SENSITIVITY ANALYSIS OF VIBRATING MOTION OF NONUNIFORM AFM PIEZOELECTRIC MICROCANTILEVER

Abstract

Piezoelectric MCs (MCs) are a special type of MCs. Having self-actuating and selfsensing abilities, they can be used as micro-robots in AFM, sensors and actuators. This paper analyzes sensitivity of vibrating motion of a piezoelectric MC with the presence of geometrical discontinuities. As resonance amplitude and natural frequency are of paramount importance in vibrating motions and they are considered in most engineering applications such as AFM and MEMS, sensitivity analysis of these two parameters is conducted. Vibrating analysis is performed based on the nonuniform beam model and the Euler-Bernoulli theory. The Sobol method is used to conduct sensitivity analysis of MC’s vibrating motion into the geometrical dimensions of layers and tip in order to specify the sensitive and insensitive parameters and their effects on vibrating motion of piezoelectric cantilever. The simulation results show that to achieve actuation ability, it is better to select a piezoelectric layer, which is thin, wide and long, and a tip, which is thin and short. The results also show that the piezoelectric layer has a different effect on natural frequency, as Lp/L becomes 0.66; natural frequency reaches its maximum amount, while the effect of other parameters on frequency is either absolutely ascending or absolutely descending.