Engineering the spectra of photon triplets generated from micro/nanofiber

Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversion in micro/nanofiber.The phase mismatching at one-third pump frequency gives rise to non-degenerate photon triplets,the joint spectral intensity of which has an elliptical locus with a fixed eccentricity of√6/3.Therefore,we propose a frequency-division scheme to separate non-degenerate photon triplets into three channels with high heralding efficiency for the first time.Choosing an appropriate pump wavelength can compensate for the fabrication errors of micro/nanofiber and also generate narrowband,non-degenerate photon triplet sources with a high signal-to-noise ratio.Furthermore,the long-period micro/nanofiber grating introduces a new controllable degree of freedom to tailor phase matching,resulting from the periodic oscillation of dispersion.In this scheme,the wavelength of photon triplets can be flexibly tuned using quasi-phase matching.We study the generation of photon triplets from this novel perspective of spectrum engineering,and we believe that this work will accelerate the practical implementation of photon triplets in quantum information processing.

Optical micro/nanofiber enabled tactile sensors and soft actuators:A review

As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.

Highly sensitive and fast response strain sensor based on evanescently coupled micro/nanofibers

Flexible strain sensors play an important role in electronic skins,wearable medical devices,and advanced robots.Herein,a highly sensitive and fast response optical strain sensor with two evanescently coupled optical micro/nanofibers(MNFs)embedded in a polydimethylsiloxane(PDMS)film is proposed.The strain sensor exhibits a gauge factor as high as 64.5 for strain≤0.5%and a strain resolution of 0.0012%which corresponds to elongation of 120 nm on a 1 cm long device.As a proof-of-concept,highly sensitive fingertip pulse measurement is realized.The properties of fast temporal frequency response up to 30 kHz and a pressure sensitivity of 102 kPa^(−1) enable the sensor for sound detection.Such versatile sensor could be of great use in physiological signal monitoring,voice recognition and micro-displacement detection.

Ultrasensitive skin‐like wearable optical sensors based on glass micro/nanofibers

Electronic skin,a class of wearable electronic sensors that mimic the functionalities of human skin,has made remarkable success in applications including health monitoring,human-machine interaction and electronic-biological interfaces.While electronic skin continues to achieve higher sensitivity and faster response,its ultimate performance is fundamentally limited by the nature of low-frequency AC currents.Herein,highly sensitive skin-like wearable optical sensors are demonstrated by embedding glass micro/nanofibers(MNFs)in thin layers of polydimethylsiloxane(PDMS).Enabled by the transition from guided modes into radiation modes of the waveguiding MNFs upon external stimuli,the skin-like optical sensors show ultrahigh sensitivity(1870 k·Pa^-1),low detection limit(7 mPa)and fast response(10μs)for pressure sensing,significantly exceeding the performance metrics of state-of-the-art electronic skins.Electromagnetic interference(EMI)-free detection of high-frequency vibrations,wrist pulse and human voice are realized.Moreover,a five-sensor optical data glove and a 2×2-MNF tactile sensor are demonstrated.These initial results pave the way toward a new category of optical devices ranging from ultrasensitive wearable sensors to optical skins.

Preparation and Characterization of Electrospun Polylactic Acid Micro/Nanofibers under Different Solvent Conditions

Electrospinning is a versatile and popular method for the fabrication of ultrafine fibers and many parameters in electrospinning can be adjusted when ideal micro/nanofibers are required.In particular,the selection of a proper solvent condition is a fundamental and crucial step to produce electrospun ultrafine fibers.In this study,a commonly used biomaterial,polylactic acid(PLA),was dissolved in 7 different solvents and PLA micro/nanofibers were prepared by electrospinning.The morphology,porosity,mechanical property and static contact angle were characterized to determine the quality of the obtained product.The results show that different solvent conditions have a significant effect on both the diameter,surface smooth degree of PLA micro/nanofibers and the properties of the fibrous membranes.

