Flexural sensitivity of high resonant atomic force microscopy cantilever based on optical lever detection

Flexural sensitivity is a key parameter of atomic force microscopy. In order to improve the dynamic atomic force microscopy's flexural sensitivity, a scanning method that drives the atomic force microscopy cantilever vibrating at its high resonant frequency is utilized. In this article, the operation principle of the high resonant atomic force microscopy is introduced and the factors that affect the sensitivity in the measurement of the displacement of the amplitude based on optical lever detection method are analyzed, and the flexural sensitivities of the cantilever vibrating at different resonant frequencies are compared theoretically and measured experimentally. The experimental results indicate that the flexural resolution of atomic force microscopy operated on the fundamental mode and the second mode is 0.30 and 0.13 nm, respectively. Both the theoretical and experimental results demonstrate that the flexural sensitivity of the high resonant cantilever is better than that of the fundamental mode cantilever. It is an effective method to improve the sensitivity of dynamic atomic force microscopy cantilever by working at higher resonant frequency.