The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the...The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the application of structural bionic approaches. Giant waterlily leaf ribs and cactus stem are investigated for their optimal framework and superior performance. Their structural characteristics are extracted and used in the bio-inspired design of Lin MC6000 gantry machining center crossbeam. By mimicking analogous network structure, the bionic model is established, which has better load-carrying capacity than conventional distribution. Finite Element Method （FEM） is used for numerical simulation. Results show better specific stiffness of the bionic model, which is increased by 17.36%. Finally the scaled models are fabricated by precision casting for static and dynamic tests. The physical experiments are compared to numerical simulation. The results show that the maximum static deformation of the bionic model is reduced by about 16.22%, with 3.31% weight reduction. In addition, the first four natural frequencies are improved obviously. The structural bionic design is a valuable reference for updating conventional mechanical structures with better performance and less material consumption.展开更多
A concept of Specific Structure Efficiency (SSE) was proposed that can be used in the lightweight effect evaluation ofstructures.The main procedures of bionic structure design were introduced systematically.The parame...A concept of Specific Structure Efficiency (SSE) was proposed that can be used in the lightweight effect evaluation ofstructures.The main procedures of bionic structure design were introduced systematically.The parameter relationship betweenhollow stem of plant and the minimum weight was deduced in detail.In order to improve SSE of pylons, the structural characteristicsof hollow stem were investigated and extracted.Bionic pylon was designed based on analogous biological structuralcharacteristics.Using finite element method based simulation, the displacements and stresses in the bionic pylon were comparedwith those of the conventional pylon.Results show that the SSE of bionic pylon is improved obviously.Static, dynamic andelectromagnetism tests were carried out on conventional and bionic pylons.The weight, stress, displacement and Radar CrossSection (RCS) of both pylons were measured.Experimental results illustrate that the SSE of bionic pylon is markedly improvedthat specific strength efficiency and specific stiffness efficiency of bionic pylon are increased by 52.9% and 43.6% respectively.The RCS of bionic pylon is reduced significantly.展开更多
Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are kn...Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.展开更多
In recent years,various highly pathogenic viruses have spread worldwide,posing serious threats to human life and property,thus creating an urgent demand for antibacterial structural materials.In this study,we develope...In recent years,various highly pathogenic viruses have spread worldwide,posing serious threats to human life and property,thus creating an urgent demand for antibacterial structural materials.In this study,we developed two types of antibacterial medium-entropy alloys (MEAs):as-cast (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(88-x)Cu_(12)Ag_(x)(x=2,4 at%)(which do not require antibacterial aging heat treatment) and heat-treated (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(99.5-x)Cu_(x)Ag_(0.5)(x=2,4 at%)(abbreviated as CuxAg0.5 and Cu12Agx).Both MEA s exhibit in transformation-induced plasticity (TRIP) and twinning-induced plasticity effects,demonstrating outstanding mechanical properties.Compared to 304 stainless steels,these ME As exhibit superior corrosion resistance,with the Cu2Ag0.5alloy performing the best,exhibiting a corrosion current density of 1.022 A·cm^(-2)and a corrosion potential of-0.297 VSCE.The antibacterial rate of the MEAs reached99.9%after 24 h of interaction with Escherichia coli and Staphylococcus aureus,with Cu 12Ag2 achieving 99.9%antimicrobial activity within 6 h,indicating a shorter activation time for antibacterial activity.According to firstprinciples calculations of state density,work function,and surface energy,Cu12Ag2 demonstrated the highest ion release capability,with a work function of 3.7 eV and surface energy of 1.9 J·m^(-2).The electrostatic adsorption of the Xanthium sibiricum bionic structure,characterized by a nanoscale spherical phase within the antibacterial phase with a size less than 350 nm,promotes ion penetration into bacterial cells,enhancing the synergistic effects of ionic,electronic,and catalytic antibacterial mechanisms.This study provides a new approach for designing high-performance alloys that integrate functional and structural properties,offering broad-spectrum,efficient antibacterial applications under load-bearing conditions.展开更多
In this study,femtosecond pulsed laser processing was applied to the magnesium alloy,followed by in situ growth of Mg-Al layered double hydroxides(LDHs),and finally modification with low surface energy materials to pr...In this study,femtosecond pulsed laser processing was applied to the magnesium alloy,followed by in situ growth of Mg-Al layered double hydroxides(LDHs),and finally modification with low surface energy materials to prepare a biomimetic of centipede-like superhydrophobic composite coating.The resulting biomimetic coating features a dual-scale structure,comprising a micron-scale laser-etched array and nano-scale LDH sheets,which together create a complex hierarchical architecture.The multistage bionic superhydrophobic coating exhibits exceptional corrosion resistance,with a reduction in corrosion current density by approximately five orders of magnitude compared to the bare magnesium alloy substrate.This remarkable corrosion resistance is attributed to the synergistic effects of the superhydrophobicity with a contact angle(CA)of 154.60°,the densification of the surface LDH nanosheets,and the NO_(3)^(-) exchange capacity.Additionally,compared to untreated AZ91D alloy,the biomimetic coating prolongs ice formation time by 250% at-40℃ and withstands multiple cycles of sandpaper abrasion and repeated tape peeling tests.Furthermore,it demonstrates excellent self-cleaning and anti-fouling properties,as confirmed by dye immersion and dust contamination tests.The construction of the multi-level bionic structured coating not only holds significant practical potential for metal protection but also provides valuable insights into the application of formed LDH materials in functional bionic coating engineering.展开更多
