Smart elastomers have attracted great interest due to their excellent adaptability to changing environments and affinity to living organisms,characterized by their ability to undergo programmable deformations or prope...Smart elastomers have attracted great interest due to their excellent adaptability to changing environments and affinity to living organisms,characterized by their ability to undergo programmable deformations or property changes in response to external stimuli(e.g.,heat,light,pH,or electric/magnetic fields).They exhibit huge potential to drive the innovation of soft actuators,robotics,biomedical devices,and wearable electronics.This special issue of Chinese Journal of Polymer Science(CJPS)is dedicated to showcasing cutting-edge advancements in liquid crystal elastomers,hydrogels and the related soft actuators,with a focus on the design,synthesis,characterization,and application of stimuli-responsive soft elastomers and their integration into functional actuation systems.展开更多
The development of actuators based on ionic polymers as soft robotics,artificial muscles,and sensors is currently considered one of the most urgent topics.They are lightweight materials,in addition to their high effic...The development of actuators based on ionic polymers as soft robotics,artificial muscles,and sensors is currently considered one of the most urgent topics.They are lightweight materials,in addition to their high efficiency,and they can be controlled by a low power source.Nevertheless,the most popular ionic polymers are derived from fossil-based resources.Hence,it is now deemed crucial to produce these actuators using sustainable materials.In this review,the use of ionic polymeric materials as actuators is reviewed through the emphasis on their role in the domain of renewablematerials.The reviewencompasses recent advancements inmaterial formulation and performance enhancement,alongside a comparative analysis with conventional actuator systems.It was found that renewable polymeric actuators based on ionic gels and conductive polymers are easier to prepare compared to ionic polymermetal composites.In addition,the proportion of actuator manufacturing utilizing renewable materials rose to 90%,particularly for ion gel actuators,which was related to the possibility of using renewable polymers as ionic or conductive substances.Moreover,the possible improvements in biopolymeric actuators will experience an annual rise of at least 10%over the next decade,correlating with the growth of their market,which aligns with the worldwide goal of reducing global warming.Additionally,compared to fossil-derived polymers,the decomposition rate of renewable materials reaches 100%,while biodegradable fossil-based substances can exceed 60%within several weeks.Ultimately,this review aims to elucidate the potential of ionic polymeric materials as a viable and sustainable solution for future actuator technologies.展开更多
Flexible underwater vehicles with high maneuverability,high efficiency,high speed,and low disturbance have shown great application potential and research significance in underwater engineering,ocean exploration,scient...Flexible underwater vehicles with high maneuverability,high efficiency,high speed,and low disturbance have shown great application potential and research significance in underwater engineering,ocean exploration,scientific investigation and other fields.The research and development of flexible stimulus-responsive actuators is key to the development of high-performance underwater vehicles.At present,the main drive methods for underwater devices include electric drive,magnetic drive,light drive,thermal drive,and chemical drive.In this work,the research progress of stimuli-responsive actuators in water environment is reviewed from the stimuli-responsive patterns,functional design,fabrication methods,and applications in water environment.Firstly,the actuation principles and characteristics of electro-responsive,magnetic-responsive,photo-responsive,thermo-responsive actuators,and chemically responsive actuators are reviewed.Subsequently,several design requirements for the desired flexible actuators are introduced.After that,the common fabrication methods are summarized.The typical application of the stimuli-responsive actuator in the water environment is further discussed in combination with the multi-stimuli-responsive characteristics.Finally,the challenges faced by the application of stimuli-responsive actuators in the water environment are analyzed,and the corresponding viewpoints are presented.This review offers guidance for designing and preparing stimulus-responsive actuators and outlines directions for further development in fields such as ocean energy exploration and surface reconnaissance.展开更多
Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control....Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control.Modern chassis-by-wire systems manage an increasing number of heterogeneous chassis execution systems,including distributed drive,all-wheel drive(AWD),brake-by-wire(BBW),steer-by-wire(SBW),rear-wheel steering(RWS),active stabilizer bar(ASB)and active suspension system(ASS),greatly enhancing the controllable degrees of freedom compared to conventional chassis configurations.To advance research in chassis domain control,it is essential to understand how these heterogeneous execution systems influence vehicle dynamics.This paper focuses on the modeling and analysis of the lateral,longitudinal,and vertical chassis control and execution systems,-as well as their impact on vehicle lateral motion.Using a vehicle simulation platform,both the vehicle dynamics model and the individual dynamics models of each execution system were developed to analyze the influence of these systems on lateral dynamics.Additionally,a hierarchical control architecture was designed to control the vehicle’s lateral stability.The effectiveness of the proposed control scheme was demonstrated and validated through hardware-in-the-loop(HIL)tests and real-world vehicle testing.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
Liquid crystal elastomers(LCEs)exhibit exceptional reversible deformation and unique physical properties owing to their order-disorder phase transition under external stimuli.Among these deformations,helical structure...Liquid crystal elastomers(LCEs)exhibit exceptional reversible deformation and unique physical properties owing to their order-disorder phase transition under external stimuli.Among these deformations,helical structures have attracted attention owing to their distinctive configurations and promising applications in biomimetics and microelectronics.However,the helical deformation behavior of fiber actuators is critically influenced by their morphologies and alignments;yet,the underlying mechanisms are not fully understood.Through a two-step azaMichael addition reaction and direct ink writing(DIW)4D printing technology,fiber-based LCE actuators with a core-sheath alignment structure were fabricated and exhibited reversible helical deformation upon heating.By adjusting the printing parameters,the filament number,width,thickness,and core-sheath structure of the fiber actuators can be precisely controlled,resulting in deformation behaviors,such as contraction,bending,and helical twisting.Finite element simulations were performed to investigate the deformation behaviors of the fiber actuators,providing insights into the variations in stress and strain during the shape-changing process,which can be used to explain the shape-morphing mechanism.These findings demonstrate that the precise tuning of printing parameters enables the controllable construction of LCE actuator morphology and customization of their functional properties,paving the way for advanced applications in smart fabrics,biomedical engineering,and flexible electronics.展开更多
