Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into...Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into one flexible strain sensor remains a huge challenge.Herein,inspired by the hysteresis strategy of the scorpion slit receptor,a bio-inspired flexible strain sensor(BFSS)with parallel through-slit arrays is designed and fabricated.Specifically,BFSS consists of conductive monolayer graphene and viscoelastic styrene–isoprene–styrene block copolymer.Under the synergistic effect of the bio-inspired slit structures and flexible viscoelastic materials,BFSS can achieve both hypersensitivity and highly selective frequency response.Remarkably,the BFSS exhibits a high gage factor of 657.36,and a precise identification of vibration frequencies at a resolution of 0.2 Hz through undergoing different morphological changes to high-frequency vibration and low-frequency vibration.Moreover,the BFSS possesses a wide frequency detection range(103 Hz)and stable durability(1000 cycles).It can sense and recognize vibration signals with different characteristics,including the frequency,amplitude,and waveform.This work,which turns the hysteresis effect into a"treasure,"can provide new design ideas for sensors for potential applications including human–computer interaction and health monitoring of mechanical equipment.展开更多
Metal and nano-ceramic nanocomposite coatings were prepared on the gray cast iron surface by the electrodeposition method. The Ni-Co was used as the metal matrix,and nano-Al2O3 was chosen as the second-phase particula...Metal and nano-ceramic nanocomposite coatings were prepared on the gray cast iron surface by the electrodeposition method. The Ni-Co was used as the metal matrix,and nano-Al2O3 was chosen as the second-phase particulates. To avoid poor inter-face bonding and stress distribution,the gradient structure of biology materials was found as the model and therefore the gradient composite coating was prepared. The morphology of the composite coatings was flatter and the microstructure was denser than that of pure Ni-Co coatings. The composite coatings were prepared by different current densities,and the 2-D and 3-D morphologies of the surface coatings were observed. The result indicated that the 2-D structure became rougher and the 3-D surface density of apices became less when the current density was increased. The content of nanoparticulates reached a maximum value at the current density of 40mA·cm-2,at the same time the properties including microhardness and wear-resistance were analyzed. The microhardness reached a maximum value and the wear volume was also less at the current density of 40mA·cm-2. The reason was that nano-Al2O3 particles caused dispersive strengthening and grain refining.展开更多
By imitating the behavioral characteristics of some typical animals, researchers develop bionic stepping motors to extend the working range of piezoelectric materials and utilize their high accuracy advantage as well....By imitating the behavioral characteristics of some typical animals, researchers develop bionic stepping motors to extend the working range of piezoelectric materials and utilize their high accuracy advantage as well. A comprehensive review of the bionic stepping motors driven by piezoelectric materials is presented in this work. The main parts of stepping piezoelectric motors, including the feeding module, clamping module, and other critical components, are introduced elaborately. We classify the bionic stepping piezoelectric motors into inchworm motors, seal motors, and inertia motors depending on their main structure modules, and present the mutual transformation relationships among the three types. In terms of the relative position relationships among the main structure modules, each of the inchworm motors, seal motors, and inertia motors can further be divided into walker type, pusher type, and hybrid type. The configurations and working principles of all bionic stepping piezoelectric motors are reported, followed by a discussion of the advantages and disadvantages of the performance for each type. This work provides theoretical support and thoughtful insights for the understanding, analysis, design, and application of the bionic stepping piezoelectric motors.展开更多
Accurate knowledge of the kinematics of the in vivo Ankle Joint Complex(AJC)is critical for understanding the biomechanical function of the foot and assessing postoperative rehabilitation of ankle disorders,as well as...Accurate knowledge of the kinematics of the in vivo Ankle Joint Complex(AJC)is critical for understanding the biomechanical function of the foot and assessing postoperative rehabilitation of ankle disorders,as well as an essential guide to the design of ankle–foot assistant devices.However,detailed analysis of the continuous 3D motion of the tibiotalar and subtalar joints during normal walking throughout the stance phase is still considered to be lacking.In this study,dynamic radiographs of the hindfoot were acquired from eight subjects during normal walking.Natural motions with six Degrees of Freedom(DOF)and the coupled patterns of the two joints were analyzed.It was found that the movements of the two joints were mostly in opposite directions(including rotation and translation),mainly in the early and late stages.There were significant differences in the Range of Motion(ROM)in Dorsiflexion/Plantarflexion(D/P),Inversion/Eversion(In/Ev),and Anterior–Posterior(AP)and Medial–Lateral(ML)translation of the tibiotalar and subtalar joints(p<0.05).Plantarflexion of the tibiotalar joint was coupled with eversion and posterior translation of the subtalar joint during the impact phase(R^(2)=0.87 and 0.86,respectively),and plantarflexion of the tibiotalar joint was coupled with inversion and anterior translation of the subtalar joint during the push-off phase(R^(2)=0.93 and 0.75,respectively).This coordinated coupled motion of the two joints may be a manifestation of the AJC to move flexibly while bearing weight and still have stability.展开更多
The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between d...The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between depth of overdischarge and mechanical properties is still a significant challenge.Studying the correlation between depth of overdischarge and mechanical properties is of great significance to improving the energy density and the ability to resist abuse of the batteries.In this paper,the mechanical properties of the battery materials during the whole process of overdischarge from discharge to complete failure were studied.The effects of depth of overdischarge on the elastic modulus and hardness of the cathode of the battery,the tensile strength and the thermal shrinkage rate of the separator,and the performance of binder were investigated.The precipitation of Cu dendrites on the separator and cathode after dissolution of anode copper foil is a key factor affecting the performance of battery materials.The Cu dendrites attached to the cathode penetrate the separator,causing irreversible damage to the coating and base film of the separator,which leads to a sharp decline in the tensile strength,thermal shrinkage rate and other properties of the separator.In addition,the Cu dendrites wrapping the cathode active particles reduce the adhesion of the active particles binder.Meanwhile,the active particles are damaged,resulting in a significant decrease in the elastic modulus and hardness of the cathode.展开更多
