Experimental investigation on the dynamics of MEMS structures

摘要

Modeling, manipulating and testing of the dynamic performances of micro-electro-mechanical systems (MEMS) devices are very important in building successful microsystems. However, MEMS devices pose several significant difficulties in characterization. The physical dimensions of MEMS devices are such that conventional measurement and characterization techniques cannot be used since the sensor would interfere with the measurement. Hence, non-contact sensing systems offer many advantages for MEMS characterization. One important issue in characterizing and troubleshooting MEMS devices is the differentiation between electrical and mechanical effects. By definition, MEMS devices are comprised of electrical and mechanical components forming integrated electro-mechanical systems. The dynamic response of these devices is often difficult to determine because of the coupled electromechanical behavior. It is also known that the dynamic response is influenced by the limitation of fabrication processes and the material conditions. Hence, this paper proposes a simpler method to verify the dynamic behavior of MEMS structures using Laser Doppler Velocimeter (LDV). Non-contact vibration measurements are thus possible with such a testing system that can lead to significant improvements in the accuracy and precision of MEMS testing. The dynamic experiments are conducted on different devices and the test results are compared with prediction