基于非均匀亲和性界面的低摩擦高承载的润滑副设计与机理研究

The development of effective lubrication is of significant importance to ensure that the micro/nano electromechanical systems (MEMS) to work in an effective and sustainable manner. Traditional liquids lubrication is not acceptable in MEMS because they will produce quite higher friction, causing power consumption and short life-span. In addition, the non-liquid lubrication is also not good enough for its lower load capacity. Hence, there is an urgent need for development of a novel lubrication method which can realize lower friction under higher load for MEMS, however there is not enough knowledge in this area. Therefore we propose to tackle this challenge through elegantly realizing the inhomogeneous surface affinity by manipulating surface wettability. The main work will include: 1) To develop an online measuring system for friction and oil film thickness. 2) To study the design principle and fabrication method of surfaces with inhomogeneous affinity. 3) To investigate the influence of inhomogeneous affinity on oil film thickness and friction of flat-on-flat contact with liquid lubrication and experimentally optimize the functional surfaces with inhomogeneous oil affinity to achieve the best lubrication. 4) To build a mathematical model for theoretical analysis of the hydrodynamic lubrication considering inhomogeneous affinity effect. In this project, the concept of designing a lubricating system with lower friction and higher load capacity simultaneously by using inhomogeneous affinity effect will be first-ever demonstrated, and in the meantime the relationship between the lubrication and the parameters of inhomogeneous surface will also be presented. The theory and experimental data will be beneficial to the lubrication design of MEMS, and also contribute to the energy saving and environmental protection.

良好的润滑是保证微/纳机电系统高效长寿工作的基础。传统的液体润滑摩擦系数高，导致系统功耗大寿命短；而非液态润滑剂无法满足系统高承载的需求。因此实现微/纳机电系统低摩擦和高承载的润滑成为一个迫切需求，但相关研究匮乏。为此本课题针对面接触液体润滑，提出构造基于图案润湿的非均匀亲和性界面，实现低摩擦与高承载并存的润滑副设计。主要研究内容包括：1）面接触液体润滑摩擦力与油膜厚度在线测量系统的开发。2）非均匀亲和性界面的设计与制备。3）基于非均匀亲和性界面的面接触液体润滑的实验研究及实现最优润滑性能的润湿图案优化。4）考虑非均匀亲和性界面效应的润滑理论建模与分析。本项目将首次验证“基于非均匀亲和性界面实现低摩擦与高承载并存的润滑副”概念的可行性，并给出非均匀亲和界面图案参数与润滑性能的定量关系及最优准则。该研究成果为微/纳机电系统润滑设计提供解决方案，也贡献于节能和环保的社会需求。

本课题针对如何使用界面滑移提高滑动副润滑性能展开研究。众所周知，良好的润滑是保证传统摩擦副（轴承，齿轮等）及新兴微/纳机电系统高效长寿工作的基础。传统的液体润滑摩擦系数高，容易导致功耗大寿命短；而非液态润滑剂无法满足系统高承载的需求。为此本课题针对面接触液体润滑，提出构造基于图案润湿的非均匀亲和性界面，实现低摩擦与高承载并存的润滑副设计。具体研究内容包括如下三部分：1）非均匀亲和性界面的设计与制备。以矩形钢块为基底，开发了在其表面制备不同图案或形状的超疏油涂层的技术，实现了润滑剂在特定区域的界面滑移。2）基于非均匀亲和性界面的面接触液体润滑的实验研究及实现最优润滑性能的润湿图案优化。采用制备的具有不同涂层图案的滑块在面接触试验机上进行了大量的流体润滑实验，发现了可以实现高承载低摩擦的图案设计并发表了相关论文。3）考虑非均匀亲和性界面效应的润滑理论建模与分析。针对非均匀亲和性界面导致的非连续固液边界条件，进行了理论建模与分析，理论分析结果与实验相吻合，验证了模型的正确性。该模型相关工作独立发表了相关论文。本项目首次验证了“基于非均匀亲和性界面实现低摩擦与高承载并存的润滑副”概念的可行性，并给出非均匀亲和界面图案参数与润滑性能的定量关系及最优准则。该研究成果为传统摩擦副及新兴微/纳机电系统润滑设计提供解决方案，也贡献于节能和环保的社会需求。