Characteristics of the higher-order resonant cantilever in dynamic atomic force microscopy

In order to improve the performances of dynamic atomic force microscopy (AFM), a higher-order resonant cantilever which is driven at its second order or even higher-order resonant frequency instead of its first order resonant frequency is proposed. Due to the increase in the frequency and quality factor of the higher-order resonant cantilever, the response time, air damping coefficient are reduced and the detecting sensitivity of the cantilever is improved. Meanwhile, because the angular deflection of the cantilever under higher-order resonant vibration is larger than that under the first order resonant vibration, the optical magnification level of the higher-order resonant cantilever is several times larger than that of the first order when the optical lever method is adopted to detect the variation of the cantilever. Theoretical analysis and experimental results show that the scanning method done by a higher-order cantilever is effective and feasible, and the scanning characteristics of dynamic AFM with the higher-order resonant cantilever are promoted obviously compared with that of the AFM operated in the first-order. © 2013 SPIE.