Parallel fabrication of silica optical microfibers and nanofibers

Optical micro/nanofibers(MNFs)taper-drawn from silica fibers possess intriguing optical and mechanical properties.Recently,MNF array or MNFs with identical geometries have been attracting more and more attention,however,current fabrication technique can draw only one MNF at a time,with a low drawing speed(typically 0.1 mm/s)and a complicated process for high-precision control,making it inefficient in fabricating multiple MNFs.Here,we propose a parallel-fabrication approach to simultaneously drawing multiple(up to 20)MNFs with almost identical geometries.For fiber diameter larger than 500 nm,measured optical transmittances of all as-drawn MNFs exceed 96.7%at 1550-nm wavelength,with a diameter deviation within 5%.Our results pave a way towards high-yield fabrication of MNFs that may find applications from MNF-based optical sensors,optical manipulation to fiber-to-chip interconnection.

Recent progress on the applications of micro/nanofibers in ultrafast optics

Ultrafast fiber lasers are indispensable components in the field of ultrafast optics,and their continuous performance advancements are driving the progress of this exciting discipline.Micro/Nanofibers(MNFs)possess unique properties,such as a large fractional evanescent field,flexible and controllable dispersion,and high nonlinearity,making them highly valuable for generating ultrashort pulses.Particularly,in tasks involving mode-locking and dispersion and nonlinearity management,MNFs provide an excellent platform for investigating intriguing nonlinear dynamics and related phenomena,thereby promoting the advancement of ultrafast fiber lasers.In this paper,we present an introduction to the mode evolution and characteristics of MNFs followed by a comprehensive review of recent advances in using MNFs for ultrafast optics applications including evanescent field modulation and control,dispersion and nonlinear management techniques,and nonlinear dynamical phenomenon exploration.Finally,we discuss the potential application prospects of MNFs in the realm of ultrafast optics.

石墨烯-PAN基复合纳米纤维的微观形貌及其抗菌性能

为了优化GO-PAN基复合纳米纤维的制备方法,探究石墨烯的质量分数对复合纳米纤维抗菌性能的影响效果,利用静电纺丝法制备了不同石墨烯质量分数的GO-PAN基复合纳米纤维,使用X射线衍射仪、扫描电子显微镜、傅里叶红外光谱、差示扫描量热仪、力学性能分析等对复合纳米纤维的宏观性能和微观结构进行表征。研究结果表明:石墨烯的添加降低了复合纳米纤维的结晶度,GO-PAN基复合纳米纤维微观上呈三维网状结构,纳米纤维无序交错排列,纤维直径为170~230 nm。随着石墨烯质量分数的增加,复合纳米纤维的拉伸强度先增大后降低,断裂延伸率持续降低,且当石墨烯质量分数增大至0.9%时,复合纤维的拉伸强度达到了最大值20.61 MPa;石墨烯的添加改善了复合纳米纤维热学性能,脱水温度提高。GO-PAN基复合纳米纤维对大肠杆菌和金黄色葡萄球菌的抑菌率均超过了95%,且石墨烯质量分数0.9%的复合纳米纤维膜对2种菌种的抑菌效率均达到最大值,抑菌率分别为97.32%、99.85%,其中复合纳米纤维膜对金黄色葡萄球菌的抑菌效率高于大肠杆菌。

高分子量壳聚糖皮芯结构微纳米纤维膜制备

高分子量壳聚糖因具有良好的抗菌性、可促进细胞和组织生长以及可降解等特性,被认为是促进伤口愈合的优良材料;然而高分子量壳聚糖纺丝液黏度大,用常规静电纺丝法难以制成微纳米纤维。为解决这个问题,采用溶液喷射纺丝法制备了高分子量壳聚糖/聚氧化乙烯微纳米纤维,纺丝液含有质量分数为1.6%的高分子量壳聚糖和2.5%~5.0%的聚氧化乙烯(相对分子质量为10万)。所制备的微纳米纤维呈直线形,表面呈不光滑波纹状。通过MatLab对扫描电子显微镜照片进行识别和计算,结果表明,当聚氧化乙烯质量分数从2.5%增加到5.0%时,纤维平均直径从133 nm增加到210 nm,直径分布变宽;微纳米纤维材料中大孔隙增多,孔隙率在0.69左右,变化不大;X射线光电子能谱和透射电子显微镜分析结果表明,所制备的高分子量壳聚糖/聚氧化乙烯喷射纺丝微纳米纤维具有皮芯结构,其中,聚氧化乙烯位于皮层,高分子量壳聚糖构成微纳米纤维的内芯;动物实验初步证明了高分子量壳聚糖皮芯结构微纳米纤维可以促进伤口愈合。

