Laser-based bionic manufacturing

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.

Design and additive manufacturing of bionic hybrid structure inspired by cuttlebone to achieve superior mechanical properties and shape memory function

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.

Design and Manufacture of Bionic Porous Titanium Alloy Spinal Implant Based on Selective Laser Melting(SLM)

In order to meet the clinical requirements of spine surgery,this paper proposed the exploratory research of computer-aided design and selective laser melting(SLM)fabrication of a bionic porous titanium spine implant.The structural design of the spinal implant is based on CT scanning data to ensure correct matching,and the mechanical properties of the implant are verified by simulation analysis and laser selective melting experiment.The surface roughness of the spinal implant manufactured by SLM without post-processing is Ra 15μm,and the implant is precisely jointed with the photosensitive resin model of the upper and lower spine.The surface micro-hardness of the implant is HV 373,tensile strengthσ_(b)=1238.7 MPa,yield strengthσ_(0.2)=1043.9 MPa,the elongation is 6.43%,and the compressive strength of porous structure under 84.60%porosity is 184.09 MPa,which can meet the requirements of the reconstruction of stable spines.Compared with the traditional implant and intervertebral fusion cage,the bionic porous spinal implant has the advantages of accurate fit,porous bionic structure and recovery of patients,and the ion release experiment proved that implants manufactured by SLM are more suitable for clinical application after certain treatments.The elastic modulus of the sample is improved after heat treatment,mainly because the microstructure of the sample changes fromα’phase toα+βdual-phase after heat treatment.In addition,the design of high-quality bionic porous spinal implants still needs to be optimized for the actual needs of doctors.

3D打印融合层叠技法在仿生服装设计中的运用

为研究现代仿生服装设计的表现形式,实现设计手法的多样化和创新,针对目前仿生服装实际设计运用中造型手法单一,制作效率低的问题,从仿生对象形态和工艺手段方面分析总结3种主要的造型技法,聚焦于3D打印技术和激光切割技术融合互补的优越性。在以海洋生物为仿生对象的实践中探索设计方法,证实这一流程的可行性,得出3D打印技术和层叠技法的融合在仿生服装的制作流程中具有仿生结构写实、制作效率较高、质感表现多样的优点,以期突破现有服装设计制作固定范式的限制,拓宽未来服装仿生设计的实践思路,并为此类服装的设计和制作提供参考。

可磁场调控的三维自组装结构及其应用

机械力诱导平面薄膜自组装为三维结构是一种重要的结构成型方法。本文通过飞秒激光将聚合物薄膜切割为二维图案化结构,并利用紫外光刻在二维结构上加工磁性层,随后经机械力诱导自组装为三维磁响应结构,并探讨了该方法制作的结构在仿生抓手、仿生舌头等方面的应用。仿真结果表明:通过有限元分析可精确预测二维平面结构在机械力诱导自组装后三维结构形貌。实验表明:三维结构依托其上磁性层可对外界磁场做出快速响应,实现对三维自组装结构的可逆非接触形貌调控。

受猪笼草启发的多孔微腔低冰黏附防除冰表面

目的 提高光滑液体注入表面(SLIPS)的防/除冰耐用性。方法 将镍箔完全浸没在无水乙醇中,使用飞秒激光照射无水乙醇环境中的镍箔表面诱导出立体多孔纳米微腔阵列结构,并使用氟硅烷改性增加表面对硅油的亲和力,最后用50 cSt的硅油旋涂在改性后的表面上。通过扫描电镜和光学显微镜对立体多孔纳米微腔结构进行形貌分析,并通过延缓结冰试验、冰黏附强度测试和高温蒸发试验,分别评价该SLIPS的延缓结冰性能、冰黏附强度和防除冰耐用性。结果 在立体多孔纳米微腔结构的毛细作用下,具有亲油憎水性的立体多孔纳米微腔表面上的蒸馏水滴也会被钉扎。相比非结构化表面,该SLIPS将延缓结冰时间提升了2.8倍,同时,在低温高湿度环境中,实现了冷凝水的自去除。在80℃高温环境下的蒸发10 min后进行结冰/除冰操作,10个周期后,该SLIPS的接触角(θ_(CA))为110°,滑动角(θ_(SA))为8.5°,以及冰黏附强度参数(τ_(ice))为3.6 kPa。结论 利用飞秒激光加工无水乙醇环境中的镍箔表面生成的立体纳米多孔微腔阵列结构能够减少SLIPS表面的润滑剂损失,可有效提高防除冰SLIPS的耐用性。

