Laser processing technologies enable the precise fabrication of arbitrary structures and devices with broad applications in micro-optics,micro-mechanics,and biomedicine.However,its adoption is limited by the large siz...Laser processing technologies enable the precise fabrication of arbitrary structures and devices with broad applications in micro-optics,micro-mechanics,and biomedicine.However,its adoption is limited by the large size,complexity,high cost,and low flexibility of optical systems.Metasurfaces enable precise multidimensional control of light fields,aligning well with the development trend toward compact,high-performance optical systems.Here,we review several recent studies on the application of metasurfaces in laser processing technologies,including 3D nanolithography,direct laser writing,and laser cutting.Metasurfaces provide an integrated operational platform with exceptional performance,poised to disrupt conventional laser processing workflows.This combination presents significant cost efficiency and substantial development potential,with promising applications in areas such as imaging,optical storage,advanced sensing,and space on-orbit manufacturing.展开更多
This review examines the state-of-the-art in spatial manipulation of ultrafast laser processing using dynamic light modulators,with a particular focus on liquid crystal-based systems.We discuss phase modulation strate...This review examines the state-of-the-art in spatial manipulation of ultrafast laser processing using dynamic light modulators,with a particular focus on liquid crystal-based systems.We discuss phase modulation strategies and highlight the current limitations and challenges in surface and bulk processing.Specifically,we emphasize the delicate balance between high-fidelity beam shaping and energy efficiency,both critical for surface and bulk processing applications.Given the inherent physical limitations of spatial light modulators such as spatial resolution,fill factor,and phase modulation range.We explore techniques developed to bridge the gap between desired intensity distributions and actual experimental beam profiles.We present various laser light modulation technologies and the main algorithmic strategies for obtaining modulation patterns.The paper includes application examples across a wide range of fields,from surgery to surface structuring,cutting,bulk photo-inscription of optical functions,and additive manufacturing,highlighting the significant enhancements in processing speed and precision due to spatial beam shaping.The diverse applications and the technological limitations underscore the need for adapted modulation pattern calculation methods.We discuss several advancements addressing these challenges,involving both experimental and algorithmic developments,including the recent incorporation of artificial intelligence.Additionally,we cover recent progress in phase and pulse front control based on spatial modulators,which introduces an extra control parameter for light excitation with high potential for achieving more controlled processing outcomes.展开更多
The biological performance of Ti-6Al-4V implant is primarily determined by their surface properties.However,traditional surface modification methods,such as acid etching,hardly make improvement in their osseointegrati...The biological performance of Ti-6Al-4V implant is primarily determined by their surface properties.However,traditional surface modification methods,such as acid etching,hardly make improvement in their osseointegration ability and antibacterial capacity.In this study,we prepared a multi-scale composite structure coated with zinc oxide(ZnO)on Ti-6Al-4V implant by an innovative technology of two-step laser processing combined with solution-assistant.Compared with the acid etching method,the physicochemical properties of surface significantly improved.The in vitro results showed that the particular dimension of micro-nano structure and the multifaceted nature of ZnO synergistically affected MC3T3-E1 osteogenesis and bacterial activities:(1)The surface morphology showed a‘contact guidance'effect on cell arrangement,which was conducive to the adhesion of filopodia and cell spreading,and the osteogenesis level of MC3T3-E1 was enhanced due to the release of zinc ions(Zn^(2+));(2)the characterization of bacterial response revealed that periodic nanostructures and Zn^(2+)released could cause damage to the cell wall of E.coli and reduce the adhesion and aggregation of S.aureus.In conclusion,the modified surface showed a synergistic effect of physical topography and chemical composition,making this a promising method and providing new insight into bone defect repairment.展开更多
The model of heat source(MHS) which reflects the thermal interaction between materials and laser during processing determines the accuracy of simulation results. To acquire desirable simulations results, although vari...The model of heat source(MHS) which reflects the thermal interaction between materials and laser during processing determines the accuracy of simulation results. To acquire desirable simulations results, although various modifications of heat sources in the aspect of absorption process of laser by materials have been purposed, the distribution of laser power density(DLPD) in MHS is still modeled theoretically. However, in the actual situations of laser processing, the DLPD is definitely different from the ideal models. So, it is indispensable to build MHS using actual DLPD to improve the accuracy of simulation results. Besides, an automatic modeling method will be benefit to simplify the tedious pre-processing of simulations. This paper presents a modeling method and corresponding algorithm to model heat source using measured DLPD. This algorithm automatically processes original data to get modeling parameters and provides a step MHS combining with absorption models. Simulations and experiments of heat transfer in steel plates irradiated by laser prove the mothed and the step MHS. Moreover, the investigations of laser induced thermal-crack propagation in glass highlight the signification of modeling heat source based on actual DLPD and demonstrate the enormous application of this method in the simulation of laser processing.展开更多
We report the femtosecond(fs)laser fabrication of biomimetic omnidirectional iridescent metallic surfaces exhibiting efficient diffraction for practically any angle of light incidence.Such diffractive behavior is real...We report the femtosecond(fs)laser fabrication of biomimetic omnidirectional iridescent metallic surfaces exhibiting efficient diffraction for practically any angle of light incidence.Such diffractive behavior is realized by means of multi-directional low-spatial-frequency,laser-induced periodic surface structures(LSFL)formed upon exploiting the cylindrical symmetry of a cylindrical vector(CV)fs field.We particularly demonstrate that the multi-directional gratings formed on stainless steel surface by a radially polarized fs beam,could mimic the omnidirectional structural coloration properties found in some natural species.Accordingly,the fabricated grating structures can spatially disperse the incident light into individual wavelength with high efficiency,exhibiting structural iridescence at all viewing angles.Analytical calculations using the grating equation reproduced the characteristic variation of the vivid colors observed as a function of incident angle.We envisage that our results will significantly contribute to the development of new photonic and light sensing devices.展开更多
