Fluid Density Sensing Using PMUTs

We present a novel method of monitoring liquid condition by tracking density which may find application in various micro as well as macro systems. It is based on transmission of ultrasound waves through liquids and employs Piezoelectric Micromachined Ultrasound Transducers (PMUTs) for actuation and reception. The PMUT-Fluid-PMUT (P-F-P) arrangement forms the entire system whose ability can be customized depending on the targeted application. In this article we discuss various aspects of making P-F-P system and experimentally show that P-F-P can be one of the most effective liquid condition monitoring systems in the near future.