A novel optical accelerometer

Author

Abbaspour-Sani, Ebrahim ; Huang, Ruey-Shing ; Yee kwok, Chee

Author_Institution

Dept. of Electron., New South Wales Univ., Sydney, NSW, Australia

Volume

16

Issue

5

fYear

1995

fDate

5/1/1995 12:00:00 AM

Firstpage

166

Lastpage

168

Abstract

A novel accelerometer based on a PIN photo-detector and a micro-machined cantilever-beam-supported optical shutter with seismic mass has been designed, fabricated, and tested. Anisotropic wet etching of <110> orientation silicon in KOH is used to fabricate an optical shutter consisting of evenly spaced vertically etched slots. The shutter, which also constitutes the seismic mass of the accelerometer, is suspended by two cantilever beams. The special structure of the device and the high aspect ratio of the cantilever beams (7.5) permit freedom of the movement for the proof mass (the shutter) on the /spl plusmn/X axis only. The actual size of the device is 3/spl times/4 mm and its amplified output varies linearly from -3.6 V to +3.6 V for accelerations from -84 g to +84 g. The measured resonant frequency of the device is 3.2 KHz. A dual diode structure is chosen for the photo-detector to compensate for temperature drift and the amplified output voltage changes by less than 40 mV for a temperature variation from 25/spl deg/C to 50/spl deg/C.<>

Keywords

acceleration measurement; accelerometers; micromechanical devices; p-i-n photodiodes; photodetectors; -3.6 to 3.6 V; 25 to 50 degC; 3.2 kHz; PIN photo-detector; Si; amplified output; aspect ratio; dual diode structure; evenly spaced vertically etched slots; micro-machined cantilever-beam-supported optical shutter; optical accelerometer; resonant frequency; seismic mass; temperature drift; Acceleration; Accelerometers; Anisotropic magnetoresistance; Geometrical optics; Optical design; Silicon; Structural beams; Temperature; Testing; Wet etching;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.382228

Filename

382228