High-performance MEMS microgyroscope

Sam Young Bae; Ken J. Hayworth; Karl Y. Yee; Kirill Shcheglov; Dean V. Wiberg

doi:10.1117/12.462826

19 April 2002 High-performance MEMS microgyroscope

Sam Young Bae, Ken J. Hayworth, Karl Y. Yee, Kirill Shcheglov, Dean V. Wiberg

Proceedings Volume 4755, Design, Test, Integration, and Packaging of MEMS/MOEMS 2002; (2002) https://doi.org/10.1117/12.462826
Event: Symposium on Design, Test, Integration, and Packaging of MEMS/MOEMS 2002, 2002, Cannes-Mandelieu, France

Abstract

This paper reports on JPL's on-going research into MEMS gyroscopes. [1-4] This paper will describe the gyroscope's fabrication- methods, a new 8-electrode layout developed to improve performance and performance statistics of a batch of six gyroscopes (of the 8- electrode design) recently rate tested. Previously in our group, T. Tang and R. Gutierrez presented the results of their extensive use of ethylene diamine pyrocatechol (EDP) to deep-etch the inertial- sensitive r4esonators and post-supporting structures in a 4- electrode gyroscope design. Today, JPL is utilizing an in-house STS DRIE, replacing the old wet-etching steps. This has demonstrated superior precision in machining symmetry of the resonators, thus significantly reducing native rocking mode frequency splits. A performance test of six gyros has shown an average, un-tuned, frequency split of 0.4% (11Hz split for rocking modes at 2.7KHz). The new JPL MEMS gyroscope has a unique 8-electrode layout, whose large electrodes can provide significant electrostatic softening of the resonator's springs. This allows matching of the Coriolis sensitive rocking modal frequencies to be improved from the native 0.4% to an average tuned frequency split of 0.02%. In separate tests, electrostatic tuning in the 8-electrode design has demonstrated the ability to match frequency-splits to within 10mHz, thus ensuring full degeneracy in even a very high Q device. In addition, a newly selected ceramic package-substrate has improved the device's dampening loses such that a mean Q of 28,000 was achieved in the six gyroscope tested. These Q's ere measured via the ring-down time method. The improved fabrication development and other modifications described have led to the JPL's MEMS gyroscope achieving an average bias instability (Allan variance 1/f floor estimate) of 11degree/hr with best in the group being 2degree/hr. In an independent test, Honeywell Inc. reported one of our MEMS gyroscopes as achieving 1degree/hr bias instability flicker floor estimate measured at constant temperature.

Citation Download Citation

Sam Young Bae, Ken J. Hayworth, Karl Y. Yee, Kirill Shcheglov, and Dean V. Wiberg "High-performance MEMS microgyroscope", Proc. SPIE 4755, Design, Test, Integration, and Packaging of MEMS/MOEMS 2002, (19 April 2002); https://doi.org/10.1117/12.462826

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available