摘要
This paper presents a novel flexible airflow sensor based on four curved microcantilevers arranged in a cross-form configuration.A self-bending method based on MEMS technology has been used to fabricate the curved microcantilevers structure,and this method can transfer a 2D plane structure into a 3D structure with good consistency in the morphology.The curved microcantilever consists of a polyimide(PI)top layer,silicon(Si)bottom layer,and platinum(Pt)piezoresistor at the root of the cantilever.The difference in the in-plane residual stress between the PI and Si layers bent the microcantilever upward.The curved-up microcantilever transfers the fluidic momentum that acts on it to drag force,which deflects the curved-up microcantilever and changes the resistance of the piezoresistor.To realize temperature compensation and decrease the noise,a reference resistor and an ambient temperature detector were integrated for the Wheatstone half-bridge measurement and temperature monitoring,respectively.The cross-form configuration of the curved-up cantilevers has high sensitivity advantages and possesses direction-sensing ability.Experimental results show that the sensitivity of the sensors increased as a function of the airflow velocity,and the sensors exhibited a maximum resolution of 4 mm⋅s^(−1) and a maximum sensitivity of 60.35 mV⋅(ms^(−1))^(−1) when the airflow velocity was larger than 38.5 m⋅s^(−1).
基金
supported financially by the National Natural Science Foundation of China under contract No.51975030 and No.52022008.
