Effect of Axial Force on the Performance of Micromachined Vibratory Rate Gyroscopes

It is reported in the published literature that the resonant frequency of a silicon micromachined gyroscope decreases linearly with increasing temperature. However, when the axial force is considerable, the resonant frequency might increase as the temperature increases. The axial force is mainly induced by thermal stress due to the mismatch between the thermal expansion coefficients of the structure and substrate. In this paper, two types of micromachined suspended vibratory gyroscopes with slanted beams were proposed to evaluate the effect of the axial force. One type was suspended with a clamped-free (C-F) beam and the other one was suspended with a clamped-clamped (C-C) beam. Their drive modes are the bending of the slanted beam, and their sense modes are the torsion of the slanted beam. The relationships between the resonant frequencies of the two types were developed. The prototypes were packaged by vacuum under 0.1 mbar and an analytical solution for the axial force effect on the resonant frequency was obtained. The temperature dependent performances of the operated mode responses of the micromachined gyroscopes were measured. The experimental values of the temperature coefficients of resonant frequencies (TCF) due to axial force were 101.5 ppm/°C for the drive mode and 21.6 ppm/°C for the sense mode. The axial force has a great influence on the modal frequency of the micromachined gyroscopes suspended with a C-C beam, especially for the flexure mode. The quality factors of the operated modes decreased with increasing temperature, and changed drastically when the micromachined gyroscopes worked at higher temperatures.

[1]  Sun Feng,et al.  Research on Thermal Characteristic in Slow-Small Temperature Changing for MEMS Linear Vibration Gyroscope , 2006, 2006 International Conference on Mechatronics and Automation.

[2]  Liu Tong-qing.  Effect of Temperature on the Young's Modulus of Silicon Nano-Films , 2007 .

[3]  D. Keymeulen,et al.  Effect of Temperature on MEMS Vibratory Rate Gyroscope , 2005, 2005 IEEE Aerospace Conference.

[4]  Cimoo Song.  Commercial vision of silicon based inertial sensors , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).

[5]  T. Akin,et al.  A single-crystal silicon symmetrical and decoupled MEMS gyroscope on an insulating substrate , 2005, Journal of Microelectromechanical Systems.

[6]  Anping Qiu,et al.  EFFECT OF STRESSES ON MICROMACHINED z-AXIS VIBRATING RATE GYROSCOPE , 2005 .

[7]  Sukhan Lee,et al.  Micromachined inertial sensors , 1999, Proceedings 1999 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human and Environment Friendly Robots with High Intelligence and Emotional Quotients (Cat. No.99CH36289).

[8]  J. Kim,et al.  Robust SOI process without footing for ultra high-performance microgyroscopes , 2003, TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664).

[9]  F. Ayazi,et al.  High Performance Matched-Mode Tuning Fork Gyroscope , 2006, 19th IEEE International Conference on Micro Electro Mechanical Systems.

[10]  Jan Soderkvist.  Micromachined vibrating gyroscopes , 1996, Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components.

[11]  Richard Dixon,et al.  Markets and applications for MEMS inertial sensors , 2006, SPIE MOEMS-MEMS.

[12]  R. Leland,et al.  Mechanical-thermal noise in MEMS gyroscopes , 2005, IEEE Sensors Journal.

[13]  Shourong Wang,et al.  Design Principle of Suspension of MEMS Gyroscope , 2006, 2006 1st IEEE International Conference on Nano/Micro Engineered and Molecular Systems.

[14]  Karl Yee,et al.  High-performance MEMS microgyroscope , 2002, Symposium on Design, Test, Integration, and Packaging of MEMS/MOEMS.

[15]  M.M.R.A. Lima,et al.  Characterisation and thermal behaviour of a borosilicate glass , 2001 .

[16]  B. Vandevelde,et al.  Effect of thermomechanical stress on resonant frequency shift of a silicon MEMS resonator , 2008, EuroSimE 2008 - International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Micro-Systems.

[17]  Shourong Wang,et al.  Temperature Effects and Compensation-Control Methods , 2009, Sensors.

[18]  Hisashi Muraoka,et al.  SEMICONDUCTOR MATERIALS :- , 2012 .

[19]  Yong-Kweon Kim,et al.  Vacuum packaged low noise gyroscope with sub mdeg/s//spl radic/Hz resolution , 2005, 18th IEEE International Conference on Micro Electro Mechanical Systems, 2005. MEMS 2005..

[20]  Chen Zhihua,et al.  High-performance micromachined gyroscope with a slanted suspension cantilever , 2009 .

[21]  Håkan Pettersson,et al.  A NOVEL SILICON BULK GYROSCOPE , 1999 .

[22]  Vikrant Bhadbhade,et al.  A novel piezoelectrically actuated flexural/torsional vibrating beam gyroscope , 2008 .

[23]  Liqiang Xie,et al.  A Z-Axis Quartz Cross-Fork Micromachined Gyroscope Based on Shear Stress Detection , 2010, Sensors.

[24]  Brian H. Houston,et al.  Thermoelastic loss observed in a high Q mechanical oscillator , 2002 .

[25]  U. Schmid,et al.  Study on the lower resolution limit and the temperature-dependent performance of a surface micromachined gyroscope , 2008, 2008 IEEE 21st International Conference on Micro Electro Mechanical Systems.