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 su...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.展开更多
Indoor air quality(IAQ) directly affects the health of occupants. Household manufacturing equipment(HME) used for hobbies or educational purposes is a new and unexplored source of air pollution. In this study, we eval...Indoor air quality(IAQ) directly affects the health of occupants. Household manufacturing equipment(HME) used for hobbies or educational purposes is a new and unexplored source of air pollution. In this study, we evaluated the characteristics of particulate and gaseous pollutants produced by a household laser processing equipment(HLPE). Various target materials were tested using a commercial HLPE under various operating conditions of laser power and sheath air flow rate. The mode diameters of the emitted particles gradually decreased as laser power increased, while the particle number concentration(PNC) and particle emission rate(PER) increased. In addition, as the sheath air flow rate quadrupled from 10 to 40 L/min, the mode diameter of the emitted particles decreased by nearly 25%, but the effect on the PNC was insignificant. When the laser induced the target materials at 53 m W, the mode diameters of particles were < 150 nm, and PNCs were > 2.0 × 10^(4) particles/cm^(3). Particularly, analyses of sampled aerosols indicated that harmful substances such as sulfur and barium were present in particles emitted from leather. The carcinogenic gaseous pollutants such as acrylonitrile, acetaldehyde, 1,3-butadiene, benzene, and C 8 aromatics(ethylbenzene) were emitted from all target materials. In an actual indoor environment, the PNC of inhalable ultrafine particles(UFPs) was > 5 × 10^(4) particles/cm^(3) during 30 min of HLPE operation. Our results suggest that more meticulous control methods are needed, including the use of less harmful target materials along with filters or adsorbents that prevent emission of pollutants.展开更多
Graphene oxide,as a 2D material with nanometer thickness,offers ultra-high mobility,chaotic properties,and low cost.These make graphene oxide memristors beneficial for reservoir computing(RC)networks.In this study,con...Graphene oxide,as a 2D material with nanometer thickness,offers ultra-high mobility,chaotic properties,and low cost.These make graphene oxide memristors beneficial for reservoir computing(RC)networks.In this study,continuous-wave(CW)laser processing is used to reduce chaotic graphene oxide(CGO)films,resulting in the non-volatile storage capability based on the reduced chaotic graphene oxide(rCGO)films.Laser power significantly impacts the characteristics of the rCGO memristor.Material characterization indicates that laser radiation can effectively reduce the oxygen content in CGO films.With optimized laser power,the rCGO memristor achieves a large ratio at 18 mW laser power.Benefiting from the short-term mem-ory characteristics,distinct conductive states are achieved,which are further utilized to construct RC networks.With a third con-trol probe,the rCGO memristor can express rich reservoir states,demonstrating accuracy in predicting the Hénon map with an NRMSE below 0.3.These findings provide the potential for developing flexible RC networks based on graphene oxide memris-tors via laser processing.展开更多
In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and &...In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and "thermal processing" and their mutual conversion, and determine the "cold processing" parameter window. The ablation threshold and incubation coefficient of 304 stainless steel foil are calculated, and the effects of scanning speed and effective pulse number on the ablation threshold are analyzed. The ANSYS software is used to simulate the radial and axial temperature distributions of the surface on 304 stainless steel foil sample and the heat-affected zone with a femtosecond laser fluence of 10 J/cm2 and an effective number of pulses of 1 200 are obtained. In the aspect of spectral detection, the Fourier transform infrared spectra of the sample before and after processing are measured and two processing mechanisms of "cold processing" and "hot processing" are confirmed, which proves that we can achieve the conversion between "cold processing" and "hot processing" by changing the laser fluence and determine the "cold processing" laser fluence range.展开更多
The first multi-function laser processing system in the domestic for clutch manufacture,with abilities of cutting, jointing and heat treatment,was reported in this paper.One external optical path,double laser heads,ad...The first multi-function laser processing system in the domestic for clutch manufacture,with abilities of cutting, jointing and heat treatment,was reported in this paper.One external optical path,double laser heads,adjust device by manual operation,automatically track were employed in this system Also the other parts of vehicles can be fabricated by this system,as well as clutches.The special processing to manufacture the clutches of heavy vehicles,which was developed by the project of this laser processing system,achieved the international standards and satisfied the economic development and nation defense in the do- mestic.展开更多
The growing demand for surface-enhanced Raman scattering sensors in biochemical detection,environmental monitoring,microfluidics,and other fields has promoted the development of highly sensitive and stable substrates....The growing demand for surface-enhanced Raman scattering sensors in biochemical detection,environmental monitoring,microfluidics,and other fields has promoted the development of highly sensitive and stable substrates.Femtosecond laser-fabricated surfaces with controlled wettability,unique micro/nanostructure designs,and tunable extreme wetting properties can significantly enhance the signal amplification and reproducibility of surface-enhanced Raman scattering techniques.In this review,we offer a comprehensive overview of recent advancements in surface-enhanced Raman scattering techniques based on superwetting surfaces fabricated by femtosecond laser processing,including fully superhydrophobic surfaces,hybrid wettability surfaces,and visual localization surfaces.The main research areas,such as pattern optimization,dynamic measurements,hot spot enhancement,and stability improvement,are highlighted.We also summarize the practical applications of surface-enhanced Raman scattering in chemical detection,microfluidic control,medical diagnosis,and food safety evaluation.Finally,the current challenges and limitations in the development of femtosecond laser-processed superwetting substrates for surface-enhanced Raman scattering are described.展开更多
Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-formi...Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-forming three-dimensional(3D)microscale functional devices and inducing fascinating and unique physical or chemical phenomena have granted this technology powerful versatility that no other technology can match.As this technology advances rapidly in various fields of application,some key challenges have emerged and remain to be urgently addressed.This review firstly introduces the fundamental principles for understanding how fs laser pulses interact with materials and the associated unique phenomena in section 2.Then micro/nano-fabrication in transparent materials by fs laser processing is presented in section 3.Thereafter,several high efficiency/throughput fabrication methods as well as pulse-shaping techniques are listed in sections 4 and 5 reviews four-dimensional(4D)and nanoscale printing realized by fs laser processing technology.Special attention is paid to the heterogeneous integration(HI)of functional materials enabled by fs laser processing in section 6.Several intriguing examples of 3D functional micro-devices created by fs laser-based manufacturing methods such as microfluidics,lab-on-chip,micro-optics,micro-mechanics,micro-electronics,micro-bots and micro-biodevices are reviewed in section 7.Finally,a summary of the review and a perspective are proposed to explore the challenges and future opportunities for further betterment of fs laser micro/nano processing technology.展开更多
The fatigue properties of laser shock processing （LSP） on both side surfaces of fastener hole with diameter of 3 mm in the LY12CZ aluminum alloy specimens were investigated. The superficial residual stress was measu...The fatigue properties of laser shock processing （LSP） on both side surfaces of fastener hole with diameter of 3 mm in the LY12CZ aluminum alloy specimens were investigated. The superficial residual stress was measured by X-ray diffraction method. Fatigue experiments of specimens with and without LSP were performed, and the microstructural features of fracture of specimens were characterized by scanning electron microscopy （SEM）. The results indicate that the compressive residual stress can be induced into the surface of specimen, and the fatigue life of the specimen with LSP is 3.5 times as long as that of specimen without LSP. The location of fatigue crack initiation is transferred from the top surface to the sub-surface after LSP, and the fatigue striation spacing of the treated specimen during the expanding fatigue crack is narrower than that of the untreated specimen. Furthermore, the diameters of the dimples on the fatigue crack rupture zone of the specimen with LSP are relatively bigger, which is related to the serious plastic deformation in the material with LSP.展开更多
In this paper, we reviewed the fabrications of functional microcavity lasers in soft materials such as polymer and protein by femtosecond laser processing. High-quality （Q） microdisks with a laser dye （Rhodamine B,...In this paper, we reviewed the fabrications of functional microcavity lasers in soft materials such as polymer and protein by femtosecond laser processing. High-quality （Q） microdisks with a laser dye （Rhodamine B, RhB） acting as gain medium were fabricated that produced whispering-gallery-mode （WGM） lasing output. We also obtained unidirectional lasing output with a low lasing threshold in a deformed spiral microcavity at room temperature. Photonic-molecule （PM） microlasers were prepared to investigate the interaction and coupling effects of different cavities, and it was found that the distance between the two disks plays an important role in the lasing behaviors. Single-mode lasing was realized from a stacked PM microlaser through Vernier effect. Furthermore we adopted the biocompatible materials, RhB-doped proteins as a host material and fabricated a three-dimensional （3D） WGM microlaser, which operated well both in air and aqueous environment. The sensing of the protein micro- lasers to Na2SO4 concentration was investigated. Our results of fabricating high-Q microlasers with different materials reveal the potential applications of femtosecond laser processing in the areas of integrated optoelectronic and ultrahigh sensitive bio-sensing devices.展开更多
Ceramic structural parts are one of the most widely utilized structural parts in the industry. However, they usually contain defects following the pressing process, such as burrs. Therefore, additional trimming is usu...Ceramic structural parts are one of the most widely utilized structural parts in the industry. However, they usually contain defects following the pressing process, such as burrs. Therefore, additional trimming is usually required, despite the deformation challenges and difficulty in positioning. This paper proposes an ultrafast laser processing system for trimming complex ceramic structural parts. Opto-electromechanical cooperative control software is developed to control the laser processing system. The trimming problem of the ceramic cores used in aero engines is studied. The regional registration method is introduced based on the iterative closest point algorithm to register the path extracted from the computer-aided design model with the deformed ceramic core. A zonal and layering processing method for three-dimensional contours on complex surfaces is proposed to generate the working data of high-speed scanning galvanometer and the computer numerical control machine tool, respectively. The results show that the laser system and the method proposed in this paper are suitable for trimming complex non-datum parts such as ceramic cores. Compared with the results of manual trimming, the method proposed in this paper has higher accuracy, efficiency, and yield. The method mentioned above has been used in practical application with satisfactory results.展开更多
The concentration of elements in molten metal of AZ31 magnesium alloy after long pulsed Nd：YAG laser processing was quantitatively analyzed by using calibration-free laser-induced breakdown spectroscopy （CF-LIBS）. ...The concentration of elements in molten metal of AZ31 magnesium alloy after long pulsed Nd：YAG laser processing was quantitatively analyzed by using calibration-free laser-induced breakdown spectroscopy （CF-LIBS）. The composition change in AZ31 magnesium alloy under different laser pulse width was also investigated. The experimental results showed that CF-LIBS can obtain satisfactory quantitative or semi-quantitative results for matrix or major elements, while only qualitative analysis was possible for minor or trace elements. Moreover, it is found that the chemical composition of molten metal will change after laser processing. The concentration of magnesium in molten metal is lower than that present in the base metal. The Mg loss increases with an increase of pulse width in the laser processing. This result shows that the selective vaporization of different elements is affected by the pulse width during laser processing.展开更多
