New miniaturized tunneling-based gyro for inertial measurement applications

Microelectromechanical (MEM) technology promises to significantly reduce the size, weight, and cost of a variety of sensor systems. For vehicular, tactical, or personal inertial/GPS navigation systems, high performance MEM gyroscopes are required with 1–100°/h resolution and stability. To date, this goal has proven difficult to achieve with low cost 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 or to employ large millimeter-size structures. We have designed, fabricated, and tested a new highly miniaturized tunneling-based gyro 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.