Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found im...Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found important applications in endomicroscopy and biomedical imaging.The potential of this versatile tool for monolithic manufacturing of dynamic micro-opto-electro-mechanical systems(MOEMSs),however,has not yet been sufficiently explored.This work introduces a 3D-nanoprinted lens actuator with a large optical aperture,optimized for remote focusing in miniaturized imaging systems.The device integrates orthoplanar linear motion springs,a self-aligned sintered micro-magnet,and a monolithic lens,actuated by dual microcoils for uniaxial motion.The use of 3D nanoprinting allows complete design freedom for the integrated optical lens,whereas the monolithic fabrication ensures inherent alignment of the lens with the mechanical elements.With a lens diameter of 1.4 mm and a compact footprint of 5.74 mm,it achieves high mechanical robustness at resonant frequencies exceeding 300 Hz while still providing a large displacement range of 200μm(±100μm).A comprehensive analysis of optical and mechanical performance,including the effects of coil temperature and polymer viscoelasticity,demonstrates its advantages over conventional micro-electro-mechanical system actuators,showcasing its potential for next-generation imaging applications.展开更多
The generation of tunably focused light at remote locations is a critical photonic functionality for a wide range of applications.Here,we present a novel concept in the emerging field of Metafibers that achieves,for t...The generation of tunably focused light at remote locations is a critical photonic functionality for a wide range of applications.Here,we present a novel concept in the emerging field of Metafibers that achieves,for the first time,fast,alignment-free,fiber-integrated spatial focus control in a monolithic arrangement.This is enabled by 3D nanoprinted intensity-sensitive phase-only on-fiber holograms,which establish a direct correlation between the intensity distribution in the hologram plane and the focus position.Precise adjustment to the relative power between the modes of a dual-core fiber generates a power-controlled interference pattern within the hologram,enabling controlled and dynamic focus shifts.This study addresses all relevant aspects,including computational optimization,advanced 3D nanoprinting,and tailored fiber fabrication.Experimental results supported by simulations validate the feasibility and efficiency of this monolithic Metafiber platform,which enables fast focus modulation and has transformative potential in optical manipulation,high-speed laser micromachining,telecommunications,and minimally invasive surgery.展开更多
The integration of functional components into flexible photonic environments is a critical area of research in integrated photonics and is essential for high-precision sensing.This work presents a novel concept of int...The integration of functional components into flexible photonic environments is a critical area of research in integrated photonics and is essential for high-precision sensing.This work presents a novel concept of interfacing square-core hollow-core waveguides with commercially available optical fibers using 3D nanoprinting,and demonstrates its practical relevance through a nanoscience-based characterization technique.In detail,this innovative concept results in a monolithic,fully fiber-integrated device with key advantages such as alignment-free operation,high-purity fundamental mode excitation,full polarization control,and a unique handling flexibility.For the first time,the application potential of a fiber-interfaced waveguide in nanoscale analysis is demonstrated by performing nanoparticle-tracking-analysis experiments.These experiments involve the tracking and analysis of individual gold nanospheres diffusing in the hollow core waveguide,enabled by nearly aberration-free imaging,extended observation times,and homogeneous light-line illumination.The study comprehensively covers design strategy,experimental implementation,key principles,optical characterization,and practical applications.The fiber-interfaced hollow-core waveguide concept offers significant potential for applications in bioanalytics,environmental sciences,quantum technologies,optical manipulation,and life sciences.It also paves the way for the development of novel all-fiber devices that exploit enhanced light-matter interaction in a monolithic form suitable for flexible and remote applications.展开更多
Piezoceramic is ubiquitously used in high-performance sensors and actuators.Three-dimensional(3D)printing of lead zirconate titanate(PZT)is attractive and highly desired for such device applications,but most of the ex...Piezoceramic is ubiquitously used in high-performance sensors and actuators.Three-dimensional(3D)printing of lead zirconate titanate(PZT)is attractive and highly desired for such device applications,but most of the existing methods are inherently limited to micron resolution,which makes them untenable for fabricating complex 3D architectures with high-definition features.Here,an electrohydrodynamic jet(E-Jet)nanoprinting strategy has been proposed to fabricate PZT 3D structures with the characteristics of flexibility and scalability.Different kinds of 3D PZT true nanostructures(resolution∼40 nm,aspect ratio∼400)were directly fabricated using a 100μm-sized nozzle.And the PZT nanostructures exhibited well-developed perovskite crystal morphology,large elastic strain(elongation≈13%),and high piezoelectric property(d_(31)≈(236.5×10^(−12))C·N^(-1)).A bionic PZT air-flow sensor was printed to monitor air-flow detection,demonstrating well sensitivity with ultra-slow air-flow of 0.02 m·s^(-1).The discovery reveals an efficient pathway to 3D-printing PZT nanostructures for next-generation high-performance piezoelectric devices.展开更多
