A MICROMECHANICAL CAPACITIVE ACCELEROMETER WITH A 2-POINT INERTIAL-MASS SUSPENSION

The design, fabrication process and measured performance of a novel silicon micromechanical capacitive accelerometer are described. It consists of a plate, used as both inertial mass and capacitor, which is attached to the support by two torsion bars. Plate rotation is measured by the related capacitance variation. The fabrication process includes standard IC-technology, silicon etching techniques and anodic glass-silicon bonding. Static sensitivities of DELTA C/C equals 0. 1 - 4. 0%/g-unit (g equals 9. 81 m/s**2) are obtained, depending on plate thickness. The lower detection limit for static acceleration is 2. 5 multiplied by 10** minus **3 g-unit. The dynamic behavior depends strongly on pressure.