New RF EMUS Transducer for Complex Fluid Characterization

摘要

Real-time measurements are of the outmost importance for developing industrial “on line” effective monitoring techniques for the elaboration of new soft materials. In this paper, we will show a new radio frequency (RF) electromagnetic ultrasonic (EMUS) transducer design and technique for remotely sensing the micro-rheological properties of complex fluids in hidden places. The new sensor consists in a single electrode loop deposited on the surfaces of an AT-cut quartz substrate magnetically coupled with a high quality RF antenna. This sensor is inductively excited by a loosely coupling with a transmitter/receiver (T/R) circular probe. A suitable electrical model of the probe/loaded EMUS transducer is proposed in order to extract the mechanical and electrical properties of a complex fluid in contact. Various tabulated Newtonian liquids (made from water–glycerol mixtures) are then studied to validate the capability of this technique to monitor their viscosity. These results show that this technique allows the online monitoring of hidden complex fluids.