Metasurface-based nanoprinting(meta-nanoprinting)has fully demonstrated its advantages in ultrahigh-density gray-scale/color image recording and display.A typical meta-nanoprinting device usually has image resolutions...Metasurface-based nanoprinting(meta-nanoprinting)has fully demonstrated its advantages in ultrahigh-density gray-scale/color image recording and display.A typical meta-nanoprinting device usually has image resolutions reaching 80 k dots per inch(dpi),far exceeding conventional technology such as gravure printing(typ.5 k dpi).Besides,by fully exploit-ing the design degrees of freedom of nanostructured metasurfaces,meta-nanoprinting has been developed from previ-ous single-channel to multiple-channels,to current multifunctional integration or even dynamic display.In this review,we overview the development of meta-nanoprinting,including the physics of nanoprinting to manipulate optical amplitude and spectrum,single-functional meta-nanoprinting,multichannel meta-nanoprinting,dynamic meta-nanoprinting and mul-tifunctional metasurface integrating nanoprinting with holography or metalens,etc.Applications of meta-nanoprinting such as image display,vortex beam generation,information decoding and hiding,information encryption,high-density optical storage and optical anti-counterfeiting have also been discussed.Finally,we conclude the opportunities and chal-lenges/perspectives in this rapidly developing research field of meta-nanoprinting.展开更多
To date,various micro/nanofabrication techniques have been developed during the global nanotechnology race,such as electron-beam lithography[1],photolithography[2],nanoimprint lithography[3],and 3D nanoprinting[4,5].B...To date,various micro/nanofabrication techniques have been developed during the global nanotechnology race,such as electron-beam lithography[1],photolithography[2],nanoimprint lithography[3],and 3D nanoprinting[4,5].Benefiting from these functional techniques,micro/nanoscale patterns can be easily generated onto a broad range of materials,including metals,semiconductors,ceramics,and polymers.However,a bold and even visionary question can be raised,is it possible to make patterns on living organisms rather than inanimate objects?Despite the emergence of numerous electronic devices for biological applications,directly processing biological samples remains a challenge due to the poor biocompatibility of many micro/nanofabrication methods[6].Researchers have attempted to prepare and transfer micro/nanopatterns onto cell surfaces[7],the structural integrity of these modifications can be compromised by the growth and development of cells during culture.Moreover,intact animal skin presents greater challenges for integration with metal patterns compared to cell surfaces.展开更多
We present the design, fabrication, and characterization of a dual polarization, mode-selective photonic lantern(PL) spatial multiplexer supporting three fiber modes (LP_(01), LP^(a)_(11), LP^(b)_(11)), measuring only...We present the design, fabrication, and characterization of a dual polarization, mode-selective photonic lantern(PL) spatial multiplexer supporting three fiber modes (LP_(01), LP^(a)_(11), LP^(b)_(11)), measuring only 300μm in length, for converting between three single-mode input sources and a single three-mode optical fiber. The PL is fabricated directly on the three sources, in this case three cores of a multi-core fiber, using a commercial two-photon polymerization-based 3D nanoprinter. Despite the diminutive size and high index contrast of the polymer core/air cladding waveguides, we observed low insertion loss multiplexing (less than-1.7 d B), low polarization dependent loss (less than-0.25 dB), mode dependent loss of-1.7 d B, low wavelength dependence, and mode group crosstalk of less than-16 dB. We demonstrate mode group multiplexed transmission using our mode-selective multiplexer/demultiplexer pair and a short three-mode fiber link in an on-off keying intensity modulation/direct detection(IM/DD) experiment, recovering two 12.5 Gb/s signals without MIMO processing.展开更多