The microstructure of the laser hardened layer on the HT20-40 gray cast iron after laser melting processing'was examined by optical microscopy,transmission electron microscopy (TEM)and scanning electron microscopy...The microstructure of the laser hardened layer on the HT20-40 gray cast iron after laser melting processing'was examined by optical microscopy,transmission electron microscopy (TEM)and scanning electron microscopy(SEM).Experimental results showed that a struc- ture with dendritic(M+A')and interdendriticly laminal transformed ledeburite (M+A'+Fe_3C)was produced after laser melting processing.The martensite is a mixture of dis- location martensite and twin martensite.Dislocation pile-ups and twins were found in the residual austenite.Microsegregation of composition and heterogeneity of microstructure were also apparent after laser melting processing.展开更多
Adhesive bonding is a promising joining technology for joining lightweight aluminum structures,offering advantages such as the absence of additional heat input,connection damage,and environmental pollution.To further ...Adhesive bonding is a promising joining technology for joining lightweight aluminum structures,offering advantages such as the absence of additional heat input,connection damage,and environmental pollution.To further enhance the strength of aluminum adhesive joints,this study investigates the influence of laser surface treatment on their mechanical properties.Specifically,the effect of laser processing patterns and their geometric parameters on aluminum alloy adhesive joints is examined.A fiber laser is used to process crater array and multi-groove pattern on A6061 aluminum surface.The impact of crater overlap ratio and groove distance on various aspects,including aluminum surface morphology,roughness(Sa),adhesive joints shear,tensile strength,and failure modes is discussed.Laser confocal microscope tests,water contact angle tests,lap shear tests,and cross tensile tests are employed to analyze these parameters.The results indicate that as the crater overlap ratio increases,the S_(a) value of the aluminum surface increases.Moreover,the shear strength of adhesive joints initially increases and then decreases,while the tensile strength consistently increases.On the other hand,an increase in groove distance leads to a decrease in S_(a),as well as a reduction in both shear and tensile strength of adhesive joints.For shear loading conditions,mechanical interlocking is identified as one of the bonding mechanisms in aluminum adhesive joints featuring crater array and multi-groove patterns.The formation of interlocking structures is found to be influenced by the aluminum surface pattern and its associated parameters,as revealed through failure surface analysis.Specifically,adhesive and crater or groove interactions contribute to the formation of interlocking structures in specimens with a crater overlap ratio of -60% or groove distances of 120,180,300,and 400μm.Conversely,specimens with overlap ratios of 0%,40%,and 60% exhibit interlocking structures formed by the adhesive and crater edge.展开更多
Over the last few decades,ultrafast laser processing has become a widely used tool for manufacturing microstructures and nanostructures.The real-time monitoring of laser material processing provides opportunities to i...Over the last few decades,ultrafast laser processing has become a widely used tool for manufacturing microstructures and nanostructures.The real-time monitoring of laser material processing provides opportunities to inspect processes and provide feedback.To date,in-situ and real-time monitoring of laser material processing has rarely been performed.To this end,we propose dual-path snapshot compressive microscopy(DP-SCM)for high-speed,large field-of-view,and high-resolution imaging for in-situ and real-time ultrafast laser processing.In the evaluation of DP-SCM,the field of view,lateral resolution,and imaging speed were measured to be 2 mm,775 nm,and 500 fps,respectively.In ultrafast laser processing,the laser scanning process is observed using a DP-SCM system when translating the sample stage and scanning the focused femtosecond laser.Finally,we monitored the development of a self-organized nanograting structure to validate the potential of our system for unveiling new material mechanisms.The proposed method serves as an add-up(plug-and-play)module for any imaging setup and has vast potential for opening new avenues for high-throughput imaging in laser material processing.展开更多
Despite the promising progress in conductive hydrogels made with pure conducting polymer,great challenges remain in the interface adhesion and robustness in longterm monitoring.To address these challenges,Prof.Seung H...Despite the promising progress in conductive hydrogels made with pure conducting polymer,great challenges remain in the interface adhesion and robustness in longterm monitoring.To address these challenges,Prof.Seung Hwan Ko and Taek-Soo Kim’s team introduced a laserinduced phase separation and adhesion method for fabricating conductive hydrogels consisting of pure poly(3,4-ethylenedioxythiophene):polystyrene sulfonate on polymer substrates.The laser-induced phase separation and adhesion treated conducting polymers can be selectively transformed into conductive hydrogels that exhibit wet conductivities of 101.4 S cm^(−1) with a spatial resolution down to 5μm.Moreover,they maintain impedance and charge-storage capacity even after 1 h of sonication.The micropatterned electrode arrays demonstrate their potential in long-term in vivo signal recordings,highlighting their promising role in the field of bioelectronics.展开更多
文摘Laser processing technologies enable the precise fabrication of arbitrary structures and devices with broad applications in micro-optics,micro-mechanics,and biomedicine.However,its adoption is limited by the large size,complexity,high cost,and low flexibility of optical systems.Metasurfaces enable precise multidimensional control of light fields,aligning well with the development trend toward compact,high-performance optical systems.Here,we review several recent studies on the application of metasurfaces in laser processing technologies,including 3D nanolithography,direct laser writing,and laser cutting.Metasurfaces provide an integrated operational platform with exceptional performance,poised to disrupt conventional laser processing workflows.This combination presents significant cost efficiency and substantial development potential,with promising applications in areas such as imaging,optical storage,advanced sensing,and space on-orbit manufacturing.