A variety of prosthetic ankles have been successfully developed to reproduce the locomotor ability for lower limb amputees in daily lives. However, they have not been shown to sufficiently improve the natural gait mec...A variety of prosthetic ankles have been successfully developed to reproduce the locomotor ability for lower limb amputees in daily lives. However, they have not been shown to sufficiently improve the natural gait mechanics commonly observed in comparison to the able-bodied, perhaps due to over-simplified designs of functional musculoskeletal structures in prostheses. In this study, a flexible bionic ankle prosthesis with joints covered by soft material inclusions is developed on the basis of the human musculoskeletal system. First, the healthy side ankle–foot bones of a below-knee amputee were reconstructed by CT imaging. Three types of polyurethane rubber material configurations were then designed to mimic the soft tissues around the human ankle, providing stability and flexibility. Finite element simulations were conducted to determine the proper design of the rubber materials, evaluate the ankle stiffness under different external conditions, and calculate the rotation axes of the ankle during walking. The results showed that the bionic ankle had variable stiffness properties and could adapt to various road surfaces. It also had rotation axes similar to that of the human ankle, thus restoring the function of the talocrural and subtalar joints. The inclination and deviation angles of the talocrural axis, 86.2° and 75.1°, respectively, as well as the angles of the subtalar axis, 40.1° and 29.9°, were consistent with the literature. Finally, dynamic characteristics were investigated by gait measurements on the same subject, and the flexible bionic ankle prosthesis demonstrated natural gait mechanics during walking in terms of ankle angles and moments.展开更多
Morphing botanical tissues and animal muscles are all fiber-mediated composites, in which fibers play a passive and active role, respectively. Herein, inspired by the mechanism of fibers functioning in morphing botani...Morphing botanical tissues and animal muscles are all fiber-mediated composites, in which fibers play a passive and active role, respectively. Herein, inspired by the mechanism of fibers functioning in morphing botanical tissues and animal muscles, we propose two sorts of fiber-dominated composite actuators. First, inspired by the deformation of awned seeds in response to humidity change, we fabricate passive fiber-dominated actuators using non-active aligned carbon fibers via 4D printing method. The effects of process parameters, structural parameters, and fiber angles on the deformation of the printed actuators are examined. The experimental results show that the orientation degree is enhanced, resulting in a better swelling effect as the printing speed increases. Then, motivated by the actuation mechanism of skeletal muscle, we prepare active fiber-dominated actuators using active polyurethane fibers via 4D printing and pre-stretching method. The effect of fiber angle and loading on the actuation mode is experimentally analyzed. The experimental results show that the rotation angle of the actuator gradually decreases with the angle from 45° to 60°. When the fiber angle is 0° and 90°, the driver basically stops rotating while shrinking along the loading direction. Based on the above actuation mechanisms, identical contraction behaviors are realized both in passive and active fiber-dominated soft actuators. This work provides a validation method for biologically actuation mechanisms via 4D printing technique and smart materials and adds further insights to the design of bioinspired soft actuators.展开更多
The biomechanical effects of acetabular revision with jumbo cups are unclear.This study aimed to compare the biomechanical effects of bionic trabecular metal vs.titanium jumbo cups for the revision of acetabular bone ...The biomechanical effects of acetabular revision with jumbo cups are unclear.This study aimed to compare the biomechanical effects of bionic trabecular metal vs.titanium jumbo cups for the revision of acetabular bone defects.We designed and reconstructed American Academy of Orthopaedic Surgeons(AAOS)type I–III acetabular bone defect models using computed tomography scans of a man without acetabular bone defects.The implantation of titanium and trabecular metal jumbo cups was simulated.Stress distribution and relative micromotion between the cup and host bone were assessed using finite element analysis.Contact stress on the screws fixing the cups was also analyzed.The contact stress analysis showed that the peak contact stress between the titanium jumbo cup and the host bone was 21.7,20.1,and 23.8 MPa in the AAOS I–III models,respectively;the corresponding values for bionic tantalum jumbo cups decreased to 4.7,6.7,and 11.1 MPa.Analysis of the relative micromotion showed that the peak relative micromotion between the host bone and the titanium metal cup was 10.2,9.1,and 11.5μm in the AAOS I–III models,respectively;the corresponding values for bionic trabecular metal cups were 17.2,18.2,and 31.3μm.The peak contact stress on the screws was similar for the 2 cup types,and was concentrated on the screw rods.Hence,acetabular reconstruction with jumbo cups is biomechanically feasible.We recommend trabecular metal cups due to their superior stress distribution and higher relative micromotion,which is within the threshold for adequate bone ingrowth.展开更多
In this article,a new optimization system that uses few features to recognize locomotion with high classification accuracy is proposed.The optimization system consists of three parts.First,the features of the mixed me...In this article,a new optimization system that uses few features to recognize locomotion with high classification accuracy is proposed.The optimization system consists of three parts.First,the features of the mixed mechanical signal data are extracted from each analysis window of 200 ms after each foot contact event.Then,the Binary version of the hybrid Gray Wolf Optimization and Particle Swarm Optimization(BGWOPSO)algorithm is used to select features.And,the selected features are optimized and assigned different weights by the Biogeography-Based Optimization(BBO)algorithm.Finally,an improved K-Nearest Neighbor(KNN)classifier is employed for intention recognition.This classifier has the advantages of high accuracy,few parameters as well as low memory burden.Based on data from eight patients with transfemoral amputations,the optimization system is evaluated.The numerical results indicate that the proposed model can recognize nine daily locomotion modes(i.e.,low-,mid-,and fast-speed level-ground walking,ramp ascent/decent,stair ascent/descent,and sit/stand)by only seven features,with an accuracy of 96.66%±0.68%.As for real-time prediction on a powered knee prosthesis,the shortest prediction time is only 9.8 ms.These promising results reveal the potential of intention recognition based on the proposed system for high-level control of the prosthetic knee.展开更多
Excessive vibration in civil and mechanical systems can lead to structural damage or harmful noise.Structural vibration can be mitigated by reducing the energy of the vibration source or by isolating the external dist...Excessive vibration in civil and mechanical systems can lead to structural damage or harmful noise.Structural vibration can be mitigated by reducing the energy of the vibration source or by isolating the external disturbance from the target structure.Depending on the tunability and power consumption of the system,existing vibration control strategies are divided into active,passive and semi-active types,providing a more stable and efficient solution for vibration control.However,conventional damping structures have difficulty in meeting the requirements of wide frequency range and high precision damping under complex operating conditions.Therefore,the design of efficient damping structures is one of the key challenges in the development of vibration control technology.Organisms have evolved over millions of years to effectively damp vibrations through special structures and composite materials to ensure their survival.Opening up damping vibration isolation technology from a bionic perspective can meet the frequency requirements of vibration damping and guarantee higher output accuracy of machinery.This review summarizes the basic principles of vibration control and analyses the vibration control strategies for different damping materials and damping structures.Meanwhile,various models of bio-damped structures are outlined.Moreover,the current status and recent progress of research on bionic damped structures based on bio-vibration control strategies are discussed.Finally,new perspectives on future developments in the field of bionic damped vibration control techniques are also presented.A comprehensive understanding of existing vibration damping mechanisms and new methods of bionic damping design will certainly trigger important applications of precision vibration control in the fields of aerospace,rail transportation and mechanical systems.展开更多
