Humidity measurement using resonating CMOS microcantilever structures

Author

Strembicke, Derek ; Robinson, A.M. ; Vermeulen, F.E. ; Seto, Mary ; Brown, Keith B.

Author_Institution

Dept. of Electr. & Comput. Eng., Alberta Univ., Edmonton, Alta., Canada

Volume

3

fYear

1999

fDate

9-12 May 1999

Firstpage

1658

Abstract

Changes in relative humidity can be detected by the modification in resonance frequency of an oscillating microcantilever. Mass changes due to the absorption of water vapour by an applied hygroscopic porous thin film create these frequency shifts. We have designed and tested a CMOS micromachined cantilever microstructure sensitive to relative humidity values ranging from 5-90%. Two thin films (1 and 1.5 /spl mu/m) of MgF/sub 2/ applied to the microstructure using the GLAD/sup TM/ deposition technique, were investigated with resonant frequency shifts of approximately 100 Hz observed over the stated humidity range.

Keywords

CMOS integrated circuits; humidity sensors; micromachining; micromechanical resonators; microsensors; CMOS microcantilever structure; GLAD deposition; MgF/sub 2/; hygroscopic porous thin film; micromachining; relative humidity measurement; resonance frequency; water vapour absorption; Absorption; Arm; CMOS technology; Humidity measurement; Magnetic field measurement; Microstructure; Piezoresistance; Resonance; Resonant frequency; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical and Computer Engineering, 1999 IEEE Canadian Conference on

Conference_Location

Edmonton, Alberta, Canada

ISSN

0840-7789

Print_ISBN

0-7803-5579-2

Type

conf

DOI

10.1109/CCECE.1999.804966

Filename

804966