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 studies. The instrument uses the optical beam deflection principle to measure cantilever motion and is compatible with commercially available microfabricated cantilevers. The instrument is designed to accommodate tube scanners with lengths up to 2 in. In order to minimize memory effects in the piezoelectric scanner, we have introduced a technique of pre‐ and postscanning to get reproducible force versus distance curves. Different linearizing algorithms to decrease the unlinearities of the scanner motions are demonstrated. As examples of the performance, we present an image of a mica surface obtained in air showing atomic scale stick–slip features, and a force measurement using the fluid cell with NaCl electrolyte showing the double layer interaction between a glass sphere and a mica surface.