Gas Flow Rate Sensing by Curvature Change of Micro Quartz Resonators

This work demonstrates a gas flow rate sensor based on the curvature change of a micro quartz resonator (MQR). We explored the relationship between the resonant frequency shift and gas flow rate theoretically and experimentally. The sensing performance was evaluated by exposing the device to nitrogen gas at different flow rates. Experimental results indicate that the response time is less than 2 s with a sensitivity of 0.16 Hz/(mL·min
^−l
) in the gas flow ranging from 100 to 800 mL/min. Compared to the conventional gas sensors, our method has many advantages including low temperature drift, rapid response time, and great reproducibility, and provides a multifunctional sensing platform to measure the concentration and flow rate successfully. To the best of our knowledge, this is the first paper about gas flow rate sensing using the mechanical bending effect of an MQR.