New miniaturized tunneling-based gyro for inertial measurement applications

Microelectromechanical (MEM) technology promises to significantly reduce th e size, weight, and cost of a variety of sensor systems. For vehicular, tac tical, or personal inertial/GPS navigation systems, high performance MEM gy roscopes are required with 1-100 degrees/h resolution and stability. To dat e, this goal has proven difficult to achieve with low cost manufacturing fo r 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 re solution without the need for precise mechanical frequency matching. Our fi rst tested devices with 300-mu m-long cantilevers have demonstrated 27 degr ees/h/root Hz noise floors. Measurements indicate that this number can be r educed to near the thermal noise floor of 3 degrees/h/root Hz when a closed loop servo, operating at the device's oscillation frequency, is implemente d around the sensor. (C) 1999 American Vacuum Society. [S0734-211X(99)10306 -8].