In nature,organisms widely use the interaction of muscle contraction and biological pipelines to form an efficient fluid control mechanism.Herein,a pneumatically powered,Bioinspired Soft Switching valve(BSS valve)with...In nature,organisms widely use the interaction of muscle contraction and biological pipelines to form an efficient fluid control mechanism.Herein,a pneumatically powered,Bioinspired Soft Switching valve(BSS valve)with short response time and low-energy consumption is described.The BSS valve is composed of flexible walls,a flexible tube and symmetrically arranged Snapping Membrane actuator(SM actuator).It functions based on tube deformation throttling caused by instability of SM actuator membrane.To realize rapid preparation of customized BSS valve,the modular manufacturing method suitable for different materials and structures based on 3D printing and mold forming was developed.Using the membrane flip rate as indicators,the displacement transient response characteristics of three structures actuators were studied,The results proved that spherical and spherical cap membrane SM actuator achieved rapid displacement response under the low critical pressure threshold.Furthermore,with critical buckling pressure and capacity utilization efficiency as indicators,we analyzed the characteristics of SM actuators with different radius and wall thickness to obtain reasonable structural parameters configuration of SM actuators.The influence of radius and thickness on SM actuator is revealed,and theoretical model formulas were formed.Two different configurations are presented.(1)Customized BSS valve structures can achieve sequential motion of flexible gripper.(2)BSS valve embedded in soft pump.The performance tests confirmed it has significant advantages in energy consumption,specific pressure,specific flow,high-frequency cycle load life,and valve can be integrated into the soft pump fluid system as a throttling unit,and provides an idea for fluid drive control integration.展开更多
Solid particle erosion is a common phenomenon in engineering fields,such as manufacturing,energy,military and aviation.However,with the rising industrial requirements,the development of anti-solid particle erosion mat...Solid particle erosion is a common phenomenon in engineering fields,such as manufacturing,energy,military and aviation.However,with the rising industrial requirements,the development of anti-solid particle erosion materials remains a great challenge.After billions of years of evolution,several natural materials exhibit unique and exceptional solid particle erosion resistance.These materials achieved the same excellent solid particle erosion resistance performance through diversified strategies.This resistance arises from their micro/nanoscale surface structure and interface material properties,which provide inspiration for novel multiple solutions to solid particle erosion.Here,this review first summarizes the recent significant process in the research of natural anti-solid particle erosion materials and their general design principles.According to these principles,several erosion-resistant structures are available.Combined with advanced micro/nanomanufacturing technologies,several artificial anti-solid particle erosion materials have been obtained.Then,the potential applications of anti-solid particle erosion materials are prospected.Finally,the remaining challenges and promising breakthroughs regarding anti-solid particle erosion materials are briefly discussed.展开更多
Shape memory polymers(SMPs)are a promising class of materials for biomedical applications due to their favorable mechanical properties,fast response,and good biocompatibility.However,it is difficult to achieve control...Shape memory polymers(SMPs)are a promising class of materials for biomedical applications due to their favorable mechanical properties,fast response,and good biocompatibility.However,it is difficult to achieve controllable sequential shape change for most SMPs due to their high deformation temperature and the simplex deformation process.Herein,shape memory composites based on polylactic acid(PLA)matrix and semi-crystalline linear polymer polycaprolactone(PCL)are fabricated using 4D printing technology.Compared with pure PLA,with the rise of PCL content,the 4D-printed PLA/PCL composites show decreased glass transition temperature(Tg)from 67.2 to 55.2°C.Through the precise control of the deformation condition,controllable sequential deformation with an outstanding shape memory effect can be achieved for the PLA/PCL shape memory composites.The response time of shape recovery is less than 1.2 s,and the shape fixation/recov-ery rates are above 92%.In order to simulate sequential petal opening and sequential drug releasing effects,a double-layer bionic flower and a drug release device,respectively,are presented by assembling PLA/PCL samples with different PLA/PCL ratios.The results indicate the potential applications of 4D-printed PLA/PCL composites in the field of bio-inspired robotics and biomedical devices.展开更多
Mammals such as humans develop skeletal muscles composed of muscle fibers and connective tissue,which have mechanical properties that enable power output with three-dimensional motion when activated.Artificial muscle-...Mammals such as humans develop skeletal muscles composed of muscle fibers and connective tissue,which have mechanical properties that enable power output with three-dimensional motion when activated.Artificial muscle-like actuators developed to date,such as the McKibben artificial muscle,often focus sole contractile elements and have rarely addressed the contribution of flexible connective tissue that forms an integral part of the structure and morphology of biological muscle.Herein,we present a class of pneumatic muscle-like actuators,termed highly mimetic skeletal muscle(HimiSK)actuator,that consist of parallelly arranged contractile units in a flexible matrix inspired by ultrasonic measurements on skeletal muscle.The contractile units act as a muscle fiber to produce active shortening force,and the flexible matrix functions as connective tissue to generate passive deformation.The application of positive pressure to the contractile units can produce a linear contraction and force.In this actuator,we assign different flexible materials as contractile units and a flexible matrix,thus forming five mold actuators.These actuators feature three-dimensional motion on activation and present both intrinsic force-velocity and force-length characteristics that closely resebmle those of a biological muscle.High output and tetanic force produced by harder contractile units improve the maximum output force by up to about 41.3%and the tetanic force by up to about 168%.Moreover,high displacement and velocity can be generated by a softer flexible matrix,with the improvement of maximum displacement up to about 33.3%and velocity up to about 73%.The results demonstrate that contractile units play a crucial role in force generation,while the flexible matrix has a significant impact on force transmission and deformation;the final force,velocity,displacement,and three-dimensional motion results from the interplay of contractile units,fluid and flexible matrix.Our approach introduces a model of the presented HimiSK actuators to better understand the mechanical behaviors,force generation,and transmission in bioinspired soft actuators,and highlights the importance of using flexible connective tissue to form a structure and configuration similar to that of skeletal muscle,which has potential usefulness in the design of effective artificial muscle.展开更多
