Figure 6: Plots of primary resonance mode frequency versus time at large compression for (a) methyl-terminated alkanethiol, (b) hydroxyl- terminated alkanethiol, and (c) amino-terminated alkanethiol, on template-stripped gold. The dashed line indicates the contact point estimated from the oscillation amplitude when the system was externally driven. For this dataset, the length of the nanotube was 2.96 μm long. The cantilever resonance frequency was 72.99 kHz and had a spring constant of 2.5 N/m.