A SCANNING FORCE MICROSCOPE DESIGNED FOR FLUID CELL MEASUREMENTS

We present a scanning force microscope working in the repulsive force mode designed for fluid-cell measurements and tip-sample interaction s tudies. The instrument uses the optical beam deflection principle to m easure cantilever motion and is compatible with commercially available microfabricated cantilevers. The instrument is designed to accommodat e tube scanners with lengths up to 2 in. In order to minimize memory e ffects in the piezoelectric scanner, we have introduced a technique of pre- and postscanning to get reproducible force versus distance curve s. Different linearizing algorithms to decrease the unlinearities of t he scanner motions are demonstrated. As examples of the performance, w e present an image of a mica surface obtained in air showing atomic sc ale stick-slip features, and a force measurement using the fluid cell with NaCl electrolyte showing the double layer interaction between a g lass sphere and a mica surface. (C) 1996 American Institute of Physics .