A new tunneling-based sensor for inertial rotation rate measurements

Abstract

Micro-electro-mechanical (MEM) technology promises to significantly reduce the size, weight, and cost of a variety of sensor systems. For vehicular and tactical-grade inertial navigation systems, high-performance MEM gyroscopes are required with 1 to 100°/h resolution and stability. To date, this goal has proven difficult to achieve in manufacturing for many of the previous approaches using Coriolis-based devices due, in part, to the need to precisely tune the drive and sense resonant frequencies. We have designed, fabricated, and tested a new highly miniaturized tunneling-based sensor that employs the high displacement sensitivity of quantum tunneling to obtain the desired resolution without the need for precise mechanical frequency matching. Our first tested devices with 300-μm-long cantilevers have demonstrated 27°/h/√Hz noise floors. Measurements indicate that this number can be reduced to near the thermal noise floor of 3°/h/√Hz when a closed loop servo, operating at the device's oscillation frequency, is implemented around the sensor.