基金supported by the French ANRT agence nationale de la recherche technologique under the CIFRE conventions industrielles de formation par la recherche framework.
文摘This review examines the state-of-the-art in spatial manipulation of ultrafast laser processing using dynamic light modulators,with a particular focus on liquid crystal-based systems.We discuss phase modulation strategies and highlight the current limitations and challenges in surface and bulk processing.Specifically,we emphasize the delicate balance between high-fidelity beam shaping and energy efficiency,both critical for surface and bulk processing applications.Given the inherent physical limitations of spatial light modulators such as spatial resolution,fill factor,and phase modulation range.We explore techniques developed to bridge the gap between desired intensity distributions and actual experimental beam profiles.We present various laser light modulation technologies and the main algorithmic strategies for obtaining modulation patterns.The paper includes application examples across a wide range of fields,from surgery to surface structuring,cutting,bulk photo-inscription of optical functions,and additive manufacturing,highlighting the significant enhancements in processing speed and precision due to spatial beam shaping.The diverse applications and the technological limitations underscore the need for adapted modulation pattern calculation methods.We discuss several advancements addressing these challenges,involving both experimental and algorithmic developments,including the recent incorporation of artificial intelligence.Additionally,we cover recent progress in phase and pulse front control based on spatial modulators,which introduces an extra control parameter for light excitation with high potential for achieving more controlled processing outcomes.
基金supported by the National Natural Science Foundation of China(51975336)Key Research and Development Program of Shandong Province(2020JMRH0202)+1 种基金the National Natural Science Foundation of China(52172282)China Postdoctoral Science Foundation(2021M690106)。
文摘The biological performance of Ti-6Al-4V implant is primarily determined by their surface properties.However,traditional surface modification methods,such as acid etching,hardly make improvement in their osseointegration ability and antibacterial capacity.In this study,we prepared a multi-scale composite structure coated with zinc oxide(ZnO)on Ti-6Al-4V implant by an innovative technology of two-step laser processing combined with solution-assistant.Compared with the acid etching method,the physicochemical properties of surface significantly improved.The in vitro results showed that the particular dimension of micro-nano structure and the multifaceted nature of ZnO synergistically affected MC3T3-E1 osteogenesis and bacterial activities:(1)The surface morphology showed a‘contact guidance'effect on cell arrangement,which was conducive to the adhesion of filopodia and cell spreading,and the osteogenesis level of MC3T3-E1 was enhanced due to the release of zinc ions(Zn^(2+));(2)the characterization of bacterial response revealed that periodic nanostructures and Zn^(2+)released could cause damage to the cell wall of E.coli and reduce the adhesion and aggregation of S.aureus.In conclusion,the modified surface showed a synergistic effect of physical topography and chemical composition,making this a promising method and providing new insight into bone defect repairment.
基金Project(2021YFF0500200) supported by the National Key R&D Program of ChinaProject(52105437) supported by the National Natural Science Foundation of China+1 种基金Project(202006120184) supported by the Heilongjiang Provincial Postdoctoral Science Foundation,ChinaProject(LBH-Z20054) supported by the China Scholarship Council。
文摘The model of heat source(MHS) which reflects the thermal interaction between materials and laser during processing determines the accuracy of simulation results. To acquire desirable simulations results, although various modifications of heat sources in the aspect of absorption process of laser by materials have been purposed, the distribution of laser power density(DLPD) in MHS is still modeled theoretically. However, in the actual situations of laser processing, the DLPD is definitely different from the ideal models. So, it is indispensable to build MHS using actual DLPD to improve the accuracy of simulation results. Besides, an automatic modeling method will be benefit to simplify the tedious pre-processing of simulations. This paper presents a modeling method and corresponding algorithm to model heat source using measured DLPD. This algorithm automatically processes original data to get modeling parameters and provides a step MHS combining with absorption models. Simulations and experiments of heat transfer in steel plates irradiated by laser prove the mothed and the step MHS. Moreover, the investigations of laser induced thermal-crack propagation in glass highlight the signification of modeling heat source based on actual DLPD and demonstrate the enormous application of this method in the simulation of laser processing.
文摘We report the femtosecond(fs)laser fabrication of biomimetic omnidirectional iridescent metallic surfaces exhibiting efficient diffraction for practically any angle of light incidence.Such diffractive behavior is realized by means of multi-directional low-spatial-frequency,laser-induced periodic surface structures(LSFL)formed upon exploiting the cylindrical symmetry of a cylindrical vector(CV)fs field.We particularly demonstrate that the multi-directional gratings formed on stainless steel surface by a radially polarized fs beam,could mimic the omnidirectional structural coloration properties found in some natural species.Accordingly,the fabricated grating structures can spatially disperse the incident light into individual wavelength with high efficiency,exhibiting structural iridescence at all viewing angles.Analytical calculations using the grating equation reproduced the characteristic variation of the vivid colors observed as a function of incident angle.We envisage that our results will significantly contribute to the development of new photonic and light sensing devices.