A theoretical analysis regarding active vibration control of rotating machines with current-controlled electrodynamic actuators between machine feet and steel frame foundation and with velocity feedback of the machine...A theoretical analysis regarding active vibration control of rotating machines with current-controlled electrodynamic actuators between machine feet and steel frame foundation and with velocity feedback of the machine feet vibrations is presented.First,a generalized mathematical formulation is derived based on a state-space description which can be used for different kinds of models(1D,2D,and 3D models).It is shown that under special boundary conditions,the control parameters can be directly implemented into the stiffness and damping matrices of the system.Based on the generalized mathematical formulation,an example of a rotating machine—described by a 2D model—with journal bearings,flexible rotor,current-controlled electrodynamic actuators,steel frame foundation,and velocity feedback of the machine feet vibrations is presented where the effectiveness of the described active vibration control system is demonstrated.展开更多
Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewi...Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewires is associated with risks,including increased exposure to X-rays and potential vascular damage during withdrawal from complex vessels.Herein,we developed sub-millimeter microtubular ionic actuators(0.6-0.8 mm outer diameter)integrated into steerable interventional catheters.These actuators can generate large deformations(>10 mm)under 7 V direct current due to enhanced ion migration,enabling precise navigation without the need for guidewires.The designed catheters achieved active bending and accurate positioning in complex arterial vascular branches within a human model.They were also able to navigate within different arterial locations(e.g.,the innominate,subclavian,and carotid arteries)in pigs without the use of guidewires,and even access the ventricle and deliver contrast medium,indicating their great potential for future endovascular therapy.展开更多
Photonic fibrous soft actuators that can modulate light and produce responsive deformation would have broad technological implications in areas,ranging from smart textiles and intelligent artificial muscles to medical...Photonic fibrous soft actuators that can modulate light and produce responsive deformation would have broad technological implications in areas,ranging from smart textiles and intelligent artificial muscles to medical devices.However,creating such multifunctional soft actuators has proved tremendously challenging.Here,we report novel cholesteric liquid crystal elastomer(CLCE)based photonic fibrous soft actuators(PFSAs).CLCE can serve as chiral photonic soft active material and allow for multiresponse in shapes and colors.We leveraged a tubularmold-based processing technology to prepare fibrous CLCE actuators,and the prepared actuators exhibit the capabilities to dynamically switch structural colors and geometrical shapes by mechanical,temperature,or light stimuli.CLCE-based PFSAs demonstrate diverse functionalities,including visual weight feedback,optically driven object manipulation,and light driven locomotion.It is anticipated that our PFSAs would offer many new possibilities for developing advanced soft actuators.展开更多
This paper endeavours to bridge the existing gap in muscular actuator design for ligament-skeletal-inspired robots,thereby fostering the evolution of these robotic systems.We introduce two novel compliant actuators,na...This paper endeavours to bridge the existing gap in muscular actuator design for ligament-skeletal-inspired robots,thereby fostering the evolution of these robotic systems.We introduce two novel compliant actuators,namely the Internal Torsion Spring Compliant Actuator(ICA)and the External Spring Compliant Actuator(ECA),and present a comparative analysis against the previously conceived Magnet Integrated Soft Actuator(MISA)through computational and experimental results.These actuators,employing a motor-tendon system,emulate biological muscle-like forms,enhancing artificial muscle technology.Then,applications of the proposed actuators in a robotic arm inspired by the human musculoskeletal system are presented.Experiments demonstrate satisfactory power in tasks like lifting dumbbells(peak power:36 W),playing table tennis(end-effector speed:3.2 m/s),and door opening,without compromising biomimetic aesthetics.Compared to other linear stiffness serial elastic actuators(SEAs),ECA and ICA exhibit high power-to-volume(361×10^(3)W/m^(3))and power-to-mass(111.6 W/kg)ratios respectively,endorsing the biomimetic design’s promise in robotic development.展开更多
As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine...As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine,soft robots,etc.However,the displacement and blocking force of the traditional sheet-type Nafion-IPMC need to be improved,and it has the limitation of unidirectional actuation.In this paper,a new type of short side chain Aquivion material is used as the polymer in the IPMC.The cylindrical IPMC is prepared by extrusion technology to improve its actuation performance and realize multi-degree-of-freedom motion.In comparison to the traditional Nafion-IPMC,the ion exchange capacity,specific capacitance,and conductivity of Aquivion-IPMC are improved by 28%,27%,and 32%,respectively,and the displacement and blocking force are improved by 57%and 25%,respectively.The cylindrical actuators can be deflected in eight directions.This indicates that Aquivion,as a polymer membrane for IPMC,holds significant application potential.By designing a cylindrical IPMC electrode distribution,the multi-degree-of-freedom deflection of IPMC can be realized.展开更多
