Reliability of electrostatically actuated MEMS resonators to random mass disturbance

Random variable-mass systems have received widespread attention and shown prominent significance with the explosive development of micro- and nanotechnologies, so there is a growing need to study the influences of mass disturbance on the systems. This paper is devoted to investigating the reliability (first passage failure) of electrostatically actuated MEMS resonators subject to the random mass disturbance. The potential failure mode considered is the adhesion failure. First, the original system is approximately replaced by a system without mass disturbance based on an equivalent transformation. Then the first passage failure indicators of the approximate system are derived by using the combination approach of the stochastic averaging and the diffusion process theory of the first passage time. The comparisons between the analytical results and those from numerical simulation show that the proposed method works very well. The effects of mass disturbance on the system reliability are explored adequately. It turns out that the presence of mass disturbance can lead to a deterioration of the resonators' reliability severely. It is remarkable that the system has multiple resonance regions with different intensities, and the reliability of the system in the case of primary resonance is much lower than that in the non-resonant case. (C) 2018 Elsevier Ltd. All rights reserved.