飞秒激光加工低维纳米材料及应用

飞秒激光具有脉宽超短、瞬时功率密度超高、非线性加工的特点,对低维纳米材料的制备和加工有着独特的优势,且具有广泛的材料适应性,能够方便快捷地针对需要精确靶向定位和图案化加工的纳米材料做出加工策略。本文综述了飞秒激光对低维纳米材料的制备加工和改性的研究现状,介绍了时空整形飞秒脉冲激光方法下制备的功能性量子点、纳米线、二维薄膜材料,和这些材料在化学催化、生物化学检测、生物相容性及电子器件等领域的应用,分析讨论了激光液相烧蚀制备纳米材料和集成化器件加工当前所面临的挑战和今后的研究重点。     

飞秒激光双光子复杂结构的微细加工

阐述了双光子激发的原理和飞秒激光三维加工的技术特点。利用自行研制的飞秒双光子微细加工系统，在优化工艺参数的基础上，加工出一系列三维微结构，并实现了可动的三维微系统一齿轮轴系统的一次成型。     

飞秒激光微加工的研究进展

综述了近年来国内外利用飞秒激光微加工的研究进展。飞秒激光脉冲作为材料微纳加工的一项工具,已经从实验室进入到工业化阶段。介绍了飞秒激光在微纳加工领域的一些研究情况,分别就飞秒激光烧蚀微加工以及双光子聚合加工进行了阐述。最后分析了飞秒激光微加工目前存在的问题及未来发展的主要方向。     

飞秒激光双光子聚合加工微纳结构

针对微/纳机电系统（MEMS/NEMS）零部件加工制造难题,研究具有亚衍射极限空间分辨率的飞秒激光双光子聚合加工方法,搭建钛蓝宝石飞秒激光微纳加工系统,对液态聚合物材料进行飞秒激光双光子聚合加工工艺试验研究。结果表明:随着激光功率的降低,单个固化点的尺寸减小,加工分辨率提高;扫描步距减小,所加工工件的表面粗糙度数值减小,但加工效率降低。基于CAD软件设计出微米墙和纳米线构成的三维微纳结构,利用飞秒激光双光子聚合加工得到该三维微纳结构实物,通过优化工艺参数加工出直径小于100 nm的纳米线,从而证明飞秒激光双光子聚合加工方法为微/纳器件的制造提供了一种有效方法。     

飞秒激光制备微透镜阵列的研究进展

微透镜阵列是重要的微光学元件,其以良好的成像性能以及小型化、轻型化的优点,被广泛应用于光通信、光信号处理、波前传感、光场调控、数据存储、医学诊断等领域.飞秒激光加工技术具有可控度高、灵活性好、无需掩模、加工精度高等优势,成为近年来微透镜阵列的重要加工方式.本文综述了微透镜阵列飞秒激光加工方法的研究进展,包括飞秒激光双光...     

基于湿度刺激响应水凝胶的飞秒激光四维打印研究

开发了一种具备湿度刺激响应的复合水凝胶前驱体,并利用飞秒激光双光子聚合技术,对该智能响应水凝胶材料进行三维微纳成形制造。系统研究了激光功率和直写速度对该水凝胶材料成形中的线宽、墙高、溶胀度以及机械模量的影响规律,进一步通过对双层结构的有限元仿真和直写结构的设计,实现了三维微纳结构在外界环境刺激下的可控形变。理论计算和实验结果表明,激光功率和直写速度能实现对智能水凝胶材料三维成形和结构性能的精确调制,实现了双层水凝胶微结构的自主可编程形状转换,推动了微纳软体机器人和精细组织工程的发展。     

利用飞秒激光双光子聚合法制作相位光栅

使用中心波长为800nm,脉冲重复频率约为83MHz,脉冲宽度为40fs的飞秒激光振荡器,研究了飞秒激光双光子聚合工艺,并制作了一个光栅常数12μm的位相光栅。     

透明材料飞秒激光三维微制备

利用飞秒激光对透明材料进行改性和加工，制备三维微结构和器件受到极大的关注。本文介绍了在透明材料内部或表面进行微制备的方法和应用，包括利用飞秒激光诱导的折射率变化来制作光波导、光栅和耦合器等；利用材料内部的微爆炸实现三维点存储和其它三维点阵结构等；通过界面的烧蚀过程进行打孔、切割和刻蚀等；利用双光子聚合制备微透镜、光子晶体和衍射光学元件等等。     