Soft underwater swimming robots driven by smart materials show unique advantages in ocean exploration,such as low noise,high flexibility and good environmental interaction ability.The dielectric elastomer(DE),as a new...Soft underwater swimming robots driven by smart materials show unique advantages in ocean exploration,such as low noise,high flexibility and good environmental interaction ability.The dielectric elastomer(DE),as a new kind of soft intelligent material,has the characteristics of a low elastic modulus,large deformation range,high energy density and fast response speed.DE actuator(DEA)drive systems use the deformation characteristics of dielectric materials to drive the mechanical system,which has become a research hotspot in the field of soft robots.In this paper,a tubular actuator based on DEs is designed and its performance is studied.Firstly,the structure and driving process of a DEA are described,and a tubular DEA is designed.Studying the elongation ratio of the DEA pre-stretching shows that when the axial elongation ratio is 3 times and the circumferential elongation ratio is 4 times,the maximum deformation effect can be obtained under voltage excitation.At a voltage of 6.0 k V,a single pipe section DEA achieves a bending angle of 25.9°and a driving force of 73.8 m N.Secondly,the effect of the DEA series on the bending angle and response characteristics is studied.The experimental results show that the maximum bending angle of the three joint actuators in series can reach 59.3°under6.0 k V voltage,which significantly improves the overall bending performance.In addition,the truncation frequency of the drive module after the series is increased to 0.62 Hz,showing better frequency response capability.The excellent performance of the pipe joint actuator in its bending angle,response characteristic and driving force is verified.展开更多
With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling an...With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling and mode switching analysis of EHA used in the primary flight control actuation systems of large aircraft,addressing the challenges associated with mode switching.First,we analyze the functional architecture and operational characteristics of multi-mode EHA,and sumarize the operating modes and implementation methods.Based on the EHA system architecture,we then develop a theoretical mathematical model and a simulation model.Using the simulation model,we analyze the performance of the EHA during normal operation.Finally,the performance of the EHA during mode switching under various functional switching scenarios is investigated.The results indicate that the EHA meets the performance requirements in terms of accuracy,bandwidth,and load capacity.Additionally,the hydraulic cylinder operates smoothly during the EHA mode switching,and the response time for switching between different modes is less than the specified threshold.These findings validate the system performance of multi-mode EHA,which helps to improve the reliability of EHA and the safety of aircraft flight control systems.展开更多
The oscillation of large space structure(LSS)can be easily induced because of its low vibration frequency.The coupling effect between LSS vibration control and attitude control can significantly reduce the overall per...The oscillation of large space structure(LSS)can be easily induced because of its low vibration frequency.The coupling effect between LSS vibration control and attitude control can significantly reduce the overall performance of the control system,especially when the scale of flexible structure increases.This paper proposes an optimal placement method of piezoelectric stack actuators(PSAs)network which reduces the coupling effect between attitude and vibration control system.First,a spacecraft with a honeycomb-shaped telescope is designed for a resolution-critical imaging scenario.The coupling dynamics of the spacecraft is established using finite element method(FEM)and floating frame of reference formulation(FFRF).Second,a coupling-effect-reducing optimal placement criterion for PSAs based on coupling-matrix enhanced Gramian is designed to reduce the coupling effect excitation while balancing controllability.Additionally,a laddered multi-layered optimizing scheme is established to increase the speed and accuracy when solving the gigantic discrete optimization problem.Finally,the effectiveness of the proposed method is illustrated through numerical simulation.展开更多
Compared with traditional hydraulic actuators, an Electro-Mechanical Actuator(EMA)is small in size and light in weight, so it has become more widely used. Aerodynamic load on aircraft control surface varies dramatical...Compared with traditional hydraulic actuators, an Electro-Mechanical Actuator(EMA)is small in size and light in weight, so it has become more widely used. Aerodynamic load on aircraft control surface varies dramatically, and a change of flight environment leads to uncertainties of motor parameters. Therefore, high-dynamic response and strong anti-disturbance capability of an EMA are of great significance for aircraft rudder control and flight attitude adjustment. In order to improve dynamic response and disturbance rejection of an EMA and simplify control parameters tuning, a robust high-dynamic servo system based on Linear Active Disturbance Rejection Control(LADRC) is proposed for an EMA employing a Permanent Magnet Synchronous Motor(PMSM).Firstly, total disturbances of the EMA are analyzed, including parameter uncertainties, load variation, and static friction. A disturbance observer based on a reduced-order Extended State Observer(ESO) is designed to improve the anti-interference ability and dynamic performance. Secondly, the servo control architecture is simplified to a double-loop system, and a composite control of position and speed with acceleration feed-forward is presented to improve the EMA frequency bandwidth.Thirdly, the ideal model of the EMA is transformed into a simple cascade integral form with a disturbance observer, which makes it convenient to analyze and design the controller. Robustness performance comparisons are realized in frequency domain. Finally, simulation and experimental results have verified the effectiveness of the proposed strategy for EMAs.展开更多
A rectangular finite element for laminated plate with bonded and/or embedded piezoelectric sensors and actuators is developed based on the variational principle and the first order shear deformation theory. The elemen...A rectangular finite element for laminated plate with bonded and/or embedded piezoelectric sensors and actuators is developed based on the variational principle and the first order shear deformation theory. The element has four-node, 20-degrees-of-freedom with one potential degree of freedom for each piezoelectric layer to represent the piezoelectric behavior. The higher order derivation of deflection is obtained by using the normal rotation expressions to take the effects of transverse shear deformation into considerations. The finite element can accurately simulate the deformation of both thin and moderately thick plates. A Fortran program is written and a number of benchmark tests are exercised to verify its effectiveness. Results are compared well with the existing data. The unbalanced composite with piezoelectric layers is then analyzed by using the model. Results show that the changes of the ratio between the thickness of positive angle layers and the negative angle layers have an effect on the deformation of the structure under the same electric loading.展开更多
