Chemical Force AFM with CNT Tips

In this paper, we focus on preparation of CNT-AFM tips, their chemical modification, and their application. The authors have been trying to use a carbon nanotube (CNT) as an AFM probe tip because of its nanoscale dimension, mechanical and chemical robustness, high aspect ratio, and so on. The first step toward this issue, we have prepared the checker pattern surface by self-assembling molecules of hexadecanethiol (-CH3 at the end, hydrophobic) and of mercaptoundecanol (-OH, hydrophilic) on to mica by microcontact printing method. Then we measured the friction forces as well as adhesion forces on this surface. The paper shows the force mapping images as well as force histograms which clearly discriminate the hydrophilic and hydrophobic parts of the sample surface: the former parts are higher than the latter ones in both friction and adhesion.