Tribology and micro devices

COLL 22

Yasuhisa Ando, Research Institute of Mechanical Systems Engineering, Tribology Research Group, Research Institute of Mechanical Systems Engineering, Tribology Research Group, National Institute of Advanced Industrial Science and Technology, Namiki 1-2-1, Tsukuba, Ibaraki, 305-8564, Japan
Friction force is proportional to the normal load as stated by Coulomb's friction law. For the extremely low normal loads found in micro-scale devices, however, Coulomb's friction law does not hold due to the effect of the adhesion force between the surfaces. It is therefore important to clarify the effects of the adhesion force when studying tribology phenomena under micro loads. In this paper, we fabricated some asperities having radii of curvature of approximately 100 to 1000 nm to control the adhesion force by using focused ion beam. Then the tribological properties were determined by using AFM (atomic force microscope) under various environmental conditions. On the other hand, the micro devices have advantage to improve the accuracy of force measurement. We also describe how the micro devices are used for the measurements in tribology.