Optical microfiber or nanofiber:a miniature fiber-optic platform for nanophotonics

An optical micro/nanofiber(MNF)is a quasi-one-dimensional free-standing optical waveguide with a diameter close to or less than the vacuum wavelength of light.Combining the tiny geometry with highrefractive-index contrast between the core and the surrounding,the MNF exhibits favorable optical properties such as tight optical confinement,strong evanescent field,and large-diameter-dependent waveguide dispersion.Meanwhile,as a quasi-one-dimensional structure with extraordinarily high geometric and structural uniformity,the MNF also has low optical loss and high mechanical strength,making it favorable for manipulating light on the micro/nanoscale with high flexibility.Over the past two decades,optical MNFs,typically being operated in single mode,have been emerging as a miniaturized fiber-optic platform for both scientific research and technological applications.In this paper,we aim to provide a comprehensive overview of the representative advances in optical MNFs in recent years.Starting from the basic structures and fabrication techniques of the optical MNFs,we highlight linear and nonlinear optical and mechanical properties of the MNFs.Then,we introduce typical applications of optical MNFs from nearfield optics,passive optical components,optical sensors,and optomechanics to fiber lasers and atom optics.Finally,we give a brief summary of the current status of MNF optics and technology,and provide an outlook into future challenges and opportunities.

基于深度学习的微纳光纤自动制备系统

在微纳光纤拉锥制备过程中,对直径的大范围、高精度和动态实时性测量是实现低损耗传输和色散调控的关键.针对现有传统制备方法直径调控范围小、操作复杂及耗时长等问题,本文基于深度学习神经网络算法实现了微纳光纤自动检测系统.利用计算机视觉中的图像分割方法,通过制作高质量多尺度微纳光纤数据集,使用基于小目标检测改进的YOLOv8-FD算法对微纳光纤直径进行自动检测.在数据集中获得了平均均值精度高达mAP^(IoU=50)=0.975和mAP^(IoU=50_95)=0.765的性能参数.实验结果表明,该系统可实现微纳光纤直径462 nm—125μm范围,误差2.95%以内的测量和自动化制备,并随着光纤直径增长,误差逐渐缩小,且该系统光学成像单个像素分辨率为65.97 nm,平均检测时间为9.6 ms.本文工作适用于对微纳光纤的高精度实时测量和自动精确制备,为低损耗传输和色散可调的微纳光纤器件发展提供新的思路.

负载生长因子的微纳米纤维创面敷料的制备与应用研究进展

伤口愈合是一个动态的、复杂的、多细胞参与的过程,理想的创面修复材料对促进伤口的愈合至关重要,为实现更好的创面愈合,可在创面修复材料中添加生长因子等物质。首先总结了碱性成纤维细胞生长因子、表皮生长因子、血小板衍生生长因子这3种生长因子的作用及其在创面愈合过程中的作用环节及机制,阐述了微纳米纤维支架、微球和纳米颗粒等生长因子的可控释放递送策略,重点讨论了负载一种或多种生长因子的微纳米纤维创面敷料。研究指出,生长因子的作用已被广泛证实,不同的生长因子参与伤口愈合的不同阶段,微纳米纤维作为一种可控释放的递送系统及理想的创面修复材料,在皮肤创面愈合医用敷料领域拥有广泛的应用前景。