Developing high-performance composite materials is of great significance as a strong support for high-end manufacturing.However,the design and optimization of composite materials lack a theoretical basis and guidance ...Developing high-performance composite materials is of great significance as a strong support for high-end manufacturing.However,the design and optimization of composite materials lack a theoretical basis and guidance scheme.Compared with traditional composite materials,natural materials are composed of relatively limited components but exhibit better mechanical properties through ingenious and reasonable synthetic strategies.Based on this,learning from nature is considered to be an effective way to break through the bottleneck of composite design and preparation.In this review,the recent progress of natural composites with excellent properties is presented.Multiple factors,including structures,components and interfaces,are first summarized to reveal the strategies of natural materials to achieve outstanding mechanical properties.In addition,the manufacturing technologies and engineering applications of bioinspired composite materials are introduced.Finally,some scientific challenges and outlooks are also proposed to promote next-generation bioinspired composite materials.展开更多
Solid particle erosion on the material surfaces is a very common phenomenon in the industrial field,which greatly affects the efficiency,service life,and even poses a great threat to life safety.However,current resear...Solid particle erosion on the material surfaces is a very common phenomenon in the industrial field,which greatly affects the efficiency,service life,and even poses a great threat to life safety.However,current research on erosion resistance is not only inefficient,but also limited to the improvement of hardness and toughness of materials.Inspired by typical scorpion(Parabuthus transvaalicus),biomimetic functional samples with exquisite anti-rosion structures were manufactured.Macroscopic morphology and structure of the biological prototype were analyzed and measured.According to above analysis,combined with response surface methodology,a set of biomimetic samples with different structural parameters were fabricated by using 3D printing technology.The anti-crosion performance of these biomimetic samples was investigated using a blasting jet machine.Based on the results of blasting jet test,as well as regression analysis and fiting,the optimal structural parameters were obtained.In addition to the static test conditions,the optimal biomimetic sample was also eroded in rotating condition and showed excellent erosion resistance property.The presence of bump and groove structures,on the one hand,reduced the croded area of biominetic sample surface.On the other hand,they made the airlow turbulent and consequently reduced the impact cnergy of solid particles,which significantly improved the erosion resistance of biomimetic materials.This study provides a new strategy to improvethe service life of components easily affected by erosion in the aviation,energy and military fields.展开更多
The objective of this study is to develop a bio robot with a high degree of biomechanical fidelity to the human musculoskeletal system in order to investigate the biomechanical principles underlying human walking.The ...The objective of this study is to develop a bio robot with a high degree of biomechanical fidelity to the human musculoskeletal system in order to investigate the biomechanical principles underlying human walking.The robot was designed to possess identical biomechanical characteristics to the human body in terms of body segment properties,joint configurations and 3D musculoskeletal geometries.These design parameters were acquired based on the medical images,3D musculoskeletal model and gait measurements of a healthy human subject.To satistyall the design criteria sinultaneously,metal 3D printing was used to construct the whole-body humanoid robot.Flexible artificial muscles were fabricated in accordance with the predefined 3D musculoskeletal geometries.A series of physical tests were con-ducted to demonstrate the capacity of the robot platform.The fabricated robot shows equivalent mechanical characteristics to the human body as originally designed.The results of the physical tests by systematically changing environmental conditions and body structures have successfully demonstrated the capability of the robot platform to investigate the structure-function interplay in the human musculoskeletal system and also its interaction with the environment during walking.This robot might provide a valuable and powerful physical platfornm towards studying hunan musculoskeletal biomechanics by generating new hypotheses and revealing new insights into human locomotion science.展开更多
The potential of clectromagnetic ficlds(EMFs)for discase treatment and health enhancement has been actively pursued over the recent decades.This review first provides a general introduction about natural EMFs and rela...The potential of clectromagnetic ficlds(EMFs)for discase treatment and health enhancement has been actively pursued over the recent decades.This review first provides a general introduction about natural EMFs and related biological effcts.Then the recent progress on the EMF treatment of some common diseases(such as cancer,diabetes,wound healing and neurological diseases,etc.)has been carefully reviewed and summarized.Yet,the blindness on the selection of therapeutic EMF parameters still hinders the broad application ofEMF therapy.Moreover,the unclear mechanism of EMF function and poor reproducibility of experimental rcsults also remain big challenges in the field of bioclectromagnetics.Bionics is a useful methodology that gains inspiration from nature to serve human life and industry.We have discussed the feasibility of applying bionic approach on the selection of the rapeutic EMFs,which is based on thefindings of natural EMFs.Finally,we advocate that the detailed information of EMFs and biological samples should be thoroughly reorded in future research and reported in publications.In addition,the publication of studies with negative results should also be allowed.展开更多
基金This work was supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.52021003)National Natural Science Foundation of China(Grant No.51835006)+6 种基金the National Natural Science Foundation of China(Grant Nos.52222509,52105301,U19A20103)Jilin University Science and Technology Innovative Research Team(Grant No.2020TD-03)Interdisciplinary Integration and Innovation Project of JLU(Grant No.JLUXKJC2021ZZ03)the Natural Science Foundation of Jilin Province(Grant No.20220101220JC)Education Department of Jilin Province(Grant No.JJKH20220979KJ)Graduate Innovation Fund of Jilin University(2023CX077)supported by“Fundamental Research Funds for the Central Universities.”。
文摘Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into one flexible strain sensor remains a huge challenge.Herein,inspired by the hysteresis strategy of the scorpion slit receptor,a bio-inspired flexible strain sensor(BFSS)with parallel through-slit arrays is designed and fabricated.Specifically,BFSS consists of conductive monolayer graphene and viscoelastic styrene–isoprene–styrene block copolymer.Under the synergistic effect of the bio-inspired slit structures and flexible viscoelastic materials,BFSS can achieve both hypersensitivity and highly selective frequency response.Remarkably,the BFSS exhibits a high gage factor of 657.36,and a precise identification of vibration frequencies at a resolution of 0.2 Hz through undergoing different morphological changes to high-frequency vibration and low-frequency vibration.Moreover,the BFSS possesses a wide frequency detection range(103 Hz)and stable durability(1000 cycles).It can sense and recognize vibration signals with different characteristics,including the frequency,amplitude,and waveform.This work,which turns the hysteresis effect into a"treasure,"can provide new design ideas for sensors for potential applications including human–computer interaction and health monitoring of mechanical equipment.
