1.3 mm2 Nav-Grade NEMS-Based Gyroscope

The research reports the design and experimental results of novel gyroscopes based on nano-resistive sensing, capable to meet navigation grade specifications within a sensor footprint of 1.3 mm
²
and a total silicon structural volume of 0.026 mm
³
only. A significant increase of the scale-factor is obtained through a combination of (i) optimization of the Coriolis force transduction into a stress on the resistive gauges, (ii) increase of the drive motion amplitude and (iii) increase of the current through the sensing gauges. Combined with low-pressure eutectic packaging, this enables approaching the thermomechanical noise limits of the sensor at about 0.004
^°
/√ hr. At the same time, electronics is developed with minimum demodulation phase errors, thus enabling optimized closed-loop quadrature compensation and minimization of drift effects. Thanks to the inherent rejection of parasitic couplings and associated drifts of the used technology, the overall stability reaches 0.02 °/hr on average on 6 samples. These performances are demonstrated for a 30-Hz system bandwidth and few hundred dps input range over several samples. Navigation grade performance are confirmed by additional in-operation experiments like gyrocompassing and in-run 9-minute long angle measurements from rate integration. [2021-0073]