Twisted optical fibers are a promising platform for manipulating circularly polarized light and orbital angular momentum beams for applications such as nonlinear frequency conversion,optical communication,or chiral se...Twisted optical fibers are a promising platform for manipulating circularly polarized light and orbital angular momentum beams for applications such as nonlinear frequency conversion,optical communication,or chiral sensing.However,integration into chip-scale technology is challenging because twisted fibers are incompatible with planar photonics and the achieved twist rates are limited.Here,we address these challenges by introducing the concept of 3D-nanoprinted on-chip twisted hollow-core light cages.We show theoretically and experimentally that the geometrical twisting of light cages forces the fundamental core mode of a given handedness to couple with selected higher-order core modes,resulting in strong circular dichroism(CD).These chiral resonances result from the angular momentum harmonics of the fundamental mode,allowing us to predict their spectral locations and the occurrence of circular birefringence.Twisted light cages enable very high twist rates and CD,exceeding those of twisted hollow-core fibers by more than two orders of magnitude(twist period,90μm;CD,0.8 dB∕mm).Moreover,the unique cage design provides lateral access to the central core region,enabling future applications in chiral spectroscopy.Therefore,the presented concept opens a path for translating twisted fiber research to on-chip technology,resulting in a new platform for integrated chiral photonics.展开更多
Wide-ranging biomedical applications spanning both research and clinical settings rely on microinjection protocols that involve using a long,hollow microneedle to deliver foreign substances directly into biological ta...Wide-ranging biomedical applications spanning both research and clinical settings rely on microinjection protocols that involve using a long,hollow microneedle to deliver foreign substances directly into biological targets,such as embryos.Unfortunately,conventional microneedles are prone to clogging—e.g.,cytoplasmic material from an embryo becoming lodged inside the needle tip during penetration,thereby obstructing delivery—motivating researchers to use top-down microfabrication techniques to modify needle tips and reduce such failure modes.Recent advancements for the submicron-scale additive manufacturing approach,“Two-Photon Direct Laser Writing(DLW)”,offer a new,bottom-up pathway for re-architecting microneedle tips to address clogging susceptibility via geometric means.Here,we investigate this potential by 3D printing monolithic 650-μm-tall,15-μm-diameter hollow microneedles comprising architectural features designed to remediate clogging phenomena:(i)a solid,fine-point tip,(ii)multiple side ports(i.e.,perpendicular to the insertion direction),and(iii)an internal microfilter.Serial microinjection experiments with live zebrafish embryos reveal that the 3D microneedles yield enhanced delivery performance without any instances of complete blockages that are pervasive among both standard glass and 3Dprinted control microneedles.These findings suggest that DLW-based 3D printing holds distinctive promise for highprecision microinjection applications,particularly in scenarios involving extensive serial injections or critical payloads and targets.展开更多
For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cas...For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cascaded metasurface that can independently encode information into multiple channels.Based on the orientation degeneracy of anisotropic metasurfaces,each single metasurface can produce a quick-response(QR)image in the near field,governed by the Malus law,while the combined channel can produce a holographic image in the far field,governed by geometric phase.The independent and physically separated trichannel design makes information encryption safer.展开更多
By its unparalleled capacity to manipulate optical parameters,metasurfaces demonstrate the ability to simultaneously manipulate the amplitude and phase of incident light.Exhibiting both near-field nanoprinting images ...By its unparalleled capacity to manipulate optical parameters,metasurfaces demonstrate the ability to simultaneously manipulate the amplitude and phase of incident light.Exhibiting both near-field nanoprinting images and far-field holography images is a quintessential illustration of this capability.In preceding investigations,image multiplexing commonly transpires within the single polarization state or orthogonal polarization states,thereby exhibiting a deficiency in terms of information security when contrasted with the nonorthogonal polarization states.In this research,a multifunctional metasurface with the capability of exhibiting four-channel images has been proposed by using a nanobrick as a quarter-wave plate.Through the adjustment of the orientation angles of each nanobrick,nanoprinting can be displayed under both linearly and circularly polarized light.Building on this,the propagation phase is combined with the geometric phase to generate diverse phase delays,enabling the metasurface to be multiplexed under two nonorthogonal polarization states to achieve four-channel image displays.Intriguingly,bidirectional nanoprinting and bidirectional holography can be achieved by altering the direction of incidence polarization states.The proposed metasurface platform can open new possibilities for creating compact multifunctional optical devices,while also enhancing applications in multichannel image displays,information anticounterfeiting,and encryption.展开更多
