1.3 mm2Nav-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 mm2 and a total silicon structural volume of 0.026 mm3 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]