Ultrasonic transducer, method of manufacturing ultrasonic transducer, ultrasonic diagnostic apparatus, and ultrasonic microscope

摘要

A ultrasonic transducer of the invention comprises: a transducer cell including a first electrode and a second electrode disposed separated from the first electrode by an air gap portion; and an electret for applying a potential difference between the first electrode and the second electrode. The electret is disposed in a region where at least a part thereof does not overlap with the transducer cell when viewed from a transmitting direction of ultrasonic waves.