MEASUREMENTS ON LANGMUIR-BLODGETT-FILMS BY FRICTION FORCE MICROSCOPY

A bidirectional force microscope (friction force microscope FFM) of a beam deflection type was built up for experiments at ambient conditions. Normal and lateral forces are measured simultaneously by detecting the deflection of a reflected laser beam with a four-quadrant photodiode. The relation of the topography measured with normal force perpendicular to the surface and the lateral force is discussed. We present FFM measurements on multilayers of Langmuir-Blodgett (LB) films. The friction is largest on the uncovered substrate and is reduced by the LB films acting as lubricant.