devices providing more capabilities in the field of robotics.More flexibility and compliance attributing to soft functional materials used in the fabrication of these devices make them ideal for delivering delicate tasks in fragile environments,such as food and biomedical sectors.Yet,the intuitive nonlinearity of soft functional materials and their anisotropic actuation in compliant mechanisms constitute an existent challenge in improving their performance.Topology optimization(TO)along with four-dimensional(4D)printing is a powerful digital tool that can be used to obtain optimal internal architectures for the efficient performance of porous soft actuators.This paper employs TO analysis for achieving high bending deflection of a 3D printed polyelectrolyte actuator,which shows bending deformations in response to electrical stimuli in an electrolyte solution.The performance of the actuator is studied in terms of maximum bending and actuation rate compared with a solid,uniformly 3D printed and topology-optimized actuator.The experimental results proved the effectiveness of TO on achieving higher bending deformation and actuation rate against a uniformly 3D printed actuator.展开更多
Actuator plays a significant role in soft robotics.This paper proposed an ultralong stretchable soft actuator(US2A)with a variable and sizeable maximum elongation.The US2A is composed of a silicone rubber tube and a b...Actuator plays a significant role in soft robotics.This paper proposed an ultralong stretchable soft actuator(US2A)with a variable and sizeable maximum elongation.The US2A is composed of a silicone rubber tube and a bellows woven sleeve.The maximal extension can be conveniently regulated by just adjusting the wrinkles’initial angle of the bellows woven sleeve.The kinematics of US2A could be obtained by geometrically analyzing the structure of the bellows woven sleeve when the silicone rubber tube is inflated.Based on the principle of virtual work,the actuating models have been established:the pressure-elongation model and the pressure-force model.These models reflect the influence of the silicone tube’s shell thickness and material properties on the pneumatic muscle’s performance,which facilitates the optimal design of US2A for various working conditions.The experimental results showed that the maximum elongation of the US2A prototype is 257%,and the effective elongation could be variably regulated in the range of 0 and 257%.The proposed models were also verified by pressure-elongation and pressure-force experiments,with an average error of 5%and 2.5%,respectively.Finally,based on the US2A,we designed a pneumatic rehabilitation glove,soft arm robot,and rigid-soft coupling continuous robot,which further verified the feasibility of US2A as a soft driving component.展开更多
A new type of soft actuator material-ionic liquid gel （ILG）, which consists of HEMA, BMIMBF4, and TiO2, can be transformed into gel state under the irradiation of ultraviolet （UV） light. In this paper, Mooney-Rivl...A new type of soft actuator material-ionic liquid gel （ILG）, which consists of HEMA, BMIMBF4, and TiO2, can be transformed into gel state under the irradiation of ultraviolet （UV） light. In this paper, Mooney-Rivlin hyperelastic model of finite element method is proposed for the first time to study the properties of the ILG. It has been proved that the content of TiO2 has a great influence on the properties of the gel, and Young＇s modulus of the gel increases with the increase of its content, despite of reduced tensile deformation. The results in this work show that when the TiO2 content is 1.0 wt%, a large tensile deformation and a strong Young＇s modulus can be obtained to be 325% and 7.8 kPa, respectively. The material parameters of ILG with TiO2 content values of 0.2 wt%, 0.5 wt%, 1.0 wt%, and 1.5 wt% are obtained, respectively, through uniaxial tensile tests, including C10, C01, C20, C11, C02, C30, C21, C12, and C03 elements. In this paper, the large-scaled general finite element software ANSYS is used to simulate and analyze the ILG, which is based on SOLID186 element and nonlinear hyperelastic Mooney-Rivlin model. The finite element simulation analysis based stress-strain curves are almost consistent with the experimental stress-strain curves, and hence the finite element analysis of ILG is feasible and credible. This work presents a new direction for studying the performance of soft actuator for the ILG, and also contributes to the design of soft robot actuator.展开更多
The multi-cavity soft actuator is assembled from single-cavity soft actuator through a reasonable geometric distribution.It has the characteristic that the pneumatic soft actuator is driven by its own deformation and ...The multi-cavity soft actuator is assembled from single-cavity soft actuator through a reasonable geometric distribution.It has the characteristic that the pneumatic soft actuator is driven by its own deformation and has more degrees of freedom.Pneumatic soft actuator is widely used as an emerging discipline and its strong compliance has been greatly developed and applied.However,as the most application potential type of soft actuators,there is still a lack of simple and effective deformation prediction methods for studying the spatial deformation of multi-cavity soft actuators.To solve this problem,a vector equation method is proposed based on the analysis of the principle of the space deformation of the two-cavity,three-cavity and four-cavity soft actuators.Furthermore,a nonlinear mathematical model of the air pressure,space position and deformation trajectory of the soft actuator end is established by combining the vector equation method.Finally,the three-channel soft actuator is verified through experiments.The results show that the mathematical model can better predict the space deformation trajectory of the soft actuator,which provides a new research method for studying the space deformation of the multi-channel soft actuator.展开更多
