Ultra-low-voltage gyroscopes based on piezoresistive NEMS for drive-motion and coriolis-motion sensing

The work presents first gyroscopes based on NEMS gauges used both for sense-motion detection and for drive-motion detection. In such a configuration, no structural element is biased at voltages larger than 1 V, so 1 to 2 orders of magnitude lower than the DC voltage conventionally applied to the rotor of capacitive gyroscopes. Following the mechanical design, also the electronics is adapted, here relying on resistive sensing also in the drive loop, which guarantees an optimal rejection of feedthrough issues. Within an area of about 1.1 (mm)² per axis, with drive mode Q factors of about 35000 at 0.3 mbar, 1.4 dphWHz angle random walk (ARW) is obtained. Bias stability given by NEMS 1/f noise becomes well visible.