Centrifugal pumps are extensively employed in ocean engineering,such as ship power systems,water transportation,and mineral exploitation.Pressure fluctuation suppression is essential for the operation stability and se...Centrifugal pumps are extensively employed in ocean engineering,such as ship power systems,water transportation,and mineral exploitation.Pressure fluctuation suppression is essential for the operation stability and service life of the centrifugal pump.In this paper,a new method of bionic structure is proposed for the blade surface of a centrifugal pump,which is inspired by the fish scale and comprises a leading edge,a trailing edge,and two symmetrical side edges.This fish scale structure is applied to the blade pressure and suction surfaces,and an impeller with a fish scale structure is constructed.A test rig for a centrifugal pump is developed to determine the pressure fluctuation in the pump with a prototype impeller and fish scale structure impeller.Results reveal that the dominant frequency of pressure fluctuation in volute is the blade passing frequency(f_(bpf))of 193.33 Hz,which is triggered by the interaction between the tongue and the impeller.The bionic structure of the fish scale effectively suppresses the pressure fluctuation amplitude at f_(bpf).From flow rates of 0.6 Q_(d)to 1.2 Q_(d),the average suppressions in pressure fluctuation amplitudes at f_(bpf)are 20.98%,5.85%,19.20%,and 25.77%.展开更多
Inspired by natural biomimetic structures exemplified by femoral bones,the shell-infill composite design has emerged as a research focus in structural optimization.However,existing studies predominantly focus on unifo...Inspired by natural biomimetic structures exemplified by femoral bones,the shell-infill composite design has emerged as a research focus in structural optimization.However,existing studies predominantly focus on uniform-thickness shell designs and lack robust methodologies for generating high-resolution porous infill configurations.To address these challenges,a novel topology optimization framework for full-scale shell-filled composite structures is developed in this paper.First,a physics-driven,non-uniform partial differential equation(PDE)filter is developed,enabling precise control of variable-thickness shells by establishing explicit mapping relationships between shell thickness and filter radii.Second,this study addresses the convergence inefficiency of traditional full-scale topology optimization methods based on local volume constraints.It is revealed that a reduced influence radius exacerbates algorithm convergence challenges,thereby impeding the design of intricate porous structures.To overcome this bottleneck,a physics-driven stress skeleton generation method is developed.By integrating stress trajectories and rasterization processing,this method constructs an initial density field,effectively guiding material evolution and significantly enhancing convergence in porous structural optimization within the full-scale framework.Classical numerical examples demonstrate that our proposed optimization framework achieves biomimetic non-uniform shell thickness optimization and enables precise control of the shell thickness.Additionally,density preprocessing effectively eliminates intermediate density regions and void aggregation.Moreover,the generated trabecular-like infill patterns with spatially graded porosity,akin to multiscale topology optimization(MTO),provide an innovative solution for multifunctional,lightweight,complex shell-infill composite structures in aerospace and biomedical applications.展开更多
To overcome the limitations of traditional exoskeletons in complex outdoor terrains,this study introduces a novel lower limb exoskeleton inspired by the snow leopard’s forelimb musculoskeletal structure.It features a...To overcome the limitations of traditional exoskeletons in complex outdoor terrains,this study introduces a novel lower limb exoskeleton inspired by the snow leopard’s forelimb musculoskeletal structure.It features a non-fully anthropomorphic design,attaching only at the thigh and ankle with a backward-knee configuration to mimic natural human knee movement.The design incorporates a single elastic element at the hip for gravity compensation and dual elastic elements at the knee for terrain adaptability,which adjust based on walking context.The design’s effectiveness was assessed by measuring metabolic cost reduction and motor output torque under various walking conditions.Results showed significant metabolic cost savings of 5.8–8.8%across different speeds and a 7.9%reduction during 9°incline walking on a flat indoor surface.Additionally,the spring element decreased hip motor output torque by 7–15.9%and knee torque by 8.1–14.2%.Outdoor tests confirmed the design’s robustness and effectiveness in reducing motor torque across terrains,highlighting its potential to advance multi-terrain adaptive exoskeleton research.展开更多
Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet s...Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet static supporting stability and dynamic terrain adaptability through the utilization of the Rigid-Elastic Hybrid(REH)dynamics model.First,a bionic foot model,named the Hinge Tension Elastic Complex(HTEC)model,was developed by extracting key features from human feet.Furthermore,the kinematics and REH dynamics of the HTEC model were established.Based on the foot dynamics,a nonlinear optimization method for stiffness matching(NOSM)was designed.Finally,the HTEC-based foot was constructed and applied onto BHR-B2 humanoid robot.The foot static stability is achieved.The enhanced adaptability is observed as the robot traverses square steel,lawn,and cobblestone terrains.Through proposed design method and structure,the mobility of the humanoid robot is improved.展开更多
Structural bionic design lacks mature and scientific theories, and the excellent structural characteristics of natural organisms sometimes cannot be transferred into engineering structures effectively. Aiming at overc...Structural bionic design lacks mature and scientific theories, and the excellent structural characteristics of natural organisms sometimes cannot be transferred into engineering structures effectively. Aiming at overcoming the existing problems, this paper summarizes three related theories: similarity theory, fuzzy evaluation theory and optimization theory. Based on the related theories, a method of structural bionic design is introduced, which includes four steps: selecting the most useful structural characteristic of natural organism; analyzing the structural characteristic finally chosen for engineering problem; completing the structural bionic design for engineering structure; and verifying the structural bionic design. Similarity theory and fuzzy evaluation theory are employed to achieve Step 1. In Step 2 and Step 3, optimization theory is employed to analyze the parameters of structures. Together with the thoughts of simplification and grouping, optimization theory can reveal the relationship between organism structure and engineering structure, providing a way to structural bionic design. A general evaluation criterion is proposed in Step 4, which is feasible to evaluate the performance of different structures. Finally, based on the method, a structural bionic design of thin-walled cylindrical shell is introduced.展开更多