丁香酚/桑皮微纳米纤维膜的制备及其性能

为进一步将废弃的桑树枝回收利用,开发功能性桑皮纤维,实现蚕桑产业副产物的高值化利用,通过微生物-酶-超声波联合脱胶法,辅以破壁工艺提取桑皮微纳米纤维,制备了丁香酚/桑皮微纳米纤维膜,研究了丁香酚质量浓度对纤维膜抗菌性、透湿性和力学性能的影响,并以巨峰葡萄为对象分析了常温(25℃)下纤维膜的水果保鲜效果,测定了贮藏过程中葡萄的外观、质量损失率、腐烂率和维生素C含量等指标的变化。结果表明:丁香酚/桑皮微纳米纤维膜具有良好的透湿性和力学性能;丁香酚质量浓度为0.4 mg/mL的丁香酚/桑皮微米纤维膜对金黄色葡萄球菌、大肠杆菌的抑菌率接近80%,丁香酚质量浓度为0.3 mg/mL的丁香酚/桑皮纳米纤维膜的抑菌率可达90%左右,且在常温下能有效保持葡萄的新鲜度,减缓水分的散失、腐烂并抑制维生素C的流失。

壳聚糖微纳米纤维复合抗菌空气滤材的制备及其性能

为制备一种绿色环保的抗菌空气过滤材料,在壳聚糖水刺非织造布(CS)的表面静电纺丝一层壳聚糖/聚氧化乙烯(CHI/PEO)纳米纤维膜,得到壳聚糖微纳米纤维复合空气滤材(CHI/PEO-CS)。对制备的CHI/PEO-CS复合膜的微观形貌、力学性能、孔径分布、透气性、过滤性能以及抗菌性能进行了系统研究。结果表明:CHI/PEO纤维直径随着PEO质量分数的增加而增大,当PEO质量分数为0.45%时,CHI/PEO纤维的成纤率最好,对应的纳米纤维直径为146 nm;CHI/PEO-CS对300 nm NaCl气溶胶颗粒的过滤效率可达99.56%,对应压降为63 Pa;当壳聚糖水刺布表面静电纺纳米纤维膜后,CHI/PEO-CS在改善其过滤性能的基础上依旧保持原水刺布较高的强力,且具有较好的透气性能(246.2 mm/s);此外,CHI/PEO-CS对大肠杆菌和金黄色葡萄球菌的拦截率分别为99.97%和99.88%,显著高于纯CS水刺布。

静电纺药物负载与应用研究进展

利用静电纺微纳米纤维进行药物递送可以实现药物的可控释放,近年来逐渐成为研究热点。为进一步推动静电纺丝在药物释放领域的应用,首先从静电纺载药纤维的制备技术出发,介绍了溶液、乳液、熔体电纺在制备载药纤维方面的特点及优缺点;随后归纳了静电纺载药纤维在药物释放方面的影响因素和药物负载方式;最后总结了静电纺载药纤维在透皮给药、黏膜给药和组织工程领域的最新研究进展,挖掘静电纺丝在药物递送领域的应用潜力。

静电纺丝技术在农药领域中的应用现状及发展前景

随着纳米技术的蓬勃发展,传统农药也被注入新的活力。静电纺丝是一种灵活高效、方便快捷的超细纤维加工及制造技术。近年来,这项技术基于静电纺丝微纳米纤维的功能化改性、药物缓控释、微量化合物吸附、清洁过滤等原理而被开发应用于农药领域。本文综述了静电纺丝技术在农药领域中的应用现状,集中论述了其在农药递送载体、农药残留分析与检测、农药污染治理方面的研究进展,并且针对该项技术在发展过程中遇到的问题和可能面临的挑战进行了讨论,同时提出了建议,旨在为静电纺丝技术在农药领域中的开发及应用提供参考。

聚乳酸/高乌甲素复合微/纳米纤维膜的制备及性能研究

以聚乳酸(PLA)及氢溴酸高乌甲素(LAH)为原料,采用静电纺丝技术制备不同PLA浓度的PLA微/纳米纤维膜及不同LAH含量的PLA/LAH复合微/纳米纤维膜,研究了纤维膜的表面形貌、化学结构、力学性能、药物缓释性能及抗炎性能。结果表明:当PLA浓度为120 mg/mL时,PLA微/纳米纤维膜的纤维直径分布均匀,平均直径达1.4μm,具有较高比表面积和高孔隙率,拉伸应力最大,达3.168 MPa;添加LAH后,纤维膜的纤维直径和形貌未发生明显改变,PLA与LAH之间是物理结合,并未发生化学反应;随着LAH含量的增加,PLA/LAH复合微/纳米纤维膜的累积药物释放率增加,当LAH质量分数为14%时累积药物释放率最高,达89%,具有良好的药物缓释性能;二甲苯致小鼠耳廓肿胀试验表明LAH质量分数为14%的PLA/LAH复合微/纳米纤维膜具有优异的抗炎效果,二甲苯致小鼠耳廓的肿胀度为4.90 mg。

