告题目： Nanopositioning and Nanomeasuring Machine and Its Tribology
纳米定位和纳米测量仪及其摩擦学

报告人： Dr.-Ing. Yonghe Liu 刘永合 博士 德国 伊尔默瑙理工大学 物理学院 微米纳米技术学院

报告时间： 3月8日（周四)上午10点

报告地点： 精仪系9003大楼四楼大会议室( 4304 ）

主办单位： 精仪系摩擦学国家重点实验室

内容简介：Nanopositioning is defined in terms of engineering as “to put a nanotool in a certain position on the surface of a workpiece at accuracy of nanometres”. It includes determining the position described by coordinates of points on the surface, and bringing tools to the points, both with the accuracy of nanometres. The former function, also called nanomeasuring, is achieved by moving a probe to determine the coordinates of points. Nanopositioning is therefore inseparable to nanomeasuring. In this talk, a brief introduction of the nanopositioning and nanomeasuring machine (NPM) developed in Technical University of Ilmenau is presented. A prominent feature of the NPM is the combination of a scanning range of centimetres and a resolution of nanometres, which distinguishes itself from the conventional atomic force microscopes and coordinate measuring systems. The scanning in wide distance is currently transported by bearings. Under direct drive, the friction of bearings comes into the positioning stage directly, and limits to a large extent the positioning accuracy. One possible way to minimize the influence of friction is to get it under a proper control through model based or experience based strategies. This requires a detailed characterization of the tribological performance of bearings. To study the bearings, bearing materials, tribological coatings and their lubrication is the main task of the tribology of nanopositioning. Topics such as the motion of linear ball bearings on nanometer scale, diamond like carbon coatings, lubrication by room temperature ionic liquids in vacuum, and temporal strain mapping of deformation near contacts will be discussed.