基金supported by the National Natural Science Foundation of China[Grant No.52175377]the National Science and Technology Major Project[Grant No.2017-VII-0002-0095]the Graduate Scientific Research and Innovation Foundation of Chongqing[Grant No.CYB22009].
文摘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.
基金supported by a grant from the National Research Foundation of Korea(NRF)funded by the Ministry of Science ICT and Future Planning of Korea(No.2019R1A2C2002398)partially supported by the Alchemist Project(No.20012263)funded by the Ministry of Trade,Industry&Energy of Korea,the KIST Institutional Programthe Sejong University Program(No.20200392)。
文摘Indoor air quality(IAQ) directly affects the health of occupants. Household manufacturing equipment(HME) used for hobbies or educational purposes is a new and unexplored source of air pollution. In this study, we evaluated the characteristics of particulate and gaseous pollutants produced by a household laser processing equipment(HLPE). Various target materials were tested using a commercial HLPE under various operating conditions of laser power and sheath air flow rate. The mode diameters of the emitted particles gradually decreased as laser power increased, while the particle number concentration(PNC) and particle emission rate(PER) increased. In addition, as the sheath air flow rate quadrupled from 10 to 40 L/min, the mode diameter of the emitted particles decreased by nearly 25%, but the effect on the PNC was insignificant. When the laser induced the target materials at 53 m W, the mode diameters of particles were < 150 nm, and PNCs were > 2.0 × 10^(4) particles/cm^(3). Particularly, analyses of sampled aerosols indicated that harmful substances such as sulfur and barium were present in particles emitted from leather. The carcinogenic gaseous pollutants such as acrylonitrile, acetaldehyde, 1,3-butadiene, benzene, and C 8 aromatics(ethylbenzene) were emitted from all target materials. In an actual indoor environment, the PNC of inhalable ultrafine particles(UFPs) was > 5 × 10^(4) particles/cm^(3) during 30 min of HLPE operation. Our results suggest that more meticulous control methods are needed, including the use of less harmful target materials along with filters or adsorbents that prevent emission of pollutants.
基金supported by National Key Research and Development Program of China (2023YFB4402500,2023YFB4402400)National Natural Science Foundation of China (621041314)+1 种基金Natural Science Foundation of Shandong Province (ZR2023LZH007)Program of Qilu Young Scholars of Shandong University.
文摘Graphene oxide,as a 2D material with nanometer thickness,offers ultra-high mobility,chaotic properties,and low cost.These make graphene oxide memristors beneficial for reservoir computing(RC)networks.In this study,continuous-wave(CW)laser processing is used to reduce chaotic graphene oxide(CGO)films,resulting in the non-volatile storage capability based on the reduced chaotic graphene oxide(rCGO)films.Laser power significantly impacts the characteristics of the rCGO memristor.Material characterization indicates that laser radiation can effectively reduce the oxygen content in CGO films.With optimized laser power,the rCGO memristor achieves a large ratio at 18 mW laser power.Benefiting from the short-term mem-ory characteristics,distinct conductive states are achieved,which are further utilized to construct RC networks.With a third con-trol probe,the rCGO memristor can express rich reservoir states,demonstrating accuracy in predicting the Hénon map with an NRMSE below 0.3.These findings provide the potential for developing flexible RC networks based on graphene oxide memris-tors via laser processing.
基金supported by the National Natural Science Foundation of China (No.11574159)the Open Fund of the State Key Laboratory of High Field Laser Physics,China (Shanghai Institute of Optics and Fine Mechanics)the Special Research Foundation of the Central University of Nankai University (No.63191108)。
文摘In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and "thermal processing" and their mutual conversion, and determine the "cold processing" parameter window. The ablation threshold and incubation coefficient of 304 stainless steel foil are calculated, and the effects of scanning speed and effective pulse number on the ablation threshold are analyzed. The ANSYS software is used to simulate the radial and axial temperature distributions of the surface on 304 stainless steel foil sample and the heat-affected zone with a femtosecond laser fluence of 10 J/cm2 and an effective number of pulses of 1 200 are obtained. In the aspect of spectral detection, the Fourier transform infrared spectra of the sample before and after processing are measured and two processing mechanisms of "cold processing" and "hot processing" are confirmed, which proves that we can achieve the conversion between "cold processing" and "hot processing" by changing the laser fluence and determine the "cold processing" laser fluence range.
文摘The first multi-function laser processing system in the domestic for clutch manufacture,with abilities of cutting, jointing and heat treatment,was reported in this paper.One external optical path,double laser heads,adjust device by manual operation,automatically track were employed in this system Also the other parts of vehicles can be fabricated by this system,as well as clutches.The special processing to manufacture the clutches of heavy vehicles,which was developed by the project of this laser processing system,achieved the international standards and satisfied the economic development and nation defense in the do- mestic.
基金National Natural Science Foundation of China,Grant/Award Number:6240032084Natural Science Foundation of Shaanxi Province,Grant/Award Number:2023-JC-QN-0711+1 种基金Fundamental Research Funds for the Central Universities111 Project。
文摘The growing demand for surface-enhanced Raman scattering sensors in biochemical detection,environmental monitoring,microfluidics,and other fields has promoted the development of highly sensitive and stable substrates.Femtosecond laser-fabricated surfaces with controlled wettability,unique micro/nanostructure designs,and tunable extreme wetting properties can significantly enhance the signal amplification and reproducibility of surface-enhanced Raman scattering techniques.In this review,we offer a comprehensive overview of recent advancements in surface-enhanced Raman scattering techniques based on superwetting surfaces fabricated by femtosecond laser processing,including fully superhydrophobic surfaces,hybrid wettability surfaces,and visual localization surfaces.The main research areas,such as pattern optimization,dynamic measurements,hot spot enhancement,and stability improvement,are highlighted.We also summarize the practical applications of surface-enhanced Raman scattering in chemical detection,microfluidic control,medical diagnosis,and food safety evaluation.Finally,the current challenges and limitations in the development of femtosecond laser-processed superwetting substrates for surface-enhanced Raman scattering are described.
