Dynamic characteristic testing for MEMS micro-devices with base excitation

摘要

The study of the dynamic characteristics of MEMS micro-devices dependson relevant testing facilities. Testing with a base excitation method was studied and employed in practical tests. A system for the dynamic characteristic testing of MEMS micro-devices was built based on a PZT transducer as the shock excitation source. A high voltage power source for the PZT transducer, which can provide large transient current, was developed for impact generation. Experiments for testing micro piezoelectric cantilevers were accomplished with the base excitation method. The impact response, i.e. electric charge signal generated by the micro piezoelectric cantilever, was acquired. By performing spectral analysis and comparison of the result with another cantilever having different resonance frequencies, the resonance frequency of the tested microstructure was determined. For comparison, simulation of the piezoelectric cantilever with a finite element analysis (FEA) method was carried out. Because the theory analysis is in good agreement with the experiment results, it can be used to estimate the actual resonance frequency of the tested microstructure. The base excitation method was also applied in the dynamic testing of microstructures under a high-g force environment. By the exclusion of the resonance peaks of PZT transducer and noise frequencies, the resonance frequency of the tested microstructure was determined. The applicability and the limitation of the method were briefly discussed.