Self Excited Vibrational Cantilever Type Viscometer Driven by Piezo Actuator

Abstract

The design and operation of new viscometers are often presented with a focus on the miniaturization of the device and online monitoring of small amounts of liquid samples. The vibrational viscometers commonly used for viscosity measurements exploit the peak value of the frequencyresponse curve obtained from excitations of the oscillator submerged in the liquid. However, for highviscosity liquids, the peak of the frequencyresponse curve is ambiguous or nonexistent, and hence hard to measure. To overcome this drawback and with a view to miniaturizing the device, we use the selfexcited oscillations produced by a velocity feedback control. Our design uses a viscometer employing a cantilever driven by a piezoactuator with analytics that do not rely on the frequencyresponse curve. A prototype piezodriven macrocantilever with an oscillating plate attached at its tip was experimentally performed according to specifications. The proposed mechanism can be integrated into microelectromechanical systems (MEMS).