AZ31B镁合金仿生TIG焊接接头的组织和性能

镁合金焊接接头的微观组织对其力学性能有显著影响,限制其更广泛应用。受大自然生物结构所表现的优异力学性能的启发,利用激光重熔技术在镁合金钨极惰性气体保护焊(TIG焊)焊接接头表面制备了与生物体表类似的“软硬”交替结构来改善其力学性能。采用激光共聚焦显微镜、扫描电镜、能谱仪、硬度计、万能拉伸试验机、有限元分析等研究了不同试样的微观组织和力学性能。结果表明:激光仿生处理后,处理区形成了细小的等轴晶粒并且显微硬度明显增加,仿生试样的强度和延展性同时提高。结合有限元分析结果可知,仿生结构对力学性能的有益影响可归因于微观组织的变化和“软硬”交替结构带来的应力传递和重分布。

面向功能表面的激光仿生制造技术研究进展

为了提升飞行器的综合性能,疏水、防冰、防腐、减阻及吸波等功能表面受到研究者的广泛关注。激光加工技术由于其材料适用范围广、加工精度高等特点,在材料加工、复杂形貌构建、微纳尺度制造等领域有着巨大的应用潜力。总结近年来采用激光制造技术在不同材料上制备功能性仿生表面的研究进展,包括疏水、防冰、综合防腐、抗菌、减阻以及吸波等仿生表面的研究。从仿生制造角度出发,展示了自然界中拥有独特功能特性的生物表面,介绍了其实现具体功能的内在原理,并列举了使用激光加工技术进行仿生表面制造的相关研究,然后对该领域所面临的挑战与发展趋势进行了讨论与展望。

硬质合金激光改性协同仿生微织构对硼掺杂金刚石涂层性能的影响

目的研制应用于超精密加工领域的高性能金刚石涂层,探究硬质合金基体表面激光微织构对硼掺杂金刚石(BDD)涂层沉积质量的影响,分析不同类型的仿生微织构对基–膜结合强度、工具切削性能的改善效果及原因。方法在硬质合金表面使用激光脉冲制备不同类型的仿生微织构,并通过热丝化学气相沉积(HFCVD)法在刀具表面沉积BDD涂层。采用数显洛氏硬度计(HRS-150)、超景深三维显微镜、扫描电子显微镜(SEM)、能谱仪(EDS)、白光干涉表面轮廓仪、拉曼光谱(Raman)对样品进行表征。通过压痕试验及铣削试验研究涂层的附着强度和刀具的切削性能。结果激光微织构边缘发生表面硬化。激光微织构区域沉积BDD涂层后,基体表面缺陷显著降低,织构内部金刚石晶粒更密集,沉积质量提升,三角织构(TT)边缘的金刚石颗粒堆积坡度最缓,不同类型的织构化BDD涂层的粗糙度、金刚石纯度、切削性能及附着强度均不同,涂层附着力与表面硬度呈正相关。硼掺杂三角织构(BDTTD)涂层刀具具有最佳的切削性能。结论织构边缘和内部具有更高的金刚石二次成核率和沉积质量。织构的存在可以提升BDD涂层的附着强度和刀具性能,并且织构边缘的涂层附着力最强,这些得益于激光烧蚀及仿生微织构对硬质合金表面的硬化及对BDD涂层内在缺陷的修复。

