【作者】 苏亚辉；

【导师】 黄文浩；

【作者基本信息】 中国科学技术大学 ， 精密仪器及机械， 2007， 博士

【摘要】 作为一种新型的激光成型技术，飞秒激光微纳加工具有真三维的制作能力和亚微米的加工分辨率等技术特点，在MEMS研究领域受到越来越广泛的重视，而微／观情况下材料的细观力学性能是MEMS研究领域中十分重要的组成部分。本文结合国家自然科学基金项目(No.50275140和No.50335050)的主要研究内容，对飞秒激光微纳加工中的成型点、面的力学性能的检测及分析方法进行了深入研究。本文的主要成果如下：首先，制备了飞秒激光微纳加工成型点；在标定无针尖微探针的弹性系数的基础上用原子力显微镜测量了成型点的力学性能；对于粘附力作用是否明显的两种状况，应用相关的弹性力学理论求解出了成型点的弹性模量；为了消除解析法形状近似所带来的误差，对于粘附力作用不明显的实验结果，使用有限元方法建立了相应的力学模型并求解出成型点的弹性模量。取得了飞秒微纳加工成型点的弹性模量低于宏观材料弹性模量的结论。其次，为了降低飞秒激光微纳加工成型点弹性模量的测试成本，利用有限元方法建立一系列经正交实验规划好的力学模型并分别予以求解，得到支持向量机训练和测试样本。借助于训练样本，用支持向量机理论进行了回归分析，获得了成型点变形量与微探针所受力之间的关系，并用测试样本予以检测，这一方法在保证测试精度的前提下大大地提高了效率。最后，在分析了重复率对飞秒激光微纳加工线、面的影响基础上加工出了用于力学性能测量用的加工面；选用Cono-Spherical压头，用纳米硬度计扫描了待测样品以确定测试区域；设计了不同的加—卸载函数，采用纳米压痕技术得到了能够准确反映测试区域弹性模量和硬度的载荷—位移曲线，从中提取出了相应的实验结果。取得了飞秒激光微纳加工面的力学性质与宏观材料的力学性质基本一致的结论。这些实验结果为研究项目的顺利完成和该领域研究工作的深入发展打下了良好的基础。此外，本文还对该技术的发展方向进行了展望。更多还原

【Abstract】 As a new technology of laser lithography in MEMS, femto-second laser two-photon photofabrication has its unique technological characteristics, including fabrication ability of true 3D microstructures, sub-micron resolution and so on. Recently, it has been gained extensive attention. The research on mechanical properties of materials at micro or nano scale is one of the most significant parts in MEMS. With the support of NSFC (No.50275140 and No.50335050), the mechanical properties of the voxels and single layer fabricated by femto-second laser two-photon photopolymerization are measured and analyzed. The main research results are listed as follows:Firstly, voxels are fabricated using two-photon photopolymerization method. The mechanical properties of voxels are investigated by atomic force microscopy equipped with calibrated tipless micro-cantilevers. To calculate the elastic modules of the voxels, different elastic models are utilized depending on whether the effects of adhesion are obvious or not. In order to eliminate the errors caused by geometrical approximations during analytical methods, the modulus of voxels is determined by applying Finite Element Method (FEM) models when adhesion is not obvious. It is found that the elastic modulus of the voxels is far below those of macro material.Secondly, to decrease the complexity of experiments, a series of mechanical models programmed by orthogonal method are constructed by FEM. These models are solved to obtain the training and testing samples for Support Vector Machine. Based on obtained training samples, the Support Vector Machine regression is performed. The relationship between the forces acting on the micro-cantilever and the deformation of voxels is acquired. Then we prove this relationship with testing samples. Such method improves the efficiency while the accuracy of the analysis can be remained.Finally, single layer suitable for mechanical tests is manufactured based on analyzing the influences of overlapping degree of voxels on micro-lines and layers. The specimen is scanned by nanoindenter equipped with Cono-Spherical tip to determine the measurement area. We measured the areas according to different loading-unloading procedures and obtain force-displacement curves, which contain the exact information of the elastic modulus and hardness of the tested material. We found that the mechanical properties of the micro-layers are in agreement with the macro ones.All these experimental results can do help to our projects and can boost the development of this research area. We also prospect the trend of this technology in the end.更多还原