4D printed smart materials is mostly relying on thermal stimulation to actuate,limiting their widely application requiring precise and localized control of the deformations.Most existing strategies for achieving local...4D printed smart materials is mostly relying on thermal stimulation to actuate,limiting their widely application requiring precise and localized control of the deformations.Most existing strategies for achieving localized control rely on hetero-geneous material systems and structural design,thereby increasing design and manufacturing complexity.Here,we endow localized electrothermal,actuation,and sensing properties in electrically-driven soft actuator through parameter-encoded 4D printing.We analyzed the effects of printing parameters on shape memory properties and conductivity,and then explored the multi-directional sensing performance of the 4D printed composites.We demonstrated an integrated actuator-sensor device capable of both shape recovery and perceiving its own position and obstacles simultaneously.Moreover,it can adjust its sensing characteristics through temporary shape programming to adapt to different application scenarios.This study achieves integrated and localized actuation-sensing without the need for multi-material systems and intricate structural designs,offering an efficient solution for the intelligent and lightweight design in the fields of soft robotics,biomedical applications,and aerospace.展开更多
As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progres...As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.展开更多
Developing flexible actuators with high transport efficiency is of great significance for the emerging applications of micro-robots in various industrial and biomedical environments.Despite recent advancements have en...Developing flexible actuators with high transport efficiency is of great significance for the emerging applications of micro-robots in various industrial and biomedical environments.Despite recent advancements have enabled soft materials to achieve complex functionalities unattainable by traditional rigid robots,achieving high-speed transport performance for solid particles remains a significant challenge.Magnetic materials,as an integral component of scientific applications,have demonstrated substantial potential in areas such as biological imaging,catalysis,and energy storage.Inspired by the flexible,soft,and elastic microciliary structures of many organisms,a soft actuator decorated with magnetic microcilia was reported.This soft magnetic microciliary actuator achieves high speed(50 mm s^(-1))transport of solid microspheres by means of magnetic field regulate their surface morphology.Overcoming the limitations of prior studies in which the speed of motion was constrained to a few millimeters per second due to hysteresis effects,this work represents a significant advancement in the emerging field of biomimetic flexible actuators and holds promise in various applications.展开更多
The design and fabrication of advanced soft actuators with programmable actuation are highly desirable in constructing intelligent soft robots.In this work,a programmable light-driven liquid crystalline network(LCN)-b...The design and fabrication of advanced soft actuators with programmable actuation are highly desirable in constructing intelligent soft robots.In this work,a programmable light-driven liquid crystalline network(LCN)-based soft actuator was judiciously designed and prepared by constructing structural anisotropy across the thickness of the film.A three-dimensional(3D)deformable LCN actuator was realized by polymerization-induced phase separation of small-molarweight monomers and polymer networks.The resultant anisotropic LCN displays anisotropic microscale nanoporous architecture across the thickness in addition to uniform alignment at the molecular scale.The actuation behaviors of LCN film are tunable by adjusting the size and distribution of nanopores in LCN bulk via changing polymerization conditions and monomer components.More importantly,the nanoporous LCN film can be harnessed as a promising template to achieve diverse light responsiveness by changing the photothermal dyes via a feasible washing and refilling process,demonstrating a reprogrammable light-driven soft actuator.展开更多
Traditional hand rehabilitation gloves usually use electrical motor as actuator with disadvantages of heaviness,bulkiness and less compliance.Recently,the soft pneumatic actuator is demonstrated to be more suitable fo...Traditional hand rehabilitation gloves usually use electrical motor as actuator with disadvantages of heaviness,bulkiness and less compliance.Recently,the soft pneumatic actuator is demonstrated to be more suitable for hand rehabilitation compared to motor because of its inherent compliance,flexibility and safety.In order to design a wearable glove in request of hand rehabilitation,a soft hoop-reinforced pneumatic actuator is presented.By analyzing the influence of its section shape and geometrical parameters on bending performance,the preferred structure of actuator is achieved based on finite element method.An improved hoop-reinforced actuator is designed after the fabrication and initial measurement,and its mathematical model is built in order to quickly obtain the bending angle response when pressurized.A series of experiment about bending performance are implemented to validate the agreement between the finite element,mathematical and experimental results,and the performance improvement of hoop-reinforced actuator.In addition,the designed hand rehabilitation glove is tested by measuring its output force and actual wearing experience.The output force can reach 2.5 to 3 N when the pressure is 200 kPa.The research results indicate that the designed glove with hoop-reinforced actuator can meet the requirements of hand rehabilitation and has prospective application in hand rehabilitation.展开更多