Over millions of years of natural evolution,organisms have developed nearly perfect structures and functions.The self-fabrication of organisms serves as a valuable source of inspiration for designing the next-generati...Over millions of years of natural evolution,organisms have developed nearly perfect structures and functions.The self-fabrication of organisms serves as a valuable source of inspiration for designing the next-generation of structural materials,and is driving the future paradigm shift of modern materials science and engineering.However,the complex structures and multifunctional integrated optimization of organisms far exceed the capability of artificial design and fabrication technology,and new manufacturing methods are urgently needed to achieve efficient reproduction of biological functions.As one of the most valuable advanced manufacturing technologies of the 21st century,laser processing technology provides an efficient solution to the critical challenges of bionic manufacturing.This review outlines the processing principles,manufacturing strategies,potential applications,challenges,and future development outlook of laser processing in bionic manufacturing domains.Three primary manufacturing strategies for laser-based bionic manufacturing are elucidated:subtractive manufacturing,equivalent manufacturing,and additive manufacturing.The progress and trends in bionic subtractive manufacturing applied to micro/nano structural surfaces,bionic equivalent manufacturing for surface strengthening,and bionic additive manufacturing aiming to achieve bionic spatial structures,are reported.Finally,the key problems faced by laser-based bionic manufacturing,its limitations,and the development trends of its existing technologies are discussed.展开更多
Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g....Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g.aerospace,automobiles,electronics,etc.Cuttlebone produced in the cuttlefish has evolved vertical walls with the optimal corrugation gradient,enabling stress homogenization,significant load bearing,and damage tolerance to protect the organism from high external pressures in the deep sea.This work illustrated that the complex hybrid wave shape in cuttlebone walls,becoming more tortuous from bottom to top,creates a lightweight,load-bearing structure with progressive failure.By mimicking the cuttlebone,a novel bionic hybrid structure(BHS)was proposed,and as a comparison,a regular corrugated structure and a straight wall structure were designed.Three types of designed structures have been successfully manufactured by laser powder bed fusion(LPBF)with NiTi powder.The LPBF-processed BHS exhibited a total porosity of 0.042% and a good dimensional accuracy with a peak deviation of 17.4μm.Microstructural analysis indicated that the LPBF-processed BHS had a strong(001)crystallographic orientation and an average size of 9.85μm.Mechanical analysis revealed the LPBF-processed BHS could withstand over 25000 times its weight without significant deformation and had the highest specific EA value(5.32 J·g^(−1))due to the absence of stress concentration and progressive wall failure during compression.Cyclic compression testing showed that LPBF-processed BHS possessed superior viscoelastic and elasticity energy dissipation capacity.Importantly,the uniform reversible phase transition from martensite to austenite in the walls enables the structure to largely recover its pre-deformation shape when heated(over 99% recovery rate).These design strategies can serve as valuable references for the development of intelligent components that possess high mechanical efficiency and shape memory capabilities.展开更多
With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of trusses.This paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on diffe...With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of trusses.This paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on different heights of trusses.Inspired by the attachment and grasping abilities of Dynastes Hercules,we utilize its foot microstructures,such as microhooks and setae,to achieve efficient contact and firm grip with the surface.The morphology and arrangement of these structures can inspire the design of robot feet to improve their grasping and stability performance.We study the biological structure of Dynastes Hercules,design and optimize the bio-inspired structure,analyze the influence of various factors from theoretical and experimental perspectives,and verify the feasibility of the scheme through simulation.We propose an ideal climbing strategy that provides useful reference for robot applications in practice.Moreover,the influence laws of various factors in this paper can be applied to robot foot design to improve their operation ability and stability performance in the space environment.This bio-inspired mechanism can improve robot working range and efficiency,which is critical for on-orbit assemblyin space.展开更多
The ability of organisms to adjust to environmental changes offers valuable insights into the development and creation of innovative smart systems. As requirements increase, the ability of smart materials to change th...The ability of organisms to adjust to environmental changes offers valuable insights into the development and creation of innovative smart systems. As requirements increase, the ability of smart materials to change their shapes has become a broader aim beyond their original capabilities. In contrast to conventional manufacturing methods, additive manufacturing (AM) skillfully combines precise three-dimensional structures and the intricate response mechanisms of biological organisms with smart materials. This combination enables the production of smart bionic structures with programmable shapes and features. Trends such as dynamic modulation, responsive- ness to multiple stimuli, and the integration of functions are emerging as significant in the development of smart bionic structures. This review first presents smart structures that nature has designed and built in various organ- isms, highlighting the relationship between the structural characteristics and patterns of deformation. The review then discusses how smart bionic structures developed using AM techniques respond to different stimuli. Addi- tionally, the potential uses of smart bionic structures in biomedicine, intelligent robotics, origami construction, and aerospace are discussed. Finally, the challenges and future prospects for smart bionic structures are exam- ined with the goal of offering innovative solutions for creating the next generation of smart systems through interdisciplinary research.展开更多
A novel three-dimensional-fiber reinforced soft pneumatic actuator(3D-FRSPA)inspired by crab claw and human hand structure that can bend and deform independently in each segment is proposed.It has an omni-directional ...A novel three-dimensional-fiber reinforced soft pneumatic actuator(3D-FRSPA)inspired by crab claw and human hand structure that can bend and deform independently in each segment is proposed.It has an omni-directional bending configuration,and the fibers twined symmetrically on both sides to improve the bending performance of FRSPA.In this paper,the static and kinematic analysis of 3D-FRSPA are carried out in detail.The effects of fiber,pneumatic chamber and segment length,and circular air chamber radius of 3D-FRSPA on the mechanical performance of the actuator are discussed,respectively.The soft mobile robot composed of 3D-FRSPA has the ability to crawl.Finally,the crawling processes of the soft mobile robot on different road conditions are studied,respectively,and the motion mechanism of the mobile actuator is shown.The numerical results show that the soft mobile robots have a good comprehensive performance,which verifies the correctness of the proposedmodel.This work shows that the proposed structures have great potential in complex road conditions,unknown space detection and other operations.展开更多
