Friction and adhesion properties of vertically aligned multi-walled carbon nanotube arrays and fluoro-nanodiamond films

Sliding friction and adhesion properties of vertically aligned multi-walled carbon nanotube (VAMWCNT) arrays and fluoro-nanodiamond (F-ND) films on glass substrate have been quantitatively investigated in current study using atomic force microscopy. It was found that VAMWCNT arrays result in lower friction compared to F-ND films. Friction forces were also found to be consistently higher in nitrogen environment than in ambient environment for both samples and a surface chemistry based hypothesis was proposed. However, no apparent dependence of relative humidity was found on adhesion forces for both F-ND and VAMWCNT samples, indicating lack of correlation between nanoscale adhesion and friction. The implications from current study for designing movable components in micro- and nanoelectromechanical system devices were also discussed.