Application of Micro Scanning Laser Doppler Vibrometer for dynamic characterization and Quality factor assessment in Micro Electro Mechanical Devices (MEMS)

摘要

Micro-Electro-Mechanical Systems (MEMS) are miniaturized devices combining together electrical and mechanical functionalities. MEMS is one of the most promising technology in the scientific and industrial field, thanks to the possibility of integration of sensors, transducers and electronic, in the same die1. Nevertheless, the spread of the micro-electro mechanical systems (MEMS) market is strictly related to the development of manufacturing technologies and to the implementation of analysis and diagnostic technique that allow to increase performances and reliability. In this paper we demonstrate the feasibility of the Laser Doppler Vibrometer, which has been designed and developed for measuring in the microscale, to characterize the dynamic of MEMS, in terms also of revealing nonlinear behaviours and to evaluate the mechanical Quality factor Q. The sensitivity of this class of devices, and their performances, is limited by intrinsic that dissipation depends upon a very complex system of different interactive factors. The mechanical Quality factor (Q) is a parameter that makes possible to quantify the dissipation mechanism of mechanical energy, and consequently the microoscillators sensitivity. The calculation of the Quality factor can be done post-processing the data acquired by the laser Doppler vibrometer.