Laser-assisted process can enable facile,mask-free,large-area,inexpensive,customizable,and miniaturized patterning of laser-induced porous graphene(LIG)on versatile carbonaceous substrates(e.g.,polymers,wood,food,text...Laser-assisted process can enable facile,mask-free,large-area,inexpensive,customizable,and miniaturized patterning of laser-induced porous graphene(LIG)on versatile carbonaceous substrates(e.g.,polymers,wood,food,textiles)in a programmed manner at ambient conditions.Together with high tailorability of its porosity,morphology,composition,and electrical conductivity,LIG can find wide applications in emerging bioelectronics(e.g.,biophysical and biochemical sensing)and soft robots(e.g.,soft actuators).In this review paper,we first introduce the methods to make LIG on various carbonaceous substrates and then discuss its electrical,mechanical,and antibacterial properties and biocompatibility that are critical for applications in bioelectronics and soft robots.Next,we overview the recent studies of LIG-based biophysical(e.g.,strain,pressure,temperature,hydration,humidity,electrophysiological)sensors and biochemical(e.g.,gases,electrolytes,metabolites,pathogens,nucleic acids,immunology)sensors.The applications of LIG in flexible energy generators and photodetectors are also introduced.In addition,LIG-enabled soft actuators that can respond to chemicals,electricity,and light stimulus are overviewed.Finally,we briefly discuss the future challenges and opportunities of LIG fabrications and applications.展开更多
As mechanical devices for moving or controlling mechanisms or systems,actuators have attracted increasing attention in various fields.Compared to traditional actuators with rigid structures,soft actuators made up of s...As mechanical devices for moving or controlling mechanisms or systems,actuators have attracted increasing attention in various fields.Compared to traditional actuators with rigid structures,soft actuators made up of stimulus-responsive soft materials are more adaptable to complex working conditions due to soft bodies and diverse control styles.Different from plate-shaped soft actuators,which have the limited deformations between two dimensional(2D)and 3D-configurations such as bending and twisting,fiber-shaped soft actuators(FSAs)own intriguing deformation modes to satisfy diverse practical applications.In this mini review,the recent progress on the controlled fabrication of the FSAs is presented.The advantages and disadvantages of each fabrication method are also demonstrated.Subsequently,the as-developed actuation mechanisms of the FSAs are displayed.Additionally,typical examples of the related applications of the FSAs in different fields have been discussed.Finally,an outlook on the development tendency of the FSAs is put forward as well.展开更多
Soft robots have unique advantages over traditional rigid robots and have broad application prospects in many fields.To expand their bioinspired applications,we propose a novel Soft Pneumatic Actuator(SPA)associated w...Soft robots have unique advantages over traditional rigid robots and have broad application prospects in many fields.To expand their bioinspired applications,we propose a novel Soft Pneumatic Actuator(SPA)associated with spiral configuration inspired by the structure and unwinding motion of the seahorse tail.Diff erent from bending motion of common soft actuators,the spiral SPA can generate unwinding motion as input air pressure increases.First,to explore the eff ect of diff erent initial spiral types on unwinding performance,three typical spiral SPAs are designed and simulated while keeping the outside arc of actuator body constant.Second,a static model of the spiral SPA is established by combining the hyperelastic material model,geometric relationships,and virtual work principle.To improve model accuracy,two geometric correction parameters are employed and their physical significance is analyzed by finite element simulations.Third,a prototype of the logarithmic spiral SPA(Log_spiral SPA)is fabricated and a Fiber Bragg Grating(FBG)sensor array is designed to detect and reconstruct unwinding shapes of the prototype.Finally,the unwinding performance,static model and output force capability of the prototype are tested and verified.Furthermore,we discuss prospects for this novel spiral SPA and test its practical applications in inchworm-like motion,assisting finger rehabilitation and object capture.展开更多
Liquid crystal elastomers are active materials that combine the anisotropic properties of liquid crystals with the elasticity of polymer networks.The LCEs exhibit remarkable reversible contraction and elongation capab...Liquid crystal elastomers are active materials that combine the anisotropic properties of liquid crystals with the elasticity of polymer networks.The LCEs exhibit remarkable reversible contraction and elongation capabilities in response to external stimuli,rendering them highly promising for diverse applications,such as soft robotics,haptic devices,shape morphing structures,etc,However,the predominant reliance on heating as the driving stimulus for LCEs has limited their practical applications.This drawback can be effectively addressed by incorporating fllers,which can generate heat under various stimuli.The recent progress in LCE composites has significantly expanded the application potential of LCEs.In this minireview,we present the design strategies for soft actuators with LCE composites,followed by a detailed exploration of photothermal and electrothermal LCE.composites as prominent examples.Furthermore,we provide an outlook on the challenges and opportunities in the feld of LCE composites.展开更多
