Electromagnetically driven torsional resonators for viscosity and mass density sensing applications

Abstract

In this contribution a conceptual study for torsional oscillators, which are electromagnetically driven and read out, is presented. The aim is to experimentally investigate the basic feasibility of a torsional resonator with application to viscosity and mass density sensing in liquids. Such a device is particularly interesting as cylindrical, torsional resonators for fluid sensing applications are hardly reported but unlike many other devices, yield pure shear wave excitation in the liquid. The design of first conceptual demonstrators for measurements in air as well as in liquids and their benefits and disadvantages are discussed in detail. A closed form as well as a reduced order model and measurement results obtained with first demonstrators are presented.

Precision density and viscosity measurement using two cantilevers with different widths

“…Special solutions with the same viscosity but different densities and the same density but different viscosities are prepared for this calibration step similar to the solutions used in recent studies [6,7,[24][25][26]. This step should be conducted for only one time for each sensor geometry.…”

Absorption Based Characterization Method for Fluid Properties Using Electrowetting-on-Dielectric Forces: Modeling and Fabrication

“…In recent works the focus often has been on sensing certain fluid properties like viscosity and density with resonant viscosity sensors or other small devices, which are feasible for arrangement inside an integrated Lab-on-a-Chip system [3]. We will see that the electrowetting effect can be utilized to build a small device allowing to differentiate between the viscosities of various fluid droplets.…”

U-shape Acoustic Liquid Densitometer

“…In particular, the operation of nuclear power plants (controlling the liquid wastes), in military and civil aviation and road transport (quality control of fuels and lubricants), food industry (milk production, syrups and other liquids) a widely range of methods and means are used to measure viscosity and density of liquids or liquefied media. These include various types of viscometers (capillary, rotational and vibrational) densitometer (float, mass, hydrostatic and vibration, radiation and ultrasonic) [4][5].…”