查看更多>>摘要：The wheel-legged biped robot is a typical ground-based mobile robot that can combine the high velocity and high efficiency pertaining to wheeled motion and the strong,obstacle-crossing performance associated with legged motion.These robots have gradually exhibited satisfactory application potential in various harsh scenarios such as rubble rescue,military opera-tions,and wilderness exploration.Wheel-legged biped robots are divided into four categories according to the open-close chain structure forms and operation task modes,and the latest technology research status is summarized in this paper.The hardware control system,control method,and application are analyzed,and the dynamic balance control for the two-wheel,biomimetic jumping control for the legs and whole-body control for integrating the wheels and legs are analyzed.In sum-mary,it is observed that the current research exhibits problems,such as the insufficient application of novel materials and a rigid-flexible coupling design;the limited application of the advanced,intelligent control methods;the inadequate under-standing of the bionic jumping mechanisms in robot legs;and the insufficient coordination ability of the multi-modal motion,which do not exhibit practical application for the wheel-legged biped robots.Finally,this study discusses the key research directions and development trends for the wheel-legged biped robots.
查看更多>>摘要：Biological water striders have advantages such as flexible movement,low disturbance to the water surface,and low noise.Researchers have developed a large number of biomimetic water strider robots based on their movement mechanism,which have broad application prospects in water quality testing,water surface reconnaissance,and search.This article mainly reviews the research progress of biomimetic water strider robots.First,the biological and kinematic characteristics of water striders are outlined,and some mechanical parameters of biological water striders are summarized.The basic equations of water strider movement are then described.Next,an overview is given of the past and current work on skating and jumping movements of biomimetic water strider robots based on surface tension and water pressure dominance.Based on the current research status of biomimetic water strider robots,the shortcomings of current research on biomimetic water striders are summarized,and the future development of biomimetic water strider robots is discussed.This article provides new insights for the design of biomimetic water strider robots.
查看更多>>摘要：Cartilage regeneration and repair are considered clinical challenges since cartilage has limited capability for reconstruc-tion.Although tissue-engineered materials have the ability to repair cartilage,they have weak mechanical characteristics and cannot resist long-term overload.On the other hand,surgery to replace the joint is frequently done to treat significant cartilage deterioration these days.However,the materials that are being used for replacement have high friction coefficients,lack shock absorption functions,and lack cushioning.Further research on natural articular cartilage structure and function may lead to bionic hydrogels,which have suitable physicochemical and biological characteristics(e.g.,tribological and mechanical properties and the ability to support loadbearing capability),but need improvements.Based on their tribologi-cal and mechanical characteristics,the current review highlights the most recent advancements of bionic hydrogels used for articular cartilage,highlighting both the field's recent progress and its potential for future research.For this reason,firstly,some important property improvement methods of bionic hydrogels are discussed and then,the recent findings of various research on the making of those bionic materials are provided and compared.It seems that by using some modifications such as product design,surface treatments,animal tests,controlling the isoelectric point of hydrogels,and computer simulation,the intended mechanical and tribological characteristics of natural articular cartilage may be attained by the bionic hydrogels.
查看更多>>摘要：Tissue engineering is nowadays an emerging approach that aims to replace or regenerate diseased or damaged organs with engineered constructs.Considering the key role of growth factors(GFs)in the tissue regeneration process,these biomolecules are considered an important part of the tissue engineering process,so the presence of growth factors in engineered scaffolds can accelerate tissue regeneration by influencing the behavior of cells.Platelet-rich plasma(PRP),as an autologous source of a variety of growth factors,is considered a therapeutic agent for the treatment of degenerative diseases.Regarding its ability to promote the healing process and tissue regeneration,PRP therapy has attracted great attention in bone and cartilage tissue engineering.Incorporating PRP and its derivatives into engineered scaffolds not only bioactivates the scaffold,but the scaffold matrix also acts as a sustained and localized growth factor release system.In addition,the presence of a scaffold can promote the bioactivity of GFs by providing an environment that facilitates their interaction,leading to enhanced effects compared to their free form.This review presents a brief overview of PRP's role in bone and cartilage tissue regeneration with the main focus on scaffold-mediated PRP delivery.In addition,the classification of platelet-rich products,current extraction techniques,terminology,and scaffold bioactivation methods are presented to provide a better understanding of the basics and the key aspects that may affect the effectiveness of therapy in bone and cartilage tissue engineering.
查看更多>>摘要：Soft robotic crawlers have limited payload capacity and crawling speed.This study proposes a high-performance inchworm-like modular robotic crawler based on fluidic prestressed composite(FPC)actuators.The FPC actuator is precurved and a pneumatic source is used to flatten it,requiring no energy cost to maintain the equilibrium curved shape.Pressurizing and depressurizing the actuators generate alternating stretching and bending motions of the actuators,achieving the crawling motion of the robotic crawler.Multi-modal locomotion(crawling,turning,and pipe climbing)is achieved by modular recon-figuration and gait design.An analytical kinematic model is proposed to characterize the quasi-static curvature and step size of a single-module crawler.Multiple configurations of robotic crawlers are fabricated to demonstrate the crawling ability of the proposed design.A set of systematic experiments are set up and conducted to understand how crawler responses vary as a function of FPC prestrains,input pressures,and actuation frequencies.As per the experiments,the maximum carrying load ratio(carrying load divided by robot weight)is found to be 22.32,and the highest crawling velocity is 3.02 body length(BL)per second(392 mm/s).Multi-modal capabilities are demonstrated by reconfiguring three soft crawlers,including a matrix crawler robot crawling in amphibious environments,and an inching crawler turning at an angular velocity of 2°/s,as well as earthworm-like crawling robots climbing a 20° inclination slope and pipe.