Soft bellows-type pneumatic actuators(SBPAs),which consist of two cavities with small chambers embedded in elastomeric structures,are an essential embranchment in the field of soft actuators.However,more analytical mo...Soft bellows-type pneumatic actuators(SBPAs),which consist of two cavities with small chambers embedded in elastomeric structures,are an essential embranchment in the field of soft actuators.However,more analytical modeling and analysis of SBPAs need to be studied.In this article,we first present the structure design,fabrication method,and material property test of the SBPA.Then,based on the plate bending theory,an analytical model and the corresponding design approach for SBPAs are established,which consider both geometric complexity and material nonlinearity.The verification results indicate that the predicted analytical results coincide well with the physical experimental measurement and simulation results.The decision coefficient is R^(2)=0.9720.The impacts of geometric dimensions and silicone material characteristics on the bending deformation of SBPAs are also explored.We further demonstrate the bionic utility of SBPAs.Such an approach can be used as a tool for the design optimization of bellows-type actuators and save the designer lots of finite element analysis with its low computational cost.This work provides a detailed investigation of the performance of SBPAs,which can be a basic module for various types of soft robots such as soft snake robots,crawling robots,and robotic arms in the future.展开更多
Remote controlled soft actuators have attracted ever-increasing interest in industrial,medical,robotics,and engineering fields.Soft actuators are charming than normal tools in executing dedicate tasks due to small vol...Remote controlled soft actuators have attracted ever-increasing interest in industrial,medical,robotics,and engineering fields.Soft actuators are charming than normal tools in executing dedicate tasks due to small volume and flexible body they have.However,it remains a challenge to design soft actuator that can adapt to multi-environments under remote stimuli with promising nano materials.Herein,we have developed a kind of near-infrared laser driven soft actuators with multi locomotive modes based on WSe2 and graphene nanosheets heterojunction.Different locomotion modes are driven by photothermal effect induced deformation to adapt to different working conditions.Moreover,the specially designed gripper driven by pulsed laser can lift a heavy load which is four times of its weight.This work broadens the choice of advanced nanomaterials for photothermal conversion of soft actuators.It is promising to realize applications including photothermal therapy and complex environment detection through the combination of the intelligent robot design and optical fiber system.展开更多
基金The Central Government Guides Local Foundation for Science and Technology Development(Grant No.YDZJSX2024B004).
文摘The soft actuator is characterized by high safety,flexibility,and adaptability.It is capable of both active and passive defor-mations.This paper presents a discrete degree of freedom(DOF)method for soft actuators to reveal DOF characteristics.The method draws on the superposition mechanism of the deformation characteristics of the sarcomere in the skeletal muscles of living organisms.Firstly,the multi-DOF deformation characteristics of the soft actuator are discretized into superimposed combinations of single-DOF micro-units.Then,the soft actuator was determined to contain deformation characteristics such as extension-contraction,bending,and twisting.Eighteen types of micro-units with basic deforma-tion characteristics were obtained depending on the axis and orientation.Further,the mapping relationship between the combination of micro-units and the motion characteristics of the soft actuator based on the GF set theory was established.Finally,an active-passive DOF co-structured soft actuator(APCSA)was developed.The graphical approach analyzes the experimental results,and it can be concluded that active and passive DOFs can coexist in the composite deformation of the soft actuator.
基金Financial support from the program of the National Natural Science Foundation of China(Grant no.52475059)Major Program of National Natural Science Founda-tion of China(NSFC)for Basic Theory and Key Technology of Tri-Co Robots(92248301)+3 种基金the Postdoctoral Research Foundation of China(No.2024M751167)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)Jiangsu Province Natural Science Foundation(No.BK20240155)supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Science and ICT(RS2024-00406534,RS-2025-25442809)。
文摘Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in long-distance and miniaturized environments.Fuel-driven actuators offer a promising solution by enabling the conversion of chemical energy into mechanical energy,supporting selfsustaining operations.Chemical energy from fuel can be converted into mechanical energy either directly or indirectly through methods such as electron transfer-induced charge injection,structural changes,fuel-to-electricity conversion,fuel combustioninduced heat,or fuel-induced pneumatic actuation.This paper provides a comprehensive review of recent developments in fuel-powered actuators,covering their fundamental principles,advancements,and challenges.It concludes with an outlook for miniaturized and autonomous robots,highlighting the great potential of integrating fuel-powered actuators.
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support provided by the Hong Kong RGC Theme-based Research Scheme(No.AoE/M-402/20)Hong Kong RGC Area of Excellence Scheme(No.AoE/E-101/23-N)+1 种基金Hong Kong RGC Theme-based Research Scheme(No.T45-406/23-R)the Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Center.
