Development of PMUT-Based High Sensitivity Gas Flow Sensor

Piezoelectric micromachined ultrasound transducers (PMUTs) and a high sensitivity PMUT-based gas flowmeter were designed, fabricated and characterised. In this work a single side measurement geometry is introduced for a simple PMUT assembly and enabling high sensitivity for the low flowrate measurement. While PMUT-based gas flow sensors of previous work serve higher flowrate ranges, the advantage of our system is that its novel sensor and measurement geometry is designed specifically for low flow rates to ensure high sensitivity in the low-flow domain. The characterised flowmeter measurement range is ± 50 sccm with a non-linearity error of 0.015%. A typical flow error within the measurement range of ± 50 sccm is ± 0.7% from the flow reading and ± 0.2% from the full-scale ( ± 50 sccm) flowrate.