Abstract
Usage of self-excitation as an excitation method has been proposed for vibration machines as well as the cantilever-probe in an atomic force microscopy (AFM). The amplitude control is carried out by producing the dynamics of the van der Pol oscillator in the cantilever. The control has been performed by applying nonlinear feedback proportional to the squared angle and the angular velocity. In this study, we propose a new control method which has high performance even in the high-frequency range and realize van der Pol oscillator in the cantilever with laterally exited fixed end by not using differential of the measurement signal, but integral control with respect to the angle at the tip of the cantilever. This control method is demonstrated by our own making analog electrical circuit. Then, the steady state amplitude of self-excited oscillation with amplitude of 4nm is experimentally realized.
