Multilateral measurement of phenomena of thin lubrication with a nm-thick lubricant film

薄膜润滑是一种仅在滑动点处形成润滑膜的润滑技术，有望成为硬盘驱动器等微型机械的润滑技术。然而，由于测量的困难，润滑现象尚未完全量化。在这项研究中，我们的目的是建立一种方法，同时测量润滑剂和润滑膜的变形所产生的横向和法向力，并获得基础知识的薄膜润滑理论的建设。对于横向力和法向力的测量，我们分别开发了基于光纤探针和基于石英音叉的方法。此外，两个阶段的成像椭圆偏振显微镜被开发用于可视化的薄膜变形。这些测量方法揭示了薄膜润滑理论建立中的一些不同于传统润滑的重要现象。

Thin film lubrication, where lubricant film is applied only to the sliding point, is expected to be lubrication technology for micro machines such as hard disk drives. However, the lubrication phenomenon has not been fully quantified due to the difficulty of measurement. In this study, we aimed at building a method that simultaneously measures the lateral and normal forces generated by lubricant and deformation of lubricant films and obtaining fundamental knowledge for construction of theory of the thin film lubrication. For measurements of lateral and normal forces, we developed optical-fiber-probe based and quartz-tuning-fork based methods, respectively. Moreover, two stage imaging ellipsometric microscopy was developed for visualization of the film deformation. These measurement method revealed important phenomena for construction of thin film lubrication theory, which are different from those in conventional lubrication.