A U-shaped wire for viscosity and mass density sensing

A resonant sensor for a fluid’s viscosity and mass density, employing an out-of-plane vibrating U-shaped tungsten wire is presented. The motivation for such a design is based on four major aspects, which are: operation in the low kilohertz range, circular cross-section of the resonator, electrodynamic actuation and read-out by means of Lorentz forces and low cross-sensitivity of the device’s resonance frequency to temperature. The setup is described in detail, an analytical model is presented and results from exper- iments using acetone–isopropanol and DI-water–glycerol solutions are discussed to show the sensor’s performance.