Carnivorous plants inspired shape-morphing slippery surfaces

Carnivorous plants,for instance,Dionaea muscipula and Nepenthes pitcher plant,inspired the innovation of advanced stimuli-responsive actuators and lubricant-infused slippery surfaces,respectively.However,hybrid bionic devices that combine the active and passive prey trapping capabilities of the two kinds of carnivorous plants remain a challenge.Herein,we report a moisture responsive shape-morphing slippery surface that enables both moisture responsive shapemorphing and oil-lubricated water repellency for simultaneous active-and passive-droplet manipulation.The moisture deformable slippery surface is prepared by creating biomimetic microstructures on graphene oxide(GO)membrane via femtosecond laser direct writing and subsequent lubricating with a thin layer of oil on the laser structured reduced GO(LRGO)surface.The integration of a lubricant-infused slippery surface with an LRGO/GO bilayer actuator endows the actuator with droplet sliding ability and promotes the moisture deformation performance due to oil-enhanced water repellency of the inert layer(LRGO).Based on the shape-morphing slippery surface,we prepared a series of proof-of-concept actuators,including a moisture-response Dionaea muscipula actuator,a smart frog tongue,and a smart flower,demonstrating their versatility for active/passive trapping,droplet manipulation,and sensing.

Cooling and Crack Suppression of Bone Material Drilling Based on Microtextured Bit Modeled on Dung Beetle

In recent years,the number of patients with orthopedic diseases such as cervical spondylosis has increased,resulting in an increase in the demand for orthopedic surgery.However,thermal necrosis and bone cracks caused by surgery severely restrict the development and progression of orthopedic surgery.For the material of cutting tool processing bone in bone surgery of drilling high temperature lead to cell death,easy to produce the problem such as crack cause secondary damage effects to restore,in this paper,a bionic drill was designed based on the micro-structure of the dung beetle's head and back.The microstructure configuration parameters were optimized by numerical analysis,and making use of the optical fiber laser marking machine preparation of bionic bit;through drilling test,the mathematical model of drilling temperature and crack generation based on micro-structure characteristic parameters was established by infrared thermal imaging technology and acoustic emission signal technology,and the cooling mechanism and crack suppression strategy were studied.The experimental results show that when the speed is 60 m/min,the cooling effects of the bionic bit T1 and T2 are 15.31%and 19.78%,respectively,and both kinds of bits show obvious crack suppression effect.The research in this paper provides a new idea for precision and efficient machining of bone materials,and the research results will help to improve the design and manufacturing technology and theoretical research level in the field of bone drilling tools.

不同硬度摩擦副对激光仿生灰铸铁磨损的影响

介绍了激光加工条纹状仿生灰铸铁试样与不同硬度的45号钢对磨副的摩擦磨损过程,研究了对磨副硬度对磨损体系的影响。分析了激光处理后的灰铸铁硬度和组织,使用自制往复式摩擦磨损试验机进行摩擦磨损试验,借助白光干涉仪分析磨损后表面形貌。结果表明:非光滑表面对对磨副的损伤机理与光滑试样不同,非光滑表面凸起对对磨副有微观切削作用。以对磨副磨损区域最大犁沟深度为评价指标,非光滑表面的平均硬度与其耐磨性没有简单的等比例关系。以仿生灰铸铁表面的磨损质量为评价指标,随对磨副硬度的增大,仿生灰铸铁试样的磨损量先增大后减小。

高能束熔覆制备仿生涂层研究综述

具有耐磨、耐腐蚀等优良性能的仿生涂层可应用于海洋、石油、化工等苛刻环境。研究自然生物材料的仿生结构、仿生涂层的制备方法和质量调控方法,对于制备先进的仿生涂层具有重大意义。从高能束熔覆技术制备仿生涂层、仿生涂层质量调控2个方面,介绍了高能束熔覆技术制备仿生涂层的研究现状。在高能束熔覆技术制备仿生涂层方面,根据不同仿生机制分类,综述了仿生涂层的强化机制以及利用高能束制备方式涂层的研究现状;在仿生涂层质量调控方面,阐述了制备过程中的工艺优化及数值模拟对调控高能束熔覆技术制备仿生涂层性能的作用;最后总结了目前研究中存在的不足,为后续研究提供了参考方向和展望。

