Title :
Electrostatically levitated spherical 3-axis accelerometer
Author :
Toda, R. ; Takeda, N. ; Murakoshi, T. ; Nakamura, S. ; Esashi, M.
Author_Institution :
Ball Semicond. Inc., Allentown, PA, USA
Abstract :
MEMS-based electrostatically levitated spherical 3-axis accelerometer has been developed. Fabrication of the spherical MEMS device is made possible by incorporating Ball Semiconductor technology and a novel sacrificial etching process utilizing xenon difluoride gas etching through gas permeable layer. 1-millimeter diameter spherical proof mass is completely suspended without any mechanical support by closed-loop controlled electrostatic forcers. 3-axis acceleration is derived from intensity of servo feedback between capacitive position sensing and the electrostatic actuation. Noise floor is estimated as 40/spl mu/G/Hz/sup 1/2/ level. After calibrating geometrical misalignment, scale factor and zero-G offset errors, linear output with minimal cross-axis error is obtained.
Keywords :
accelerometers; closed loop systems; electrostatic devices; microsensors; sputter etching; MEMS device; XeF/sub 2/; ball semiconductor technology; capacitive position sensing; closed-loop control; cross-axis error; electrostatic actuation; electrostatic levitation; fabrication method; gas permeable layer; geometrical misalignment; noise floor; proof mass; sacrificial etching; scale factor; servo feedback; spherical three-axis accelerometer; xenon difluoride gas etching; zero-G offset error; Acceleration; Accelerometers; Electrostatics; Etching; Fabrication; Force control; Microelectromechanical devices; Servomechanisms; Weight control; Xenon;
Conference_Titel :
Micro Electro Mechanical Systems, 2002. The Fifteenth IEEE International Conference on
Conference_Location :
Las Vegas, NV, USA
Print_ISBN :
0-7803-7185-2
DOI :
10.1109/MEMSYS.2002.984369