Top-down lithography techniques are needed for manufacturing uniform device structures based on emerging 2D-layered materials.Mechanical exfoliation approaches based on nanoimprint and nanoprint principles are capable...Top-down lithography techniques are needed for manufacturing uniform device structures based on emerging 2D-layered materials.Mechanical exfoliation approaches based on nanoimprint and nanoprint principles are capable of producing ordered arrays of multilayer transition metal dichalcogenide microstructures with a high uniformity of feature dimensions.In this study,we present a study on the applicability of nanoimprint-assisted shear exfoliation for generating ultrathin monolayer and few-layer MoS_(2) structures as well as the critical limits of feature dimensions produced via such nanoimprint and nanoprint-based processes.In particular,this work shows that give a lateral feature size of MoS_(2) structures that are pre-patterned on a bulk stamp,there exists a critical thickness or aspect ratio value,below which the exfoliated layered structures exhibit major defects.To exfoliate a highquality,uniform monolayer or few-layer structures,the characteristic lateral feature sizes of such structures need to be in the sub-100 nm regimes.In addition,the exfoliated MoS_(2) flakes of critical thicknesses exhibit prominent interlayer twisting features on their cleaved surfaces.Field-effect transistors made from these MoS_(2) flakes exhibit multiple(or quasi-analog-tunable)charge memory states.This work advances the knowledge regarding the limitations and application scope of nanoimprint and nanoprint processes in manufacturing nano/microstructures based on layered materials and provides a method for producing multi-bit charge memory devices.展开更多
While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of control...While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of controlled assembly of macromolecules such as star polymers[molecular weight(M_(w))∼383 kDa,hydrodynamic radius R∼13.8 nm]in droplets.This work extends this concept to smaller molecules,in this case,poly(ethylene glycol)bis-tetrazine(PEGbisTz,M_(w) 8.1 kDa,R∼1.5 nm).The key to controlled molecular assembly is to first deliver ultrasmall volumes(sub-fL)of solution containing PEG-bisTz to a substrate.The solvent evaporates rapidly due to the minute volume,thus forcing the assembly of solute,whose overall size and dimension are dictated by the initial liquid geometry and size.Using prepatterned surfaces,this work revealed that the initial liquid shape can be further tuned,and we could control the final assembly of solute such as PEGbisTz molecules.The degree of control was demonstrated by varying the micropatterns and delivery conditions.This work demonstrated the validity of controlled assembly for PEG-bisTz and enables three-dimensional(3D)nanoprinting of functional materials.The technology has promising applications in nanophotonics,nanoelectronics,nanocomposite materials,and tissue engineering.展开更多
State-of-the-art commercially available 3D laser micro-and nanoprinters using polymeric photoresists based on two-or multi-photon absorption rely on high-power pico-or femtosecond lasers,leading to fairly large and ex...State-of-the-art commercially available 3D laser micro-and nanoprinters using polymeric photoresists based on two-or multi-photon absorption rely on high-power pico-or femtosecond lasers,leading to fairly large and expensive instruments.Lately,we have introduced photoresists based on two-step absorption instead of two-photon absorption,allowing for the use of small and inexpensive continuous-wave 405 nm wavelength GaN semiconductor laser diodes with light-output powers below 1 mW.Here,using the identical photoresist system and similar laser diodes,we report on the design,construction,and characterization of a 3D laser nanoprinter that fits into a shoe box.This shoe box contains all optical components,namely the mounted laser,the collimation-and beam-shaping optics,a miniature MEMS xy-scanner,a tube lens,the focusing microscope objective lens(NA=1.4,100×magnification),a piezo slip-stick z-stage,the sample holder,a camera monitoring system,LED sample illumination,as well as the miniaturized control electronics employing a microcontroller.We present a gallery of example 3D structures printed with this instrument.We achieve about 100 nm lateral spatial resolution and focus scan speeds of about 1 mm/s.Potentially,our shoe-box-sized system can be made orders of magnitude less expensive than today’s commercial systems.展开更多
文摘Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found important applications in endomicroscopy and biomedical imaging.The potential of this versatile tool for monolithic manufacturing of dynamic micro-opto-electro-mechanical systems(MOEMSs),however,has not yet been sufficiently explored.This work introduces a 3D-nanoprinted lens actuator with a large optical aperture,optimized for remote focusing in miniaturized imaging systems.The device integrates orthoplanar linear motion springs,a self-aligned sintered micro-magnet,and a monolithic lens,actuated by dual microcoils for uniaxial motion.The use of 3D nanoprinting allows complete design freedom for the integrated optical lens,whereas the monolithic fabrication ensures inherent alignment of the lens with the mechanical elements.With a lens diameter of 1.4 mm and a compact footprint of 5.74 mm,it achieves high mechanical robustness at resonant frequencies exceeding 300 Hz while still providing a large displacement range of 200μm(±100μm).A comprehensive analysis of optical and mechanical performance,including the effects of coil temperature and polymer viscoelasticity,demonstrates its advantages over conventional micro-electro-mechanical system actuators,showcasing its potential for next-generation imaging applications.
