MEMS-based Measurement of Rheological Fluid Properties

摘要

Silicon microcantilevers can be used to measure the rheological properties of complex fluids. In the method presented in this paper, the measurement of the microcantilever's dynamic spectrum is used to extract the hydrodynamic force exerted by the surrounding fluid on the microcantilever and consequently the rheological fluid properties. The originality of the proposed method relies in the fact that not only may the viscosity of the fluid be measured but also the fluid's viscoelasticity, i.e., both viscous and elastic properties, which are key parameters in the case of complex fluids. In this method the use of analytical equations allows the fluid's complex shear modulus to be extracted and expressed as a function of the frequency. Viscoelastic spectral characteristics of fluids can be determined in analogy to rheograms recorded with standard laboratory equipment, and extend the .frequencies of investigation to the range 1-100 kHz.