微织构和表面改性协同诱导硅基超疏水表面设计、制备及减摩抗磨机理研究

在微/纳机电系统中，尺度效应使得表面力远大于体积力成为决定微器件可靠性和寿命的关键因素。针对极端间隙微/纳界面存在严重黏着和磨损的关键问题，本项目以单晶硅为基底进行超疏水表面设计、制备并探讨其减摩抗磨作用机理。建立微/纳复合表面织构润湿模型，探究微织构特征参数对液滴润湿状态的影响规律，提出微织构诱导硅基表面获得超疏水性能的设计准则；借助刻蚀技术加工有序微织构并修饰低表面能复合分子膜，实验揭示微织构与复合分子膜对超疏水性能的协同效应机理；结合摩擦学原理和接触黏着理论，建立极端间隙微/纳界面间微流体模型和低表面能改性后多尺度微织构硅基表面的接触力学模型和摩擦学模型；实验研究分子膜和微织构对减黏、减摩、抗磨性能的协同作用机理；得到“微织构特征参数/分子膜特性-超疏水性-摩擦特性”关系模型，为具有最优摩擦学特性的硅基超疏水表面在微/纳机电系统中的应用提供理论基础。

In the micro/nano electromechanical system, surface forces are much larger than body forces due to the scale effects, which becomes a key factor for the reliability and lifetime of the micro device. However, there are severe issues in regards to adhesion and wear on the micro/nano interfaces with extreme-gaps. To further understanding in this area, this proposal studies the design and preparation of superhydrophobic surface on the silicon (Si) substrate, as well as the mechanism of its antifriction and antiwear properties. Detailed research contents are as follows: by establishing the wetting model of a droplet on micro/nanoscale textured surface, the influence of the micro-texture feature parameters on the wetting state of droplets are analyzed, and the design principles to superhydrophobicity of Si substrate, which is induced by micro-texture are discussed; micro-texture arrays are prepared by etching technology and modified by compound molecular film of low surface energy, to demonstrate the synergistic effects of the micro-texture and compound molecular film on the superhydrophobicity by experiments; based on the tribology and contact adhesive theory, the microfluidic mode between the micro/nano surfaces with extreme-gaps is built, in addition to which, the contact mechanical model and tribology model of the micro-textured Si substrate modified with low-surface-energy compound molecular film are created, too; synergistic effects of the micro-texture and molecular film on anti-adhesion and antiwear performances are studied experimentally; the correlation model of “micro-texture feature parameters/molecular film properties – superhydrophobicity – friction” is gained, which provides theoretical basis for the application of the Si-based superhydrophobic surface with optimized friction property in the micro/nano electromechanical system.