基金German Research Foundation(DFG)via the grants SCHM2655/21-1,SCHM2655/23-1,QI 140/2-1。
文摘The generation of tunably focused light at remote locations is a critical photonic functionality for a wide range of applications.Here,we present a novel concept in the emerging field of Metafibers that achieves,for the first time,fast,alignment-free,fiber-integrated spatial focus control in a monolithic arrangement.This is enabled by 3D nanoprinted intensity-sensitive phase-only on-fiber holograms,which establish a direct correlation between the intensity distribution in the hologram plane and the focus position.Precise adjustment to the relative power between the modes of a dual-core fiber generates a power-controlled interference pattern within the hologram,enabling controlled and dynamic focus shifts.This study addresses all relevant aspects,including computational optimization,advanced 3D nanoprinting,and tailored fiber fabrication.Experimental results supported by simulations validate the feasibility and efficiency of this monolithic Metafiber platform,which enables fast focus modulation and has transformative potential in optical manipulation,high-speed laser micromachining,telecommunications,and minimally invasive surgery.
基金supported by the German Research Foundation via the grants SCHM2655/15-1 and SCHM2655/22-1supported by Fundacao para a Ciencia e a Tecnologia(FCT/MCTES)by national funds(OE)UIDB/50025/2020,UIDP/50025/2020&CEECINST/00013/2021/CP2779/CT0014through the PhD research grant 2022.09911.BD.
文摘The integration of functional components into flexible photonic environments is a critical area of research in integrated photonics and is essential for high-precision sensing.This work presents a novel concept of interfacing square-core hollow-core waveguides with commercially available optical fibers using 3D nanoprinting,and demonstrates its practical relevance through a nanoscience-based characterization technique.In detail,this innovative concept results in a monolithic,fully fiber-integrated device with key advantages such as alignment-free operation,high-purity fundamental mode excitation,full polarization control,and a unique handling flexibility.For the first time,the application potential of a fiber-interfaced waveguide in nanoscale analysis is demonstrated by performing nanoparticle-tracking-analysis experiments.These experiments involve the tracking and analysis of individual gold nanospheres diffusing in the hollow core waveguide,enabled by nearly aberration-free imaging,extended observation times,and homogeneous light-line illumination.The study comprehensively covers design strategy,experimental implementation,key principles,optical characterization,and practical applications.The fiber-interfaced hollow-core waveguide concept offers significant potential for applications in bioanalytics,environmental sciences,quantum technologies,optical manipulation,and life sciences.It also paves the way for the development of novel all-fiber devices that exploit enhanced light-matter interaction in a monolithic form suitable for flexible and remote applications.
基金supported by National Natural Science Foundation of China(Grant No.52105577)Natural Science Foundation of Zhejiang Province(Grant No.LQ22E050001)+3 种基金Natural Science Foundation of Ningbo(Grant Nos.2024J427 and 2023J376)China Postdoctoral Science Foundation(Grant No.2024M753510)Ningbo Yongjiang Talent Introduction Programme(Grant No.2021A-137-G)Research Grants Council of the Hong Kong Special Administrative Region,China(Grant Nos.11200623 and RFS2021-1S05).
文摘Piezoceramic is ubiquitously used in high-performance sensors and actuators.Three-dimensional(3D)printing of lead zirconate titanate(PZT)is attractive and highly desired for such device applications,but most of the existing methods are inherently limited to micron resolution,which makes them untenable for fabricating complex 3D architectures with high-definition features.Here,an electrohydrodynamic jet(E-Jet)nanoprinting strategy has been proposed to fabricate PZT 3D structures with the characteristics of flexibility and scalability.Different kinds of 3D PZT true nanostructures(resolution∼40 nm,aspect ratio∼400)were directly fabricated using a 100μm-sized nozzle.And the PZT nanostructures exhibited well-developed perovskite crystal morphology,large elastic strain(elongation≈13%),and high piezoelectric property(d_(31)≈(236.5×10^(−12))C·N^(-1)).A bionic PZT air-flow sensor was printed to monitor air-flow detection,demonstrating well sensitivity with ultra-slow air-flow of 0.02 m·s^(-1).The discovery reveals an efficient pathway to 3D-printing PZT nanostructures for next-generation high-performance piezoelectric devices.
