Composite Diaphragm Ultrasonic Transducers Employing Air-Gap Structure

Abstract

This paper aims at discussing the possibility of applying an air-gap structure to the development of composite diaphragm ultrasonic transducer arrays. Analysis suggests that low-loss, wide-bandwidth transducers could be realised using Pyrex-glass/ZnO/Pyrex-glass composite diaphragms fabricated on an air-gap. It is also shown that the transducer performance is considerably improved with another polyimide matching layer. A transducer consisting of a Pyrex-glass/ZnO/Pyrex-glass composite diaphragm on an air-gap was experimentally fabricated, and its basic performance was shown.