基金supported by National Key R&D Program of China(Grant Nos.2021YFB2802000 and 2022YFB2804300)Science and Technology Commission of Shanghai Municipality(Grant No.21DZ1100500)+3 种基金Shanghai Municipal Science and Technology Major Projectthe Shanghai Frontiers Science Center Program(2021-2025 No.20)National Natural Science Foundation of China(Grant No.61975123)Shanghai Scienceand Technology Innovation Action Plan(Grant No.23JC1403100)。
文摘Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-forming three-dimensional(3D)microscale functional devices and inducing fascinating and unique physical or chemical phenomena have granted this technology powerful versatility that no other technology can match.As this technology advances rapidly in various fields of application,some key challenges have emerged and remain to be urgently addressed.This review firstly introduces the fundamental principles for understanding how fs laser pulses interact with materials and the associated unique phenomena in section 2.Then micro/nano-fabrication in transparent materials by fs laser processing is presented in section 3.Thereafter,several high efficiency/throughput fabrication methods as well as pulse-shaping techniques are listed in sections 4 and 5 reviews four-dimensional(4D)and nanoscale printing realized by fs laser processing technology.Special attention is paid to the heterogeneous integration(HI)of functional materials enabled by fs laser processing in section 6.Several intriguing examples of 3D functional micro-devices created by fs laser-based manufacturing methods such as microfluidics,lab-on-chip,micro-optics,micro-mechanics,micro-electronics,micro-bots and micro-biodevices are reviewed in section 7.Finally,a summary of the review and a perspective are proposed to explore the challenges and future opportunities for further betterment of fs laser micro/nano processing technology.
基金Project (51175002) supported by the National Natural Science Foundation of ChinaProject (090414156) supported by the Natural Science Foundation of Anhui Province,China
文摘The fatigue properties of laser shock processing （LSP） on both side surfaces of fastener hole with diameter of 3 mm in the LY12CZ aluminum alloy specimens were investigated. The superficial residual stress was measured by X-ray diffraction method. Fatigue experiments of specimens with and without LSP were performed, and the microstructural features of fracture of specimens were characterized by scanning electron microscopy （SEM）. The results indicate that the compressive residual stress can be induced into the surface of specimen, and the fatigue life of the specimen with LSP is 3.5 times as long as that of specimen without LSP. The location of fatigue crack initiation is transferred from the top surface to the sub-surface after LSP, and the fatigue striation spacing of the treated specimen during the expanding fatigue crack is narrower than that of the untreated specimen. Furthermore, the diameters of the dimples on the fatigue crack rupture zone of the specimen with LSP are relatively bigger, which is related to the serious plastic deformation in the material with LSP.
文摘In this paper, we reviewed the fabrications of functional microcavity lasers in soft materials such as polymer and protein by femtosecond laser processing. High-quality （Q） microdisks with a laser dye （Rhodamine B, RhB） acting as gain medium were fabricated that produced whispering-gallery-mode （WGM） lasing output. We also obtained unidirectional lasing output with a low lasing threshold in a deformed spiral microcavity at room temperature. Photonic-molecule （PM） microlasers were prepared to investigate the interaction and coupling effects of different cavities, and it was found that the distance between the two disks plays an important role in the lasing behaviors. Single-mode lasing was realized from a stacked PM microlaser through Vernier effect. Furthermore we adopted the biocompatible materials, RhB-doped proteins as a host material and fabricated a three-dimensional （3D） WGM microlaser, which operated well both in air and aqueous environment. The sensing of the protein micro- lasers to Na2SO4 concentration was investigated. Our results of fabricating high-Q microlasers with different materials reveal the potential applications of femtosecond laser processing in the areas of integrated optoelectronic and ultrahigh sensitive bio-sensing devices.
基金the National Key R&D Program of China(Grant No.2016YFB1102500)the Key R&D Project in Shaanxi Province(Grant No.2019ZDLGY01-07)the Science and Technology Program of Jiangsu Province,China(Grant No.SBK2019041271).
文摘Ceramic structural parts are one of the most widely utilized structural parts in the industry. However, they usually contain defects following the pressing process, such as burrs. Therefore, additional trimming is usually required, despite the deformation challenges and difficulty in positioning. This paper proposes an ultrafast laser processing system for trimming complex ceramic structural parts. Opto-electromechanical cooperative control software is developed to control the laser processing system. The trimming problem of the ceramic cores used in aero engines is studied. The regional registration method is introduced based on the iterative closest point algorithm to register the path extracted from the computer-aided design model with the deformed ceramic core. A zonal and layering processing method for three-dimensional contours on complex surfaces is proposed to generate the working data of high-speed scanning galvanometer and the computer numerical control machine tool, respectively. The results show that the laser system and the method proposed in this paper are suitable for trimming complex non-datum parts such as ceramic cores. Compared with the results of manual trimming, the method proposed in this paper has higher accuracy, efficiency, and yield. The method mentioned above has been used in practical application with satisfactory results.
