Jpn. J. Appl. Phys. 42 (2003) pp. 2468-2472  |Next Article|  |Table of Contents|
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Electrostatically Levitated Ring-Shaped Rotational-Gyro/Accelerometer

Takao Murakoshi, Yasuo Endo, Keisuke Fukatsu, Sigeru Nakamura and Masayoshi Esashi¹

(Received September 19, 2002; accepted for publication November 20, 2002)

This paper reports an electrostatically levitated inertia measurement system which is based on the principle of a rotational gyro. The device has several advantages: the levitation of the rotor in a vacuum eliminates mechanical friction resulting in high sensitivity; the position control for the levitation allows accelerations to be sensed in the tri-axis; and the fabrication of the device by a micromachining technique has the cost advantages afforded by miniaturization. Latest measurements yield a noise floor of the gyro and that of the accelerometer as low as 0.15 deg/h^1/2 and 30 µG/Hz^1/2, respectively. This performance is achieved by a new sensor design. To further improve of the previous device, a ring-shaped structure is designed and fabricated by deep reactive ion etching using inductively coupled plasma. The rotor levitation is performed with capacitive detection and electrostatic actuation. Multiaxis closed-loop control is realized by differential capacitance sensing and frequency multiplying. The rotation of the micro gyro is based on the principle of a planar variable capacitance motor.

URL: http://jjap.jsap.jp/link?JJAP/42/2468/
DOI: 10.1143/JJAP.42.2468

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