A MEMS density sensor based on mircro-rectangular cantilever

A rectangle cantilever-type micro density sensor was researched based on MEMS (Micro Electro-mechanical System) technology. A Ti-Pt-Au coil and a Wheatstone full bridge were made on the top of the rectangle cantilever-type sensitive chip. The sensitive chip was placed in uniform strong magnetic field. The resonant frequency of the sensitive chip was changed with the change of the AC current´s frequency. The resonant frequency of rectangle cantilever could be measured through the Wheatstone full bridge circuit and lock-in amplifier, and then the fluid density associated with the resonant frequency of the sensitive chip could be calculated. The static analysis, modal analysis, a first-order and third-order harmonic response analysis of the rectangle cantilever were performed with ANSYS software. The best locations of the four force-sensitive resistor of Wheatstone bridge were studied.