Reliability Assessment of Micromachined Fixed–Fixed Beam Based on FE Simulation and Probabilistic Sampling

Recent trends in structural mechanics applications of finite-element methods (FEM) show an increasing demand for efficient analysis tools. This paper presents a realistic approach for modeling a fixed-fixed beam structure used in microelectromechanical systems based on finite-element analysis (FEA). The use of probabilistic methods to assess the electromechanical behavior of the beam under the presence of micromachine manufacturing and process uncertainties is also presented. The finite-element model of the beam is constructed using the commercial code ANSYS (10.0). In the standard approach of modeling, existing literature assumes deterministic values for design parameters. However, fabrication of the device introduces some amount of variation in these parameters. In this paper, the probabilistic approach is discussed to account for the variability in fabrication. FEA guides the design of fixed-fixed beam to achieve a robust and reliable design in a most efficient way. From the probabilistic analysis, it was observed that the changes in length and thickness tend to be the most influencing parameters, which need to be tightly controlled.