Abstract
A friction force acts at the surface of elements and it's not affected by the volume of elements. Therefore, with the decrease of the size of moving elements, a knowledge of friction is becoming important to analyze movements of micro-machines. In the present paper, we studied the static friction coefficient for various thin films. In order to measure the static friction coefficient, millimeter-size mover was driven electrostatically on those thin films. The electrostatic forces which can drive the mover are different among those thin films because of differences in the friction coefficient. Therefore, we determined the static friction coefficient from the minimum electrostatic force. It was found that the friction coefficient of SiO2 thin film against metalic thin films show a smaller value. However, the friction coefficient between SiO2-SiO2 thin film shows a little larger value. It was also found that the friction coefficient of thin films show a little larger value than that of lump.