Firstly, a multi-field coupling finite element formulation of composited beam laminated with the photostrictive actuators is developed in this paper. Moreover, an optimal fuzzy active control algorithm is also propose...Firstly, a multi-field coupling finite element formulation of composited beam laminated with the photostrictive actuators is developed in this paper. Moreover, an optimal fuzzy active control algorithm is also proposed on the basis of the combination of optimal control and fuzzy one.This method opens a new avenue to resolve the contradiction between the linear system control method and nonlinear actuating characteristics of photostrictive actuators. The desired control for suppressing multi-modal vibration of photoelectric laminated beam is firstly obtained through optimal control and then the fuzzy control is used to approach the desired mechanical strain induced by photostrictive actuators. Thus, the multi-mode vibration control of beam is realized.In the design process of optimal fuzzy controller, the design of fuzzy control is independent of optimal control. The simulation results demonstrate that the proposed control method can effectively realize multi-modal vibration control of photoelectric laminated beams, and the control effect of optimal fuzzy control is better than that of optimal state feedback control.展开更多
Due to the limited output capability of piezoelectric diaphragm pumps, the driving voltage is frequently increased to obtain the desired output. However, the excessive voltage application may lead to a large deformati...Due to the limited output capability of piezoelectric diaphragm pumps, the driving voltage is frequently increased to obtain the desired output. However, the excessive voltage application may lead to a large deformation in the piezoelectric ceramics, which could cause it to breakdown or become damaged. Therefore, increasing the number of chambers to obtain the desired output is proposed. Using a check-valve quintuple-chamber pump with quintuple piezoelectric actuators, the characteristics of the pump under different driving modes are investigated through experiments. By changing the number and connection mode of working actuators, pump performances in terms of flow rate and backpressure are tested at a voltage of 150 V with a frequency range of 60 Hz -400 Hz. Experiment results indicate that the properties of the multiple-chamber pump change significantly with distinct working chambers even though the number of pumping chambers is the same. Pump performance declines as the distance between the working actuators increases. Moreover, pump performance declines dramatically when the working piezoelectric actuator closest to the outlet is involved. The maximum backpressures of the pump with triple, quadruple, and quintuple actuators are increased by 39%, 83%, and 128%, respectively, compared with the pump with double working actuators; the corresponding maximum flow rates of the pumps are simply increased by 25.9%, 49.2%, and 67.8%, respectively. The proposed research offers practical guidance for the effective utilization of the multiple-chamber pumps under different driving modes.展开更多
A closed-loop control allocation method is proposed for a class of aircraft with multiple actuators. Nonlinear dynamic inversion is used to design the baseline attitude controller and derive the desired moment increme...A closed-loop control allocation method is proposed for a class of aircraft with multiple actuators. Nonlinear dynamic inversion is used to design the baseline attitude controller and derive the desired moment increment. And a feedback loop for the moment increment produced by the deflections of actuators is added to the angular rate loop, then the error between the desired and actual moment increment is the input of the dynamic control allocation. Subsequently, the stability of the closed-loop dynamic control allocation system is analyzed in detail. Especially, the closedloop system stability is also analyzed in the presence of two types of actuator failures： loss of effectiveness and lock-in-place actuator failures, where a fault detection subsystem to identify the actuator failures is absent. Finally, the proposed method is applied to a canard rotor/wing （CRW） aircraft model in fixed-wing mode, which has multiple actuators for flight control. The nonlinear simulation demonstrates that this method can guarantee the stability and tracking performance whether the actuators are healthy or fail.展开更多
The nonlinear static characteristic of a piezoelectric unimorph cantilever micro actuator driven by a strong applied electric field is studied based on the couple stress theory.The cantilever actuator consists of a pi...The nonlinear static characteristic of a piezoelectric unimorph cantilever micro actuator driven by a strong applied electric field is studied based on the couple stress theory.The cantilever actuator consists of a piezoelectric layer,a passive（elastic）layer and two electrode layers.First,the nonlinear static characteristic of the actuator caused by the electrostriction of the piezoelectric layer under a strong applied electric field is analyzed using the Rayleigh-Ritz method.Secondly,since the thickness of the cantilever beam is in micro scale and there exists a size effect,the size dependence of the deformation behavior is evaluated using the couple stress theory.The results show that the nonlinearities of the beam deflection increase along with the increase of the applied electric field which means that softening of the micro beam rigidity exists when a strong external electric field is applied.Meanwhile,the optimal value of the thickness ratio for the passive layer and the piezoelectric layer is not around 1.0 which is usually adopted by some previous researchers.Since there exists a size effect of the micro beam deflection,the optimal value of this thickness ratio should be greater than 1.0 in micro scale.展开更多
文摘Smart elastomers have attracted great interest due to their excellent adaptability to changing environments and affinity to living organisms,characterized by their ability to undergo programmable deformations or property changes in response to external stimuli(e.g.,heat,light,pH,or electric/magnetic fields).They exhibit huge potential to drive the innovation of soft actuators,robotics,biomedical devices,and wearable electronics.This special issue of Chinese Journal of Polymer Science(CJPS)is dedicated to showcasing cutting-edge advancements in liquid crystal elastomers,hydrogels and the related soft actuators,with a focus on the design,synthesis,characterization,and application of stimuli-responsive soft elastomers and their integration into functional actuation systems.