自润滑仿生微织构的激光烧固加工及其摩擦学性能

为进一步提高边界摩擦和干摩擦工况下摩擦副的摩擦学性能,提出了一种仿生正六边形织构与固体粉末烧结相结合的自润滑仿生正六边形表面微织构。通过激光加工和烧结填充的工艺制备微织构,研究了激光加工参数对织构制备的影响。研究了不同载荷下仿生微织构的摩擦系数、磨损损失和耐磨机理。结果表明,样品的摩擦系数随载荷的增大而增加,但仿生织构样品的摩擦系数和磨损率均小于光滑样品,在100 N下摩擦系数最高降低48.6%,磨损率系数降低40.01%。仿生微织构中的混合粉末在干摩擦条件下成为摩擦副间的润滑介质,生成表面润滑层,提高了仿生微织构的摩擦磨损性能。

A Novel Approach for the Fabrication of Sharkskin Structured Bionic Surfaces with Hydrophobic Wettability:Laser Processing and Ordered Abrasive Belt Grinding

A new process for the fabrication of sharkskin bionic structures on metal surfaces is proposed.The sharkskin bionic surface was successfully machined on the surface of IN718 by laser sequencing of the abrasive belt surface,laser processing of the layered scale-like structure,and ribbed texture grinding.The flexible contact properties of belt grinding allow ribbed structures to be machined uniformly on a hierarchical,scale-like microstructure.Sharkskin bionic microstructures with radii greater than 75µm were prepared after parameter optimisation.The influence of processing parameters on the geometrical accuracy of the microstructure was investigated,the microstructure microform and elemental distribution were analyzed,and the relationship between the ribbed microstructure and chemical properties of the surface of the bionic sharkskin on wettability was revealed.The results indicate that reducing the laser power and increasing the laser scan rate can reduce the laser thermal effect and improve the microstructure processing accuracy.The laser ablation process is accompanied by a violent chemical reaction that introduces a large amount of oxygen and carbon elements and infiltrates them at a certain depth.The wettability of the surface undergoes a transition from hydrophilic(contact angle 69.72°)to hydrophobic(contact angle 131.56°)due to the adsorption of C-C/C-H and the reduction of C=O/O=C-O during the placement process.The ribbed microstructure changes the solid-liquid contact on the surface into a solid-liquid-gas contact,which has an enhanced effect on hydrophobicity.This study is a valuable guide to the processing of hydrophobic layered bionic microstructures.

Compression Behavior and Failure Mechanisms of Bionic Porous NiTi Structures Built via Selective Laser Melting

Inspired by the crystal microstructure of metals and the bamboo,the bionic porous NiTi structures with the porosities in the range of 75.8%–84.9%were built via selective laser melting(SLM).The compression behavior and the failure mechanisms of the porous NiTi structures were evaluated.It demonstrated an increase in the elastic modulus and ultimate strength when the porosity was decreased,from 3.06 to 7.66 GPa and from 34.1 to 147.6 MPa,respectively.The relationship between the elastic modulus and the porosity obtained by the finite element analysis exhibited similar tendency with the experiment,and agreed well with the Gibson-Ashby model’s prediction.Based on the theoretical model above and the observation of the deformation processing,the plastic deformation behavior and failure mechanisms of the SLMed porous NiTi structures were analyzed.

