Case studies of a planar piezoresistive vibration sensor: Measuring transient time history signal waves

With the development of the economy, more and more social problems are exposed to us. There is a clear need for rational methods of monitoring the safety of civil structures over time. Similarly, home-security systems require several low-power sensor nodes in order to monitor the motion of windows or doors. On the other hand, by using a novel cavity-first micromachining process, a planar piezoresistive vibration sensor can be fabricated that has both a simple structure and fewer packaging difficulties. To determine whether such piezoresistive-based vibration sensors can satisfy previous demands, this paper presents a comprehensive evaluation of the given sensors. We measured random vibrations, transient time history waves, and earthquake vibrations using the developed vibration sensors. Before reporting the results of this evaluation, we offer an analysis of the sensor's functional features with regard to noise density. As the results show, the piezoresistive planar vibration sensor performs ideally and can be used to monitor residential security or the conditions of civil structures in real time. Moreover, we demonstrate how several advanced civilian and industrial applications are feasible with this sensor.