We have developed a simple tapping mode in atomic force microscopy usi
ng a capacitive electrostatic force. In this technique, the probe-to-s
ample distance is modulated by the capacitive force between tip and sa
mple induced by a sinusoidal bias applied to the conductive probe inst
ead of a conventional mechanical vibration. The electrostatic force ve
rsus distance curve of the probe indicates that it is necessary to use
a rather stiff cantilever to prevent the snapping of the tip into the
surface due to the adhesive force at the surface. We have succeeded i
n obtaining topographic images of a conductive surface as well as a so
ft polystyrene sample with a low tracking and lateral force through th
is method. (C) 1996 American Institute of Physics.