基金supported by National Natural Science Foundation of China(Nos.61405147,51375348)the Scientific Research Fund of Zhejiang Provincial Education Department,China(No.Y201430387)
文摘The concentration of elements in molten metal of AZ31 magnesium alloy after long pulsed Nd：YAG laser processing was quantitatively analyzed by using calibration-free laser-induced breakdown spectroscopy （CF-LIBS）. The composition change in AZ31 magnesium alloy under different laser pulse width was also investigated. The experimental results showed that CF-LIBS can obtain satisfactory quantitative or semi-quantitative results for matrix or major elements, while only qualitative analysis was possible for minor or trace elements. Moreover, it is found that the chemical composition of molten metal will change after laser processing. The concentration of magnesium in molten metal is lower than that present in the base metal. The Mg loss increases with an increase of pulse width in the laser processing. This result shows that the selective vaporization of different elements is affected by the pulse width during laser processing.
文摘The microstructure of the laser hardened layer on the HT20-40 gray cast iron after laser melting processing'was examined by optical microscopy,transmission electron microscopy (TEM)and scanning electron microscopy(SEM).Experimental results showed that a struc- ture with dendritic(M+A')and interdendriticly laminal transformed ledeburite (M+A'+Fe_3C)was produced after laser melting processing.The martensite is a mixture of dis- location martensite and twin martensite.Dislocation pile-ups and twins were found in the residual austenite.Microsegregation of composition and heterogeneity of microstructure were also apparent after laser melting processing.
基金sponsored by Fundamental Research Funds for the Central Universities(No.FRF-BD-20-08A,No.FRF-BD-19-003A).
文摘Adhesive bonding is a promising joining technology for joining lightweight aluminum structures,offering advantages such as the absence of additional heat input,connection damage,and environmental pollution.To further enhance the strength of aluminum adhesive joints,this study investigates the influence of laser surface treatment on their mechanical properties.Specifically,the effect of laser processing patterns and their geometric parameters on aluminum alloy adhesive joints is examined.A fiber laser is used to process crater array and multi-groove pattern on A6061 aluminum surface.The impact of crater overlap ratio and groove distance on various aspects,including aluminum surface morphology,roughness(Sa),adhesive joints shear,tensile strength,and failure modes is discussed.Laser confocal microscope tests,water contact angle tests,lap shear tests,and cross tensile tests are employed to analyze these parameters.The results indicate that as the crater overlap ratio increases,the S_(a) value of the aluminum surface increases.Moreover,the shear strength of adhesive joints initially increases and then decreases,while the tensile strength consistently increases.On the other hand,an increase in groove distance leads to a decrease in S_(a),as well as a reduction in both shear and tensile strength of adhesive joints.For shear loading conditions,mechanical interlocking is identified as one of the bonding mechanisms in aluminum adhesive joints featuring crater array and multi-groove patterns.The formation of interlocking structures is found to be influenced by the aluminum surface pattern and its associated parameters,as revealed through failure surface analysis.Specifically,adhesive and crater or groove interactions contribute to the formation of interlocking structures in specimens with a crater overlap ratio of -60% or groove distances of 120,180,300,and 400μm.Conversely,specimens with overlap ratios of 0%,40%,and 60% exhibit interlocking structures formed by the adhesive and crater edge.
基金supported by the National Natural Science Foundation of China(62271414)Science Fund for Distinguished Young Scholars of Zhejiang Province(LR23F010001)Research Center for Industries of the Future(RCIF)at Westlake University.and Key Project of the Westlake Institute for Optoelectronics(Grant No.2023GD007).
文摘Over the last few decades,ultrafast laser processing has become a widely used tool for manufacturing microstructures and nanostructures.The real-time monitoring of laser material processing provides opportunities to inspect processes and provide feedback.To date,in-situ and real-time monitoring of laser material processing has rarely been performed.To this end,we propose dual-path snapshot compressive microscopy(DP-SCM)for high-speed,large field-of-view,and high-resolution imaging for in-situ and real-time ultrafast laser processing.In the evaluation of DP-SCM,the field of view,lateral resolution,and imaging speed were measured to be 2 mm,775 nm,and 500 fps,respectively.In ultrafast laser processing,the laser scanning process is observed using a DP-SCM system when translating the sample stage and scanning the focused femtosecond laser.Finally,we monitored the development of a self-organized nanograting structure to validate the potential of our system for unveiling new material mechanisms.The proposed method serves as an add-up(plug-and-play)module for any imaging setup and has vast potential for opening new avenues for high-throughput imaging in laser material processing.
基金supported by the National Natural Science Foundation of China(52475610)Zhejiang Provincial Natural Science Foundation of China(LDQ24E050001).
文摘Despite the promising progress in conductive hydrogels made with pure conducting polymer,great challenges remain in the interface adhesion and robustness in longterm monitoring.To address these challenges,Prof.Seung Hwan Ko and Taek-Soo Kim’s team introduced a laserinduced phase separation and adhesion method for fabricating conductive hydrogels consisting of pure poly(3,4-ethylenedioxythiophene):polystyrene sulfonate on polymer substrates.The laser-induced phase separation and adhesion treated conducting polymers can be selectively transformed into conductive hydrogels that exhibit wet conductivities of 101.4 S cm^(−1) with a spatial resolution down to 5μm.Moreover,they maintain impedance and charge-storage capacity even after 1 h of sonication.The micropatterned electrode arrays demonstrate their potential in long-term in vivo signal recordings,highlighting their promising role in the field of bioelectronics.