Surface micro-texture on sapphire fabricated by laser ablation trajectory regulation

Fabrication of the surface micro-texture on the C-plane sapphire is undertaken by a355 nm Ultraviolet(UV)pulsed laser.The surface micro-textures of sapphire with different laser scanning line spacing ranging from 10 lm to 100 lm are obtained,where the selection range of scanning line spacing is controlled in the range of the groove width and plasma width to obtain a surface of high Peak-Valley(PV)value.A reasonable processing order is proposed to manufacture different types of surface micro-textures on sapphire by laser ablation trajectory regulation.In the multiple-passes laser ablation of sapphire by the UV nanosecond pulsed laser,the scanning lines in each direction is treated as once scanning.On this basis,the multiple processing can be carried out to avoid the influence of the subsequent scanning on the machined groove.In addition,the effect of different scanning line spacing on the PV value is quantified and different types of surface microtextures on sapphire,including the squares,the rhombuses and the hexagons,are successfully fabricated,which can be applied in the friction reduction or anti-reflection field.

基于飞秒激光和自组装技术提高树脂涂层疏水性的工艺

目的针对超疏水涂料功能持久性差的问题,提出一种将飞秒激光加工技术与微球近场效应原理相结合在氟化有机硅树脂表面制备微纳米仿生结构的解决方案。方法模仿蝴蝶翅膀鳞片微结构特征,以平滑的氟化有机硅树脂表面为基体,采用纳米自组装技术在其表面生长一层二氧化硅微球薄膜,然后设置飞秒激光器的参数,利用激光脉冲能量加工单层二氧化硅微球薄膜,二氧化硅微球颗粒对激光能量有进一步的聚焦加强作用,可以加工微纳米尺寸的结构。重点研究激光功率和扫描速度等参量对氟硅树脂图案形貌及疏水性的影响,并对比分析超疏水涂料和仿生微纳米表面的疏水功能持久性。结果激光扫描速度和功率参量对仿生表面疏水性能的影响较大,在激光功率为9 mW、扫描速度为10 mm/s、加工间距为10μm时可以获得最佳疏水性能,其接触角达到150°以上,通过常用的摩擦磨损测试实验,对比分析实验结果发现,氟硅树脂层经历200~1000次摩擦后,其接触角(CA)的下降幅度低于传统涂料组,说明具有仿生纳米坑结构的表面的耐磨性更强。结论利用飞秒激光加工的纳米微孔阵列结构可以明显提高氟硅树脂的疏水特性,并具有优异的持久性。

仿生齿轮抗接触疲劳性能的试验研究

为了提高传动齿轮的抗接触疲劳性能,依据生物耦合耐磨原理,模仿潮间带贝类体表设计了9种条纹状组织非光滑仿生表面形态和软硬相间结构,利用激光微区处理技术进行了仿生抗接触疲劳圆柱滚子试件的制备。利用仿生圆柱滚子试件对滚模拟了齿轮副的啮合传动,通过正交试验及其优化方法优选出适合的仿生表面制备工艺参数和形态分布参数,从而制备出具有良好环境适应性和实用性的仿生齿轮。经啮合传动试验表明,仿生齿轮的抗接触疲劳性能较普通齿轮提高20%以上,表面润滑条件改善、碎屑有效收集、散热面积增大、裂纹传播阻断等综合作用是仿生齿轮抗接触疲劳性能提高的主要原因。

仿生非光滑表面45^#钢模具的热疲劳性能

利用动物体表仿生学原理制备45#钢模具非光滑表面试样,通过自约束冷热疲劳试验方法,对比研究了光滑与非光滑试样的热疲劳特性,观察分析了热疲劳裂纹在仿生非光滑表面上扩展的形貌和内部机理.结果表明,非光滑单元体对热疲劳裂纹有阻断作用,仿生非光滑表面使模具的热疲劳抗力显著提高,模具表面的热疲劳性能在非光滑单元体的某一密度范围内达到最佳状态.在细晶强化、合金强化等强化机制下,由仿生非光滑单元体构筑的'桩钉'效应是导致模具抗热疲劳性提高的主要原因.