Example II:
Variable-Tapping-Force Study of Radial Compressibility of Multiwalled Carbon
Nanotubes
The force with which the tapping probe strikes the surface can be controlled by varying the imaging set-point
S = A/Ao,
where Ao and A denote respectively the amplitudes of a freely oscillating and tapping cantilever.
Variable-force experiments were used to study the radial deformability of multiwalled carbon nanotubes deposited on a patterned silicon wafer.
M.F.Yu, T. Kowalewski, R.Ruoff PRL, 2000