Vibration reduction has always been one of hot and important topics in mechanical engineering,especially for the special measurement instrument.In this paper,a novel limb-inspired bionic structure is proposed to gener...Vibration reduction has always been one of hot and important topics in mechanical engineering,especially for the special measurement instrument.In this paper,a novel limb-inspired bionic structure is proposed to generate negative stiffness and design a new quasi-zero stiffness isolator via torsion springs,distinguishing from the existing tension spring structures in the literature.The nonlinear mathematical model of the proposed structure is developed and the corresponding dynamic properties are further investigated by using the Harmonic Balance method and ADAMS verification.To evaluate the vibration isolation performance,typical three-springs quasi-zero stiffness(TS QZS)system is selected to compare with the proposed bionic structure.And the graphical processing unit(GPU)parallel technology is applied to perform necessary two-parameter analyses,providing more insights into the effects of parameters on the transmissibility.It is shown that the proposed structure can show advantages over the typical TS QZS system in a wider vibration isolation range for harmonic excitation case and shorter decay time for the impact excitation case.展开更多
Each specific structure of organisms is the best choice under specific circumstances.The excellent characteristic structures of these organisms have great application potential in the design and multi-functional optim...Each specific structure of organisms is the best choice under specific circumstances.The excellent characteristic structures of these organisms have great application potential in the design and multi-functional optimization of energy-absorbing structures such as vehicle collisions,satellite landings,and military equipment.In this paper,using the principle of structural bionics,using the advantages of the honeycomb structure and the light weight and high strength of beetle elytra,four bionic lattice structures are studied:CH,ZPRH,SCH and IBE.Using NiTi shape memory alloy,a unique material as the base material,samples are prepared using selective laser melting(SLM)technology.By comparing the test results of the quasi-static compression test with the results of the numerical simulation,it is found that compared with the other three bionic lattice structures,the SCH structure has the best energy absorption effect in the effective stroke in the test,and the specific energy absorption can reach 6.32 J/g.ZPRH,SCH,and IBE structures not only have good and stable deformation behavior,but also have excellent impact resistance and shape memory properties.The design of these structures provides a reference for the design of anti-shock cushioning structures with self-recovery functions in the future.展开更多
Thin-walled structures have been used in many fields due to their superior mechanical properties.In this paper,two types of hierarchical multi-cell tubes,inspired by the self-similarity of Pinus sylvestris,are propose...Thin-walled structures have been used in many fields due to their superior mechanical properties.In this paper,two types of hierarchical multi-cell tubes,inspired by the self-similarity of Pinus sylvestris,are proposed to enhance structural energy absorption performance.The finite element models of the hierarchical structures are established to validate the crashworthiness performance under axial dynamic load.The theoreticalmodel of themean crushing force is also derived based on the simplified super folded element theory.The finite element results demonstrate that the energy absorption characteristics and deformation mode of the bionic hierarchical thin-walled tubes are further improved with the increase of hierarchical sub-structures.It can be also obtained that the energy absorption performance of corner self-similar tubes is better than edge self-similar tubes.Furthermore,multiobjective optimization of the hierarchical tubes is constructed by employing the response surface method and genetic algorithm,and the corresponding Pareto front diagram is obtained.This research provides a new idea for the crashworthiness design of thin-walled structures.展开更多
Because of the complex nerve anatomy and limited regeneration ability of natural tissue,the current treatment effect for long-distance peripheral nerve regeneration and spinal cord injury(SCI)repair is not satisfactor...Because of the complex nerve anatomy and limited regeneration ability of natural tissue,the current treatment effect for long-distance peripheral nerve regeneration and spinal cord injury(SCI)repair is not satisfactory.As an alternative method,tissue engineering is a promising method to regenerate peripheral nerve and spinal cord,and can provide structures and functions similar to natural tissues through scaffold materials and seed cells.Recently,the rapid development of 3D printing technology enables researchers to create novel 3D constructs with sophisticated structures and diverse functions to achieve high bionics of structures and functions.In this review,we first outlined the anatomy of peripheral nerve and spinal cord,as well as the current treatment strategies for the peripheral nerve injury and SCI in clinical.After that,the design considerations of peripheral nerve and spinal cord tissue engineering were discussed,and various 3D printing technologies applicable to neural tissue engineering were elaborated,including inkjet,extrusion-based,stereolithography,projection-based,and emerging printing technologies.Finally,we focused on the application of 3D printing technology in peripheral nerve regeneration and spinal cord repair,as well as the challenges and prospects in this research field.展开更多
基金Acknowledgements The research was sponsored by the Natural Science Foundation of China （50975012）, and the Scientific Research Foundation for the Outstanding Young Scientist of Shandong Province （2008BS05007）.
文摘The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the application of structural bionic approaches. Giant waterlily leaf ribs and cactus stem are investigated for their optimal framework and superior performance. Their structural characteristics are extracted and used in the bio-inspired design of Lin MC6000 gantry machining center crossbeam. By mimicking analogous network structure, the bionic model is established, which has better load-carrying capacity than conventional distribution. Finite Element Method （FEM） is used for numerical simulation. Results show better specific stiffness of the bionic model, which is increased by 17.36%. Finally the scaled models are fabricated by precision casting for static and dynamic tests. The physical experiments are compared to numerical simulation. The results show that the maximum static deformation of the bionic model is reduced by about 16.22%, with 3.31% weight reduction. In addition, the first four natural frequencies are improved obviously. The structural bionic design is a valuable reference for updating conventional mechanical structures with better performance and less material consumption.
