Remote measurement of shear viscosity with ultrasound-stimulated vibroacoustic spectrography

Ultrasound-stimulated vibro-acoustic spectrography (USVAS) is a new method that uses ultrasound to vibrate the object at an arbitrary low frequency. By measuring the acoustic field resulting from object vibration, information about the mechanical characteristics of the medium can be obtained. Using USVAS, here we present a method for measuring the shear viscosity of liquids. A tuning fork is immersed in the liquid, and its frequency response is remotely measured using USVAS. The shear viscosity is then calculated based on the resonance frequency and the bandwidth of the tuning fork. The shear viscosity of isopropyl alcohol, determined by this method, is in agreement with the published data. USVAS promises a new way for remote evaluation of material properties.