基金funded by the Russian Science Foundation(RSF),grantNo.24-23-00558,https://rscf.ru/en/project/24-23-00558/(accessed on 04 February 2025).
文摘The development of actuators based on ionic polymers as soft robotics,artificial muscles,and sensors is currently considered one of the most urgent topics.They are lightweight materials,in addition to their high efficiency,and they can be controlled by a low power source.Nevertheless,the most popular ionic polymers are derived from fossil-based resources.Hence,it is now deemed crucial to produce these actuators using sustainable materials.In this review,the use of ionic polymeric materials as actuators is reviewed through the emphasis on their role in the domain of renewablematerials.The reviewencompasses recent advancements inmaterial formulation and performance enhancement,alongside a comparative analysis with conventional actuator systems.It was found that renewable polymeric actuators based on ionic gels and conductive polymers are easier to prepare compared to ionic polymermetal composites.In addition,the proportion of actuator manufacturing utilizing renewable materials rose to 90%,particularly for ion gel actuators,which was related to the possibility of using renewable polymers as ionic or conductive substances.Moreover,the possible improvements in biopolymeric actuators will experience an annual rise of at least 10%over the next decade,correlating with the growth of their market,which aligns with the worldwide goal of reducing global warming.Additionally,compared to fossil-derived polymers,the decomposition rate of renewable materials reaches 100%,while biodegradable fossil-based substances can exceed 60%within several weeks.Ultimately,this review aims to elucidate the potential of ionic polymeric materials as a viable and sustainable solution for future actuator technologies.
基金supported by the National Key Research and Development Program of China(2022YFB4703401)the Ministry of Education Joint Fund(8091B032250)the Fundamental Research Funds for the Central Universities(B240205045)。
文摘Flexible underwater vehicles with high maneuverability,high efficiency,high speed,and low disturbance have shown great application potential and research significance in underwater engineering,ocean exploration,scientific investigation and other fields.The research and development of flexible stimulus-responsive actuators is key to the development of high-performance underwater vehicles.At present,the main drive methods for underwater devices include electric drive,magnetic drive,light drive,thermal drive,and chemical drive.In this work,the research progress of stimuli-responsive actuators in water environment is reviewed from the stimuli-responsive patterns,functional design,fabrication methods,and applications in water environment.Firstly,the actuation principles and characteristics of electro-responsive,magnetic-responsive,photo-responsive,thermo-responsive actuators,and chemically responsive actuators are reviewed.Subsequently,several design requirements for the desired flexible actuators are introduced.After that,the common fabrication methods are summarized.The typical application of the stimuli-responsive actuator in the water environment is further discussed in combination with the multi-stimuli-responsive characteristics.Finally,the challenges faced by the application of stimuli-responsive actuators in the water environment are analyzed,and the corresponding viewpoints are presented.This review offers guidance for designing and preparing stimulus-responsive actuators and outlines directions for further development in fields such as ocean energy exploration and surface reconnaissance.
基金Supported by National Nature Science Foundation of China(Grant Nos.52325212,52372394)National Key Research and Development Program of China(Grant Nos.2022YFE0117100,2021YFB2501201)+1 种基金Industry-University-Research Innovation Fund for Chinese Universities(Grand No.2024HT010)Fundamental Research Funds for the Central Universities.
文摘Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control.Modern chassis-by-wire systems manage an increasing number of heterogeneous chassis execution systems,including distributed drive,all-wheel drive(AWD),brake-by-wire(BBW),steer-by-wire(SBW),rear-wheel steering(RWS),active stabilizer bar(ASB)and active suspension system(ASS),greatly enhancing the controllable degrees of freedom compared to conventional chassis configurations.To advance research in chassis domain control,it is essential to understand how these heterogeneous execution systems influence vehicle dynamics.This paper focuses on the modeling and analysis of the lateral,longitudinal,and vertical chassis control and execution systems,-as well as their impact on vehicle lateral motion.Using a vehicle simulation platform,both the vehicle dynamics model and the individual dynamics models of each execution system were developed to analyze the influence of these systems on lateral dynamics.Additionally,a hierarchical control architecture was designed to control the vehicle’s lateral stability.The effectiveness of the proposed control scheme was demonstrated and validated through hardware-in-the-loop(HIL)tests and real-world vehicle testing.