基金support by National Natural Science Foundation of China(Grant No.50975012)
文摘A concept of Specific Structure Efficiency (SSE) was proposed that can be used in the lightweight effect evaluation ofstructures.The main procedures of bionic structure design were introduced systematically.The parameter relationship betweenhollow stem of plant and the minimum weight was deduced in detail.In order to improve SSE of pylons, the structural characteristicsof hollow stem were investigated and extracted.Bionic pylon was designed based on analogous biological structuralcharacteristics.Using finite element method based simulation, the displacements and stresses in the bionic pylon were comparedwith those of the conventional pylon.Results show that the SSE of bionic pylon is improved obviously.Static, dynamic andelectromagnetism tests were carried out on conventional and bionic pylons.The weight, stress, displacement and Radar CrossSection (RCS) of both pylons were measured.Experimental results illustrate that the SSE of bionic pylon is markedly improvedthat specific strength efficiency and specific stiffness efficiency of bionic pylon are increased by 52.9% and 43.6% respectively.The RCS of bionic pylon is reduced significantly.
基金supported by the Science and Technology Development Program of Jilin Province(No.20240101122JC)and(No.20240101143JC)the Key Scientific and Technological Research and Development Projects of Jilin Provincial Science and Technology Department(Grant Number 20230201108GX)。
文摘Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.
基金financially supported by the National Natural Science Foundation of China(Nos.12404230 and 52061027)Zhejiang Provincial Natural Science Foundation of China(No.LY23E010002)+2 种基金the Science and Technology Program Project of Gansu Province(Nos.22YF7GA155 and 22ZD6GA008)Lanzhou Youth Science and Technology Talent Innovation Project(No.2023-QN-91)the support from Gansu Provincial Computing Center
文摘In recent years,various highly pathogenic viruses have spread worldwide,posing serious threats to human life and property,thus creating an urgent demand for antibacterial structural materials.In this study,we developed two types of antibacterial medium-entropy alloys (MEAs):as-cast (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(88-x)Cu_(12)Ag_(x)(x=2,4 at%)(which do not require antibacterial aging heat treatment) and heat-treated (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(99.5-x)Cu_(x)Ag_(0.5)(x=2,4 at%)(abbreviated as CuxAg0.5 and Cu12Agx).Both MEA s exhibit in transformation-induced plasticity (TRIP) and twinning-induced plasticity effects,demonstrating outstanding mechanical properties.Compared to 304 stainless steels,these ME As exhibit superior corrosion resistance,with the Cu2Ag0.5alloy performing the best,exhibiting a corrosion current density of 1.022 A·cm^(-2)and a corrosion potential of-0.297 VSCE.The antibacterial rate of the MEAs reached99.9%after 24 h of interaction with Escherichia coli and Staphylococcus aureus,with Cu 12Ag2 achieving 99.9%antimicrobial activity within 6 h,indicating a shorter activation time for antibacterial activity.According to firstprinciples calculations of state density,work function,and surface energy,Cu12Ag2 demonstrated the highest ion release capability,with a work function of 3.7 eV and surface energy of 1.9 J·m^(-2).The electrostatic adsorption of the Xanthium sibiricum bionic structure,characterized by a nanoscale spherical phase within the antibacterial phase with a size less than 350 nm,promotes ion penetration into bacterial cells,enhancing the synergistic effects of ionic,electronic,and catalytic antibacterial mechanisms.This study provides a new approach for designing high-performance alloys that integrate functional and structural properties,offering broad-spectrum,efficient antibacterial applications under load-bearing conditions.
基金supported by the National Natural Science Foundation of China(No.52331004,U2106216)the Natural Science Foundation of Shandong Province(No.ZR2022ZD12)+2 种基金the Key R&D Program of Shandong Province,China(2023ZLGX05,2023CXGC010406)Key Program of Natural Science Foundation of Shandong Province of China(No.ZR2022ZD12,ZR2024ZD14)the Taishan Scholarship of Climbing Plan(No.tspd20230603)。
文摘In this study,femtosecond pulsed laser processing was applied to the magnesium alloy,followed by in situ growth of Mg-Al layered double hydroxides(LDHs),and finally modification with low surface energy materials to prepare a biomimetic of centipede-like superhydrophobic composite coating.The resulting biomimetic coating features a dual-scale structure,comprising a micron-scale laser-etched array and nano-scale LDH sheets,which together create a complex hierarchical architecture.The multistage bionic superhydrophobic coating exhibits exceptional corrosion resistance,with a reduction in corrosion current density by approximately five orders of magnitude compared to the bare magnesium alloy substrate.This remarkable corrosion resistance is attributed to the synergistic effects of the superhydrophobicity with a contact angle(CA)of 154.60°,the densification of the surface LDH nanosheets,and the NO_(3)^(-) exchange capacity.Additionally,compared to untreated AZ91D alloy,the biomimetic coating prolongs ice formation time by 250% at-40℃ and withstands multiple cycles of sandpaper abrasion and repeated tape peeling tests.Furthermore,it demonstrates excellent self-cleaning and anti-fouling properties,as confirmed by dye immersion and dust contamination tests.The construction of the multi-level bionic structured coating not only holds significant practical potential for metal protection but also provides valuable insights into the application of formed LDH materials in functional bionic coating engineering.
基金supported by the Open Fund of Science and Technology on Thermal Energy and Power Laboratory[TPL2021A02]the State Key Laboratory of Hydroscience and Engineering[sklhse-2023-E-01].