文摘Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators driven by magnetic force remotely.Nevertheless,the further study of magnetic responsive actuators with complex three-dimensional geometries and multiple functions is still limited by uncomplicated de-sign and flexible locomotion.This work provides a novel scheme integrating the origami method and modular designs,which defines the inner properties of magnetic material,extending the functions of magnetic responsive actuators with various modules.The directions of the inner magnetic moments can be programmed and the deformation degrees can be regulated by this approach,which promotes the fabrication of complicated soft actuators with multiple functions by integrating with modular designs.Especially,a movable actuator with various sensing modulus is designed by the origami method,which can perform the sensing application to external ultra-violet(UV),heat,and pH stimuli.Moreover,a mi-croneedle modular actuator which can be controlled wirelessly by a magnetic field was demonstrated for the potential application in the biomedical field.This proposed scheme for engineering magnetic respon-sive material with modular designs has shown great potential to improve the feasibility,versatility,and multiple functionalities of soft actuators.
基金supported by the National Natural Science Foundation of China(Nos.51973155,52173181,and 52173262)Jiangsu Innovation Team Program,Natural Science Foundation of Tianjin(20JCYBJC00810).
文摘In nature,many living organisms exhibiting unique structural coloration and soft-bodied actuation have inspired scientists to develop advanced structural colored soft actuators toward biomimetic soft robots.However,it is challenging to simultaneously biomimic the angle-independent structural color and shape-morphing capabilities found in the plum-throated cotinga flying bird.Herein,we report biomimetic MXene-based soft actuators with angle-independent structural color that are fabricated through controlled self-assembly of colloidal SiO_(2) nanoparticles onto highly aligned MXene films followed by vacuum-assisted infiltration of polyvinylidene fluoride into the interstices.The resulting soft actuators are found to exhibit brilliant,angle-independent structural color,as well as ultrafast actuation and recovery speeds(a maximum curvature of 0.52 mm−1 can be achieved within 1.16 s,and a recovery time of~0.24 s)in response to acetone vapor.As proof-of-concept illustrations,structural colored soft actuators are applied to demonstrate a blue gripper-like bird’s claw that can capture the target,artificial green tendrils that can twine around tree branches,and an artificial multicolored butterfly that can flutter its wings upon cyclic exposure to acetone vapor.The strategy is expected to offer new insights into the development of biomimetic multifunctional soft actuators for somatosensory soft robotics and next-generation intelligent machines.
文摘Soft robots and actuators are emerging devices providing more capabilities in the field of robotics.More flexibility and compliance attributing to soft functional materials used in the fabrication of these devices make them ideal for delivering delicate tasks in fragile environments,such as food and biomedical sectors.Yet,the intuitive nonlinearity of soft functional materials and their anisotropic actuation in compliant mechanisms constitute an existent challenge in improving their performance.Topology optimization(TO)along with four-dimensional(4D)printing is a powerful digital tool that can be used to obtain optimal internal architectures for the efficient performance of porous soft actuators.This paper employs TO analysis for achieving high bending deflection of a 3D printed polyelectrolyte actuator,which shows bending deformations in response to electrical stimuli in an electrolyte solution.The performance of the actuator is studied in terms of maximum bending and actuation rate compared with a solid,uniformly 3D printed and topology-optimized actuator.The experimental results proved the effectiveness of TO on achieving higher bending deformation and actuation rate against a uniformly 3D printed actuator.
基金National Natural Science Foundation of China(Grant No.U2013212)Key Research and Development Program of Zhejiang(Grant No.2021C04015)Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.RF-C2019004)。
文摘Actuator plays a significant role in soft robotics.This paper proposed an ultralong stretchable soft actuator(US2A)with a variable and sizeable maximum elongation.The US2A is composed of a silicone rubber tube and a bellows woven sleeve.The maximal extension can be conveniently regulated by just adjusting the wrinkles’initial angle of the bellows woven sleeve.The kinematics of US2A could be obtained by geometrically analyzing the structure of the bellows woven sleeve when the silicone rubber tube is inflated.Based on the principle of virtual work,the actuating models have been established:the pressure-elongation model and the pressure-force model.These models reflect the influence of the silicone tube’s shell thickness and material properties on the pneumatic muscle’s performance,which facilitates the optimal design of US2A for various working conditions.The experimental results showed that the maximum elongation of the US2A prototype is 257%,and the effective elongation could be variably regulated in the range of 0 and 257%.The proposed models were also verified by pressure-elongation and pressure-force experiments,with an average error of 5%and 2.5%,respectively.Finally,based on the US2A,we designed a pneumatic rehabilitation glove,soft arm robot,and rigid-soft coupling continuous robot,which further verified the feasibility of US2A as a soft driving component.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51538009 and 51605334)the Natural Science Foundation of Shanghai Municipality,China(Grant No.08002360285)
文摘A new type of soft actuator material-ionic liquid gel （ILG）, which consists of HEMA, BMIMBF4, and TiO2, can be transformed into gel state under the irradiation of ultraviolet （UV） light. In this paper, Mooney-Rivlin hyperelastic model of finite element method is proposed for the first time to study the properties of the ILG. It has been proved that the content of TiO2 has a great influence on the properties of the gel, and Young＇s modulus of the gel increases with the increase of its content, despite of reduced tensile deformation. The results in this work show that when the TiO2 content is 1.0 wt%, a large tensile deformation and a strong Young＇s modulus can be obtained to be 325% and 7.8 kPa, respectively. The material parameters of ILG with TiO2 content values of 0.2 wt%, 0.5 wt%, 1.0 wt%, and 1.5 wt% are obtained, respectively, through uniaxial tensile tests, including C10, C01, C20, C11, C02, C30, C21, C12, and C03 elements. In this paper, the large-scaled general finite element software ANSYS is used to simulate and analyze the ILG, which is based on SOLID186 element and nonlinear hyperelastic Mooney-Rivlin model. The finite element simulation analysis based stress-strain curves are almost consistent with the experimental stress-strain curves, and hence the finite element analysis of ILG is feasible and credible. This work presents a new direction for studying the performance of soft actuator for the ILG, and also contributes to the design of soft robot actuator.
