聚焦离子束致形变微纳加工研究进展

聚焦离子束技术(focused ion beam,FIB)由于其高精度刻蚀、定点加工、实时成像等优势,常用于精密加工、TEM制样等领域。其工作机理通常为:刻蚀、淀积与成像。而基于FIB新的加工手段正在被探索和研究,其中就包括两种聚焦离子束致形变技术,分别为聚焦离子束应力引入致形变技术(FIB-stress induced deformation,FIBSID)和聚焦离子束物质再分布致形变技术(FIB-material-redistribution induced deformation,FIB-MRD)。前者通过控制FIB辐照时离子注入与溅射之间的竞争关系实现悬臂梁的多角度弯曲,后者利用粒子与物质作用时的瑞利不稳定性构建纳米结构,在一定意义上扩充了聚焦离子束的应用范围。运用上述方法可以加工三维微纳螺旋,悬浮光滑纳米弦以及大规模阵列化纳米网孔等多样化微/纳功能构件,在微流控系统,太赫兹通信,光学天线等领域具有很强的应用前景。

基于MEMS微镜的激光干涉直写设备曝光时间优化

使用微机电系统(MEMS)微镜搭建的光扫描式激光干涉直写设备具有体积小、直写速度快、光路简单等优点,但是其扫描时需要对曝光时间进行修正以达到均匀的曝光效果。介绍了该激光干涉直写设备的光路组成以及控制方法,利用查表法对生成的曝光图样和曝光时间参数进行了优化,使像素点直径变化从84%降低到了6%,解决了应用MEMS微镜激光干涉直写设备时存在的曝光时间不均匀的问题。

Preparation of micro-nanostructure on titanium implants and its bioactivity

Surface modification of medical implants was considered as an effective method to improve the cellular behaviors and the integration of tissue onto materials. The micro-nanostructured surface on the titanium alloy was prepared by laser treatment and multiple acid etching. The surface morphologies of different titanium alloy substrates were characterized by scanning electron microscopy (SEM). The effects of micro-nanostructured surfaces on the cellular responses were investigated in vitro by observing hydroxyapatite formation, cell morphology and cell adhesion. The results indicate that the micro-sized structure promoted the adhesion and proliferation of cultured osteoblasts. Furthermore, the micro-nanostructured surface was more conducive to cell adhension stretching compared with the micro-structured surface. All results suggest that the micro-nanostructured surface improved the biocompatibility and integration of tissue onto titanium alloy implants.

光谱调制反射镜的数控加工控制结构函数

在千焦耳拍瓦高功率放大系统设计中,激光脉冲的时空和光谱整形技术一直受到人们的广泛关注。利用经光学微纳超精细加工而成的电介质结构反射镜可在高功率条件下实现啁啾脉冲的光谱整形。在光谱整形介质结构反射镜的设计与制造中,需要根据加工精度来合理设计数控加工的控制结构函数以及加工刻蚀深度结构函数。针对神光Ⅱ千焦耳拍瓦高功率放大系统设计中提出的多层介质光谱调制反射镜,推导出数控加工的控制结构函数及其刻蚀深度结构函数,并通过数值模拟计算,分析了调制结构反射镜逼近调制函数的效果及其光谱调制特性。