空间柔性阵列天线薄膜阵面制造技术研究

简要阐述了空间柔性天线的进展,分析了空间柔性天线薄膜阵面制造关键技术。研究了薄膜阵面电磁波传输金属薄膜制备技术、薄膜阵面图形化制造技术、薄膜阵面拼接用材料评价、薄膜阵面的裁切技术等。采用磁控溅射技术,通过溅射功率、走带张力、走带速度的调节,在有机柔性薄膜基材上镀制了不同厚度的金属铜膜,实现了有机柔性薄膜基材的表面金属化;利用飞秒激光刻蚀精度高,不损伤柔性薄膜基材的特点,获得了图形化的金属薄膜阵面单元;对3M92号胶带与改性聚酰亚胺胶接材料的拼接强度与耐高低温性能进行了试验对比,发现改性聚酰亚胺胶接材料的强度与耐高低温性能更好,更适合薄膜阵面的拼接;对比了用纳秒激光和飞秒激光裁切的薄膜微观形貌,结果表明,用飞秒激光裁切的切面光滑,无烧蚀与毛刺,适合于高精度薄膜阵面的制造。研究为空间柔性阵列薄膜天线的制造提供了大量的基础数据。

空间薄膜阵面预应力导入效应及影响因素

空间薄膜阵面结构由于其显著特点正得到日益广泛的研究和应用。首先以一个三角形薄膜阵面为数值分析对象,论文给出了膜面预应力导入的分析方法,并分析了薄膜阵面的预应力导入效应。在此基础上,提出边缘悬链线影响的分析方法,用五个应力特征参数描述阵面和悬链线受力,引入应力波动系数描述阵面和悬链线受力均匀度。以四边形阵面为例进行数值分析,结果表明:在合适的边缘悬链线型及矢跨比下,阵面的导入应力分布更均匀,刚度更大。论文所提出的分析方法和结论对薄膜阵面结构设计研发具有参考价值。

空间薄膜阵面结构褶皱分析

薄膜褶皱是空间薄膜阵面形面误差主要因素,其制约阵面技术性能参数。首先,基于ABAQUS软件,建立薄膜褶皱数值仿真过程和方法;对正方形薄膜阵面进行了褶皱数值模拟分析,包括分析模型和参数分析,考虑了预应力值、膜边形式(膜边、索边、卡框边)、粘结缝及粘结缝模拟方法、剪应力值对阵面褶皱的影响,取得了阵面褶皱参数特征和规律。论文方法和结论对薄膜阵面结构设计研发具有参考价值。

测试真空中薄膜阵面自振特性的等代方法

大气环境下,空气产生的附加质量会大大折减薄膜阵面的刚度,致使薄膜阵面的自振特性与在实际真空工作环境中存在较大误差。基于针对真空中薄膜阵面动力特性进行试验验证,而开展真空测试试验仍然存在困难的实际情况,为忽略空气附加质量的影响,提出以大气环境下的网格膜等代真空中薄膜测试自振特性的方法。通过对比两者振动特性数值分析结果以及采用双轴张拉装置和非接触式位移动态采集设备进行试验验证,研究得到以大气环境下网格膜自振频率等代真空中阵面膜频率的结论公式。

空间薄膜阵面结构褶皱的实验研究

阵面薄膜上的褶皱会显著影响航天器性能,褶皱控制也是薄膜航天器研发的难点。本文采用白光扫描技术,测试了一个正方形薄膜阵面结构在纯剪切作用下的褶皱特性。测试结果显示,随着剪切力的增大,结构膜面褶皱数增加,褶皱幅度增大,膜面平整度降低。随着膜面预应力的增大,膜面上的褶皱数略有增大,褶皱幅度有所减小,膜面平整度有所提高。测试结果还显示,膜面上粘结缝的存在、以及粘结缝与剪切力间的方位关系对膜面褶皱有复杂的影响。论文所得结论对薄膜阵面结构设计研发具有参考价值。

Surface enhanced fluorescence by porous alumina with nanohole arrays

The fluorescence enhancement of Rhodanfine 6G （Rh6G） fluorophore in the close vicinity of porous alumina film with ordered nanohole arrays is investigated. Experimental observations show that the nonmetallic substrate with hole arrays enhances the fluorescence intensity. By comparing the fluorescence emissions that are excited with 325 nm and 532 nm, better fluorescence enhancement is obtained with excitation at a shorter wavelength. The study suggests that higher fluorescence excitation effi- ciency due to the energy transfer from oxygen vacancies to Rh6G fluorophore molecules is responsible for better fluorescence enhancement. The contribution of the scattering of nanohole arrays to the fluorescence enhancement is also proposed based on the intensity increase and reduced lifetime when the energy transfer from oxygen vacancy is absent. The result of the current study is useful for developing non-metal substrates in the study of spectroscopic enhancement, and is expected to advance the applications of porous alumina to microanalysis.

Enhanced absorption of Ag diamond-type nanoantenna arrays

The optical metal nanoantenna on thin film solar cell is effective to enhance light absorption. In this paper, the diamond-type Ag nanoantenna arrays are proposed for increasing the efficiency of solar cells by localized surface plasmons resonance(LSPR). The effect of metal nanoantenna on the absorption enhancement is theoretically investigated by the finite difference time domain(FDTD) method. Broadband absorption enhancements in both visible and near-infrared regions are demonstrated in case of solar cell with diamond-type Ag nanoantennas. The spectral response is manipulated by geometrical parameters of the nanoantennas. The maximum enhancement factor of 1.51 for solar cell is obtained. For comparison, the other three nanoantennas are also analyzed. The results show that the solar cell with optimized diamond-type nanoantenna arrays is more efficient in optical absorption.