A novel micromachined viscosity and density sensor based on resonant torsional paddle

Author

Li, Hao ; Wang, Junbo ; Li, Xiang ; Chen, Deyong

Author_Institution

State Key Lab. of Transducer Technol., Inst. of Electron., Beijing, China

fYear

2011

fDate

28-31 Oct. 2011

Firstpage

496

Lastpage

499

Abstract

A micromachined resonant torsional paddle is presented to sense the viscosity and density of the liquid. The paddle is designed to work with torsional vibrating mode to improve the sensitivity. To simplify the fabrication, low-stressed SiN_x with 5 um in thickness is used as the paddle. A positive-feedback circuitry is used to compensate the energy loss by the big damp in liquid, so that the SNR and the Q-factor of the paddle can be improved obviously. Characteristics experiments show that the Q-factor of the paddle in alcohol is enhanced from 2.65 to 24.55, and the torsional resonant frequency and the Q-factor of the paddle decrease with the density and the viscosity of the mixture solution respectively.

Keywords

density measurement; micromachining; microsensors; silicon compounds; vibrations; viscosity measurement; Q-factor; SNR; SiN_x; energy loss; micromachined liquid density sensor; micromachined liquid viscosity sensor; micromachined resonant torsional paddle; positive-feedback circuitry; size 5 mum; torsional resonant frequency; torsional vibrating mode; Electrodes; Fabrication; Magnetic liquids; Micromechanical devices; Q factor; Resonant frequency; Viscosity;

fLanguage

English

Publisher

ieee

Conference_Titel

Sensors, 2011 IEEE

Conference_Location

Limerick

ISSN

1930-0395

Print_ISBN

978-1-4244-9290-9

Type

conf

DOI

10.1109/ICSENS.2011.6127062

Filename

6127062