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financially supported by the National Natural Science Foundation of China(Nos.52103145 and 11832007)Science&Technology Department of Sichuan Province(No.2025ZNSFSC0352)State Key Laboratory of Polymer Materials Engineering(No.sklpme-2024-1-03)。
文摘Liquid crystal elastomers(LCEs)exhibit exceptional reversible deformation and unique physical properties owing to their order-disorder phase transition under external stimuli.Among these deformations,helical structures have attracted attention owing to their distinctive configurations and promising applications in biomimetics and microelectronics.However,the helical deformation behavior of fiber actuators is critically influenced by their morphologies and alignments;yet,the underlying mechanisms are not fully understood.Through a two-step azaMichael addition reaction and direct ink writing(DIW)4D printing technology,fiber-based LCE actuators with a core-sheath alignment structure were fabricated and exhibited reversible helical deformation upon heating.By adjusting the printing parameters,the filament number,width,thickness,and core-sheath structure of the fiber actuators can be precisely controlled,resulting in deformation behaviors,such as contraction,bending,and helical twisting.Finite element simulations were performed to investigate the deformation behaviors of the fiber actuators,providing insights into the variations in stress and strain during the shape-changing process,which can be used to explain the shape-morphing mechanism.These findings demonstrate that the precise tuning of printing parameters enables the controllable construction of LCE actuator morphology and customization of their functional properties,paving the way for advanced applications in smart fabrics,biomedical engineering,and flexible electronics.
文摘A theoretical analysis regarding active vibration control of rotating machines with current-controlled electrodynamic actuators between machine feet and steel frame foundation and with velocity feedback of the machine feet vibrations is presented.First,a generalized mathematical formulation is derived based on a state-space description which can be used for different kinds of models(1D,2D,and 3D models).It is shown that under special boundary conditions,the control parameters can be directly implemented into the stiffness and damping matrices of the system.Based on the generalized mathematical formulation,an example of a rotating machine—described by a 2D model—with journal bearings,flexible rotor,current-controlled electrodynamic actuators,steel frame foundation,and velocity feedback of the machine feet vibrations is presented where the effectiveness of the described active vibration control system is demonstrated.
基金the National Natural Science Foundation of China(No.52375293)the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and astronautics,Nos.1005-IZD2300225 and IZD2400217)+2 种基金the Nanjing Life and Health Technology Special Project(No.202305031)the Clinical Competence Enhancement Project in Healthcare(No.JSPH-MB-2022-4)the Medical Engineering Translational Fund of Jiangsu Province Hospital(No.NM202402).
文摘Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewires is associated with risks,including increased exposure to X-rays and potential vascular damage during withdrawal from complex vessels.Herein,we developed sub-millimeter microtubular ionic actuators(0.6-0.8 mm outer diameter)integrated into steerable interventional catheters.These actuators can generate large deformations(>10 mm)under 7 V direct current due to enhanced ion migration,enabling precise navigation without the need for guidewires.The designed catheters achieved active bending and accurate positioning in complex arterial vascular branches within a human model.They were also able to navigate within different arterial locations(e.g.,the innominate,subclavian,and carotid arteries)in pigs without the use of guidewires,and even access the ventricle and deliver contrast medium,indicating their great potential for future endovascular therapy.
基金financially supported by the National Natural Science Foundation of China(Nos.52273111 and 51873197)the Natural Science Foundation of Zhejiang Province of China(No.LR22E030004)the Foundation of Westlake University。
文摘Photonic fibrous soft actuators that can modulate light and produce responsive deformation would have broad technological implications in areas,ranging from smart textiles and intelligent artificial muscles to medical devices.However,creating such multifunctional soft actuators has proved tremendously challenging.Here,we report novel cholesteric liquid crystal elastomer(CLCE)based photonic fibrous soft actuators(PFSAs).CLCE can serve as chiral photonic soft active material and allow for multiresponse in shapes and colors.We leveraged a tubularmold-based processing technology to prepare fibrous CLCE actuators,and the prepared actuators exhibit the capabilities to dynamically switch structural colors and geometrical shapes by mechanical,temperature,or light stimuli.CLCE-based PFSAs demonstrate diverse functionalities,including visual weight feedback,optically driven object manipulation,and light driven locomotion.It is anticipated that our PFSAs would offer many new possibilities for developing advanced soft actuators.
基金research project funded by the National Natural Science Foundation of China(NSFC)under Grant 91948302 and Grant 52021003Research England fund at NERIC.
文摘This paper endeavours to bridge the existing gap in muscular actuator design for ligament-skeletal-inspired robots,thereby fostering the evolution of these robotic systems.We introduce two novel compliant actuators,namely the Internal Torsion Spring Compliant Actuator(ICA)and the External Spring Compliant Actuator(ECA),and present a comparative analysis against the previously conceived Magnet Integrated Soft Actuator(MISA)through computational and experimental results.These actuators,employing a motor-tendon system,emulate biological muscle-like forms,enhancing artificial muscle technology.Then,applications of the proposed actuators in a robotic arm inspired by the human musculoskeletal system are presented.Experiments demonstrate satisfactory power in tasks like lifting dumbbells(peak power:36 W),playing table tennis(end-effector speed:3.2 m/s),and door opening,without compromising biomimetic aesthetics.Compared to other linear stiffness serial elastic actuators(SEAs),ECA and ICA exhibit high power-to-volume(361×10^(3)W/m^(3))and power-to-mass(111.6 W/kg)ratios respectively,endorsing the biomimetic design’s promise in robotic development.
基金financial support from the National Natural Science Foundation of China(Grant No.U1637101)The Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(1005-ZAG23011).
