Abstract
A novel testing technique to determinate the dynamic response of the microstructure is presented. In this study, a bulk acoustic wave hammer generated by a pulsed ultrasonic transducer is used to excite the microstructures. Thus the dynamic response of the microstructure in a wide frequency range is excited. Based on this novel method and test apparatus, the dynamic response of the microstructure including the resonant frequency, mode shape and the modal damping of the microstructure can be measured in a single excitation. Experimental results of the microbeams with different length agree well with theoretical predictions. In summary, the proposed BAW hammer technique has the following advantages. The sample preparation for this approach is very easy since it is not necessary to deposit an additional film for thermal or electrical purpose. In this regard, the experimental results of this technique are more accurate since there is no additional film to influence the dynamic behavior of the test sample. Moreover, there is no uncertain side effect such as thermal and acoustic coupling, caused by this approach. Since the test apparatus is also very simple, this approach has the potential to do the on-line test for batch production.
