MEMS
University of Ljubljana
Faculty for mathematics and physics
Department of physics
Seminar
MEMS ACCELEROMETERS
Author: Matej Andrejašiˇ c Mentor: doc. dr. Igor Poberaj
Marec 2008
Abstract:
MEMS accelerometers are one of the simplest but also most applicable micro-electromechanical systems. They became indispensable in automobile industry, computer and audio-video technology. This seminar presents MEMS technology as a highly developing industry. Special attention is given to the capacitor accelerometers, how do they work and their applications. The seminar closes with quite extensively described MEMS fabrication.
1
1
Introduction
An accelerometer is an electromechanical device that measures acceleration forces. These forces may be static, like the constant force of gravity pulling at our feet, or they could be dynamic - caused by moving or vibrating the accelerometer. There are many types of accelerometers developed and reported in the literature. The vast majority is based on piezoelectric crystals, but they are too big and to clumsy. People tried to develop something smaller, that could increase applicability and started searching in the field of microelectronics. They developed MEMS (micro electromechanical systems) accelerometers.
The first micro machined accelerometer was designed in 1979 at Stanford University, but it took over 15 years before such devices became accepted mainstream products for large volume applications [1]. In the 1990s MEMS accelerometers revolutionised the automotive-airbagsystem industry. Since then they have enabled unique features and applications ranging from hard-disk protection on laptops to game controllers. More recently, the same sensor-core technology has become available in fully integrated, full-featured devices suitable for industrial applications [2].
Micro machined accelerometers are a highly enabling technology with a huge commercial potential. They provide lower power, compact and
Faculty for mathematics and physics
Department of physics
Seminar
MEMS ACCELEROMETERS
Author: Matej Andrejašiˇ c Mentor: doc. dr. Igor Poberaj
Marec 2008
Abstract:
MEMS accelerometers are one of the simplest but also most applicable micro-electromechanical systems. They became indispensable in automobile industry, computer and audio-video technology. This seminar presents MEMS technology as a highly developing industry. Special attention is given to the capacitor accelerometers, how do they work and their applications. The seminar closes with quite extensively described MEMS fabrication.
1
1
Introduction
An accelerometer is an electromechanical device that measures acceleration forces. These forces may be static, like the constant force of gravity pulling at our feet, or they could be dynamic - caused by moving or vibrating the accelerometer. There are many types of accelerometers developed and reported in the literature. The vast majority is based on piezoelectric crystals, but they are too big and to clumsy. People tried to develop something smaller, that could increase applicability and started searching in the field of microelectronics. They developed MEMS (micro electromechanical systems) accelerometers.
The first micro machined accelerometer was designed in 1979 at Stanford University, but it took over 15 years before such devices became accepted mainstream products for large volume applications [1]. In the 1990s MEMS accelerometers revolutionised the automotive-airbagsystem industry. Since then they have enabled unique features and applications ranging from hard-disk protection on laptops to game controllers. More recently, the same sensor-core technology has become available in fully integrated, full-featured devices suitable for industrial applications [2].
Micro machined accelerometers are a highly enabling technology with a huge commercial potential. They provide lower power, compact and
References: [1] I. Lee, G. H. Yoon, J. Park, S. Seok, K. Chun, K. Lee, Development and analysis of the vertical capacitive accelerometer, Sensors and Actuators A 119 (2005) 8-18 A (not so) short introduction (http://memscyclopedia.org/introMEMS.html (18.2.2008)) [3] S. Beeby, G. Ensell, M. Kraft, N.White, MEMS mechanical sensors (Artech house inc., USA, 2004) [4] S. E. Lyshevski, Mems and Nems: systems, devices and structures (CRC Press LLC, USA, 2002) [5] http://www.analog.com/UploadedFiles/Obsolete_Data_Sheets/66309706ADXL05.pdf (10.3.2008) Papers, pp. 1169-1172, June 1997. [7] http://www.analog.com/en/prod/0„764_800_ADXL202%2C00.html (10.3.2008) [8] http://www.analog.com/en/content/0,2886,764%255F800%255F122115%255F0,00.html (14.2.2008) [9] C and actuators (Springer, USA, 2006) [10] http://rfdesign.com/military_defense_electronics/news/accelerometer_proves_accurate_0509/ (14.2.2008) [11] F accelerometers Solid-State Electronics 47 (2003) 357-360 [12] http://en.wikipedia.org/wiki/Accelerometer (14.2.2008) [13] S. Beeby, G. Ensell, M. Kraft, N.White, MEMS mechanical sensors (Artech house inc., USA, 2004) [14] http://www.sensorsmag.com/articles/0399/0399_44/main.shtml (14.2.2008) 17