基金the National Natural Science Foundation of China(No.11604205)。
文摘The multi-cavity soft actuator is assembled from single-cavity soft actuator through a reasonable geometric distribution.It has the characteristic that the pneumatic soft actuator is driven by its own deformation and has more degrees of freedom.Pneumatic soft actuator is widely used as an emerging discipline and its strong compliance has been greatly developed and applied.However,as the most application potential type of soft actuators,there is still a lack of simple and effective deformation prediction methods for studying the spatial deformation of multi-cavity soft actuators.To solve this problem,a vector equation method is proposed based on the analysis of the principle of the space deformation of the two-cavity,three-cavity and four-cavity soft actuators.Furthermore,a nonlinear mathematical model of the air pressure,space position and deformation trajectory of the soft actuator end is established by combining the vector equation method.Finally,the three-channel soft actuator is verified through experiments.The results show that the mathematical model can better predict the space deformation trajectory of the soft actuator,which provides a new research method for studying the space deformation of the multi-channel soft actuator.
基金supported in part by National Natural Science Foundation of China under Grant 52305304Jilin Youth Growth Technology Project under Grant 20230508147RC+2 种基金the Science and Technology Research Project of Jilin Provincial Education Department(No.JJKH20231193KJ)supported in part by the National Natural Science Foundation of China under Grant 52021003in part by the Natural Science Foundation of Jilin Province under Grant 20210101053JC.
文摘4D printed smart materials is mostly relying on thermal stimulation to actuate,limiting their widely application requiring precise and localized control of the deformations.Most existing strategies for achieving localized control rely on hetero-geneous material systems and structural design,thereby increasing design and manufacturing complexity.Here,we endow localized electrothermal,actuation,and sensing properties in electrically-driven soft actuator through parameter-encoded 4D printing.We analyzed the effects of printing parameters on shape memory properties and conductivity,and then explored the multi-directional sensing performance of the 4D printed composites.We demonstrated an integrated actuator-sensor device capable of both shape recovery and perceiving its own position and obstacles simultaneously.Moreover,it can adjust its sensing characteristics through temporary shape programming to adapt to different application scenarios.This study achieves integrated and localized actuation-sensing without the need for multi-material systems and intricate structural designs,offering an efficient solution for the intelligent and lightweight design in the fields of soft robotics,biomedical applications,and aerospace.
基金financial supports from the National Natural Science Foundation of China(No.61975173)the Key Research and Development Project of Zhejiang Province(No.2022C03103,2023C01045).
文摘As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.
基金financially supported by the National Natural Science Foundation of China(Nos.22105014 and 52472293)the China Postdoctoral Science Foundation(Nos.2020M680296 and 2022T150035)+3 种基金the High-level Talent Project of Shenyang Ligong University(Nos.1010147001302)the Special fund of Basic Scientific Research Expenses for Undergraduate Universities in Liaoning Province(Nos.LJ212410144077 and LJ212410144072)Beijing Young Talent Support Program,the 111 Projectthe Fundamental Research Funds for the Central Universities
文摘Developing flexible actuators with high transport efficiency is of great significance for the emerging applications of micro-robots in various industrial and biomedical environments.Despite recent advancements have enabled soft materials to achieve complex functionalities unattainable by traditional rigid robots,achieving high-speed transport performance for solid particles remains a significant challenge.Magnetic materials,as an integral component of scientific applications,have demonstrated substantial potential in areas such as biological imaging,catalysis,and energy storage.Inspired by the flexible,soft,and elastic microciliary structures of many organisms,a soft actuator decorated with magnetic microcilia was reported.This soft magnetic microciliary actuator achieves high speed(50 mm s^(-1))transport of solid microspheres by means of magnetic field regulate their surface morphology.Overcoming the limitations of prior studies in which the speed of motion was constrained to a few millimeters per second due to hysteresis effects,this work represents a significant advancement in the emerging field of biomimetic flexible actuators and holds promise in various applications.
