Piezoelectric MEMS resonators for monitoring grape must fermentation

Fecha

2016-11-11

Autores

Toledo, Javier
Jiménez-Márquez, Francisco
Úbeda, Juan
Ruiz-Díez, Víctor
Pfusterschmied, Georg
Schmid, Ulrich
Sánchez-Rojas, José Luis

Título de la revista

ISSN de la revista

Título del volumen

Editor

Journal of Physics: Conference Series - 27th Micromechanics and Microsystems Europe Workshop.

Enlace externo

Resumen

The traditional procedure followed by winemakers for monitoring grape must fermentation is not automated, has not enough accuracy or has only been tested in discrete must samples. In order to contribute to the automation and improvement of the wine fermentation process, we have designed an AlN-based piezoelectric microresonator, serving as a density sensor and being excited in the 4th-order roof tile-shaped vibration mode. Furthermore, conditioning circuits were designed to convert the one-port impedance of the resonator into a resonant two-port transfer function. This allowed us to design a Phase Locked Loop-based oscillator circuit, implemented with a commercial lock-in amplifier with an oscillation frequency determined by the vibrating mode. We were capable of measuring the fermentation kinetics by both tracking the resonance frequency and by determining the quality factor measurements of the microresonator. Moreover, the resonator was calibrated with an artificial model solution of grape must and then applied for the monitoring of real grape must fermentation. Our results demonstrate the high potential of MEMS resonators to detect the decrease in sugar and the increase in ethanol concentrations during the grape must fermentation with a resolution of 100 μg/ml and a sensitivity of 0.16 Hz/μg/ml as upper limits.

Descripción

Citación