基金We are grateful for financial supports from the National Key Research and Development Program of China(Grant No.2021YFE0205800)National Natural Science Foundation of China(Grant Nos.12174292,62205252,11904267 and 91950110)the Fundamental Research Funds for the Central Universities(Grant Nos.2042022kf0024,2042022kf1013 and 2042022kf1011).
文摘Metasurface-based nanoprinting(meta-nanoprinting)has fully demonstrated its advantages in ultrahigh-density gray-scale/color image recording and display.A typical meta-nanoprinting device usually has image resolutions reaching 80 k dots per inch(dpi),far exceeding conventional technology such as gravure printing(typ.5 k dpi).Besides,by fully exploit-ing the design degrees of freedom of nanostructured metasurfaces,meta-nanoprinting has been developed from previ-ous single-channel to multiple-channels,to current multifunctional integration or even dynamic display.In this review,we overview the development of meta-nanoprinting,including the physics of nanoprinting to manipulate optical amplitude and spectrum,single-functional meta-nanoprinting,multichannel meta-nanoprinting,dynamic meta-nanoprinting and mul-tifunctional metasurface integrating nanoprinting with holography or metalens,etc.Applications of meta-nanoprinting such as image display,vortex beam generation,information decoding and hiding,information encryption,high-density optical storage and optical anti-counterfeiting have also been discussed.Finally,we conclude the opportunities and chal-lenges/perspectives in this rapidly developing research field of meta-nanoprinting.
基金supported by the National Natural Science Foundation of China(52203305,U21A20494,and 61927820)。
文摘To date,various micro/nanofabrication techniques have been developed during the global nanotechnology race,such as electron-beam lithography[1],photolithography[2],nanoimprint lithography[3],and 3D nanoprinting[4,5].Benefiting from these functional techniques,micro/nanoscale patterns can be easily generated onto a broad range of materials,including metals,semiconductors,ceramics,and polymers.However,a bold and even visionary question can be raised,is it possible to make patterns on living organisms rather than inanimate objects?Despite the emergence of numerous electronic devices for biological applications,directly processing biological samples remains a challenge due to the poor biocompatibility of many micro/nanofabrication methods[6].Researchers have attempted to prepare and transfer micro/nanopatterns onto cell surfaces[7],the structural integrity of these modifications can be compromised by the growth and development of cells during culture.Moreover,intact animal skin presents greater challenges for integration with metal patterns compared to cell surfaces.
文摘We present the design, fabrication, and characterization of a dual polarization, mode-selective photonic lantern(PL) spatial multiplexer supporting three fiber modes (LP_(01), LP^(a)_(11), LP^(b)_(11)), measuring only 300μm in length, for converting between three single-mode input sources and a single three-mode optical fiber. The PL is fabricated directly on the three sources, in this case three cores of a multi-core fiber, using a commercial two-photon polymerization-based 3D nanoprinter. Despite the diminutive size and high index contrast of the polymer core/air cladding waveguides, we observed low insertion loss multiplexing (less than-1.7 d B), low polarization dependent loss (less than-0.25 dB), mode dependent loss of-1.7 d B, low wavelength dependence, and mode group crosstalk of less than-16 dB. We demonstrate mode group multiplexed transmission using our mode-selective multiplexer/demultiplexer pair and a short three-mode fiber link in an on-off keying intensity modulation/direct detection(IM/DD) experiment, recovering two 12.5 Gb/s signals without MIMO processing.