文摘Centrifugal pumps are extensively employed in ocean engineering,such as ship power systems,water transportation,and mineral exploitation.Pressure fluctuation suppression is essential for the operation stability and service life of the centrifugal pump.In this paper,a new method of bionic structure is proposed for the blade surface of a centrifugal pump,which is inspired by the fish scale and comprises a leading edge,a trailing edge,and two symmetrical side edges.This fish scale structure is applied to the blade pressure and suction surfaces,and an impeller with a fish scale structure is constructed.A test rig for a centrifugal pump is developed to determine the pressure fluctuation in the pump with a prototype impeller and fish scale structure impeller.Results reveal that the dominant frequency of pressure fluctuation in volute is the blade passing frequency(f_(bpf))of 193.33 Hz,which is triggered by the interaction between the tongue and the impeller.The bionic structure of the fish scale effectively suppresses the pressure fluctuation amplitude at f_(bpf).From flow rates of 0.6 Q_(d)to 1.2 Q_(d),the average suppressions in pressure fluctuation amplitudes at f_(bpf)are 20.98%,5.85%,19.20%,and 25.77%.
基金supported by the Defense Industrial Technology Development Program.
文摘Inspired by natural biomimetic structures exemplified by femoral bones,the shell-infill composite design has emerged as a research focus in structural optimization.However,existing studies predominantly focus on uniform-thickness shell designs and lack robust methodologies for generating high-resolution porous infill configurations.To address these challenges,a novel topology optimization framework for full-scale shell-filled composite structures is developed in this paper.First,a physics-driven,non-uniform partial differential equation(PDE)filter is developed,enabling precise control of variable-thickness shells by establishing explicit mapping relationships between shell thickness and filter radii.Second,this study addresses the convergence inefficiency of traditional full-scale topology optimization methods based on local volume constraints.It is revealed that a reduced influence radius exacerbates algorithm convergence challenges,thereby impeding the design of intricate porous structures.To overcome this bottleneck,a physics-driven stress skeleton generation method is developed.By integrating stress trajectories and rasterization processing,this method constructs an initial density field,effectively guiding material evolution and significantly enhancing convergence in porous structural optimization within the full-scale framework.Classical numerical examples demonstrate that our proposed optimization framework achieves biomimetic non-uniform shell thickness optimization and enables precise control of the shell thickness.Additionally,density preprocessing effectively eliminates intermediate density regions and void aggregation.Moreover,the generated trabecular-like infill patterns with spatially graded porosity,akin to multiscale topology optimization(MTO),provide an innovative solution for multifunctional,lightweight,complex shell-infill composite structures in aerospace and biomedical applications.
基金sponsored by the Fundamental Research Funds for the Central Universities[N2329001].
文摘To overcome the limitations of traditional exoskeletons in complex outdoor terrains,this study introduces a novel lower limb exoskeleton inspired by the snow leopard’s forelimb musculoskeletal structure.It features a non-fully anthropomorphic design,attaching only at the thigh and ankle with a backward-knee configuration to mimic natural human knee movement.The design incorporates a single elastic element at the hip for gravity compensation and dual elastic elements at the knee for terrain adaptability,which adjust based on walking context.The design’s effectiveness was assessed by measuring metabolic cost reduction and motor output torque under various walking conditions.Results showed significant metabolic cost savings of 5.8–8.8%across different speeds and a 7.9%reduction during 9°incline walking on a flat indoor surface.Additionally,the spring element decreased hip motor output torque by 7–15.9%and knee torque by 8.1–14.2%.Outdoor tests confirmed the design’s robustness and effectiveness in reducing motor torque across terrains,highlighting its potential to advance multi-terrain adaptive exoskeleton research.
基金supported by the National Natural Science Foundation of China(Grant No.62073041)the Open Fund of Laboratory of Aerospace Servo Actuation and Transmission(Grant No.LASAT-2023A04)the Fundamental Research Funds for the Central Universities(Grant Nos.2024CX06011,2024CX06079)。
文摘Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet static supporting stability and dynamic terrain adaptability through the utilization of the Rigid-Elastic Hybrid(REH)dynamics model.First,a bionic foot model,named the Hinge Tension Elastic Complex(HTEC)model,was developed by extracting key features from human feet.Furthermore,the kinematics and REH dynamics of the HTEC model were established.Based on the foot dynamics,a nonlinear optimization method for stiffness matching(NOSM)was designed.Finally,the HTEC-based foot was constructed and applied onto BHR-B2 humanoid robot.The foot static stability is achieved.The enhanced adaptability is observed as the robot traverses square steel,lawn,and cobblestone terrains.Through proposed design method and structure,the mobility of the humanoid robot is improved.
基金Supported by National Natural Science Foundation of China (No. 50975012)Research Fund for the Doctoral Program of Higher Education of China (No. 20091102110022)
文摘Structural bionic design lacks mature and scientific theories, and the excellent structural characteristics of natural organisms sometimes cannot be transferred into engineering structures effectively. Aiming at overcoming the existing problems, this paper summarizes three related theories: similarity theory, fuzzy evaluation theory and optimization theory. Based on the related theories, a method of structural bionic design is introduced, which includes four steps: selecting the most useful structural characteristic of natural organism; analyzing the structural characteristic finally chosen for engineering problem; completing the structural bionic design for engineering structure; and verifying the structural bionic design. Similarity theory and fuzzy evaluation theory are employed to achieve Step 1. In Step 2 and Step 3, optimization theory is employed to analyze the parameters of structures. Together with the thoughts of simplification and grouping, optimization theory can reveal the relationship between organism structure and engineering structure, providing a way to structural bionic design. A general evaluation criterion is proposed in Step 4, which is feasible to evaluate the performance of different structures. Finally, based on the method, a structural bionic design of thin-walled cylindrical shell is introduced.
