文摘
A silicon gas-flow sensor based on lift force is described. The sensing structure is made of two equal plates arranged to be deflected by the lift force. The deflection is detected with polysilicon piezoresistors connected in a Wheatstone bridge configuration. Due to its symmetric design, the sensor suppresses artifacts caused by acceleration forces. Here this ability is verified both theoretically and experimentally. A flow sensitivity of 0.054 μV/V/(1/min)2 has been measured. Due to the lift-force sensor design, the sensitivity is independent of the flow direction and the induced pressure drop is relatively low. The pressure drop and the flow sensitivity normalized to the pressure drop have been studied as functions of the flow attack angle.