高吸水材料及其在纺织领域的应用

为了进一步提升纯棉产品吸湿速干性能,满足市场对纯棉产品吸湿含水能力的高要求,介绍了高吸水聚合物的发展、分类及高吸水原理。从使用常规方式制备高吸水纤维与采用静电纺丝方式制备高吸水微纳米纤维两方面,探究了高吸水聚合物在纺织领域的应用,并结合微纳米镶嵌纺技术对高吸水、高含水具有润湿功能的纯棉纺织品开发进行了展望。认为:合理利用高吸水性材料,结合微纳米镶嵌纺技术,是开发纯棉类高吸水功能纺织品的重要研究方向。

汉麻植物活性物/单宁酸/AgNPs/PAN复合微纳纤维膜的实验设计及抗菌活性研究

汉麻植物含有丰富的抗菌类活性物,可缓解由抗生素滥用导致的耐药性问题。该文使用高压静电纺丝技术设计了一种复合抗菌微纳米纤维膜,包含汉麻植物活性物质(HPA)、单宁酸(TA)、银纳米颗粒(Ag NPs)和聚丙烯腈(PAN)。实验发现:在PAN质量浓度为0.1kg/L、HPA和TA质量浓度均为0.03kg/L、AgNO3质量浓度为0.01 kg/L、施加电压为17 kV、接收距离为14 cm、供液速率为1 mL/h时,制备条件最佳;在HPA的添加质量浓度为0.03kg/L时微纳纤维的形貌均一,直径均匀,药物负载和热稳定性良好;抗菌测试结果显示,不同HPA质量浓度的微纳纤维膜均能有效抑制大肠杆菌和金黄色葡萄球菌的生长,其中对金黄色葡萄球菌的抗菌作用明显,抗菌率均达95%以上。因此,该实验设计和制备的HPA/TA/Ag/PAN复合纤维膜在抗菌方面具有良好的应用前景。

Controllable fabrication of Au micro/nanostructures on self-doped polyaniline nanofibers via electrochemical deposition and its application for DNA immobilization

Four electrochemical methods, cyclic voltammetric deposition, potentiostatic electrodeposition, multi-potential step electrodeposition and three-step electrodeposition, were used to fabricate Au micro/nanostructures on self-doped polyaniline nanofibers-coated glassy carbon electrodes (Au/nanoSPAN/GCEs). The Au micro/nanostructures deposited on the nanoSPAN-modified electrodes were shown by scanning electron microscopy to exhibit different morphologies, such as Au nanoparticle clusters, monodisperse nanoparticles and homogeneously dispersed flower-like microparticles, depending on the deposition method. This phenomenon demonstrates that control over the morphology of Au metal can be easily achieved by adjusting the electrodeposition method. The electrochemical behaviors of the Au/nanoSPAN/GCEs also varied with above four methods, which were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. In comparison with Au nanoparticle clusters and monodisperse Au nanoparticles, homogeneously dispersed flower-like Au microparticles had the largest surface area and obviously enhanced electrochemical response towards the redox reactions of [Fe(CN)6]3–/4– on the modified electrode. DNA immobilization on the Au/nanoSPAN/GCEs was investigated by differential pulse voltammetry using [Fe(CN)6]3–/4– as an indicator. The efficiency of DNA immobilization was inherently related to their different Au micro/nanostructure morphologies. The Au/nano-SPAN/GCE fabricated by three-step electrodeposition showed the largest capacity for immobilization of single stranded DNA, which makes it a promising DNA biosensor.