基金the National Natural Science Foundation of China (No50635030)the National Basic Research of China (No2007CB616913)the Program for New Century Excellent Talents in University (2005)
文摘Metal and nano-ceramic nanocomposite coatings were prepared on the gray cast iron surface by the electrodeposition method. The Ni-Co was used as the metal matrix,and nano-Al2O3 was chosen as the second-phase particulates. To avoid poor inter-face bonding and stress distribution,the gradient structure of biology materials was found as the model and therefore the gradient composite coating was prepared. The morphology of the composite coatings was flatter and the microstructure was denser than that of pure Ni-Co coatings. The composite coatings were prepared by different current densities,and the 2-D and 3-D morphologies of the surface coatings were observed. The result indicated that the 2-D structure became rougher and the 3-D surface density of apices became less when the current density was increased. The content of nanoparticulates reached a maximum value at the current density of 40mA·cm-2,at the same time the properties including microhardness and wear-resistance were analyzed. The microhardness reached a maximum value and the wear volume was also less at the current density of 40mA·cm-2. The reason was that nano-Al2O3 particles caused dispersive strengthening and grain refining.
基金Natural Science Foundation of Jilin Province,20220101216JC,Shupeng WangTalent Introduction Fund of Jilin University,451210330007,Shupeng Wang.
文摘By imitating the behavioral characteristics of some typical animals, researchers develop bionic stepping motors to extend the working range of piezoelectric materials and utilize their high accuracy advantage as well. A comprehensive review of the bionic stepping motors driven by piezoelectric materials is presented in this work. The main parts of stepping piezoelectric motors, including the feeding module, clamping module, and other critical components, are introduced elaborately. We classify the bionic stepping piezoelectric motors into inchworm motors, seal motors, and inertia motors depending on their main structure modules, and present the mutual transformation relationships among the three types. In terms of the relative position relationships among the main structure modules, each of the inchworm motors, seal motors, and inertia motors can further be divided into walker type, pusher type, and hybrid type. The configurations and working principles of all bionic stepping piezoelectric motors are reported, followed by a discussion of the advantages and disadvantages of the performance for each type. This work provides theoretical support and thoughtful insights for the understanding, analysis, design, and application of the bionic stepping piezoelectric motors.
基金supported by the National Natural Science Foundation of China(52175270,91848204)the Project of Scientific and Technological Development Plan of Jilin Province(20220508130RC).
文摘Accurate knowledge of the kinematics of the in vivo Ankle Joint Complex(AJC)is critical for understanding the biomechanical function of the foot and assessing postoperative rehabilitation of ankle disorders,as well as an essential guide to the design of ankle–foot assistant devices.However,detailed analysis of the continuous 3D motion of the tibiotalar and subtalar joints during normal walking throughout the stance phase is still considered to be lacking.In this study,dynamic radiographs of the hindfoot were acquired from eight subjects during normal walking.Natural motions with six Degrees of Freedom(DOF)and the coupled patterns of the two joints were analyzed.It was found that the movements of the two joints were mostly in opposite directions(including rotation and translation),mainly in the early and late stages.There were significant differences in the Range of Motion(ROM)in Dorsiflexion/Plantarflexion(D/P),Inversion/Eversion(In/Ev),and Anterior–Posterior(AP)and Medial–Lateral(ML)translation of the tibiotalar and subtalar joints(p<0.05).Plantarflexion of the tibiotalar joint was coupled with eversion and posterior translation of the subtalar joint during the impact phase(R^(2)=0.87 and 0.86,respectively),and plantarflexion of the tibiotalar joint was coupled with inversion and anterior translation of the subtalar joint during the push-off phase(R^(2)=0.93 and 0.75,respectively).This coordinated coupled motion of the two joints may be a manifestation of the AJC to move flexibly while bearing weight and still have stability.
基金supported by the National Natural Science Foundation of China(92266206,52227810)the Jilin Province Science and Technology Development Plan(YDZJ202101ZYTS129)the Fundamental Research Funds for the Central Universities(2022-JCXK-11)。
文摘The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between depth of overdischarge and mechanical properties is still a significant challenge.Studying the correlation between depth of overdischarge and mechanical properties is of great significance to improving the energy density and the ability to resist abuse of the batteries.In this paper,the mechanical properties of the battery materials during the whole process of overdischarge from discharge to complete failure were studied.The effects of depth of overdischarge on the elastic modulus and hardness of the cathode of the battery,the tensile strength and the thermal shrinkage rate of the separator,and the performance of binder were investigated.The precipitation of Cu dendrites on the separator and cathode after dissolution of anode copper foil is a key factor affecting the performance of battery materials.The Cu dendrites attached to the cathode penetrate the separator,causing irreversible damage to the coating and base film of the separator,which leads to a sharp decline in the tensile strength,thermal shrinkage rate and other properties of the separator.In addition,the Cu dendrites wrapping the cathode active particles reduce the adhesion of the active particles binder.Meanwhile,the active particles are damaged,resulting in a significant decrease in the elastic modulus and hardness of the cathode.
基金supported by the National Key Research and Development Program of China(No.2018YFC2001300)the National Natural Science Foundation of China(No.52005209,91948302,No.91848204,No.52021003)the Natural Science Foundation of Jilin Province(No.20210101053JC,No.20220508130RC).
文摘A variety of prosthetic ankles have been successfully developed to reproduce the locomotor ability for lower limb amputees in daily lives. However, they have not been shown to sufficiently improve the natural gait mechanics commonly observed in comparison to the able-bodied, perhaps due to over-simplified designs of functional musculoskeletal structures in prostheses. In this study, a flexible bionic ankle prosthesis with joints covered by soft material inclusions is developed on the basis of the human musculoskeletal system. First, the healthy side ankle–foot bones of a below-knee amputee were reconstructed by CT imaging. Three types of polyurethane rubber material configurations were then designed to mimic the soft tissues around the human ankle, providing stability and flexibility. Finite element simulations were conducted to determine the proper design of the rubber materials, evaluate the ankle stiffness under different external conditions, and calculate the rotation axes of the ankle during walking. The results showed that the bionic ankle had variable stiffness properties and could adapt to various road surfaces. It also had rotation axes similar to that of the human ankle, thus restoring the function of the talocrural and subtalar joints. The inclination and deviation angles of the talocrural axis, 86.2° and 75.1°, respectively, as well as the angles of the subtalar axis, 40.1° and 29.9°, were consistent with the literature. Finally, dynamic characteristics were investigated by gait measurements on the same subject, and the flexible bionic ankle prosthesis demonstrated natural gait mechanics during walking in terms of ankle angles and moments.
