Modal analysis of microgrippers used in assembly of MEMS devices

This paper describes the modal analysis of microgrippers that are used to construct out-of-plane three-dimensional (3D) microstructures. During microassembly, some major sources of precision loss are the vibrations transmitted to the microgripper as result of attached resonating force sensors and seismic activity. Since resonant force sensors are used to measure the microassembly forces, the resonance frequencies of the resonator must be selected so as not to coincide with the microgripper modal frequencies. The study reported here uses computer modeling to predict the microgripper mode shapes and modal periods to see how it reacts under harmonic excitations. A 3D solid finite element model was created using both SolidWorks and ANSYS to study the modal analysis. The results obtained using this model showed agreement with analytical results calculated using a simplified model of the microgripper.