High Resolution Viscosity Measurement by Thermal Noise Detection

Sensors

Felipe Aguilar Sandoval²  Manuel Sepúlveda²  Ludovic Bellon¹  Francisco Melo² 

[1] Laboratoire de Physique, Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS, 46 Allée d’Italie, Lyon F-69007, France; E-Mail:;Departamento de Física, Universidad de Santiago de Chile, Avenida Ecuador 3493, Estación Central, Santiago 9170124, Chile; E-Mail:

关键词: thermal fluctuations;    viscosity in liquids;    MEMS;   

DOI  :  10.3390/s151127905

来源: mdpi

【 摘 要 】

An interferometric method is implemented in order to accurately assess the thermal fluctuations of a micro-cantilever sensor in liquid environments. The power spectrum density (PSD) of thermal fluctuations together with Sader’s model of the cantilever allow for the indirect measurement of the liquid viscosity with good accuracy. The good quality of the deflection signal and the characteristic low noise of the instrument allow for the detection and corrections of drawbacks due to both the cantilever shape irregularities and the uncertainties on the position of the laser spot at the fluctuating end of the cantilever. Variation of viscosity below 0.03 mPa·s was detected with the alternative to achieve measurements with a volume as low as 50 μL.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.