【作者】 蒋喆；

【导师】 程先华；

【作者基本信息】 上海交通大学 ， 机械设计及理论， 2007， 硕士

【摘要】 微机电系统(MEMS)具有体积小、质量轻、集成度高等特点,但MEMS结构微型化后,其构件间的间隙往往处在微纳米量级,摩擦和粘着等摩擦学问题严重影响了MEMS的可靠性。分子有序薄膜技术可以有效改善构件表面的摩擦、降低磨损,是解决MEMS摩擦磨损问题的有效途径之一。近30年来发展起来的自组装技术是制备分子有序薄膜技术的有效技术。自组装薄膜优异的润滑性能引起了研究者极大的兴趣,因此,分子自组装膜的制备及其摩擦学性能研究逐渐成为摩擦学研究领域的热点。本论文针对微机电系统中微构件表面改性问题,利用稀土的特殊物理化学性质,运用自组装技术制备了具有优异摩擦学性能的硅烷/稀土纳米自组装薄膜,取得了原创性的研究成果。第一,运用自组装技术,在硅烷薄膜的基础上,成功制备了硅烷/稀土复合薄膜。运用原子力显微镜(AFM)观察了薄膜的表面形貌,运用X射线光电子能谱仪(XPS)分析了薄膜表面典型元素的化学状态,并利用接触角测定仪评价了其表面能。研究了薄膜自组装的组装过程和组装机理。第二,通过热力学计算得知,稀土La在组装过程中的自由能变化均为负值,其健能差为-336 KJ/mol;稀土La能够化学吸附于基底并与基更多还原

【Abstract】 Micro-electromechanical-systems (MEMS) are of the characteristic such as small size, light weight and compact integration. Friction, wear and stiction are the important factors affecting the performance and reliability of MEMS. Surface modification of the microstructure materials has been an effective means of improving friction, reducing wear, restraining stiction and enhancing stability of MEMS. Molecular thin films technique is one of the effective ways to improve friction and reduce wear in order to enhance the stability and reliability of MEMS.Self-assembly technique is an effective technique developed in the recent 30 years preparing super thin film. The researchers are interested in the excellent lubricant performance of self-assembled monolayers (SAMs) and pay a lot of attention to the preparation and tribological behavior of self-assembled monolayers.In this paper, self-sssemble technique has been used to prepare thin films in view of the defects of currently used surface modification methods in MEMS. The mechanical and tribological properties have been improved due to the special physical chemical characteristics of rare earths. Some significant original results have been obtained.Firstly, silane/rare earth composite films were prepared by self-sssemble technique on the substrate of silane SAMs. The films’surface morphology of the films was analyzed by atomic force microscopy (AFM); the chemical composition and phase transformation of the films’typical elements was analyzed by X-ray photoelectron spectroscopy (XPS); the films’surface energy was evaluated by contact angle measuring equipment. The process and mechanism of the self-assembly was researched by the experimental results.Secondly, the variation value of the rare earth free energy is -336 KJ/mol in self-assembly processes by thermofynamic calculation, which indicated that the RE can更多还原