Study of Screen‐Printed PZT Cantilevers Both Self‐Actuated and Self‐Read‐Out

Abstract

Usually, resonating cantilevers come from silicon technology and are activated with pure bending mode. In this work, we suggest to combine high‐sensitive cantilever structure with both self‐actuated and self‐read‐out piezoelectric thick‐film for high electrical–mechanical coupling. This cantilever is realized through screen‐printing deposition associated with a sacrificial layer. It is composed of a PZT layer between two gold electrodes. Optimum performances of piezoelectric ceramics generally imply the use of mechanical pressure and very high sintering temperature that are not compatible with the screen‐printing process. Addition of eutectic composition Li2CO3‐Bi2O3‐CuO or borosilicate glass‐frit to PZT powder and application of isostatic pressure improve the sintering at a given temperature. Firing temperature of 850°C, 900°C, and 950°C is tested. Microstructural, electrical and mechanical characterizations are achieved. In addition to the bending mode, the in‐plane 31‐longitudinal vibration mode and the out‐of‐plane 33‐thickness resonance mode are revealed. Correlations between experimental results and modeling of the different vibration modes are established. The piezoelectric parameters of PZT cantilevers approach those of ceramics. Quality factors between 300 and 400 associated with the unusual 31‐longitudinal mode make screen‐printed PZT cantilevers good candidates for detection in liquid and gaseous media.