A new tunneling-based sensor for inertial rotation rate measurements

Microelectromechanical (MEM) technology promises to significantly reduce th e 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 1-100 degrees/h resolution and stability, To date, this goal has proven difficult to achieve in manufacturing for many of the previ ous approaches using Coriolis-based devices due, in part, to the need to pr ecisely tune the drive and sense resonant frequencies. We have designed, fa bricated, and tested a new highly miniaturized tunneling-based sensor that employs the high displacement sensitivity of quantum tunneling to obtain th e desired resolution without the need for precise mechanical frequency matc hing, Our first tested devices with 300-mu m-long cantilevers have demonstr ated 27 degrees/h/root Hz noise floors. Measurements indicate that this num ber can be reduced to near the thermal noise floor of 3 degrees/h/root Hz w hen a closed-loop servo, operating at the;device's oscillation frequency, i s implemented around the sensor. [391].