一种MEMS微结构谐振频率的测试技术

Resonance Frequency Measuring Technique of MEMS Microstructures

MEMS技术的发展离不开相应的测试技术与装置,建立了一种简单的MEMS微结构动态特性的测试装置,以压电陶瓷为核心的基座激励装置实现对微结构的冲击,以微器件自身的输出作为被测信号.结合MEMS工艺中批量制作的特点在同一测试装置的同一次测试中安装两种不同尺寸的被测微压电悬臂梁试件,采集两个梁的冲击响应信号及它们的联合输出信号,通过FFT频谱分析,比较三种情况下的频谱分析结果并提取出梁的固有频率,采用对比测试的方法获得压电微悬臂梁的谐振频率.试验结果与理论分析一致,该方法具有测试装置简单、实用性强等特点.

Structural dynamics is very important to the design of MEMS devices and it provides both opportunities and challenges for researchers in this field. This paper seeks to present a simple dynamic testing device for microstructures. The piezoelectric ceramic is chosen as shock excitation source, and it applies a shock excitation to the micro piezoelectric cantilever. The electric charge generated by the deformation of micro piezoelectric cantilever is acquired as the impulse response signal. By acquiring the different impulse response signals of two different micro piezoelectric cantilevers and their combined output at the same testing device and performing frequency analysis, the natural frequencies of different micro piezoelectric canti- levers are extracted through comparing the frequency analysis results. The experimental results are in agreement with theoretical analysis result and stable. The dynamic testing technology based on correlation method has wide applicability and the testing device is simple.