SCANNING FORCE MICROSCOPIES CAN IMAGE PATTERNED SELF-ASSEMBLED MONOLAYERS

This paper demonstrates that scanning probe microscopies (SPMs) can image patterned self-assembled monolayers (SAMs) formed by microcontact printing. Lateral force microscopy (LFM) and force modulation microscopy (FMM) showed contrast between regions of patterned SAMs terminated by different chemical functionalities. Normal force microscopy (NFM) typically showed less contrast than LFM or FMM but provided information about the topography of the surface. Chemical functionality (at the interface between the SAM and air) dominated imaging in these experiments. Changes in the morphology of the surface or changes in the humidity of the environment for imaging did not influence significantly the contrast in our experiments. The sharpness of the contrast suggests the use of LFM and SAMs in studying tribology on the submicrometer scale.