Title :
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
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 SiNx 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; SiNx; 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;
Conference_Titel :
Sensors, 2011 IEEE
Conference_Location :
Limerick
Print_ISBN :
978-1-4244-9290-9
DOI :
10.1109/ICSENS.2011.6127062