文摘As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine,soft robots,etc.However,the displacement and blocking force of the traditional sheet-type Nafion-IPMC need to be improved,and it has the limitation of unidirectional actuation.In this paper,a new type of short side chain Aquivion material is used as the polymer in the IPMC.The cylindrical IPMC is prepared by extrusion technology to improve its actuation performance and realize multi-degree-of-freedom motion.In comparison to the traditional Nafion-IPMC,the ion exchange capacity,specific capacitance,and conductivity of Aquivion-IPMC are improved by 28%,27%,and 32%,respectively,and the displacement and blocking force are improved by 57%and 25%,respectively.The cylindrical actuators can be deflected in eight directions.This indicates that Aquivion,as a polymer membrane for IPMC,holds significant application potential.By designing a cylindrical IPMC electrode distribution,the multi-degree-of-freedom deflection of IPMC can be realized.
基金Project supported by the Science and Technology Research Project of Henan Province in China(Grant No.222102220022)。
文摘Soft underwater swimming robots driven by smart materials show unique advantages in ocean exploration,such as low noise,high flexibility and good environmental interaction ability.The dielectric elastomer(DE),as a new kind of soft intelligent material,has the characteristics of a low elastic modulus,large deformation range,high energy density and fast response speed.DE actuator(DEA)drive systems use the deformation characteristics of dielectric materials to drive the mechanical system,which has become a research hotspot in the field of soft robots.In this paper,a tubular actuator based on DEs is designed and its performance is studied.Firstly,the structure and driving process of a DEA are described,and a tubular DEA is designed.Studying the elongation ratio of the DEA pre-stretching shows that when the axial elongation ratio is 3 times and the circumferential elongation ratio is 4 times,the maximum deformation effect can be obtained under voltage excitation.At a voltage of 6.0 k V,a single pipe section DEA achieves a bending angle of 25.9°and a driving force of 73.8 m N.Secondly,the effect of the DEA series on the bending angle and response characteristics is studied.The experimental results show that the maximum bending angle of the three joint actuators in series can reach 59.3°under6.0 k V voltage,which significantly improves the overall bending performance.In addition,the truncation frequency of the drive module after the series is increased to 0.62 Hz,showing better frequency response capability.The excellent performance of the pipe joint actuator in its bending angle,response characteristic and driving force is verified.
基金supported by the Chinese Civil Aircraft Project(No.MJ-2017-S49).
文摘With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling and mode switching analysis of EHA used in the primary flight control actuation systems of large aircraft,addressing the challenges associated with mode switching.First,we analyze the functional architecture and operational characteristics of multi-mode EHA,and sumarize the operating modes and implementation methods.Based on the EHA system architecture,we then develop a theoretical mathematical model and a simulation model.Using the simulation model,we analyze the performance of the EHA during normal operation.Finally,the performance of the EHA during mode switching under various functional switching scenarios is investigated.The results indicate that the EHA meets the performance requirements in terms of accuracy,bandwidth,and load capacity.Additionally,the hydraulic cylinder operates smoothly during the EHA mode switching,and the response time for switching between different modes is less than the specified threshold.These findings validate the system performance of multi-mode EHA,which helps to improve the reliability of EHA and the safety of aircraft flight control systems.
基金supported by National Natural Science Foundation of China(No.U23B6001).
文摘The oscillation of large space structure(LSS)can be easily induced because of its low vibration frequency.The coupling effect between LSS vibration control and attitude control can significantly reduce the overall performance of the control system,especially when the scale of flexible structure increases.This paper proposes an optimal placement method of piezoelectric stack actuators(PSAs)network which reduces the coupling effect between attitude and vibration control system.First,a spacecraft with a honeycomb-shaped telescope is designed for a resolution-critical imaging scenario.The coupling dynamics of the spacecraft is established using finite element method(FEM)and floating frame of reference formulation(FFRF).Second,a coupling-effect-reducing optimal placement criterion for PSAs based on coupling-matrix enhanced Gramian is designed to reduce the coupling effect excitation while balancing controllability.Additionally,a laddered multi-layered optimizing scheme is established to increase the speed and accuracy when solving the gigantic discrete optimization problem.Finally,the effectiveness of the proposed method is illustrated through numerical simulation.
基金supported by the Shaanxi Provincial Key R&D Program, China (No. 2017KW-ZD-05)the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2018JQ5187)the Fundamental Research Funds for the Central Universities,China(Nos.3102017JC06004, 3102017OQD029)
文摘Compared with traditional hydraulic actuators, an Electro-Mechanical Actuator(EMA)is small in size and light in weight, so it has become more widely used. Aerodynamic load on aircraft control surface varies dramatically, and a change of flight environment leads to uncertainties of motor parameters. Therefore, high-dynamic response and strong anti-disturbance capability of an EMA are of great significance for aircraft rudder control and flight attitude adjustment. In order to improve dynamic response and disturbance rejection of an EMA and simplify control parameters tuning, a robust high-dynamic servo system based on Linear Active Disturbance Rejection Control(LADRC) is proposed for an EMA employing a Permanent Magnet Synchronous Motor(PMSM).Firstly, total disturbances of the EMA are analyzed, including parameter uncertainties, load variation, and static friction. A disturbance observer based on a reduced-order Extended State Observer(ESO) is designed to improve the anti-interference ability and dynamic performance. Secondly, the servo control architecture is simplified to a double-loop system, and a composite control of position and speed with acceleration feed-forward is presented to improve the EMA frequency bandwidth.Thirdly, the ideal model of the EMA is transformed into a simple cascade integral form with a disturbance observer, which makes it convenient to analyze and design the controller. Robustness performance comparisons are realized in frequency domain. Finally, simulation and experimental results have verified the effectiveness of the proposed strategy for EMAs.