Femtosecond Laser 4D Printing of Light-Driven Intelligent Micromachines

Intelligent micromachines that respond to external light stimuli have a broad range of potential applications, such as microbots, biomedicine, and adaptive optics. However, artificial light-driven intelligent micromachines with a low actuation threshold, rapid responsiveness, and designable and precise 3D transformation capability remain unachievable to date. Here, a single-material and one-step 4D printing strategy are proposed to enable the nanomanufacturing of agile and low-threshold light-driven 3D micromachines with programmable shape-morphing characteristics. The as-developed carbon nanotube-doped composite hydrogel simultaneously enhanced the light absorption, thermal conductivity, and mechanical modulus of the crosslinked network, thus significantly increasing the light sensitivity and response speed of micromachines. Moreover, the structural design and assembly of asymmetric microscale mechanical metamaterial unit cells enable the highly efficient additive nanomanufacturing of 3D shape-morphable micromachines with large dynamic modulation and spatiotemporal controllability. Using this strategy, the world's smallest artificial beating heart with programmable light-stimulus responsiveness for the cardiac cycle is successfully printed. This 4D printing method paves the way for the construction of multifunctional intelligent micromachines for bionics, drug delivery, integrated microsystems, and other fields.     

利用飞秒激光直写技术制备钙钛矿微盘激光器

利用溶液法制备的钙钛矿微/纳米晶虽然可以得到性能良好的微型激光器,但是其所需生长周期较长且缺乏重复性.为了解决这一问题,提出了利用飞秒激光直写技术制备高重复性钙钛矿微盘激光器的新方法.首先使用双源共蒸的方法在石英玻璃衬底上沉积FAPbI3钙钛矿薄膜,然后采用飞秒激光直写技术在FAPbI3钙钛矿薄膜上制备不同直径的微盘激...     

Customizable and Reconfigurable Surface Properties of Printed Micro-objects by 3D Direct Laser Writing via Nitroxide Mediated Photopolymerization

Photoactivated Reversible Deactivation Radical Polymerization (RDRP) technologies have emerged very recently in the field of 3D printing systems especially at the macroscale in vat-photopolymerization-based processes such as digital light processing (DLP). Contrary to conventional free radical photopolymerization, photoRDRP in 3D printing leads to 3D objects with living character and thus confers them the unique ability to be post-modified after fabrication. While 3D direct laser writing (3D DLW) by two photon polymerization has become a standard for fabrication of complex 3D micro-objects, the use of RDRP and its associated benefits has so far been under-investigated at that scale. Herein, a photoresist suitable for 3D DLW based on nitroxide mediated photopolymerization (NMP2) is developed. The photopolymerization efficiency for fabrication of micro-structures and their subsequent post-modification are investigated regarding the laser power and the wavelength of excitation. Moreover, highly tunable, precise, and successive surface patterning of 2D and 3D multi-material microstructures are demonstrated thanks to the spatial and temporal control offered by the photo-induced post-modification. This work highlights new directions to be explored in order to accelerate the adoption of RDRP in 3D printing based on photopolymerization.     

飞秒激光加工微光学元件的研究

利用低功率飞秒激光振荡器进行材料表面加工的研究并将其应用于微光学元件的加工制作领域;对飞秒激光倍频光以及飞秒激光与光刻胶材料相互作用进行了实验;以光刻胶作为牺牲层进行表面加工获得了各种玻璃光栅及光掩模板;利用光学显微镜和原子力显微镜(AFM)对实验结果进行检测,得到微米量级的特征线宽;所得光栅的光学性能通过He-Ne激光器进行检测,实验结果与理论值一致。该研究为微光学元件的加工制作提供了新的方法。     

可见光波段飞秒激光双光子微纳加工研究

基于矢量衍射理论,计算了多个可见光波段激光经紧聚焦后在焦点附近的双光子点扩散函数。计算结果表明,双光子吸收效应的作用区域随着波长的减小而减小。采用多个可见光波段飞秒激光光源进行了双光子光聚合加工,并对加工分辨率和加工阈值进行了分析。实验结果表明,在每个激光波长条件下,降低光子流密度能够提高加工分辨率;随着加工波长的减小,双光子加工的阈值逐渐降低。     

飞秒激光在生物医学中的应用

飞秒激光问世以来,其优越的特性受到越来越多的重视。本文要介绍和评述了飞秒激光的特点及其在现代医学和生物学中的各种应用。     

3D Laser Nanoprinting of Functional Materials

3D laser nanoprinting represents a revolutionary manufacturing approach as it allows maskless fabrication of 3D nanostructures at a resolution beyond the optical diffraction limit. Specifically, it endows the printed structures novel physical, chemical, or mechanical properties not observed at macroscopic scale. However, 3D laser nanoprinting typically relies on the photopolymerization process, indicating its limitation on the printable materials and functionalities. The capability to print diverse functional materials beyond polymer will enable a lot of new device applications in nanophotonics, microelectronics, and so on. One of the strategies is to use the 3D-printed polymer structures as skeletons for functional material deposition, while another is to mix the functional components with the photocurable molecules and print the nanocomposites. More recently, several laser nanoprinting techniques beyond photopolymerization are also developed. In this review, the cutting-edge technical innovation is summarized and a couple of examples are highlighted showing exciting applications of the printed structures in magnetic microrobots, photonics, and optoelectronics. Finally, the vision for existing challenges and future development in this field is shared.