基金supported in part by the National Natural Science Foundation of China under Grant 52005209,Grant 91948302,Grant 52021003,Grant No 52105295in part by the Natural Science Foundation of Jilin Province under Grant 20210101053JCThis work also supported in part by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003).
文摘Morphing botanical tissues and animal muscles are all fiber-mediated composites, in which fibers play a passive and active role, respectively. Herein, inspired by the mechanism of fibers functioning in morphing botanical tissues and animal muscles, we propose two sorts of fiber-dominated composite actuators. First, inspired by the deformation of awned seeds in response to humidity change, we fabricate passive fiber-dominated actuators using non-active aligned carbon fibers via 4D printing method. The effects of process parameters, structural parameters, and fiber angles on the deformation of the printed actuators are examined. The experimental results show that the orientation degree is enhanced, resulting in a better swelling effect as the printing speed increases. Then, motivated by the actuation mechanism of skeletal muscle, we prepare active fiber-dominated actuators using active polyurethane fibers via 4D printing and pre-stretching method. The effect of fiber angle and loading on the actuation mode is experimentally analyzed. The experimental results show that the rotation angle of the actuator gradually decreases with the angle from 45° to 60°. When the fiber angle is 0° and 90°, the driver basically stops rotating while shrinking along the loading direction. Based on the above actuation mechanisms, identical contraction behaviors are realized both in passive and active fiber-dominated soft actuators. This work provides a validation method for biologically actuation mechanisms via 4D printing technique and smart materials and adds further insights to the design of bioinspired soft actuators.
基金This work was supported by funding from China Postdoctoral Science Foundation(No:2020M670863)Jilin Scientific and Technological Development Program(No:20230203089SF).
文摘The biomechanical effects of acetabular revision with jumbo cups are unclear.This study aimed to compare the biomechanical effects of bionic trabecular metal vs.titanium jumbo cups for the revision of acetabular bone defects.We designed and reconstructed American Academy of Orthopaedic Surgeons(AAOS)type I–III acetabular bone defect models using computed tomography scans of a man without acetabular bone defects.The implantation of titanium and trabecular metal jumbo cups was simulated.Stress distribution and relative micromotion between the cup and host bone were assessed using finite element analysis.Contact stress on the screws fixing the cups was also analyzed.The contact stress analysis showed that the peak contact stress between the titanium jumbo cup and the host bone was 21.7,20.1,and 23.8 MPa in the AAOS I–III models,respectively;the corresponding values for bionic tantalum jumbo cups decreased to 4.7,6.7,and 11.1 MPa.Analysis of the relative micromotion showed that the peak relative micromotion between the host bone and the titanium metal cup was 10.2,9.1,and 11.5μm in the AAOS I–III models,respectively;the corresponding values for bionic trabecular metal cups were 17.2,18.2,and 31.3μm.The peak contact stress on the screws was similar for the 2 cup types,and was concentrated on the screw rods.Hence,acetabular reconstruction with jumbo cups is biomechanically feasible.We recommend trabecular metal cups due to their superior stress distribution and higher relative micromotion,which is within the threshold for adequate bone ingrowth.
基金This research was supported in part by the National Key Research and Development Program of China under Grant 2018YFC2001300in part by the National Natural Science Foundation of China under Grant 91948302,Grant 91848204,and Grant 52021003the Project of Scientific and Technological Development Plan of Jilin Province under Grant 20220508130RC.
文摘In this article,a new optimization system that uses few features to recognize locomotion with high classification accuracy is proposed.The optimization system consists of three parts.First,the features of the mixed mechanical signal data are extracted from each analysis window of 200 ms after each foot contact event.Then,the Binary version of the hybrid Gray Wolf Optimization and Particle Swarm Optimization(BGWOPSO)algorithm is used to select features.And,the selected features are optimized and assigned different weights by the Biogeography-Based Optimization(BBO)algorithm.Finally,an improved K-Nearest Neighbor(KNN)classifier is employed for intention recognition.This classifier has the advantages of high accuracy,few parameters as well as low memory burden.Based on data from eight patients with transfemoral amputations,the optimization system is evaluated.The numerical results indicate that the proposed model can recognize nine daily locomotion modes(i.e.,low-,mid-,and fast-speed level-ground walking,ramp ascent/decent,stair ascent/descent,and sit/stand)by only seven features,with an accuracy of 96.66%±0.68%.As for real-time prediction on a powered knee prosthesis,the shortest prediction time is only 9.8 ms.These promising results reveal the potential of intention recognition based on the proposed system for high-level control of the prosthetic knee.
基金funded by the National Key Research and Development Program of China (No.2018YFA0703300)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No.52021003)+2 种基金National Natural Science Foundation of China (No.51835006、51875244、52105298、52105301 and U19A20103)China Postdoctoral Science Foundation (No.2021M701386,2022T150258)the Open Project of Key Laboratory for Cross-Scale Micro and Nano Manufacturing (Ministry of Education)of Changchun University of Science and Technology (No.CMNM-KF202106).
文摘Excessive vibration in civil and mechanical systems can lead to structural damage or harmful noise.Structural vibration can be mitigated by reducing the energy of the vibration source or by isolating the external disturbance from the target structure.Depending on the tunability and power consumption of the system,existing vibration control strategies are divided into active,passive and semi-active types,providing a more stable and efficient solution for vibration control.However,conventional damping structures have difficulty in meeting the requirements of wide frequency range and high precision damping under complex operating conditions.Therefore,the design of efficient damping structures is one of the key challenges in the development of vibration control technology.Organisms have evolved over millions of years to effectively damp vibrations through special structures and composite materials to ensure their survival.Opening up damping vibration isolation technology from a bionic perspective can meet the frequency requirements of vibration damping and guarantee higher output accuracy of machinery.This review summarizes the basic principles of vibration control and analyses the vibration control strategies for different damping materials and damping structures.Meanwhile,various models of bio-damped structures are outlined.Moreover,the current status and recent progress of research on bionic damped structures based on bio-vibration control strategies are discussed.Finally,new perspectives on future developments in the field of bionic damped vibration control techniques are also presented.A comprehensive understanding of existing vibration damping mechanisms and new methods of bionic damping design will certainly trigger important applications of precision vibration control in the fields of aerospace,rail transportation and mechanical systems.