基金supported by the National Natural Science Foundation of China (Nos. 52235006 and 52025053)the National Key Research and Development Program of China (No. 2022YFB4600500)
文摘Over millions of years of natural evolution,organisms have developed nearly perfect structures and functions.The self-fabrication of organisms serves as a valuable source of inspiration for designing the next-generation of structural materials,and is driving the future paradigm shift of modern materials science and engineering.However,the complex structures and multifunctional integrated optimization of organisms far exceed the capability of artificial design and fabrication technology,and new manufacturing methods are urgently needed to achieve efficient reproduction of biological functions.As one of the most valuable advanced manufacturing technologies of the 21st century,laser processing technology provides an efficient solution to the critical challenges of bionic manufacturing.This review outlines the processing principles,manufacturing strategies,potential applications,challenges,and future development outlook of laser processing in bionic manufacturing domains.Three primary manufacturing strategies for laser-based bionic manufacturing are elucidated:subtractive manufacturing,equivalent manufacturing,and additive manufacturing.The progress and trends in bionic subtractive manufacturing applied to micro/nano structural surfaces,bionic equivalent manufacturing for surface strengthening,and bionic additive manufacturing aiming to achieve bionic spatial structures,are reported.Finally,the key problems faced by laser-based bionic manufacturing,its limitations,and the development trends of its existing technologies are discussed.
基金supported by the National Natural Science Foundation of China(Grant No.52225503)National Key Research and Development Program of China(Grant No.2022YFB3805701)+1 种基金Development Program of Jiangsu Province(Grant Nos.BE2022069 and BE2022069-1)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX21-0207).
文摘Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g.aerospace,automobiles,electronics,etc.Cuttlebone produced in the cuttlefish has evolved vertical walls with the optimal corrugation gradient,enabling stress homogenization,significant load bearing,and damage tolerance to protect the organism from high external pressures in the deep sea.This work illustrated that the complex hybrid wave shape in cuttlebone walls,becoming more tortuous from bottom to top,creates a lightweight,load-bearing structure with progressive failure.By mimicking the cuttlebone,a novel bionic hybrid structure(BHS)was proposed,and as a comparison,a regular corrugated structure and a straight wall structure were designed.Three types of designed structures have been successfully manufactured by laser powder bed fusion(LPBF)with NiTi powder.The LPBF-processed BHS exhibited a total porosity of 0.042% and a good dimensional accuracy with a peak deviation of 17.4μm.Microstructural analysis indicated that the LPBF-processed BHS had a strong(001)crystallographic orientation and an average size of 9.85μm.Mechanical analysis revealed the LPBF-processed BHS could withstand over 25000 times its weight without significant deformation and had the highest specific EA value(5.32 J·g^(−1))due to the absence of stress concentration and progressive wall failure during compression.Cyclic compression testing showed that LPBF-processed BHS possessed superior viscoelastic and elasticity energy dissipation capacity.Importantly,the uniform reversible phase transition from martensite to austenite in the walls enables the structure to largely recover its pre-deformation shape when heated(over 99% recovery rate).These design strategies can serve as valuable references for the development of intelligent components that possess high mechanical efficiency and shape memory capabilities.
基金supported in part by the National Nature Science Foundation of China[No.62073229]Jiangsu Policy Guidance Program(International Science and Technology Cooperation)The Belt and Road Initiative Innovative Cooperation Projects(No.BZ2021016)EDL fund of Beijing Institute of Space Mechanics and Electricity(Grant No.EDL19092127).
文摘With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of trusses.This paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on different heights of trusses.Inspired by the attachment and grasping abilities of Dynastes Hercules,we utilize its foot microstructures,such as microhooks and setae,to achieve efficient contact and firm grip with the surface.The morphology and arrangement of these structures can inspire the design of robot feet to improve their grasping and stability performance.We study the biological structure of Dynastes Hercules,design and optimize the bio-inspired structure,analyze the influence of various factors from theoretical and experimental perspectives,and verify the feasibility of the scheme through simulation.We propose an ideal climbing strategy that provides useful reference for robot applications in practice.Moreover,the influence laws of various factors in this paper can be applied to robot foot design to improve their operation ability and stability performance in the space environment.This bio-inspired mechanism can improve robot working range and efficiency,which is critical for on-orbit assemblyin space.
基金supported by National Natural Science Foundation of China(Grant Nos.52235006,52025053)National Key Research and Development Program of China(Grant No.2022YFB4600500).
文摘The ability of organisms to adjust to environmental changes offers valuable insights into the development and creation of innovative smart systems. As requirements increase, the ability of smart materials to change their shapes has become a broader aim beyond their original capabilities. In contrast to conventional manufacturing methods, additive manufacturing (AM) skillfully combines precise three-dimensional structures and the intricate response mechanisms of biological organisms with smart materials. This combination enables the production of smart bionic structures with programmable shapes and features. Trends such as dynamic modulation, responsive- ness to multiple stimuli, and the integration of functions are emerging as significant in the development of smart bionic structures. This review first presents smart structures that nature has designed and built in various organ- isms, highlighting the relationship between the structural characteristics and patterns of deformation. The review then discusses how smart bionic structures developed using AM techniques respond to different stimuli. Addi- tionally, the potential uses of smart bionic structures in biomedicine, intelligent robotics, origami construction, and aerospace are discussed. Finally, the challenges and future prospects for smart bionic structures are exam- ined with the goal of offering innovative solutions for creating the next generation of smart systems through interdisciplinary research.
基金work is supported by the Fundamental Research Funds for the Central Universities(Grant No.B230205021)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(GrantNo.KYCX22_0592).The financial supports are gratefully acknowl-edged.