文摘A rectangular finite element for laminated plate with bonded and/or embedded piezoelectric sensors and actuators is developed based on the variational principle and the first order shear deformation theory. The element has four-node, 20-degrees-of-freedom with one potential degree of freedom for each piezoelectric layer to represent the piezoelectric behavior. The higher order derivation of deflection is obtained by using the normal rotation expressions to take the effects of transverse shear deformation into considerations. The finite element can accurately simulate the deformation of both thin and moderately thick plates. A Fortran program is written and a number of benchmark tests are exercised to verify its effectiveness. Results are compared well with the existing data. The unbalanced composite with piezoelectric layers is then analyzed by using the model. Results show that the changes of the ratio between the thickness of positive angle layers and the negative angle layers have an effect on the deformation of the structure under the same electric loading.
基金supported by the National Natural Science Foundation of China, China (No. 11572151)
文摘Firstly, a multi-field coupling finite element formulation of composited beam laminated with the photostrictive actuators is developed in this paper. Moreover, an optimal fuzzy active control algorithm is also proposed on the basis of the combination of optimal control and fuzzy one.This method opens a new avenue to resolve the contradiction between the linear system control method and nonlinear actuating characteristics of photostrictive actuators. The desired control for suppressing multi-modal vibration of photoelectric laminated beam is firstly obtained through optimal control and then the fuzzy control is used to approach the desired mechanical strain induced by photostrictive actuators. Thus, the multi-mode vibration control of beam is realized.In the design process of optimal fuzzy controller, the design of fuzzy control is independent of optimal control. The simulation results demonstrate that the proposed control method can effectively realize multi-modal vibration control of photoelectric laminated beams, and the control effect of optimal fuzzy control is better than that of optimal state feedback control.
基金Supported by National Natural Science Foundation of China(Grant Nos.51205366,51205367,51377147)Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ13E050007)
文摘Due to the limited output capability of piezoelectric diaphragm pumps, the driving voltage is frequently increased to obtain the desired output. However, the excessive voltage application may lead to a large deformation in the piezoelectric ceramics, which could cause it to breakdown or become damaged. Therefore, increasing the number of chambers to obtain the desired output is proposed. Using a check-valve quintuple-chamber pump with quintuple piezoelectric actuators, the characteristics of the pump under different driving modes are investigated through experiments. By changing the number and connection mode of working actuators, pump performances in terms of flow rate and backpressure are tested at a voltage of 150 V with a frequency range of 60 Hz -400 Hz. Experiment results indicate that the properties of the multiple-chamber pump change significantly with distinct working chambers even though the number of pumping chambers is the same. Pump performance declines as the distance between the working actuators increases. Moreover, pump performance declines dramatically when the working piezoelectric actuator closest to the outlet is involved. The maximum backpressures of the pump with triple, quadruple, and quintuple actuators are increased by 39%, 83%, and 128%, respectively, compared with the pump with double working actuators; the corresponding maximum flow rates of the pumps are simply increased by 25.9%, 49.2%, and 67.8%, respectively. The proposed research offers practical guidance for the effective utilization of the multiple-chamber pumps under different driving modes.
基金Program for New Century Excellent Talents in University (NCET-10-0032)
文摘A closed-loop control allocation method is proposed for a class of aircraft with multiple actuators. Nonlinear dynamic inversion is used to design the baseline attitude controller and derive the desired moment increment. And a feedback loop for the moment increment produced by the deflections of actuators is added to the angular rate loop, then the error between the desired and actual moment increment is the input of the dynamic control allocation. Subsequently, the stability of the closed-loop dynamic control allocation system is analyzed in detail. Especially, the closedloop system stability is also analyzed in the presence of two types of actuator failures： loss of effectiveness and lock-in-place actuator failures, where a fault detection subsystem to identify the actuator failures is absent. Finally, the proposed method is applied to a canard rotor/wing （CRW） aircraft model in fixed-wing mode, which has multiple actuators for flight control. The nonlinear simulation demonstrates that this method can guarantee the stability and tracking performance whether the actuators are healthy or fail.
基金The National Natural Science Foundation of China(No.10772086,10772085)
文摘The nonlinear static characteristic of a piezoelectric unimorph cantilever micro actuator driven by a strong applied electric field is studied based on the couple stress theory.The cantilever actuator consists of a piezoelectric layer,a passive（elastic）layer and two electrode layers.First,the nonlinear static characteristic of the actuator caused by the electrostriction of the piezoelectric layer under a strong applied electric field is analyzed using the Rayleigh-Ritz method.Secondly,since the thickness of the cantilever beam is in micro scale and there exists a size effect,the size dependence of the deformation behavior is evaluated using the couple stress theory.The results show that the nonlinearities of the beam deflection increase along with the increase of the applied electric field which means that softening of the micro beam rigidity exists when a strong external electric field is applied.Meanwhile,the optimal value of the thickness ratio for the passive layer and the piezoelectric layer is not around 1.0 which is usually adopted by some previous researchers.Since there exists a size effect of the micro beam deflection,the optimal value of this thickness ratio should be greater than 1.0 in micro scale.