基金supported by the National Natural Science Foundation of China(nos.52075216,91948302,and 91848204).
文摘In nature,organisms widely use the interaction of muscle contraction and biological pipelines to form an efficient fluid control mechanism.Herein,a pneumatically powered,Bioinspired Soft Switching valve(BSS valve)with short response time and low-energy consumption is described.The BSS valve is composed of flexible walls,a flexible tube and symmetrically arranged Snapping Membrane actuator(SM actuator).It functions based on tube deformation throttling caused by instability of SM actuator membrane.To realize rapid preparation of customized BSS valve,the modular manufacturing method suitable for different materials and structures based on 3D printing and mold forming was developed.Using the membrane flip rate as indicators,the displacement transient response characteristics of three structures actuators were studied,The results proved that spherical and spherical cap membrane SM actuator achieved rapid displacement response under the low critical pressure threshold.Furthermore,with critical buckling pressure and capacity utilization efficiency as indicators,we analyzed the characteristics of SM actuators with different radius and wall thickness to obtain reasonable structural parameters configuration of SM actuators.The influence of radius and thickness on SM actuator is revealed,and theoretical model formulas were formed.Two different configurations are presented.(1)Customized BSS valve structures can achieve sequential motion of flexible gripper.(2)BSS valve embedded in soft pump.The performance tests confirmed it has significant advantages in energy consumption,specific pressure,specific flow,high-frequency cycle load life,and valve can be integrated into the soft pump fluid system as a throttling unit,and provides an idea for fluid drive control integration.
基金The authors are grateful to the National Nature Science Foundation of China （Grant No. 50635030） and the development project on industrialization of bionic non-adhesive cooker （Grant No. 2006D90304010） for the support of this work.
基金Supported by National Key Research and Development Program of China(Grant No.2018YFA0703300)National Natural Science Foundation of China(Grant Nos.51835006,51875244,51675220,U19A20103)+9 种基金JLU Science and Technology Innovative Research Team(Grant No.2017TD-04)China Postdoctoral Science Foundation Funded Project(Grant No.2018T110246)Science and Technology Research Project of Education Department of Jilin Province(Grant Nos.20190141,JJKH20190135KJ)Joint Construction Project of Jilin University and Jilin Province(Grant No.SF2017-3-4)Scientific and Technological Development Program of Changchun City(Double Ten Project-19SS001)Science and Technology Development Program of Jilin Province(Technology R&D Project-20190302021GX)Graduate Innovation Fund of Jilin University(Grant No.2016020)Postdoctoral Innovative Talent Support Program(Grant No.BX20190139)Joint Fund of the Ministry of Education for Equipment Research(Grant No.6141A02022131)Fundamental Research Funds for the Central Universities.
文摘Solid particle erosion is a common phenomenon in engineering fields,such as manufacturing,energy,military and aviation.However,with the rising industrial requirements,the development of anti-solid particle erosion materials remains a great challenge.After billions of years of evolution,several natural materials exhibit unique and exceptional solid particle erosion resistance.These materials achieved the same excellent solid particle erosion resistance performance through diversified strategies.This resistance arises from their micro/nanoscale surface structure and interface material properties,which provide inspiration for novel multiple solutions to solid particle erosion.Here,this review first summarizes the recent significant process in the research of natural anti-solid particle erosion materials and their general design principles.According to these principles,several erosion-resistant structures are available.Combined with advanced micro/nanomanufacturing technologies,several artificial anti-solid particle erosion materials have been obtained.Then,the potential applications of anti-solid particle erosion materials are prospected.Finally,the remaining challenges and promising breakthroughs regarding anti-solid particle erosion materials are briefly discussed.
基金supported by the Project of National Key Research and Development Program of China(Nos.2018YFB1105100 and 2018YFC2001300)the National Natural Science Foundation of China(Nos.5167050531,51822504,91848204,91948302,and 52021003)+2 种基金the Key Scientific and Technological Project of Jilin Province(No.20180201051GX)the Program for JLU Science and Technology Innovative Research Team(No.2017TD-04)the Scientific Research Project of Education Department of Jilin Province(No.JJKH20211084KJ).
文摘Shape memory polymers(SMPs)are a promising class of materials for biomedical applications due to their favorable mechanical properties,fast response,and good biocompatibility.However,it is difficult to achieve controllable sequential shape change for most SMPs due to their high deformation temperature and the simplex deformation process.Herein,shape memory composites based on polylactic acid(PLA)matrix and semi-crystalline linear polymer polycaprolactone(PCL)are fabricated using 4D printing technology.Compared with pure PLA,with the rise of PCL content,the 4D-printed PLA/PCL composites show decreased glass transition temperature(Tg)from 67.2 to 55.2°C.Through the precise control of the deformation condition,controllable sequential deformation with an outstanding shape memory effect can be achieved for the PLA/PCL shape memory composites.The response time of shape recovery is less than 1.2 s,and the shape fixation/recov-ery rates are above 92%.In order to simulate sequential petal opening and sequential drug releasing effects,a double-layer bionic flower and a drug release device,respectively,are presented by assembling PLA/PCL samples with different PLA/PCL ratios.The results indicate the potential applications of 4D-printed PLA/PCL composites in the field of bio-inspired robotics and biomedical devices.
基金the National Natural Science Foundation of China(Nos.52075216,91948304,and 91848202).
文摘Mammals such as humans develop skeletal muscles composed of muscle fibers and connective tissue,which have mechanical properties that enable power output with three-dimensional motion when activated.Artificial muscle-like actuators developed to date,such as the McKibben artificial muscle,often focus sole contractile elements and have rarely addressed the contribution of flexible connective tissue that forms an integral part of the structure and morphology of biological muscle.Herein,we present a class of pneumatic muscle-like actuators,termed highly mimetic skeletal muscle(HimiSK)actuator,that consist of parallelly arranged contractile units in a flexible matrix inspired by ultrasonic measurements on skeletal muscle.The contractile units act as a muscle fiber to produce active shortening force,and the flexible matrix functions as connective tissue to generate passive deformation.The application of positive pressure to the contractile units can produce a linear contraction and force.In this actuator,we assign different flexible materials as contractile units and a flexible matrix,thus forming five mold actuators.These actuators feature three-dimensional motion on activation and present both intrinsic force-velocity and force-length characteristics that closely resebmle those of a biological muscle.High output and tetanic force produced by harder contractile units improve the maximum output force by up to about 41.3%and the tetanic force by up to about 168%.Moreover,high displacement and velocity can be generated by a softer flexible matrix,with the improvement of maximum displacement up to about 33.3%and velocity up to about 73%.The results demonstrate that contractile units play a crucial role in force generation,while the flexible matrix has a significant impact on force transmission and deformation;the final force,velocity,displacement,and three-dimensional motion results from the interplay of contractile units,fluid and flexible matrix.Our approach introduces a model of the presented HimiSK actuators to better understand the mechanical behaviors,force generation,and transmission in bioinspired soft actuators,and highlights the importance of using flexible connective tissue to form a structure and configuration similar to that of skeletal muscle,which has potential usefulness in the design of effective artificial muscle.
