Preparation and characterization of EVA/ZnO composites as piezoelectric elements for ultrasonic transducers

Abstract

Films of EVA/ZnO composites prepared to be piezoelectric active elements for ultrasonic transducers. These films are prepared by solvent casting technique. Different ZnO percentages were used (1, 2, 3 and 4%). The EVA/ZnO composites were characterized using x-ray diffraction and scanning electron microscope (SEM) techniques. The mechanical properties were studied by both ultrasonic measurements and a tensile testing machine. By TGA, thermal properties of EVA/ZnO composites were determined. The piezoelectric properties of films investigated. To evaluate the films as piezoelectric material: acoustic impedance, frequency, sensitivity, ultrasonic attenuation coefficient and quality factor measured. The results deduced that the most suitable composite was EVA/ZnO 3%; It almost met the criteria of the highly sensitive ultrasonic transducer of high frequency. In addition, the prepared films of different ZnO concentrations could operate under high temperatures. Therefore, they could be used in high-temperature transducers.