Damping analysis of a quad beam MEMS piezoresistive accelerometer

ABSTRACT

This article presents the simulation and experimental validation of damping for an MEMS (micro-electromechanical systems) piezoresistive accelerometer with an optimized mass dimension and air gap. A commercially available device should be able to withstand acceleration shock having a full-scale range of at least from 100 g to 1000 g irrespective of its nominal operation range. To achieve this, a micromachined silicon accelerometer is bonded with top and bottom Pyrex glasses. These glass plates provide viscous damping to the proof mass during its movement influencing the performance of the accelerometer. To improve the damping characteristics, the proposed accelerometer device is electroplated with gold on top of the device and an optimum distance of 27 µm is maintained between top/bottom glasses. It is observed that the vibrations are detected in a much earlier stage when the device is electroplated with gold with an optimum air gap distance of 27 µm. Experimental results prove an optimized air gap device for an electroplated gold with a proof thickness of 170 µm as a reduction of 23.26% from the resonant peak of electroplated gold device with a proof thickness of 270 µm. This device aims to design a typical air craft sensing motion application.

KEYWORDS:

• Damping
• vibrations
• piezoresisitve
• stability
• resonance

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

J. Grace Jency

J. Grace Jency received Ph.D in Electronics and Communication Department in Karunya Institute of Technology and Sciences in the field of MEMS piezoresistive accelerometer. She is currently working as a Assistant professor in Karunya Institute of Technology and Sciences, Coimbatore. Her areas of interest include Digital Electronics,  MEMS in biomedical applications and flexible capacitors.

M. Sekar

M. Sekar received his doctorate in Mechanical Design from Kyungpook National University, S. Korea. He carried out his research under Korean Government Research Fund (KRF) and authored more than 100 research articles in reputed international journals and conferences. His major research interests include computational geometry, micro machining, motion control and vibration. Dr. Sekar is currently the Principal at AAA College of Engineering and Technology, Tamilnadu and brings his rich industrial experience to the academica, which he gained during his industrial career in auto majors. He is well exposed to the international education systems and culture. Dr. Sekar is certified Six Sigma Black Belt professional. He is also a fellow of Institution of Engineers (India) and fellow of Indian Institute of Production Engineering. Dr. Sekar has expertise in programming tools like MATLAB, dSPACE, C++, Computer Aided Design and conducted several faculty development programmes and conferences.

A. Ravi Sankar

A. Ravi Sankar received a Ph.D. in Electronics and Electrical Communication Engineering from the Indian Institute of Technology Kharagpur and an M. Tech. in VLSI Design from PSG College of Technology, Coimbatore. He is a professor of School of Electronics Engineering (SENSE) at the Vellore Institute of Technology, Chennai campus. His research interests include MEMS and Microsystems and VLSI Design.