Bistable Flow Sensor 

We introduced and developed a new flow velocity measurement technique based on snap-through detection of an electrostatically actuated, bistable micromechanical beam. An induced elecro-thermal Joule heating, and the convective air cooling, change the beam curvature, and consequently the critical snap-through voltage. Our results show that the bifurcation based sensor has higher sensitivity and lower power consumption than other thermal flow sensors. The overheat ratio can be significantly lower for this sensing principle than conventional thermal sensing elements. Additionally, snap through collapse is abrupt and fast, thus easily detectable. Electrostatically induced snap-through in curved, micromechanical beams opens new directions for the design and implementation of downscaled flow sensors for autonomous applications and environmental sensors.