文摘A novel three-dimensional-fiber reinforced soft pneumatic actuator(3D-FRSPA)inspired by crab claw and human hand structure that can bend and deform independently in each segment is proposed.It has an omni-directional bending configuration,and the fibers twined symmetrically on both sides to improve the bending performance of FRSPA.In this paper,the static and kinematic analysis of 3D-FRSPA are carried out in detail.The effects of fiber,pneumatic chamber and segment length,and circular air chamber radius of 3D-FRSPA on the mechanical performance of the actuator are discussed,respectively.The soft mobile robot composed of 3D-FRSPA has the ability to crawl.Finally,the crawling processes of the soft mobile robot on different road conditions are studied,respectively,and the motion mechanism of the mobile actuator is shown.The numerical results show that the soft mobile robots have a good comprehensive performance,which verifies the correctness of the proposedmodel.This work shows that the proposed structures have great potential in complex road conditions,unknown space detection and other operations.
基金supported by the National Natural Science Foundation of China(Grants 11832009 and 11672104)the Chair Professor of Lotus Scholars Program in Hunan province(Grants XJT2015408)。
文摘Vibration reduction has always been one of hot and important topics in mechanical engineering,especially for the special measurement instrument.In this paper,a novel limb-inspired bionic structure is proposed to generate negative stiffness and design a new quasi-zero stiffness isolator via torsion springs,distinguishing from the existing tension spring structures in the literature.The nonlinear mathematical model of the proposed structure is developed and the corresponding dynamic properties are further investigated by using the Harmonic Balance method and ADAMS verification.To evaluate the vibration isolation performance,typical three-springs quasi-zero stiffness(TS QZS)system is selected to compare with the proposed bionic structure.And the graphical processing unit(GPU)parallel technology is applied to perform necessary two-parameter analyses,providing more insights into the effects of parameters on the transmissibility.It is shown that the proposed structure can show advantages over the typical TS QZS system in a wider vibration isolation range for harmonic excitation case and shorter decay time for the impact excitation case.
基金National Key R&D Program of China(No.2018YFB1105100)National Natural Science Foundation of China(No.51975246)+5 种基金Jilin Province Science and Technology Development Plan(No.YDZJ202101ZYTS134)State Key Laboratory of Automotive Simulation and Control—ziyoutansuoxiangmu(202013)Open Project Program of Key Laboratory for Cross-Scale Micro and Nano Manufacturing,Ministry of Education,Changchun University of Science and Technology(CMNM-KF202109)Program for JLU Science and Technology Innovative Research Team(No.2019TD-34)Interdisciplinary Research Fund for Doctoral Postgraduates of Jilin University(No.101832020DJX052)Interdisciplinary Cultivation Project for Young Teachers and Students(No.415010300078)。
文摘Each specific structure of organisms is the best choice under specific circumstances.The excellent characteristic structures of these organisms have great application potential in the design and multi-functional optimization of energy-absorbing structures such as vehicle collisions,satellite landings,and military equipment.In this paper,using the principle of structural bionics,using the advantages of the honeycomb structure and the light weight and high strength of beetle elytra,four bionic lattice structures are studied:CH,ZPRH,SCH and IBE.Using NiTi shape memory alloy,a unique material as the base material,samples are prepared using selective laser melting(SLM)technology.By comparing the test results of the quasi-static compression test with the results of the numerical simulation,it is found that compared with the other three bionic lattice structures,the SCH structure has the best energy absorption effect in the effective stroke in the test,and the specific energy absorption can reach 6.32 J/g.ZPRH,SCH,and IBE structures not only have good and stable deformation behavior,but also have excellent impact resistance and shape memory properties.The design of these structures provides a reference for the design of anti-shock cushioning structures with self-recovery functions in the future.
基金The authors are grateful to the National Natural Science Foundation of China(Grant No.11902183)the Doctoral Research Foundation of Shandong University of Technology(Grant No.4041/418017).
文摘Thin-walled structures have been used in many fields due to their superior mechanical properties.In this paper,two types of hierarchical multi-cell tubes,inspired by the self-similarity of Pinus sylvestris,are proposed to enhance structural energy absorption performance.The finite element models of the hierarchical structures are established to validate the crashworthiness performance under axial dynamic load.The theoreticalmodel of themean crushing force is also derived based on the simplified super folded element theory.The finite element results demonstrate that the energy absorption characteristics and deformation mode of the bionic hierarchical thin-walled tubes are further improved with the increase of hierarchical sub-structures.It can be also obtained that the energy absorption performance of corner self-similar tubes is better than edge self-similar tubes.Furthermore,multiobjective optimization of the hierarchical tubes is constructed by employing the response surface method and genetic algorithm,and the corresponding Pareto front diagram is obtained.This research provides a new idea for the crashworthiness design of thin-walled structures.
基金financially sponsored by the National Key Research and Development Program of China(2018YFA0703000)the National Natural Science Foundation of China(No.U1909218)+2 种基金the Joint Funds of Guangdong Basic and Applied Basic Research Foundation(2019A1515110261)the Special Projects in Key Fields from the Department of Education of Guangdong Province(2022ZDZX2059)the Dongguan Science and Technology of Social Development Program(20221800905072)。
文摘Because of the complex nerve anatomy and limited regeneration ability of natural tissue,the current treatment effect for long-distance peripheral nerve regeneration and spinal cord injury(SCI)repair is not satisfactory.As an alternative method,tissue engineering is a promising method to regenerate peripheral nerve and spinal cord,and can provide structures and functions similar to natural tissues through scaffold materials and seed cells.Recently,the rapid development of 3D printing technology enables researchers to create novel 3D constructs with sophisticated structures and diverse functions to achieve high bionics of structures and functions.In this review,we first outlined the anatomy of peripheral nerve and spinal cord,as well as the current treatment strategies for the peripheral nerve injury and SCI in clinical.After that,the design considerations of peripheral nerve and spinal cord tissue engineering were discussed,and various 3D printing technologies applicable to neural tissue engineering were elaborated,including inkjet,extrusion-based,stereolithography,projection-based,and emerging printing technologies.Finally,we focused on the application of 3D printing technology in peripheral nerve regeneration and spinal cord repair,as well as the challenges and prospects in this research field.
