Modeling The Stiffness And Inertial Characteristics Of Mems' Supporting Beams

MEMS sensors usually work at frequencies well above 1kHz. At these frequencies, supporting beams do not only contribute to the elasticity of the system but also to its inertia. However, the supporting beams' inertia is not equal to any modal mass since excitation frequency is not equal to any eigenfrequency of the supporting beams. Based on a FEA model of the supporting beams it is possible to determine this inertial contribution at any working frequency thus allowing to set up a simple lumped parameter model that correctly reproduces the dynamic behaviour of the device