Synchronous determination of the rheological and acoustic properties of fluids using an oscillating fiber sensor and an ultrasonic microscope with phase contrast

A MEMS viscometer for unadulterated human blood

“…Noise is denoted by noise   and is defined as, the change in damping ratio that occurs due to the average change in gap height that would result from ther ma l z , with ther ma l z being calculated from equation (13). The resulting signal to noise ratio is then simply defined as,  is the initial squeeze-film damping ratio, associated with the effective viscosity of whole unadulterated human blood at the minimum rms shear rate, 0  .…”

“…These include, measurement of the torsional vibration of an oscillating tube, acoustic wave sensors, thickness shear mode resonators, and oscillating fibre sensors. [9], [10], [11], [12], [13] Some of the earliest work using an oscillating microstructure for measuring viscosity was carried out by Andrews et.al. [14] This work clearly demonstrated that, the phase angle between the driving force and resulting motion of an oscillating microstructure may be related to the viscosity of the gas via an expression for the squeeze-film damping ratio of the microstructure.…”