查看更多>>摘要：Geckos can efficiently navigate complex terrains due to their multi-level adhesive system that is present on their toes.The setae are responsible for the gecko's extraordinary adhesion and have garnered wide attention from the scientific community.The majority of the reported works in the literature that have dealt with the peeling models mainly focus on the gecko hierar-chical adhesive system,with limited attention given to investigating the influence of gecko toe structure on the detachment.Along these lines,to gain a deeper understanding of the rapid and effortless detachment abilities of gecko toes,the peeling behavior of gecko toes on vertical surfaces was primarily investigated in this work.More specifically,the detachment time of a single toe on a smooth acrylic plate was measured to be 0.41±0.21 s.Moreover,it was observed that the toe assumed a"U"-shaped structure upon complete detachment.Additionally,Finite Element Analysis(FEA)models for three different types of gecko toes were developed to simulate both the displacement-peel and the moment-peel modes.Increasing the segmenta-tion of the adhesive layer led to a gradual decrease in the resultant force,as well as the normal and tangential components.Lastly,a gecko-inspired toe model was constructed and powered by Shape Memory Alloy(SMA).A systematic comparison between the vertical drag separation and the outward flip separation was also conducted.From our analysis,it was clearly demonstrated that outward peel separation significantly necessitated the reduction of the peeling force,thus confirming the advantageous nature of the outward motion in gecko toe detachment.Our data not only contribute to a deeper understand-ing of the gecko detachment behavior but also offer valuable insights for the advancement of the wall-climbing robot feet.
查看更多>>摘要：Bionic manta underwater vehicles will play an essential role in future oceans and can perform tasks,such as long-duration reconnaissance and exploration,due to their efficient propulsion.The manta wings'deformation is evident during the swim-ming process.To improve the propulsion performance of the unmanned submersible,the study of the deformation into the bionic pectoral fin is necessary.In this research,we designed and fabricated a flexible bionic pectoral fin,which is based on the Fin Ray® effect with active and passive deformation(APD)capability.The APD fin was actively controlled by two servo motors and could be passively deformed to variable degrees.The APD fin was moved at 0.5 Hz beat frequency,and the propulsive performance was experimentally verified of the bionic pectoral fins equipped with different extents of defor-mation.These results showed that the pectoral fin with active-passive deformed capabilities could achieve similar natural biological deformation in the wingspan direction.The average thrust(T)under the optimal wingspan deformation is 61.5％higher than the traditional passive deformed pectoral fins.The obtained results shed light on the design and optimization of the bionic pectoral fins to improve the propulsive performance of unmanned underwater vehicles(UUV).
查看更多>>摘要：Lizards use the synergy between their feet and tail to climb on slopes and vertical terrains.They use their soft adhesive feet with millions of small hairs to increase their contact area with the terrain surface and press their tails against the terrain to actively maintain stability during climbing.Inspired by this,we propose a bio-inspired climbing robot based on a new approach wherein the synergy between soft feet and an active tail with a soft adhesive tip allows the robot to climb stably on even and uneven terrains at different slope angles.We evaluate and compare the climbing performance of the robot on three different terrains(hard,soft,and fluffy)at different slope angles.Various robot configurations are employed,including those with standard hard feet and soft feet in combination with an active tail—with and without a soft tip.The experimental results show that the robot having soft feet and a tail with the soft tip achieves the best climbing performance on all ter-rains,with maximum climbing slopes of 40°,45°,and 50° on fluffy,soft,and hard terrains,respectively.Its payload capacity depends on the type of terrain and the inclination angle.Moreover,our robot performs multi-terrain transitions(climbing from horizontal to sloped terrains)on three different terrains of a slope.This approach can allow a climbing robot to walk and climb on different terrains,extending the operational range of the robot to areas with complex terrains and slopes,e.g.,in inspection,exploration,and construction.
查看更多>>摘要：The robotic airship is one of the most unique and promising green aircraft,however,as a"lighter-than-air aircraft"and"thermal aircraft",its long-endurance flight has great difficulties in decreasing drag and controlling buoyancy and pressure under thermal effects.In this work,we reported a robotic airship inspired by the Physalia physalis,imitating its morphol-ogy,physiological structure,and biological behaviors.The hull is designed by imitating the morphology of the Physalia physalis,and the gasbags including a helium balloon,two ballonets,and a thermoregulation gasbag are designed by imitat-ing the physiological structure and biological behaviors of the pneumatophore,bladder,and gland of the Physalia physalis,respectively.Experimental results show that the bionic airship has an increase of about 40％in lift-to-drag and decreases the pressure in helium balloon by 47.5％under thermal effects,and has better aerodynamic performances and thermoregulation performances than conventional airships.
查看更多>>摘要：Inspired by the way sea turtles rely on the Earth's magnetic field for navigation and locomotion,a novel magnetic soft robotic turtle with programmable magnetization has been developed and investigated to achieve biomimetic locomotion patterns such as straight-line swimming and turning swimming.The soft robotic turtle(12.50 mm in length and 0.24 g in weight)is integrated with an Ecoflex-based torso and four magnetically programmed acrylic elastomer VHB-based limbs containing samarium-iron-nitrogen particles,and was able to carry a load more than twice its own weight.Similar to the limb locomo-tion characteristics of sea turtles,the magnetic torque causes the four limbs to mimic sinusoidal bending deformation under the influence of an external magnetic field,so that the turtle swims continuously forward.Significantly,when the bending deformation magnitudes of its left and right limbs differ,the soft robotic turtle switches from straight-line to turning swim-ming at 6.334 rad/s.Furthermore,the tracking swimming activities of the soft robotic turtle along specific planned paths,such as square-shaped,S-shaped,and double U-shaped maze,is anticipated to be utilized for special detection and targeted drug delivery,among other applications owing to its superior remote directional control ability.
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