基金supported by the National Natural Science Foundation of China(Grant No.52202081)Natural Science Foundation of Jiangxi Province(Grant No.20232BAB204030).
文摘The design and fabrication of advanced soft actuators with programmable actuation are highly desirable in constructing intelligent soft robots.In this work,a programmable light-driven liquid crystalline network(LCN)-based soft actuator was judiciously designed and prepared by constructing structural anisotropy across the thickness of the film.A three-dimensional(3D)deformable LCN actuator was realized by polymerization-induced phase separation of small-molarweight monomers and polymer networks.The resultant anisotropic LCN displays anisotropic microscale nanoporous architecture across the thickness in addition to uniform alignment at the molecular scale.The actuation behaviors of LCN film are tunable by adjusting the size and distribution of nanopores in LCN bulk via changing polymerization conditions and monomer components.More importantly,the nanoporous LCN film can be harnessed as a promising template to achieve diverse light responsiveness by changing the photothermal dyes via a feasible washing and refilling process,demonstrating a reprogrammable light-driven soft actuator.
基金Project(51305202)supported by the National Natural Science Foundation of China
文摘Traditional hand rehabilitation gloves usually use electrical motor as actuator with disadvantages of heaviness,bulkiness and less compliance.Recently,the soft pneumatic actuator is demonstrated to be more suitable for hand rehabilitation compared to motor because of its inherent compliance,flexibility and safety.In order to design a wearable glove in request of hand rehabilitation,a soft hoop-reinforced pneumatic actuator is presented.By analyzing the influence of its section shape and geometrical parameters on bending performance,the preferred structure of actuator is achieved based on finite element method.An improved hoop-reinforced actuator is designed after the fabrication and initial measurement,and its mathematical model is built in order to quickly obtain the bending angle response when pressurized.A series of experiment about bending performance are implemented to validate the agreement between the finite element,mathematical and experimental results,and the performance improvement of hoop-reinforced actuator.In addition,the designed hand rehabilitation glove is tested by measuring its output force and actual wearing experience.The output force can reach 2.5 to 3 N when the pressure is 200 kPa.The research results indicate that the designed glove with hoop-reinforced actuator can meet the requirements of hand rehabilitation and has prospective application in hand rehabilitation.
基金financial support from the NSF grant(ECCS-1917630)and University of Missouri-Columbia startup fund.
文摘Laser-assisted process can enable facile,mask-free,large-area,inexpensive,customizable,and miniaturized patterning of laser-induced porous graphene(LIG)on versatile carbonaceous substrates(e.g.,polymers,wood,food,textiles)in a programmed manner at ambient conditions.Together with high tailorability of its porosity,morphology,composition,and electrical conductivity,LIG can find wide applications in emerging bioelectronics(e.g.,biophysical and biochemical sensing)and soft robots(e.g.,soft actuators).In this review paper,we first introduce the methods to make LIG on various carbonaceous substrates and then discuss its electrical,mechanical,and antibacterial properties and biocompatibility that are critical for applications in bioelectronics and soft robots.Next,we overview the recent studies of LIG-based biophysical(e.g.,strain,pressure,temperature,hydration,humidity,electrophysiological)sensors and biochemical(e.g.,gases,electrolytes,metabolites,pathogens,nucleic acids,immunology)sensors.The applications of LIG in flexible energy generators and photodetectors are also introduced.In addition,LIG-enabled soft actuators that can respond to chemicals,electricity,and light stimulus are overviewed.Finally,we briefly discuss the future challenges and opportunities of LIG fabrications and applications.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant No.21875160)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(Grant No.KF2219)+1 种基金JK20202A030463,the Natural Science Foundation of Tianjin City(Grant No.20JCQNJC00870)the Scientific Research Project of Tianjin Municipal Education Commission(Grant No.2020KJ054).
文摘As mechanical devices for moving or controlling mechanisms or systems,actuators have attracted increasing attention in various fields.Compared to traditional actuators with rigid structures,soft actuators made up of stimulus-responsive soft materials are more adaptable to complex working conditions due to soft bodies and diverse control styles.Different from plate-shaped soft actuators,which have the limited deformations between two dimensional(2D)and 3D-configurations such as bending and twisting,fiber-shaped soft actuators(FSAs)own intriguing deformation modes to satisfy diverse practical applications.In this mini review,the recent progress on the controlled fabrication of the FSAs is presented.The advantages and disadvantages of each fabrication method are also demonstrated.Subsequently,the as-developed actuation mechanisms of the FSAs are displayed.Additionally,typical examples of the related applications of the FSAs in different fields have been discussed.Finally,an outlook on the development tendency of the FSAs is put forward as well.
