Adhesion force measurement on ZnO microrods on silicon surface during atomic force microscope probe manipulation

Abstract

Atomic force microscopy was demonstrated to be a reliable tool to assemble zinc oxide microrods by dragging the rods with the cantilever, a process referred to as “manipulation”. Strong rod-substrate adhesion can be traced to a trapped fluid layer between rod and substrate, allowing imaging of the rods before and after manipulation. To measure this adhesion force, the manipulation process was automated via programmed cantilever movement with acquisition of cantilever deflection signals. Force-distance spectroscopies and cantilever stiffness measurements were used to convert normal deflection signals to force units. The adhesion force is typically in the order of 70nN.