基金financial support from the German Research Foundation via Grant Nos.MA 4699/2-1,MA 4699/9-1,SCHM2655/11-1,SCHM2655/15-1,SCHM2655/8-1,SCHM2655/22-1,and WE 5815/5-1 and via project number 512648189。
文摘Twisted optical fibers are a promising platform for manipulating circularly polarized light and orbital angular momentum beams for applications such as nonlinear frequency conversion,optical communication,or chiral sensing.However,integration into chip-scale technology is challenging because twisted fibers are incompatible with planar photonics and the achieved twist rates are limited.Here,we address these challenges by introducing the concept of 3D-nanoprinted on-chip twisted hollow-core light cages.We show theoretically and experimentally that the geometrical twisting of light cages forces the fundamental core mode of a given handedness to couple with selected higher-order core modes,resulting in strong circular dichroism(CD).These chiral resonances result from the angular momentum harmonics of the fundamental mode,allowing us to predict their spectral locations and the occurrence of circular birefringence.Twisted light cages enable very high twist rates and CD,exceeding those of twisted hollow-core fibers by more than two orders of magnitude(twist period,90μm;CD,0.8 dB∕mm).Moreover,the unique cage design provides lateral access to the central core region,enabling future applications in chiral spectroscopy.Therefore,the presented concept opens a path for translating twisted fiber research to on-chip technology,resulting in a new platform for integrated chiral photonics.
基金supported in part by U.S.National Institutes of Health(NIH)Award Numbers 1R41GM153053 and 1R41MH135827U.S.National Science Foundation(NSF)Award Numbers 1943356 and 1938527Maryland Industrial Partnerships(MIPS)Award Numbers 6523 and 7422.
文摘Wide-ranging biomedical applications spanning both research and clinical settings rely on microinjection protocols that involve using a long,hollow microneedle to deliver foreign substances directly into biological targets,such as embryos.Unfortunately,conventional microneedles are prone to clogging—e.g.,cytoplasmic material from an embryo becoming lodged inside the needle tip during penetration,thereby obstructing delivery—motivating researchers to use top-down microfabrication techniques to modify needle tips and reduce such failure modes.Recent advancements for the submicron-scale additive manufacturing approach,“Two-Photon Direct Laser Writing(DLW)”,offer a new,bottom-up pathway for re-architecting microneedle tips to address clogging susceptibility via geometric means.Here,we investigate this potential by 3D printing monolithic 650-μm-tall,15-μm-diameter hollow microneedles comprising architectural features designed to remediate clogging phenomena:(i)a solid,fine-point tip,(ii)multiple side ports(i.e.,perpendicular to the insertion direction),and(iii)an internal microfilter.Serial microinjection experiments with live zebrafish embryos reveal that the 3D microneedles yield enhanced delivery performance without any instances of complete blockages that are pervasive among both standard glass and 3Dprinted control microneedles.These findings suggest that DLW-based 3D printing holds distinctive promise for highprecision microinjection applications,particularly in scenarios involving extensive serial injections or critical payloads and targets.
基金supported by the National Key Research and Development Program of China(No.2021YFE0205800)the National Natural Science Foundation of China(Nos.12174292,11904267,and 91950110)the Fundamental Research Funds for the Central Universities(Nos.2042022kf1013,2042022kf0024,and 2042021kf0018)。
文摘For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cascaded metasurface that can independently encode information into multiple channels.Based on the orientation degeneracy of anisotropic metasurfaces,each single metasurface can produce a quick-response(QR)image in the near field,governed by the Malus law,while the combined channel can produce a holographic image in the far field,governed by geometric phase.The independent and physically separated trichannel design makes information encryption safer.
基金supported by the National Natural Science Foundation of China (NSFC) (Nos.62175070 and 61774062)the Natural Science Foundation of Guangdong Province (No.2021A1515010352)the Science and Technology Program of Guangzhou (No.2019050001)。
文摘By its unparalleled capacity to manipulate optical parameters,metasurfaces demonstrate the ability to simultaneously manipulate the amplitude and phase of incident light.Exhibiting both near-field nanoprinting images and far-field holography images is a quintessential illustration of this capability.In preceding investigations,image multiplexing commonly transpires within the single polarization state or orthogonal polarization states,thereby exhibiting a deficiency in terms of information security when contrasted with the nonorthogonal polarization states.In this research,a multifunctional metasurface with the capability of exhibiting four-channel images has been proposed by using a nanobrick as a quarter-wave plate.Through the adjustment of the orientation angles of each nanobrick,nanoprinting can be displayed under both linearly and circularly polarized light.Building on this,the propagation phase is combined with the geometric phase to generate diverse phase delays,enabling the metasurface to be multiplexed under two nonorthogonal polarization states to achieve four-channel image displays.Intriguingly,bidirectional nanoprinting and bidirectional holography can be achieved by altering the direction of incidence polarization states.The proposed metasurface platform can open new possibilities for creating compact multifunctional optical devices,while also enhancing applications in multichannel image displays,information anticounterfeiting,and encryption.