基金This workwas supported by the National Key Research and Development Program of China(No.2018YFA0703300)the Foundation for Innovative Research Groups oftheNational Natural Science Foundation of China(No.52021003)+3 种基金Jilin University Science and Technology Innovative Research Team(No.2020TD-03)the Natural Science Foundation of Jilin Province(No.20200201232JC)Interdisciplinary Integration and Innovation Project of JLU(No.JLUXKJC2021ZZ03)"Fundamental Research Funds for the Central Universities".
文摘Developing high-performance composite materials is of great significance as a strong support for high-end manufacturing.However,the design and optimization of composite materials lack a theoretical basis and guidance scheme.Compared with traditional composite materials,natural materials are composed of relatively limited components but exhibit better mechanical properties through ingenious and reasonable synthetic strategies.Based on this,learning from nature is considered to be an effective way to break through the bottleneck of composite design and preparation.In this review,the recent progress of natural composites with excellent properties is presented.Multiple factors,including structures,components and interfaces,are first summarized to reveal the strategies of natural materials to achieve outstanding mechanical properties.In addition,the manufacturing technologies and engineering applications of bioinspired composite materials are introduced.Finally,some scientific challenges and outlooks are also proposed to promote next-generation bioinspired composite materials.
基金supported by the National Key Research and Development Program of China(No.2018YFA0703300)the National Natural Science Foundation of China(Nos.51835006,51675220 and 51875244)+5 种基金the Pre-research Joint Foundation of Equipment Development Department and Ministry of Education(No.6141A02022131)the JLU Science and Technology Innovative Research Team(No.2017TD-04)the Joint Construction Project of Jilin University and Jilin Province(No.SF2017-3-4)the Natural Science Foundation of Jilin Province of China(No.20170101115JC)the Science and technology research project of education department of Jilin province(No.20190141)the Opening Project of the Key Laboratory of Bionic Enginccring(Ministry of Education),Jilin University(No.KF20200002).
文摘Solid particle erosion on the material surfaces is a very common phenomenon in the industrial field,which greatly affects the efficiency,service life,and even poses a great threat to life safety.However,current research on erosion resistance is not only inefficient,but also limited to the improvement of hardness and toughness of materials.Inspired by typical scorpion(Parabuthus transvaalicus),biomimetic functional samples with exquisite anti-rosion structures were manufactured.Macroscopic morphology and structure of the biological prototype were analyzed and measured.According to above analysis,combined with response surface methodology,a set of biomimetic samples with different structural parameters were fabricated by using 3D printing technology.The anti-crosion performance of these biomimetic samples was investigated using a blasting jet machine.Based on the results of blasting jet test,as well as regression analysis and fiting,the optimal structural parameters were obtained.In addition to the static test conditions,the optimal biomimetic sample was also eroded in rotating condition and showed excellent erosion resistance property.The presence of bump and groove structures,on the one hand,reduced the croded area of biominetic sample surface.On the other hand,they made the airlow turbulent and consequently reduced the impact cnergy of solid particles,which significantly improved the erosion resistance of biomimetic materials.This study provides a new strategy to improvethe service life of components easily affected by erosion in the aviation,energy and military fields.
基金supported by the project of National Key R&D Program of China(No.2018YFC2001300)the project of National Natural Science Foundation of China(Nos.91948302 and 91848204)+2 种基金the projects of UK Engineering Physical Science Research Council(EP/KO19759/1 and EP/I033602/1)the projects of National Natural Science Foundation of China(Nos.52005209 and 51675222)the Chinese Postdoctoral International Exchange Program.
文摘The objective of this study is to develop a bio robot with a high degree of biomechanical fidelity to the human musculoskeletal system in order to investigate the biomechanical principles underlying human walking.The robot was designed to possess identical biomechanical characteristics to the human body in terms of body segment properties,joint configurations and 3D musculoskeletal geometries.These design parameters were acquired based on the medical images,3D musculoskeletal model and gait measurements of a healthy human subject.To satistyall the design criteria sinultaneously,metal 3D printing was used to construct the whole-body humanoid robot.Flexible artificial muscles were fabricated in accordance with the predefined 3D musculoskeletal geometries.A series of physical tests were con-ducted to demonstrate the capacity of the robot platform.The fabricated robot shows equivalent mechanical characteristics to the human body as originally designed.The results of the physical tests by systematically changing environmental conditions and body structures have successfully demonstrated the capability of the robot platform to investigate the structure-function interplay in the human musculoskeletal system and also its interaction with the environment during walking.This robot might provide a valuable and powerful physical platfornm towards studying hunan musculoskeletal biomechanics by generating new hypotheses and revealing new insights into human locomotion science.
基金supported by National Natural Science Foundation of China(51975245 and 52075214)Jilin Provincial Science&Technology Department(20190303039SF)Key Scientific&Technological Research&Development Projects in Jilin Province(2020C023-3).
文摘The potential of clectromagnetic ficlds(EMFs)for discase treatment and health enhancement has been actively pursued over the recent decades.This review first provides a general introduction about natural EMFs and related biological effcts.Then the recent progress on the EMF treatment of some common diseases(such as cancer,diabetes,wound healing and neurological diseases,etc.)has been carefully reviewed and summarized.Yet,the blindness on the selection of therapeutic EMF parameters still hinders the broad application ofEMF therapy.Moreover,the unclear mechanism of EMF function and poor reproducibility of experimental rcsults also remain big challenges in the field of bioclectromagnetics.Bionics is a useful methodology that gains inspiration from nature to serve human life and industry.We have discussed the feasibility of applying bionic approach on the selection of the rapeutic EMFs,which is based on thefindings of natural EMFs.Finally,we advocate that the detailed information of EMFs and biological samples should be thoroughly reorded in future research and reported in publications.In addition,the publication of studies with negative results should also be allowed.
