Abstract
This paper reports a novel design concept of torsional gyroscope with robust drive mode and its implementation. The proposed design utilizes dynamic amplification of torsional oscillations instead of resonance in drive oscillator, which essentially is a 2-DOF oscillator, to eliminate the requirement of mode-matching. The frequency response of drive oscillator has two resonance peaks and a flat region between the peaks, where the amplitude is less sensitive to ambient damping resulting in robust drive mode. The frequency response of 1-DOF sense oscillator has one resonance peak which is designed to coincide with the flat region to minimize the effects of change in geometry and material properties of the device, due to inevitable fabrication imperfections, on the device performance. The design equations of electrostatic moment, moments of inertia, and spring constants are presented. The concepts of anti-resonance and zero-phase frequencies are introduced. The design is then implemented using SU-8 based UV-LIGA process having 8 µm thick Ni–Fe as the key structural layer. The fabricated device is also characterized for amplitude and phase spectral responses using Polytec MSA-500 Micro System Analyzer. The resonance frequencies of drive oscillator are observed at about 5.66 and 13.11 kHz against the design values of 5.37 and 13.18 kHz, respectively. The resonance frequency of sense oscillator is found at about 10.05 kHz against the design value of 10 kHz. The anti-resonance and zero-phase frequencies are observed at about 10.08 and 9.97 kHz, respectively against the design value of 10 kHz.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Acar C, Shkel AM (2004) Structural design and experimental characterization of torsional micromachined gyroscopes with non-resonant drive mode. J Micromech Microeng 14:15–25
Acar C, Shkel A (2008) MEMS vibratory gyroscopes: structural approaches to improve robustness. Springer, New York
Alper SE, Akin T (2000) A planar gyroscope using standard surface micromachining process. In: The 14th European conference on solid-state transducers, Copenhagen, pp 387–390
Frazier AB, Allen MG (1993) Metallic microstructures fabricated using photosensitive polyimide electroplating molds. J Microelectromech Syst 2(2):87–94
Jain A, Gopal R (2014) 2-DOF vibratory gyroscope fabricated by SU-8 based UV-LIGA process. Microsyst Technol 20:1291–1297
Jain A, Shekhar C, Gopal R (2014) Fabrication of two-gimbal Ni–Fe torsional micro-gyroscope by SU-8 based UV-LIGA process. Microsyst Technol. doi:10.1007/s00542-014-2268-7
Luo JK, Flewitt AJ, Spearing SM, Fleck NA, Milne WI (2004) Young’s modulus of electroplated Ni thin film for MEMS applications. Mater Lett 58(17–18):2306–2309
Verma P, Gopal R, Arya SK (2013) Analytical modeling and simulation of a 2-DOF drive and 1-DOF sense gyro-accelerometer. Microsyst Technol 19:1239–1248
Young WC, Budynas RG (2002) Roark’s formulas for stress and strain, vol 7. McGraw Hill, New York
Acknowledgments
This research work was supported by Council of Scientific and Industrial Research (CSIR) under 12th five year plan. The authors would like to thank following members of CSIR-CEERI: Mr. Ashok Kumar Gupta for mask-making facility; Dr. Jamil Akhtar and Mr. Gopal Singh Negi for oxidation facility, Dr. K. J. Rangra, Dr. Maninder Kaur and Mr. Prem Kumar for SEM facility; Mr. Dhirendra Kumar, Mr. Supriyo Das, Mr. Gajendra Singh Meena and Mr. Hitesh Kumar Sharma for their help in fabrication.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jain, A., Gopal, R. Novel design concept of torsional gyroscope with robust drive mode and its implementation. Microsyst Technol 21, 2197–2206 (2015). https://doi.org/10.1007/s00542-014-2327-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00542-014-2327-0