基金This work was supported by NSF grant#CMMI-1636132.
文摘Top-down lithography techniques are needed for manufacturing uniform device structures based on emerging 2D-layered materials.Mechanical exfoliation approaches based on nanoimprint and nanoprint principles are capable of producing ordered arrays of multilayer transition metal dichalcogenide microstructures with a high uniformity of feature dimensions.In this study,we present a study on the applicability of nanoimprint-assisted shear exfoliation for generating ultrathin monolayer and few-layer MoS_(2) structures as well as the critical limits of feature dimensions produced via such nanoimprint and nanoprint-based processes.In particular,this work shows that give a lateral feature size of MoS_(2) structures that are pre-patterned on a bulk stamp,there exists a critical thickness or aspect ratio value,below which the exfoliated layered structures exhibit major defects.To exfoliate a highquality,uniform monolayer or few-layer structures,the characteristic lateral feature sizes of such structures need to be in the sub-100 nm regimes.In addition,the exfoliated MoS_(2) flakes of critical thicknesses exhibit prominent interlayer twisting features on their cleaved surfaces.Field-effect transistors made from these MoS_(2) flakes exhibit multiple(or quasi-analog-tunable)charge memory states.This work advances the knowledge regarding the limitations and application scope of nanoimprint and nanoprint processes in manufacturing nano/microstructures based on layered materials and provides a method for producing multi-bit charge memory devices.
基金supported by the National Science Foundation(nos.CHE-1808829 and DMR 1809612)National Institutes of Health(no.R01DC014461)the United States,and the Gordon and Betty Moore Foundation.
文摘While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of controlled assembly of macromolecules such as star polymers[molecular weight(M_(w))∼383 kDa,hydrodynamic radius R∼13.8 nm]in droplets.This work extends this concept to smaller molecules,in this case,poly(ethylene glycol)bis-tetrazine(PEGbisTz,M_(w) 8.1 kDa,R∼1.5 nm).The key to controlled molecular assembly is to first deliver ultrasmall volumes(sub-fL)of solution containing PEG-bisTz to a substrate.The solvent evaporates rapidly due to the minute volume,thus forcing the assembly of solute,whose overall size and dimension are dictated by the initial liquid geometry and size.Using prepatterned surfaces,this work revealed that the initial liquid shape can be further tuned,and we could control the final assembly of solute such as PEGbisTz molecules.The degree of control was demonstrated by varying the micropatterns and delivery conditions.This work demonstrated the validity of controlled assembly for PEG-bisTz and enables three-dimensional(3D)nanoprinting of functional materials.The technology has promising applications in nanophotonics,nanoelectronics,nanocomposite materials,and tissue engineering.
基金We thank Vincent Hahn,Michael Thiel(Nanoscribe),and Matthias Blaicher(Nanoscribe)for discussions.We acknowledge funding by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy for the Excellence Cluster“3D Matter Made to Order”(2082/1-390761711)by the Carl Zeiss Foundation,by the Helmholtz program“Science and Technology of Nanosystems”,by the Karlsruhe School of Optics and Photonics(KSOP),by the Max Planck School of Photonics(MPSP)by Nanoscribe-A BICO company.
文摘State-of-the-art commercially available 3D laser micro-and nanoprinters using polymeric photoresists based on two-or multi-photon absorption rely on high-power pico-or femtosecond lasers,leading to fairly large and expensive instruments.Lately,we have introduced photoresists based on two-step absorption instead of two-photon absorption,allowing for the use of small and inexpensive continuous-wave 405 nm wavelength GaN semiconductor laser diodes with light-output powers below 1 mW.Here,using the identical photoresist system and similar laser diodes,we report on the design,construction,and characterization of a 3D laser nanoprinter that fits into a shoe box.This shoe box contains all optical components,namely the mounted laser,the collimation-and beam-shaping optics,a miniature MEMS xy-scanner,a tube lens,the focusing microscope objective lens(NA=1.4,100×magnification),a piezo slip-stick z-stage,the sample holder,a camera monitoring system,LED sample illumination,as well as the miniaturized control electronics employing a microcontroller.We present a gallery of example 3D structures printed with this instrument.We achieve about 100 nm lateral spatial resolution and focus scan speeds of about 1 mm/s.Potentially,our shoe-box-sized system can be made orders of magnitude less expensive than today’s commercial systems.