基金mainly supported by the National Natural Science Foundation,China(No.U1813216 and No.61903215)The Guangdong Natural Science Foundation,China(No.2018A030310679)+1 种基金The Basic Research Program of Shenzhen,China(No.JCYJ20180306174321766)The Open Project of Shenzhen Institute of Artificial Intelligence and Robotics for Society,China(No.ACO1202005004)。
文摘Soft robots have unique advantages over traditional rigid robots and have broad application prospects in many fields.To expand their bioinspired applications,we propose a novel Soft Pneumatic Actuator(SPA)associated with spiral configuration inspired by the structure and unwinding motion of the seahorse tail.Diff erent from bending motion of common soft actuators,the spiral SPA can generate unwinding motion as input air pressure increases.First,to explore the eff ect of diff erent initial spiral types on unwinding performance,three typical spiral SPAs are designed and simulated while keeping the outside arc of actuator body constant.Second,a static model of the spiral SPA is established by combining the hyperelastic material model,geometric relationships,and virtual work principle.To improve model accuracy,two geometric correction parameters are employed and their physical significance is analyzed by finite element simulations.Third,a prototype of the logarithmic spiral SPA(Log_spiral SPA)is fabricated and a Fiber Bragg Grating(FBG)sensor array is designed to detect and reconstruct unwinding shapes of the prototype.Finally,the unwinding performance,static model and output force capability of the prototype are tested and verified.Furthermore,we discuss prospects for this novel spiral SPA and test its practical applications in inchworm-like motion,assisting finger rehabilitation and object capture.
基金supported by the Fundamental Research Funds for the Central Universities[YWF-22-K-101]National Natural Science Foundation of China[12202120]Science Technology and Innovation Program of Shenzhen[JCYJ20220531095210022].
文摘Liquid crystal elastomers are active materials that combine the anisotropic properties of liquid crystals with the elasticity of polymer networks.The LCEs exhibit remarkable reversible contraction and elongation capabilities in response to external stimuli,rendering them highly promising for diverse applications,such as soft robotics,haptic devices,shape morphing structures,etc,However,the predominant reliance on heating as the driving stimulus for LCEs has limited their practical applications.This drawback can be effectively addressed by incorporating fllers,which can generate heat under various stimuli.The recent progress in LCE composites has significantly expanded the application potential of LCEs.In this minireview,we present the design strategies for soft actuators with LCE composites,followed by a detailed exploration of photothermal and electrothermal LCE.composites as prominent examples.Furthermore,we provide an outlook on the challenges and opportunities in the feld of LCE composites.
基金supported by the National Key Laboratory of Vehicular Transmission of China under Grant JCKYS2019208005.
文摘Soft bellows-type pneumatic actuators(SBPAs),which consist of two cavities with small chambers embedded in elastomeric structures,are an essential embranchment in the field of soft actuators.However,more analytical modeling and analysis of SBPAs need to be studied.In this article,we first present the structure design,fabrication method,and material property test of the SBPA.Then,based on the plate bending theory,an analytical model and the corresponding design approach for SBPAs are established,which consider both geometric complexity and material nonlinearity.The verification results indicate that the predicted analytical results coincide well with the physical experimental measurement and simulation results.The decision coefficient is R^(2)=0.9720.The impacts of geometric dimensions and silicone material characteristics on the bending deformation of SBPAs are also explored.We further demonstrate the bionic utility of SBPAs.Such an approach can be used as a tool for the design optimization of bellows-type actuators and save the designer lots of finite element analysis with its low computational cost.This work provides a detailed investigation of the performance of SBPAs,which can be a basic module for various types of soft robots such as soft snake robots,crawling robots,and robotic arms in the future.
基金This work was financed by the National Natural Science Foundation of China(No.62175225)Zhejiang Provincial Natural Science Foundation of China(No.LZ21E020004)Fundamental Research Funds for the Provincial Universities of Zhejiang,Young Top Talent Plan of Zhejiang(No.ZJWR0308004).
文摘Remote controlled soft actuators have attracted ever-increasing interest in industrial,medical,robotics,and engineering fields.Soft actuators are charming than normal tools in executing dedicate tasks due to small volume and flexible body they have.However,it remains a challenge to design soft actuator that can adapt to multi-environments under remote stimuli with promising nano materials.Herein,we have developed a kind of near-infrared laser driven soft actuators with multi locomotive modes based on WSe2 and graphene nanosheets heterojunction.Different locomotion modes are driven by photothermal effect induced deformation to adapt to different working conditions.Moreover,the specially designed gripper driven by pulsed laser can lift a heavy load which is four times of its weight.This work broadens the choice of advanced nanomaterials for photothermal conversion of soft actuators.It is promising to realize applications including photothermal therapy and complex environment detection through the combination of the intelligent robot design and optical fiber system.
