Figure 6: Hardening to softening behaviour.
From: Automated circuit fabrication and direct characterization of carbon nanotube vibrations
(a–e) Amplitude of vibration of carbon nanotube (CNT) versus excitation frequency for different pressures, as marked inside each panel. Blue triangles are data for up sweep and red triangles for down sweep. The yellow and purple dashed lines are the theoretical solutions according to Supplementary Equations 33 and 34, for up and down sweep, respectively. (f) Left axis: Extracted non-linear spring constant, α, as function of pressure. Right axis: Extracted coefficient of linear damping, γ, versus chamber pressure. Vib., Vibration.
